Processing of corn-based dog foods through pelleting, baking and extrusion and their effect on apparent total tract digestibility and colonic health of adult dogs

Different food processing parameters may alter starch granule structure and its cooking degree. With lower thermomechanical energy, more resistant starch (RS) is retained in the food, which may benefit gastrointestinal (GI) health. The objective of this study was to determine the effect of food processing on dietary utilization and dog gut health. Experimental diets containing 56% corn as the sole starch source were produced through pelleting, baking, and extrusion and compared to a baked control diet in which the corn was replaced with dextrose. The extruded diet resulted in the highest level (P < 0.05) of in vitro starch cook and lowest RS, while baked was intermediate and pelleted had the lowest starch cook and highest RS. To evaluate the in vivo effects of these treatments, 12 dogs were adapted to foods for 9 d, and feces were collected for 5 d in a replicated 4 × 4 Latin square design. Feces were scored for consistency using an ordinal scale, and parametric data included apparent digestibility (ATTD), parameters indicative of gut health, and the microbial composition, which was centered log-ratio transformed before operational taxonomic unit (OTU) analyses. Fecal scores were analyzed by ordinal logistic regression, and parametric data were analyzed as mixed models. Overall ATTD was greater (P < 0.05) in extruded, followed by baked and pelleted. Dogs fed the control had osmotic diarrhea, whereas dogs fed the other treatments had mostly acceptable fecal scores, with extrusion leading to the best fecal quality. The control also led to high fecal pH and low SCFAs, indicating dysbiosis. All corn foods had similar (P > 0.05) fecal SCFAs and extruded tended (P = 0.055) to promote higher fecal butyrate than baked and pelleted. The microbiome of dogs fed the corn foods had similar α diversity indices, and OTUs at the species and phyla levels were mostly alike and different from the control. In conclusion, the higher levels of in vitro RS did not translate into a better in vivo fermentation profile, and extruded kibble performed best regarding fecal quality, ATTD, and fecal SCFAs.

Evaluation of Soybean Ingredients in Pet Foods Applications: Systematic Review

Soybean use has been low in pet foods, even though they are an excellent source of protein, polyunsaturated fatty acids, and gut fermentable fibers. The purpose of this evaluation was to conduct a systematic review of the public literature to explore how soybeans have been researched for pet food applications since 2000 and to provide strengths, weaknesses, opportunities, and threats for soybeans in the pet food industry. The review covered a total of 44 articles related to soybean ingredients and their potential value in the pet food arena. The articles were categorized by their research contents and narratively summarized to demonstrate useful information to both the pet and soybean industries. When soybean-based products have been adequately processed to reduce the antinutritive factors, they are comparable to processed animal proteins in nutritional value, palatability, and functionality in pet food processing. We conclude that various food processing technologies and the versatility of soybean ingredients allow soybean to have considerable inclusion potential in pet foods. More research on dietary soybean ingredients regarding pet food processing, fermentation benefits on health, and consumer acceptance will be needed to understand soybean's position in the future pet food industry.

Efficacy of Liquid Smoke to Mitigate Infestations of the Storage Mite, Tyrophagus putrescentiae, in a Model Semi-Moist Pet Food

The storage mite Tyrophagus putrescentiae infests a wide range of food products including pet food. Control of this mite depends on chemical methods such as fumigation and spraying with insecticides. Methyl bromide was used as a fumigant for high-value stored products, especially to control mite infestation in dry-cured hams and cheeses, but it is now banned for most uses in many countries because of its atmospheric ozone-depleting effects. Effective alternatives to methyl bromide are needed to develop integrated pest management programs for this pest. Liquid smoke is a naturally derived flavoring and preservative with known antimicrobial properties. The objective of this study was to investigate the efficacy of liquid smoke preparations, with varying phenol and carbonyl concentrations and pH, on the survivability and orientation behavior of T. putrescentiae in a model semi-moist pet food. The mite survivability assays using liquid smoke-treated and untreated semi-moist pet food samples indicated that there was no difference among treatments (p > 0.05) for mite infestation and survival. Two-choice behavioral assays using semi-moist pet food cubes dipped in varying concentrations (0%, 0.3%, 1%, 5%, 10%, 25%, 50%, or 100% v/v) of liquid smoke preparations found that some of the liquid smoke preparations containing medium to high carbonyl content repelled the mites. In conclusion, liquid smoke did not kill or inhibit the mite population growth in semi-moist pet food. However, some liquid smoke fractions containing medium to high carbonyl content were repellent to mites and may retard mite infestation in stored semi-moist foods.

Comparison of the Effect of Corn-fermented Protein and Traditional Ingredients on the Fecal Microbiota of Dogs

Corn-fermented protein (CFP), a co-product from the ethanol industry, is produced using post-fermentation technology to split the protein and yeast from fiber prior to drying. The objective of this study was to determine the effect of CFP compared to traditional ingredients on the fecal microbiota of dogs. The four experimental diets included a control with no yeast and diets containing either 3.5% brewer's dried yeast, 2.5% brewer's dried yeast plus 17.5% distiller's dried grains with solubles, or 17.5% CFP. The experimental diets were fed to adult dogs (n = 12) in a 4 × 4 replicated Latin square design. Fresh fecal samples (n = 48) were analyzed by 16S metagenomic sequencing. Raw sequences were processed through mothur. Community diversity was evaluated in R. Relative abundance data were analyzed within the 50 most abundant operational taxonomic units using a mixed model of SAS. Alpha and beta diversity were similar for all treatments. Predominant phyla among all samples were Firmicutes (73%), Bacteroidetes (15%), Fusobacteria (8%), and Actinobacteria (4%). There were no quantifiable (p > 0.05) shifts in the predominant phyla among the treatments. However, nine genera resulted in differences in relative abundance among the treatments. These data indicate that compared to traditional ingredients, CFP did not alter the overall diversity of the fecal microbiota of healthy adult dogs over 14 days.

Apparent total tract digestibility and palatability of extruded diets with graded levels of whole soybeans by dogs

Fat has high energy density and is considered one of the primary energy sources for dogs, however, increasing fat level in dry dog food has been challenging due to the lubrication and limitation of the coating system. The objective was to determine the effect of whole soybeans (WSB) on nutrient digestibility, stool quality, and palatability by dogs. The corn gluten meal, chicken fat, and brewers rice were replaced by WSB at 10, 20, and 30% (WSB10, WSB20, and WSB30, respectively) in the base diet (WSB0). Twelve beagles were randomly assigned. The digestibility trial was duplicated 4 × 4 Latin square design where dogs were allowed a 9-d adaptation followed by a 5-d total fecal collection for each period. Least-square means were analyzed with a single degree of freedom contrasts and significance at α = 0.05. Palatability was determined with a 2-bowl test by 20 beagles for 2 d with each WSB diet compared to the WSB0. First choice preference between two diets and total food consumption were recorded. Individual intake ratios (IR) were calculated (intake of each diet/total intake) for each dog. First choice (FC) was analyzed by a Chi-square probability, and the diet consumption was compared by a Wilcoxon signed rank test and a 2-way analysis of variance. Fecal moisture, output, and defecation frequency increased linearly (P < 0.05) as WSB increased. Apparent total tract digestibility of dry matter, organic matter, crude protein, fat, and gross energy decreased linearly (P < 0.05) as dogs fed the increased level of WSB. The fresh fecal pH in dogs decreased linearly (P < 0.05) as WSB content increased. The acetate, propionate, and the total short-chain fatty acid concentration increased linearly (P < 0.05) while the total branched-chain fatty acid concentration decreased linearly (P < 0.05) as WSB increased. Dogs had greater (P < 0.05) FC for WSB diets than WSB0, but there was no difference among treatments for diet consumption and IR. In conclusion, additional thermal processing before extrusion may improve nutrient digestibility of WSB. The stool quality and palatability were not affected, and fermentation in hindgut increased by WSB by dogs.

Application of Acidulants to Control Salmonella spp. in Rendered Animal Fats and Oils with Different Levels of Unsaturation

Salmonella-contaminated pet foods could potentially become a source of human salmonellosis. This study evaluated the survival of Salmonella without and with the addition of acidulants in different fat types (chicken fat (CF), canola oil (CO), Menhaden fish oil (FO), lard (La), and tallow (Ta)) commonly used to coat dry pet food kibbles. The minimum inhibitory concentration (MIC) of individual acidulants and the combination were determined using the broth microdilution method. Autoclave-sterilized rendered fats were treated with pre-determined concentrations of antimicrobial acidulants (0.5% sodium bisulfate (SBS), 0.5% phosphoric acid (PA), 0.25% lactic acid (LA), etc.) and incubated overnight at 45 °C. The treated fats were inoculated with approximately eight logs of a Salmonella cocktail. Microbiological analyses were conducted separately for the fat-phase and water-phase at predetermined time intervals (0, 2, 6, 12, and 24 h) by plating them onto TSA plates. After incubating at 37 °C for 24 h, the plate count results were expressed as log CFU/mL. The MIC of SBS was 0.3125%, and of PA and LA were both 0.1953% against cocktail Salmonella serotypes. We observed a possible synergistic effect when SBS and organic acid were combined. All the acidulant tested at targeted concentrations individually as well as in combination with organic acids were highly effective against Salmonella spp. (non-detectable within 2 h) across different fat types. A potent anti-bactericidal effect leading to non-detectable Salmonella immediately (<1 h) at 45 °C was observed in the aqueous phase of the fish oil system, even without the addition of acidulants. These findings are significant for the dry pet food industries, where potential post-processing contamination of Salmonella could be controlled by treating fats and oils with acidulants.

Substrate degradation and postbiotic analysis of alternative fiber ingredients fermented using an in vitro canine fecal inoculum model

Many fiber ingredients are used by the pet food industry; however, little data are available regarding the fermentation characteristics of alternative fibers currently being used. The objectives of this study were to determine organic matter disappearance (OMD) and postbiotic production from various fruit and vegetable fiber sources using an in vitro dog fecal inoculum model. Apple pomace (AP), blueberry pomace (BP), cranberry pomace (CP), tomato pomace (TP), and pea fiber (PF) were used as experimental treatments. Inoculum was prepared using freshly voided feces under anaerobic conditions. Predigested fibers were inoculated and incubated for 1, 3, 6, and 12 h at 39ºC. Short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), total volatile fatty acids (VFA), and OMD were determined for each fiber source and time point in triplicate. After 12 h or incubation, OMD was similar (P>0.05; average of 18.5%) among treatments. Proportionally, acetate was greater for BP and AP (P<0.05; average of 80.1%) than for the other treatments (68.3 to 71.2%). Molar proportions of propionate was greatest (P<0.05) for CP (26.8%) compared to the remaining treatments (13.6 to 20.7%). Butyrate was proportionally greater for PF (7.7%; P<0.05) than for BP and CP (average of 4.8%) and was lowest for AP (3.8%); however, TP was not different from PF (P>0.05; average of 7.25%). Total VFA concentration was highest for AP (P<0.05) followed by TP (1.17 and 0.75 mmol*g -1 of substrate, respectively). Both BP and PF were similar (average of 0.48 mmol*g -1 of substrate) and lower than for TP, with CP having the lowest VFA concentration (0.21 mmol*g -1 of substrate) among all treatments. Additionally, when comparing molar concentrations, AP and TP (average of 0.0476 mmol*g -1 of substrate) had greater butyrate concentrations than did PF (0.0344 mmol*g -1 of substrate). The AP, BP, and TP treatments had both linear and quadratic relationships (Table 7; P<0.05) for acetate, propionate, and butyrate concentrations across time. Cranberry pomace only demonstrated a linear relationship for propionate (P<0.05), whereas acetate and butyrate had quadratic relationships with time. Pea fiber only demonstrated quadratic relationships between acetate, propionate, and butyrate concentrations and time (P<0.05). Overall, the fiber substrates evaluated were marginally to moderately fermentable when incubated for up to 12 h with canine fecal inoculum.

Evaluation of corn-fermented protein as a dietary ingredient in extruded dog and cat diets

Most pet foods utilize traditional ingredients like corn, wheat, and soy. These ingredients and other grains, such as distillers dried grains (DDG), have been used by the pet food industry. Corn-fermented protein (CFP) is a nutrient-dense enhancement on DDG but has not been evaluated in pet food. Therefore, it was the objective of this study to determine the effect of CFP in the production of extruded pet diets, and to determine the effect on nutrient utilization (digestibility) and stool consistency in dogs, and palatability in dogs and cats. Experimental diets with treatment protein sources (corn gluten meal [CGM], soybean meal [SBM], and CFP) were produced in triplicate using a single-screw extruder. Processing parameters and kibble samples were collected at timed intervals during diet production. Kibbles were evaluated for physical dimension and texture. No differences (P > 0.05) were observed in any physical dimension or texture parameters evaluated, with exception of radial expansion, which was lower (P < 0.05) for CFP kibble compared to others. The CFP kibble required a smaller (P < 0.05) mass restriction valve opening, to keep similar bulk density among dietary treatments. However, there was no difference (P > 0.05) in specific mechanical energy among treatments during diet production. Twelve beagles were fed the experimental diets in a 3 × 3 replicated Latin Square design in which four dogs were randomly assigned to each of three treatments for each period. Diets were formulated to be isonitrogenous and were supplemented with titanium dioxide to serve as an external marker in order to estimate apparent total tract digestibility. Dogs were housed individually and fed twice daily, and water was available ad libitum. Feces were collected after feedings. The diet produced with CGM was more digestible (P < 0.05) than CFP and SBM for dry matter, organic matter, crude protein, crude fat, and gross energy. Further, the CFP diet was also less (P < 0.05) digestible than the SBM diet for dry matter and organic matter. Dogs fed the diet containing CFP had higher (P < 0.05) fecal mass than those fed SBM and CGM. The CFP diet also resulted in a higher fecal score (P < 0.05) than those fed diets with the CGM diet, but similar (P > 0.05) to the SBM diet. For palatability assessment, dogs had a preference (P < 0.05) for CGM over SBM or CFP, but cats showed a preference (P < 0.05) for SBM and CFP over CGM. Results indicate that CFP is acceptable for use in dog and cat diets. Further research should be conducted to evaluate the use of these ingredients at lower inclusion levels.

Evaluation of a yeast β-glucan blend in a pet food application to determine its impact on stool quality, apparent nutrient digestibility, and intestinal health when fed to dogs

Oral supplementation of β-glucans may be able to improve the health of companion animals. However, little is understood regarding the effects of yeast β-glucan on diet processing and intestinal function. Therefore, the objectives of this research were to determine the carry through of yeast β-glucan during extruded diet production and its impact on diet utilization by dogs. Three diets were formulated to contain increasing levels of a yeast β-glucan blend at 0, 0.012 and 0.023% inclusion. Processing inputs were held constant during extrusion to allow for evaluation of output parameters and physical characteristics of kibble. Yeast β-glucan concentration was analyzed in extruded diets using the glucan enzymatic method, resulting in &gt;100% recovery. Twenty-four Labrador Retrievers were assigned to one of three dietary groups of 8 dogs each with an equal distribution of sex and age. Dogs were fed dietary treatments for 24-d adaption followed by 4-d total fecal collection. Feces were scored on a 1-5 scale, with 1 representing liquid diarrhea and 5 hard pellet-like with a fecal score of 3.5-4 considered ideal. Fresh fecal samples were collected for analysis of short chain fatty acid concentrations. Apparent total tract digestibility was calculated by total fecal collection (TFC) and titanium (TI) marker methods. Data were analyzed using a mixed model procedure in software (version 9.4, SAS Institute, Inc., Cary, NC). Dry bulk density, kibble diameter, and kibble length did not differ among dietary treatments. Intake was similar among dietary treatments (P &gt; 0.05). Dogs required about 26% more food than estimated [130*BWkg0.75] to maintain body weight among all treatments. Fecal score was not different (P &gt; 0.05) among dietary treatments but was lower than ideal at an average of 2.6. Nutrient digestibility was not affected (P &gt; 0.05) by inclusion of the yeast β-glucan. By method, the TFC procedure resulted in higher (P&lt; 0.05) digestibility values when compared to the TI procedure. In addition, yeast β-glucan did not alter short or branched chain fatty acid proportions. Overall, processing parameters, physical characteristics of kibble, stool quality, nutrient digestibility, and intestinal health in dogs were not affected by the yeast β-glucan blend.

Dietary yeast beta 1,3/1,6 glucan supplemented to adult Labrador Retrievers alters peripheral blood immune cell responses to vaccination challenge without affecting protective immunity

Yeast-derived 1,3/1,6 β-glucans may alter host immunity to produce robust and quickly resolved responses that align with companion animal health goals. In adult dogs, immunomodulation by yeast 1,3/1,6 β-glucans in extruded kibble diet have not been well documented. The study objective was to evaluate systemic immune responses in dogs fed kibble diets with two yeast 1,3/1,6 β-glucans doses before and after vaccine challenge. Twenty-four adult Labrador Retrievers were assigned to three dietary treatments consisting of a basal diet (control) supplemented with 0.012% or 0.023% (0.5 or 1×, respectively) yeast 1,3/1,6 β-glucan with equal sex representation within each treatment (8 dogs/diet). Animals were fed experimental diets for a 29-d acclimation period, after which baseline blood samples were collected before administration of a combination canine distemper virus, parvovirus, and adenovirus-2 vaccine. Blood samples were collected weekly for 21 d following vaccination with whole blood for CBC analysis, serum for titer and cytokine assays, and peripheral blood mononuclear cells (PBMC) isolated for flow cytometric immune cell profiling. Data were analyzed using the MIXED procedure with diet and timepoint fixed effects. Serum titer was analyzed by Kruskal-Wallis test (SAS 9.4; P ≤ 0.05). Prior to vaccination, β-glucan diets did not affect serum cytokines, antibody titer, or immune cell populations. In the first 7 d post-vaccination (dpv), PBMC CD21low B cells increased 36.5% to 58.1% in all groups but the magnitude of change was lesser in the 0.5× β-glucan diet resulting in 25.6% lower CD21low populations compared to control-fed dogs (P = 0.007). By 21 dpv, B-cell populations recovered to baseline levels in dogs fed 1× β-glucan, but CD21high cells remained elevated 50.5% in dogs fed 0.5× β-glucan diets compared with baseline (P < 0.0001). While no differences in serum titer or cytokines were observed, feeding both β-glucan diets maintained stable blood monocytes, whereas a 53.0% decrease between baseline and 14 dpv was observed in control-fed dogs (P = 0.01). Collectively, these outcomes suggest that a 1× dose of 1,3/1,6 yeast β-glucan in extruded kibble diets altered monocytes associated with trained immunity, did not reduce PBMC CD21low B-cell responsiveness, and simultaneously contributed to B-cell population resolution by 21 dpv in adult dogs. Additional research to assess the functionality of these changes is needed.

Diet production and utilization of corn fermented protein compared to traditional yeast in healthy adult cats

The inclusion of yeast in pet food can provide health benefits and increase palatability. Corn fermented protein is a co-product from ethanol production which contains approximately 20% to 25% yeast. The objective of this study was to determine the effects of the yeast in CFP on diet production and utilization when fed to healthy adult cats. The four experimental diets included a control with 15% soybean meal (CON) and diets containing either 3.5% brewer's dried yeast (BDY), 2.5% brewer's dried yeast plus 17.5% distillers dried grains with solubles (BDY+DDGS), or 17.5% corn fermented protein (CFP). All treatments except CON were formulated to contain 3.5% yeast. Experimental diets were fed to adult cats (n = 11) in an incomplete 4 × 4 replicated Latin square design. Cats were adapted to diet for 9 d followed by a 5-d total fecal collection. Titanium dioxide (0.4%) was added to all diets as an external marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and cat and period as random effects. Preconditioner discharge temperature was greater (P < 0.05) for CON and BDY (average, 96 °C) compared to BDY + DDGS and CFP (average, 91 °C). Extruder screw speed, die temperature, kibble toughness, and kibble hardness were greatest (P < 0.05) for CFP. The bulk density of BDY + DDGS at 392 g/L was greater (P < 0.05) than BDY and CFP (average, 342 g/L). The sectional expansion index of kibble for CFP was greater (P < 0.05) than BDY + DDGS and smaller (P < 0.05) than CON but similar to BDY. Fecal output was greatest (P < 0.05) for cats fed BDY + DDGS. Nutrient digestibility was lowest (P < 0.05) for BDY + DDGS. The concentrations of short-chain and branched-chain fatty acids in fecal samples were not altered (P > 0.05) by dietary treatment. Cats had no preference (P > 0.05) when comparing CON to BDY or BDY + DDGS. However, cats consumed significantly less CFP compared to CON. The significant differences for bulk density, fecal output, and nutrient digestibility among dietary treatments are likely due to a greater fiber effect of DDGS compared to CFP. Therefore, the yeast component in CFP may provide greater kibble expansion and nutrient utilization compared to DDGS when fed to cats.

Effects of liquid smoke preparations on shelf life and growth of wild type mold and Aspergillus flavus in a model semi moist pet food

Liquid smoke is a naturally derived flavor component and preservative with known antimicrobial properties. To our knowledge, there is a paucity of information on antifungal potential of liquid smoke against toxigenic fungi like Aspergillus flavus that produce mycotoxins in human and pet foods. Semi-moist pet food with high moisture content (20-30%) is susceptible to mold contamination and requires intervention. The objectives of this study were to determine the effects of liquid smoke preparations on the growth of wild-type mold and A. flavus in semi-moist pet food. Semi-moist pet food was formulated with eight different liquid smoke preparations (S1-S8) containing varying amounts of organic acids, phenol and carbonyl compounds (ranging from low to high) at 0% (untreated), 0.5, 1, 2, and 4% (w/w). A positive control consisted of 0.2% potassium sorbate known to inhibit mold growth. Shelf life was estimated by storing the samples at 28°C and 65-70% RH over 30 days and recording the number of days until the appearance of visible wild-type mold. In another experiment, samples were spot inoculated with A. flavus (∼10,000 CFU/mL), incubated at 25°C, and analyzed for fungal growth at sampling intervals of 2 days over a 35-day period. Liquid smoke at 0.5, 1, 2, and 4% extended the shelf life of samples on an average by a total of 11.6, 12.5, 17.2, and 24.1 days when compared to the untreated samples (7.7 days). The smoke preparations Cloud S-C100 (S3) and Code-10 (S6) (high carbonyl, medium/low phenol) were the most effective (P < 0.05) in prolonging the number of days to visible mold growth (26-28 days). In the challenge study with A. flavus, Cloud S-C100 (S3), Cloud S-AC15 (S8) (high to medium carbonyl, low phenol), and Code 10 (S6) (base smoke) reduced (P < 0.05) mold counts by 1.0, 1.7, and 2.5 logs when compared to the untreated samples at 1, 2, and 4%, respectively. Addition of smoke at 0.5% did not reduce mold counts. The carbonyl preparations of liquid smoke were the most effective at enhancing shelf life of semi-moist pet food, and at inhibiting A. flavus growth.

A review of food additives to control the proliferation and transmission of pathogenic microorganisms with emphasis on applications to raw meat-based diets for companion animals

Raw meat-based diets (RMBDs) or sometimes described as biologically appropriate raw food (BARFs) are gaining in popularity amongst dog and cat owners. These pet guardians prefer their animals to eat minimally processed and more “natural” foods instead of highly heat-processed diets manufactured with synthetic preservatives. The market for RMBDs for dogs and cats is estimated at $33 million in the United States. This figure is likely underestimated because some pet owners feed their animals raw diets prepared at home. Despite their increasing demand, RMBDs have been plagued with numerous recalls because of contamination from foodborne pathogens like Salmonella, E. coli, or Campylobacter. Existing literature regarding mitigation strategies in RMBD's for dogs/cats are very limited. Thus, a comprehensive search for published research was conducted regarding technologies used in meat and poultry processing and raw materials tangential to this trade (e.g., meats and poultry). In this review paper, we explored multiple non-thermal processes and GRAS approved food additives that can be used as potential antimicrobials alone or in combinations to assert multiple stressors that impede microbial growth, ultimately leading to pathogen inactivation through hurdle technology. This review focuses on use of high-pressure pasteurization, organic acidulants, essential oils, and bacteriophages as possible approaches to commercially pasteurize RMBDs effectively at a relatively low cost. A summary of the different ways these technologies have been used in the past to control foodborne pathogens in meat and poultry related products and how they can be applied successfully to impede growth of enteric pathogens in commercially produced raw diets for companion animals is provided.

Evaluation of graded levels of corn-fermented protein on stool quality, apparent nutrient digestibility, and palatability in healthy adult cats

Dried distillers' grains, coproducts from the ethanol industry, may provide sustainable ingredients for pet food. Due to new post-fermentation separation techniques, corn-fermented protein (CFP) is higher in protein and lower in fiber compared with traditional dried distillers' grains, increasing its appeal for inclusion into pet food. Therefore, the objectives of this study were to determine the effects of increasing levels of CFP on stool quality, apparent total tract digestibility (ATTD), and palatability in adult cats. Four extruded diets were fed to 11 adult cats in an incomplete 4 × 4 replicated Latin square design. The control diet contained 15% soybean meal (0C) and CFP was exchanged for soybean meal at either 5%, 10%, or 15% (5C, 10C, 15C). Cats were fed each dietary treatment for 9-d adaption followed by 5-d total fecal collection. Feces were scored on a 1 to 5 scale, with 1 representing liquid diarrhea and 5 representing hard pellet-like (Carciofi et al., 2008). A fecal score of 3.5 to 4 was considered ideal. Titanium dioxide was added to all diets (0.4%) as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and cat and period as random effects. Fecal dry matter percent and dry fecal output were greater (P < 0.05) at elevated levels of CFP. Stool scores were maintained (P > 0.05) throughout treatments (average; 4). Dry matter, organic matter, crude protein, and gross energy ATTD decreased when cats were fed 15C. There was no difference in ATTD of fat or total dietary fiber among treatments. For palatability assessment, cats preferred 5C over 0C but had no preference with increased CFP inclusion. These results suggest that CFP is comparable to SBM, but there may be a maximum inclusion level of 10% when fed to cats.

Evaluation of Torula yeast as a protein source in extruded feline diets

The objective of this work was to evaluate the use of a Torula yeast (TY) on diet processing, palatability, and total tract nutrient digestibility in extruded feline diets. Four dietary treatments were compared, differing by protein source: TY, pea protein concentrate (PP), soybean meal (SM), and chicken meal (CM). Diets were produced using a single-screw extruder under similar processing conditions. Palatability assessment was conducted as a split plate design where both first choice and intake ratio (IR) were determined. Apparent total tract digestibility (ATTD) of nutrients was estimated using Titanium dioxide as an indigestible marker. During diet production, specific mechanical energy of TY and SM (average of 187 kJ/kg) was greater (P < 0.05) than for PP (138 kJ/kg); however, CM was similar to all treatments (167 kJ/kg). Kibble diameter, piece volume, and sectional expansion ratio were greatest for TY (P < 0.05). Additionally, both bulk and piece density were lowest (P < 0.05) for TY. Kibble hardness was lower for TY and SM (P < 0.05; average of 2.10 Newtons) compared to CM and PP (average of 2.90 Newtons). During the palatability trial, TY was chosen first a greater number of times than CM (P < 0.05; 36 vs. 4, respectively), but differences were not found between TY and PP (25 vs. 15, respectively) or TY and SM (24 vs. 16, respectively). Cats had a greater IR (P < 0.05) of TY compared to CM and PP (0.88 and 0.73, respectively). However, there was no difference in preference between TY and SM. ATTD of dry matter (DM) and organic matter (OM) was greater (P < 0.05) for CM (87.43% and 91.34%, respectively) than other treatments. Both DM and OM ATTD of TY were similar (P < 0.05) to PP and SM (average of 86.20% and average of 89.76%, respectively). Ash ATTD was greater (P < 0.05) for cats fed TY and SM (average of 37.42%), intermediate for PP (32.79%), and lowest for CM (23.97%). Crude protein (CP) ATTD of TY was similar to all other treatments (average of 89.97%), but fat ATTD was lower (P < 0.05; 92.52%) than other treatments (93.76% to 94.82%). Gross energy ATTD was greater (P < 0.05) for CM than TY (90.97% vs. 90.18%, respectively); however, TY was similar to PP and SM (average of 90.22%). Total dietary fiber ATTD was similar between TY and CM (average of 66.20%) and greater (P < 0.05) than PP and SM (average of 58.70%). The TY used in this study facilitated diet formation, increased diet preference, and was highly digestible when fed to cats.

PSXI-21 Validation of a Method to Determine Dogs’ Preference for Flavors

There is little information regarding dogs’ preference for a given flavor, especially in water. Therefore, the objective of this study was to validate the method of using a consumption test to determine the dogs’ ability to discriminate water-based flavors. There were three phases of the study to validate the model using water as a flavor carrier. First was to measure position bias, second to evaluate for preference for specific elemental flavors, and third to evaluate the dogs’ ability to district by dose. To eliminate confounding variables; salt (salty), dextrose (sweet), citric acid (sour) and MSG (umami) were mixed with tap water to create colorless and odorless test solutions (salt 0.5%, dextrose 4%, citric acid 0.1%, MSG 0.035%), with tap water as the control. For evaluating dose sensitivity, salt waters at increasing levels of concentration (0%, 0.25%, 0.5%, 1%, 2%) were evaluated. In this study, twelve adult Beagle dogs (average age one year) were individually housed. Using a randomized block design, ceramic bowls, labeled A-E, were placed along the back wall of each pen and filled with 400g of the control or test solutions. Bowl position was randomized daily, to account for any position bias; and water disappearance was measured for five days. Data were analyzed using a mixed model (SAS version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and the dog and day as random effects. Of the elemental flavors, sweet was most preferred (average 250.05g/day) with sour and salty (average 96.45g/day and 85.77g /day) least preferred (p &lt;0.05). Regarding dose distinction, a linear decrease (p&lt;0.05) in water disappearance was observed as salt concentration increased. These results suggest that dogs do have the ability to distinct between flavors. It also suggests that dogs do have the ability to discriminate between different doses.

111 Organic Matter Disappearance and Production of Short- and Branched-Chain Fatty Acids from Whole Soybeans and Selected Fiber Sources Used in pet Foods by a Canine in Vitro Fermentation Model

Soluble fiber can be fermented by microflora in the colon resulting in short-chain fatty acid (SCFA) production. SCFA can be used as an energy source for the host, enterocytes, colonocytes, and immune cells, supporting cell differentiation and gut health. An in vitro model has been used to predict the colonic fermentability of fibers. Whole soybean (WSB) contains oligosaccharides and non-starch polysaccharides that may behave as beneficial fermentable substrates. The objective of this study was to determine the effect of WSB oligosaccharides on in vitro fermentation using dog feces as inoculum. Treatments included total dietary fiber residues from WSB, soy hull (SH), pea fiber (PF), beet pulp (BP), soybean oligosaccharides (WSBOS), and raffinose, stachyose, and verbascose (WSBRSV). The fecal samples were collected from three Beagle dogs and maintained in anaerobic conditions until dilution and substrate inoculation. Test tubes containing enzymatic pretreated fiber sources and inoculum were incubated for 1, 2, 4, 8, and 12 hours at 39°C. Organic matter disappearance (OMD), pH, and SCFA were determined for each fiber source and time point. The data were subjected to ANOVA using the general linear model procedure (SAS, v 9.4). Least square mean differences were assessed using Tukey’s post hoc test. WSBOS and WSBRSV had greater OMD and butyrate than BP (P &lt; 0.05; 43.59 and 60.18% vs 40.96% OMD; 293.33 and 266.67 vs 130umol/g, respectively). BP and WSBRSV had the lowest pH (6.66 and 6.74, respectively) at 12 h (P &lt; 0.05). WSB had similar butyrate compared with BP (average 118umol/g). PF and SH were poorly fermented with the least OMD (18.59% and 20.45%, respectively) and butyrate (46.67umol/g and 66.67umol/g, respectively) compared with other fiber sources. In conclusion, soybean oligosaccharides were highly fermentable and produced the greatest amount of butyrate, and WSB was moderately fermentable compared to the BP.

121 Comparison of Corn Fermented Protein (CFP) to Traditional Yeast and Distillers Grain fed to Healthy Adult Cats

Co-products from the ethanol industry may be able to provide high-quality sustainable protein sources for pet foods. Unlike traditional co-products, corn fermented protein (CFP) contains a yeast component which may provide additional benefits. The objective of this study was to determine, by exchange, the effects of the yeast in corn fermented protein on diet utilization. The four experimental diets included a control with no yeast (CON) and diets containing either 3.5% brewer’s dried yeast (BDY), 17.5% distiller’s dried grains with solubles plus 2.5% brewer’s dried yeast (BDY+DDGS), or 17.5% CFP (CFP). It was assumed that CFP contained 20% yeast and all treatments except CON were formulated to contain 3.5% yeast. Experimental diets were fed to adult cats (n = 11) in a replicated 4 x 4 Latin Square design. Cats were adapted to diet for 9 days followed by a 5-d total fecal collection. Titanium dioxide (0.4%) was added to all diets as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and cat and period as random effects. Dry fecal output of cats was greatest for BDY+DDGS at 20.2 g/d compared with the other treatments at an average of 16.3 g/d (P &lt; 0.05). Defecations per day were also greatest for cats consuming BDY+DDGS (P &lt; 0.05). When comparing CFP with BDY+DDGS, the digestibility of dry matter, organic matter, and gross energy was about 3% greater (P &lt; 0.05) for CFP. Short or branched chain fatty acids in fecal samples were not altered by dietary treatment. The increase in fecal output and decrease in digestibility with BDY+DDGS indicates a greater fiber effect in the DDGS compared with the CFP. Therefore, the yeast component in CFP may be providing a greater nutrient utilization when fed to cats.

A Review of Application Strategies and Efficacy of Probiotics in Pet Food

In companion animal nutrition, probiotics (direct-fed microbials) are marketed as functional ingredients that add value to pet foods due to the impact they have on gastrointestinal and immune health of dogs and cats. The nature of the beneficial effect each probiotic strain exerts depends on its metabolic properties and perhaps most importantly, the arrival of a sufficient number of viable cells to the large bowel of the host. Pet food manufacturing processes are designed to improve food safety and prolong shelf-life, which is counterproductive to the survival of direct-fed microbials. Therefore, a prerequisite for the effective formulation of pet foods with probiotics is an understanding of the conditions each beneficial bacterial strain needs to survive. The aims of this chapter are: (1) To summarize the inherent characteristics of probiotic strains used in commercial pet foods, and (2) To review recently published literature on the applications of probiotics to pet foods and their associated challenges to viability.

Sensory attributes, dog preference ranking, and oxidation rate evaluation of sorghum-based baked treats supplemented with soluble animal proteins

Treats are offered to dogs to reinforce the animal-owner bond and as rewards. Wheat, which contains gluten (gliadin and glutenin proteins), is often used in treats. The US is a leading producer of sorghum which might be an alternative; however, it does not have functional properties to form viscoelastic doughs, because is mainly composed of kafirin protein. Therefore, the objectives of this study were to determine the effects of supplementing soluble animal proteins in whole sorghum rotary molded baked dog treats on dog preference, sensory attributes, and oxidation rate. The treats were produced in triplicate in a 2x4 + 1 augmented factorial arrangement of treatments. Two whole sorghum flours (WWS and WRS), four protein sources [none (NC), spray-dried plasma (SDP), egg protein (EP), and gelatin (GL)], and a positive control with wheat (WWF-GTN) were evaluated. A preference ranking test with twelve dogs was performed. Additionally, five trained panelists scored the intensity of appearance, aroma, flavor, texture/mouthfeel, and aftertaste attributes. Finally, the treats were stored at 30°C and 60% RH, and hexanal concentrations were measured on days 0, 28, 56, and 112. The data was analyzed using the statistical software SAS for the animal and oxidation rate evaluations with significance considered at P<0.05. The descriptive sensory evaluation data was analyzed using multivariate analysis (XLSTAT). The dogs did not detect differences among WWF-GTN, WWS, or WRS treats when evaluated together. However, the WWF-GTN, WWS-SDP and WWS-EP treatments were preferred among the white sorghum treatments. The EP treatments led to some consumption difficulties by dogs because of their hard texture. The panelists reported a high degree of variation in the appearance and texture across treatments. The WRS and WWS treats with SDP or EP were darker, while NC treats had more surface cracks. Initial crispness, hardness, and fracturability were higher in EP treatments compared to all other sorghum treatments. The predominant flavor and aftertaste identified were "grainy." The hexanal values for all treats were <1.0 mg/kg except for the EP treatments that had higher values (2.0-19.3 mg/kg) across the shelf-life test. This work indicated that the replacement of WWF-GTN by WWS and WRS, along with soluble animal proteins like SDP or GL would produce comparable preference by dogs, oxidation rates, product aromatics, flavor, aftertaste attributes, and, at a lower degree, product texture.

Temperature-Dependent Antimicrobial Activity of Menhaden Fish Oil In Vitro and on Pet Food Kibbles against Salmonella

ABSTRACT

Fish oil inclusion into a dry pet food provides a source of long-chain omega-3 fatty acids. Polyunsaturated fatty acids in fish oil have antibacterial activity against various foodborne pathogens, such as Salmonella and pathogenic Escherichia coli. The purpose of this study was to determine the effect of temperature applied to dry pet food kibbles on the antimicrobial activity of menhaden fish oil against Salmonella spp. Sterile menhaden oil was inoculated with ∼8 log of a Salmonella cocktail (∼3% moisture; Salmonella Enteritidis, Salmonella Heidelberg, and Salmonella Typhimurium) and incubated at 25, 37, and 45°C. Microbiological evaluation of the water phase was done after 2 h on tryptic soy agar. Sterile kibbles were coated with fish oil (7.0%, w/w). Canola oil coating was kept as a control. One hour after coating, the kibbles were inoculated with ∼9 log of Salmonella and incubated at the respective temperature. The microbiological evaluation was conducted at 0, 2, 6, 12, and 24 h. The oil phase of the fish oil system was negative for Salmonella after 2 h of incubation and confirmed by enrichment and PCR. From the water phase, 8.1 and 7.3 log were recovered at 25 and 37°C, respectively, and no Salmonella was detected at 45°C. On the kibble, menhaden oil had higher antimicrobial (P ≤ 0.05) activity after 12 h at 25°C and throughout the experiment at 37°C. At 45°C, the fish oil had a superior antimicrobial activity against the Salmonella cocktail after 2 h. When the fish oil alone was compared at different temperatures, a higher antimicrobial activity was observed at 37 and 45°C across all time points. The results indicate antimicrobial activity of menhaden oil increases with temperature. This is an important finding to the pet food industry: a higher fat holding temperature (∼45°C) and the application process may help mitigate Salmonella on extruded kibbles.

HIGHLIGHTS

Effects of Antimicrobial Addition on Lipid Oxidation of Rendered Chicken Fat

This study evaluated the effects of antimicrobial acidulant addition on lipid oxidation of rendered chicken fat. Chicken fat was untreated (control) or treated with either sodium bisulfate (SBS) or lactic acid (LA) at 0.5% w/w and incubated for 6 weeks at 40°C. Peroxide value (PV), p-anisidine value (AV) and free fatty acid (FFA) levels were measured at day 0 (D0), 1(D1), 3 (D3), 5 (D5), and 7 (D7), and week 2 (W2), 3 (W3), 4 (W4), 5 (W5), and 6 (W6). The FFA level of untreated-control fat was ~7% and remained consistent throughout the incubation until W6 (~8.5%; P&lt;0.05). The FFA values in SBS treated fat were constant (range 7.25-8.30%) throughout the incubation, whereas the FFA in LA treated fat peaked at W5 (9.3%; P&lt;0.05). For the control fat, PVs were between 0.56-0.67 meq/100gm until W1 then declined. For the SBS treated fat, the PVs remained low and similar to the control with the exception of a slight increase on W4 to 0.38 meqv/100gm (P&lt;0.05). In the LA treated fat the PV was greater than (P&lt;0.05) the control from W1 and increased to a peak on W5 (2.52 meq/100gm). The AV of control fat averaged 2.12 at D0 and increased through W2. In control and LA treated fat, the AV values declined slightly thereafter, whereas SBS treated fat increased (P&lt;0.05) to 10.28 on W5. This study indicates that when included at antimicrobial effective levels LA may reduce the shelf-life of chicken fat, but SBS had a minimal effect over 6 weeks of storage.

A Low to Medium-Shear Extruded Kibble with Greater Resistant Starch Increased Fecal Oligosaccharides, Butyric Acid, and Other Saccharolytic Fermentation By-Products in Dogs

The objective of this study was to assess whether diets with increased resistant starch (RS) had a positive effect on markers of colonic health in dogs. Three identical diets were extruded with high, medium and low shear (HS, MS and LS) to incrementally increase RS, and fed to 24 dogs in a replicated 3 × 3 William's Latin square design for 28-day periods. Fasting blood and fresh feces were collected on the last week of each period. Fecal quality was maintained among treatments. Gut integrity markers were measured by ELISA. Fecal short-chain fatty acids (SCFAs) were measured by LC MS/MS. In addition, the microbiota of dogs was determined from fresh feces by 16s rRNA high throughput sequencing. Untargeted metabolomics of both feces and serum were determined by UPLC. Data were analyzed using mixed models. There were no treatment effects on satiety hormones or gut integrity markers. Dogs fed LS or MS diets had marginal evidence (p < 0.10) for decreased fecal pH and for higher concentration (p < 0.05) of butyric acid and fecal oligosaccharides, succinate and lactate. Also, dogs fed the MS or LS diets had a shift towards more saccharolytic bacteria.

PSV-B-21 Evaluation of whole soybeans as an ingredient in dog diets: Apparent total tract digestibility and stool quality of extruded diets with graded levels of dehulled whole soybeans by dogs

Increasing the amount of liquid fat to the ration during extrusion can negatively affect product density and product expansion. Ingredients, like whole soybeans (WSB), which are high in fat may aid increased energy density while avoiding production issues. In a preliminary extrusion project, the effects on the process of foods were evaluated, followed by animal evaluation. The objective of this study was to determine the effect of dehulled WSB on nutrient digestibility and stool quality by dogs. Experimental diets were extruded with 0%, 10%, 20%, and 30% WSB (WSB0, WSB10, WSB20, and WSB30, respectively). Seven castrated male and three spayed female Beagles of similar age (6.25 ± 0.452 years) were individually housed and fed the experimental diets. The study was designed as replicated 4 × 4 Latin square where dogs were allowed 9-d adaptation followed by 5-d total fecal collection for each period. Titanium dioxide was added to all diets (0.4%) to serve as an indigestible dietary marker to determine apparent total tract digestibility (ATTD). Least-square means of fecal parameters and ATTD were analyzed with a single degree of freedom contrasts and significance at α = 0.05. There was no difference among treatments for food intake or fecal scores. However, there were linear increases (P &lt; 0.05) in DM fecal output, as is fecal output, fecal moisture, and defecation frequency stools/day as WSB increased in the diets. Apparent total tract digestibility of dry matter, crude protein, acid hydrolyzed ether extract, and gross energy decreased linearly as dogs were fed increasing levels of WSB in the diets (P &lt; 0.05). In conclusion, additional thermal processing before extrusion may improve nutrient digestibility, although stool quality was not affected by the inclusion of WSB.

108 Evaluation of Graded Levels of Grain Distillers Dried Yeast (GDDY) on Apparent Nutrient Digestibility and Stool Quality in Healthy Adult Dogs

Yeast and distillers’ grains from ethanol products have been included in pet food for many years. However, their combination has not been evaluated in pet food. Grain distillers dried yeast (GDDY) is a combination of fermented grains which is rich in yeast. The objectives of this study were to determine the effects of increasing levels of GDDY on apparent total tract digestibility (ATTD) and stool quality in adult dogs. Four extruded diets were fed to twelve adult Beagle dogs in a replicated 4 x 4 Latin Square design. The control diet contained 15% soybean meal (15S) and GDDY was exchanged for soybean meal at either 5%, 10%, or 15% (5G, 10G, 15G). Dogs were fed each dietary treatment for 9-d adaption followed by 5-d total fecal collection. Feces were scored on a 1–5 scale, with 1 representing liquid diarrhea. Titanium dioxide was added to all diets (0.4%) as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and dog and period as random effects. No differences (P &gt; 0.05) were observed in wet fecal output or fecal pH (average; 112.74g/d and 5.77). Fecal DM and defecations per day were greater (P &lt; 0.05) at elevated levels of GDDY. Stool scores were higher (P &lt; 0.05) when dogs consumed diets containing GDDY versus 15S (average; 3.85 vs 3.67). Organic matter ATTD was the greatest (P &lt; 0.05) for dogs fed 15S compared to GDDY treatments (average; 87.64% vs 86.67%). Dogs fed 10G had the lowest (P &lt; 0.05) ATTD for crude protein compared to all others (average; 87.92% vs 88.78%). These results suggest that levels of GDDY between 5 and 15% are comparable to soybean meal when fed to adult dogs.

PSV-B-24 Palatability assessment of graded levels of grain distillers dried yeast (GDDY) fed to healthy adult cats

Traditionally, yeast products have been added to companion animal diets to improve palatability. Grain distillers dried yeast (GDDY), a coproduct from ethanol production which contains yeast, may be a viable option in pet food. The objective of this study was to determine the effects of increasing levels of GDDY in cat diets compared to soybean meal. The control diet contained 15% soybean meal (CON) and GDDY was exchanged for soybean meal at either 5%, 10%, or 15% (5G, 10G, 15G). For each test, experimental treatments were compared to the control. Twenty cats were presented two bowls each containing approximately 100g of diet once daily for 2 days. Cats were given diet access for 4 hours and bowl placement was reversed on the second day. Total food consumption and first choice preference were recorded for each cat. Individual intake ratios (IR) were calculated (intake of each diet/total intake) and first choice (FC) was analyzed with a Chi2 test. When comparing 5G to CON, the IR was 0.970 with FC of 30/40 occasions (P = 0.0016). The IR for 10G was 0.538 and FC was 18/40 with no difference from the CON (P = 0.5271). The IR for 15G was 0.590 and FC was 19/40 with no difference from the CON (P = 0.7518). Overall, these results suggest that cats may prefer GDDY over soybean meal, but preference may be influenced by inclusion level with the greatest impact observed at 5% and no detrimental impact at 10 or 15%.

PSV-B-18 Characterization of the fecal microbiome of healthy adult beagle dogs supplemented with graded levels of bacillus coagulans GBI-30, 6086

This study aimed to evaluate the effect of Bacillus coagulans GBI-30, 6086 on the fecal microbiome of healthy adult dogs. Extruded diets containing graded levels of probiotic applied either to the base ration before extrusion or as a topical coating post-extrusion were randomly assigned to ten individually-housed Beagle dogs (7 castrated males, 3 spayed females) of similar age (5.75 ± 0.23 yr) and body weight (12.3 ± 1.5 kg) in a 5 x 5 replicated Latin square with 16-d adaptation and 5-d total fecal collection for each period. Five dietary treatments were formulated to deliver a dose of 0-, 6-, 7-, 8-, or 9-log10 CFU·dog-1·d-1. Fresh fecal samples (n=50) were analyzed by 16S rRNA gene pyrosequencing. Community diversity was evaluated in R (v4.0.3, R Core Team, 2019). Relative abundance data were analyzed using a mixed model (v9.4, SAS Institute, Inc., Cary, NC) with treatment and period as fixed effects and dog as a random effect. Results were considered significant at P &lt; 0.05. Predominant phyla were Firmicutes (mean 81.2% ± 5), Actinobacteria (mean 9.9% ± 4.4), Bacteroidetes (mean 4.5% ± 1.7), Proteobacteria (mean 1.3% ± 0.7), and Fusobacteria (mean 1.1% ± 0.6). No evidence of shifts in predominant phyla, class, family, or genus taxonomic levels were observed except for the Bacillus genus, which had a greater relative abundance (P = 0.0189) in the low probiotic coating and high probiotic coating treatment groups compared to the extruded probiotic group. Alpha-diversity indices (Richness, Chao1, ACE, Shannon, Simpson, Inverse Simpson, and Fisher) and beta-diversity metrics (principal coordinate analysis and multi-dimensional scaling) were similar for all treatments. This data indicates that supplementation with Bacillus coagulans GBI-30, 6086 at a dose of up to 9 log10 CFU·d-1 did not alter the overall diversity of the fecal microbiome of healthy adult dogs over a 21-d period.

PSIII-4 Nutritional evaluation of yeast biomass from candida utilis as a protein source in cat diets

Yeast products have found much favor within companion animal nutrition. A recently developed proprietary process has introduced an enhanced yeast biomass from Candida utilis (merchandised as SylPro®) into the animal food marketplace. Candida utilis has been shown to be a valuable protein in canine, swine and aquaculture diets; however, no previous research has evaluated its use in feline diets. Therefore, the current objective was to determine the nutrient digestibility of diets containing SylPro® yeast biomass (SYL) as the primary protein source relative to soybean meal (SOY), pea protein concentrate (PEA), and chicken meal (CKN) fed to cats. Apparent total tract digestibility (ATTD) of diets were estimated using Titanium dioxide as an indigestible marker. The DM ATTD for SYL was lower (P &lt; 0.0001) than CKN (86.39 vs. 87.43%, respectively) but similar to both SOY (85.66%) and PEA (86.54%). The OM ATTD of SYL, SOY, and PEA were not different (P &lt; 0.0001) and were each lower than CKN (average of 89.60 vs. 91.16%, respectively). The CP ATTD for SYL (89.9%) was not different from the other three treatments (P = 0.0200). Crude fat ATTD of SYL was lower (92.52%; P &lt; 0.0001) than all treatments with PEA being greatest (94.82%) and CKN and SOY intermediate (average of 93.84%). The SYL and CKN had higher TDF ATTD (average of 66.20%; P &lt; 0.0001) relative to PEA and SOY (average of 49.79%). The GE ATTD of SYL was lower than CKN (90.18 vs. 90.97%, respectively; P = 0.0154) but similar to both SOY (90.18%) and PEA (90.30%). In conclusion, all diets were highly digestible but CKN preformed the best. The SYL diet was similar to CKN for ATTD of CP and TDF. The SYL diet was also similar to both SOY and PEA for ATTD of DM, OM, CP and GE.

PSV-B-22 Evaluation of whole soybeans as an ingredient in dog diets: Canine palatability of extruded diets with graded levels of dehulled whole soybeans

Increasing the amount of liquid fat in the ration during extrusion can negatively affect product density and product expansion. High-fat ingredients, such as whole soybeans (WSB), may increase energy density while avoiding production issues. In a preliminary extrusion project, the addition of graded levels of WSB on food processing was evaluated. The objective of this study was to determine the effect of incremental addition of whole soybeans in dry dog food on palatability. Experimental diets were extruded with 0%, 10%, 20%, and 30% WSB (WSB0, WSB10, WSB20, and WSB30, respectively). Palatability was determined with a 2-bowl test by beagle dogs (n = 20) for 2 days with each WSB diet compared to the WSB0. First choice preference and total food consumption were recorded for each dog. Individual intake ratios (IR) were calculated (intake of each diet/total intake). First choice (FC) was analyzed by a Chi2 probability, and the consumption of each diet was compared by a Wilcoxon signed rank test and a 2-way analysis of variance (2-way ANOVA). Dogs had greater (P &lt; 0.05) first choice for WSB diets relative to the WSB0, but there was no significant difference among treatments for the food consumption and intake ratio. When comparing WSB0 to WSB10, FC occurred in 13/40 occasions (P &lt; 0.05). The FC for WSB0 occurred in 12/40 occasions compared to WSB20 and in 11/40 occasions compared to WSB30 (P &lt; 0.05). Overall, dogs favored WSB diets over the control diet showing a higher score in the indication of aroma, but this did not result in higher consumption. In conclusion, palatability was not affected by the inclusion of WSB in the dry dog food.

115 Stability of Thiamine Supplied by Vitamin Premix and Yeast Ingredients in Canned Cat Food

Despite numerous process modifications, thiamine retention of canned cat food has not improved. Yeasts possess a binding protein which may provide a thiamine form able to withstand retort processing. Therefore, the objective was to evaluate dried yeasts as thiamine sources in canned cat food. Treatments were arranged as a 2ｘ4 factorial with 2 levels of vitamin premix (with or without) and 4 sources of yeast (none (NY), LBV, BY, or EA). Inclusion of LBV matched the thiamine contribution from the vitamin premix and BY and EA were capped at 5%. Three replicates were processed in a horizontal still retort to an average total F0 of 79.23 minutes. Thiamine degradation was calculated as the difference between pre- and post-retort thiamine contents. Data were analyzed as a randomized complete block design with pre-retort thiamine content as a covariate and production day as a random effect. The Fisher’s LSD post hoc comparison test was performed with ⍺ = 0.05. On average, experimental formulas retained 33.75% thiamine. Thiamine degradation was not affected by the inclusion of vitamin premix (P = 0.0670), but was affected by the inclusion of yeast (P = 0.0232) and the interaction between vitamin premix and yeast (P = 0.0002). Thiamine loss between NY (-31.3 mg/kg DM) and BY (-33.8 mg/kg DM) were similar (P &gt; 0.05) whereas EA (-40.5 mg/kg DM) and LBV (-55.6 mg/kg DM) lost more (P &lt; 0.05) thiamine than NY. The treatment of EA with vitamin premix (-70.3 mg/kg DM) lost more (P &lt; 0.05) thiamine than no yeast, BY, or EA without vitamin premix (average -17.4 mg/kg DM) and all others (average -57.3 mg/kg DM) were intermediate (P &gt; 0.05). Inclusion of vitamin premix with yeast did not minimize thiamine loss and BY exhibited similar thiamine degradation as intrinsic thiamine in standard ingredients.

PSV-B-27 The effects of carbohydrate hydrocolloids on firmness, toughness, and expressible moisture of wet pet food

In a previous experiment, inclusion of guar gum, kappa carrageenan, locust bean gum, and xanthan gum were observed to influence the texture of wet pet food. However, limited published research has addressed their texture and water holding. Therefore, the objective was to quantify the differences in texture and expressible moisture (EM) due to common hydrocolloids in wet pet foods. Treatments included 1% dextrose (D) and 0.5% guar gum with either 0.5% dextrose (DG), 0.5% kappa carrageenan (KCG), 0.5% locust bean gum (LBG), or 0.5% xanthan gum (XGG) in a chicken-based product processed in three replicate batches. Processing occurred in a still retort at 121 °C and 144.79 kPa for an average 81.25 minute cook cycle and 79.58 minute cooling cycle. Texture analysis was conducted with a modified back extrusion while products remained in the can (n = 5) and firmness (peak force measurement) and toughness (positive area under the curve) were recorded during a 2 cm penetration. Expressible moisture was analyzed by centrifugal methods. Data were analyzed as a 1-way ANOVA with the fixed effect of treatment and the random effect of batch. Fisher’s LSD post hoc test was used to separate means. The KCG treatment exhibited the highest (P &lt; 0.05) firmness (27.00 N) and D and DG the lowest (average 8.75 N) with LBG and XGG intermediate (average 15.59 N). More differentiation was noted in toughness, with D (67 N x mm) less tough (P &lt; 0.05) than DG (117 N x mm). The D treatment had the highest (P &lt; 0.05) EM (49.91%) and was the only treatment to separate into 2 phases. The LBG and XGG treatments had the lowest (P &lt; 0.05) EM (average 16.54%) with DG and KCG intermediate (average 25.26%). Carbohydrate hydrocolloids utilize different mechanisms to provide structure, which likely caused the differences in texture and EM observed.

A review: nutrition and process attributes of corn in pet foods

Corn is one of the largest cereal crops worldwide and plays an important role in the U.S. economy. The pet food market is growing every year, and although corn is well utilized by dogs, some marketing claims have attributed a negative image to this cereal. Thus, the objective of this work was to review the literature regarding corn and its co-products, as well as describe the processing of these ingredients as they pertain to pet foods. Corn is well digested by both dogs and cats and provides nutrients. The processing of corn generates co-products such as corn gluten meal and distillers dried grains with solubles that retain quality protein, and fibrous components that dilute dietary energy. Further, corn has much functionality in extrusion processing. It may yield resistant starch under certain processing conditions, promoting colonic health. Carotenoids in corn may enhance immune support in companion animals if concentrated. Mycotoxin contamination in grains represent a health hazard but are well controlled by safety measures. Genetically modified (GM) corn is still controversial regarding its long-term potential for mutagenicity or carcinogenicity, thus more long-term studies are needed. In conclusion, the negative perception by some in the pet food market may not be warranted in pet foods using corn and its co-products.

Evaluation of graded levels of Bacillus coagulans GBI-30, 6086 on apparent nutrient digestibility, stool quality, and intestinal health indicators in healthy adult dogs

Bacillus coagulans GBI-30, 6086 is a commercially available spore-forming non-toxigenic microorganism approved for use in dog foods with high resiliency to stresses associated with commercial manufacturing. The objectives of this research were to examine the effect of B. coagulans on stool quality, nutrient digestibility, and intestinal health markers in healthy adult dogs. Extruded diets containing graded levels of B. coagulans applied either to the base ration before extrusion or to the exterior of the kibble as a topical coating after extrusion were randomly assigned to 10 individually housed adult beagle dogs (7 castrated males and 3 spayed females) of similar age (5.75 ± 0.23 yr) and body weight (12.3 ± 1.5 kg). The study was designed as a 5 × 5 replicated Latin square with 16-d adaptation followed by 5-d total fecal collection for each period. Five dietary treatments were formulated to deliver a dose of 0-, 6-, 7-, 8-, and 9-log10 colony-forming units (CFU) per dog per day for the control (CON), extruded B. coagulans (PEX), and low, moderate, and high B. coagulans coating levels (PCL, PCM, and PCH), respectively. Food-grade TiO2 was added to all diets at a level of 0.4% to serve as an indigestible dietary marker for digestibility calculations. Data were analyzed using a mixed model through SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and room (i.e., replicate), period, and dog(room) as random effects. Apparent total tract digestibility of organic matter, crude protein, crude fat, and gross energy calculated by the marker method were numerically greatest for dogs fed the 9-log10 dose treatment with increases (P < 0.05) observed in gross energy and organic matter digestibility compared with the negative control. No significant differences were observed in food intake, stool quality, fecal pH, fecal ammonia, fecal short-chain fatty acids, or branched-chain fatty acids for the extruded B. coagulans treatment (PEX) or the coated B. coagulans treatments (PCL, PCM, and PCH) compared with CON. These results suggest that B. coagulans has a favorable impact on nutrient digestibility and no apparent adverse effects when added to extruded diets at a daily intake level of up to 9-log10 CFU in healthy adult dogs.

A Comparison of Salmonella Survival and Detection Using an Enrichment Technique in Dry- and Wet-Inoculated Rendered Chicken Fat Treated with Sodium Bisulfate

ABSTRACT

The differences in the recovery of Salmonella from rendered chicken fat treated with sodium bisulfate (SBS) when inoculated with a dry versus wet inoculum were evaluated. Food-grade rendered chicken fat was inoculated with a dry inoculum and a wet inoculum containing a cocktail of Salmonella serovars (Enteritidis, Heidelberg, and Typhimurium). In addition, the effect of an antimicrobial treatment (SBS) against Salmonella in both the aqueous phase and fat phase of the chicken fat was evaluated. The untreated control samples in the aqueous phase had a consistent level of Salmonella (∼7 log) when both the dry and wet inocula were used. In the SBS-treated aqueous phase, Salmonella pathogens were not detectable after 6 h when the wet inoculum was used; when the dry inoculum was used, Salmonella pathogens were not detectable at 24 h. Salmonella pathogens were detected for up to 6 h in the SBS-treated fat phase when the dry inoculum was used compared with 2 h with the wet inoculum. The 24-h fat samples that failed to show growth on Trypticase soy agar were enriched for Salmonella isolation, followed by confirmation by PCR using primers for the invA gene. SBS-treated and control samples from the dry-inoculated rendered chicken fat and the inoculated control from the wet-inoculated rendered chicken fat tested positive for Salmonella. However, the SBS-treated sample from the wet-inoculated fat was negative for Salmonella. The use of dry SBS powder against dry Salmonella inoculum in the fat matrix caused only ∼2.8-log reduction after 24 h compared with ∼2.2-log reduction in the positive control. However, the recovery of Salmonella from untreated control fat was lower and was not different (P > 0.05) from that recovered from the SBS-treated fat. The results suggest that viable but nonculturable states of Salmonella may develop in rendered chicken fat or that injured cells may be present, which indicates that testing should include an enrichment and appropriate molecular confirmation instead of agar plating alone.

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PSVI-20 The Effect of Resistant Starch Type II on Satiety Hormones of Fasting Dogs

Resistant starches comprise the starch fraction that escapes small intestine (SI) digestion and reaches the colon, where it is fermented by saccharolytic bacteria that produce beneficial postbiotics. Moreover, slowly digestible starches lower glycemic index and may promote satiety. The objectives of this study were to assess whether diets having increased RS perturbed fasting levels of satiety hormones in dogs. Diets with three levels of resistant starch (RS type II) were produced via extrusion at three levels of mechanical energy. Nine male and 15 female adult Beagle dogs were fed the low, medium and high RS foods in a 3x3 Latin square design (n = 24). The study was approved by IACUC at Hill’s Pet Nutrition (# 883.0.0.0). Fasting blood was collected in the morning on days 27 and 28 of each period, and serum was separated and frozen at -70°C until analysis. Satiety hormones were measured by ELISA. Data was first converted to natural log to approximate normal distribution and then analyzed as a mixed model by the GLIMMIX procedure from SAS (v 9.4) with diet as fixed effect and dog and period as random effects. Ghrelin, gastric inhibitory polypeptide (GIP), glucagon-like peptide 1 (GLP-1), glucagon, leptin, pancreatic polypeptide (PP) and peptide YY (PYY) were not different across treatments likely due to the fasting state of dogs. Surprisingly, only insulin increased with higher RS consumption. It is possible that more propionate (not measured) was produced in the colon of dogs fed the high RS diet, which went through gluconeogenesis in the liver and resulted in a change in the time of glucose entering the blood stream. This could explain the insulin increase during fasting, but needs to be verified by measurement of fecal SCFA. Future research should explore the effect of type II RS on satiety hormones at multiple time points postprandial.

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PSVI-23 Evaluation of graded levels of Bacillus coagulans (GBI-30, 6086) on apparent nutrient digestibility, stool quality, and intestinal health indicators in healthy adult dogs

Functional pet foods, such as those containing probiotics, are considered a key growth driver in the $37 billion market of dog and cat foods in the United States. Of particular interest to pet food applications is the patented bacterial strain Bacillus coagulans (GBI-30, 6086), a commercially available spore-forming non-toxigenic microorganism with high resiliency to stresses associated with commercial manufacturing. The objectives of this research were to examine the effect of Bacillus coagulans on stool quality, nutrient digestibility, and intestinal health markers in healthy dogs. High-protein, grain-free extruded diets containing graded levels of probiotic applied through extrusion or as a topical coating were fed to ten adult Beagle dogs of similar age. The study was designed as 5 x 5 replicated Latin square with 16-d adaptation followed by 5-d total fecal collection for each period. The five dietary treatments were formulated to deliver a dose of 0-, 6-, 7-, 8-, and 9-log10 colony-forming units (CFU) per dog per day. Data were analyzed using a mixed model through SAS (version 9.3, SAS Institute, Inc., Cary, NC) with treatment and period as fixed effects and dog as random effect. Apparent digestibility of organic matter, crude protein, crude fat, and gross energy were greatest for dogs fed the 9-log10 dose treatment (85.8, 83.6, 91.7, 84.0%, respectively), with increases (P &lt; 0.05) observed in gross energy and organic matter digestibility compared to the negative control. Crude protein digestibility tended (P &lt; 0.10) to increase as probiotic dose increased. No significant differences were observed in food intake, stool quality, fecal pH, fecal ammonia, or fecal short chain fatty acids. These results suggest that Bacillus coagulans has a favorable impact on nutrient digestibility and no apparent adverse effects when added to extruded diets at a daily intake level of up to 9-log10 CFU in healthy adult dogs.

PSVI-29 Post-Extrusion In-vitro Fermentability of Fiber in Extruded Dog Foods

Previous work has evaluated fermentation of fiber ingredients; however, the effect of extrusion has rarely been explored. The objective was to determine post-extrusion fiber fermentability with a dog fecal in vitro model. Dietary treatments containing 10% apple pomace (AP), blueberry pomace (BP), or miscanthus grass (MM) were compared to a control (CD) with no added fiber. Diets were produced with a single screw extruder under set processing conditions. In addition, higher (MH) and lower (ML) mechanical energy was applied to miscanthus treatments. Post-extrusion samples were pre-digested and residual fibers fermented for 1, 3, 6, and 12-hours. Short chain fatty acids (SCFA) and organic matter disappearance (OMD) were determined for each fiber and time point. Data were analyzed as a completely randomized design with statistical software (SAS, v 9.4). The OMD was greatest (P &lt; 0.05; 56.1%) for CD than AP, MM, and BP (average 35.19%). Total SCFA concentration was greatest (P &lt; 0.05) for CD followed by AP and BP, and lowest for MM (1.53, average 1.19, and 0.92 mmol*g-1 of substrate, respectively). Acetate proportions were highest (P &lt; 0.05) for BP (60.85%) and lowest for CD (52.86%), with AP and MM intermediate (average 56.57%). Propionate proportions were similar (P &lt; 0.05) across all treatments (average 21.18%). Butyrate proportions were highest (P &lt; 0.05) for CD (11.91%) and lowest for BP and MM (average 9.60%), with AP similar (10.15%) to all treatments. Processing did not affect (P &lt; 0.05) OMD, SCFA concentration or proportions among the different mechanical energy inputs to the miscanthus grass treatments. When corrected for total fiber, CD had the lowest SCFA concentration (P &lt; 0.05; 6.74 mmol*100g-1of diet) compared to all other treatments (average 12.8 mmol*100g-1of diet). While, CD was most fermentable on a gram of fiber basis; on a dietary basis, all fiber treatments had greater concentrations of total SCFA and butyrate.

78 The effects of guar gum and other select gums and gelling carbohydrates on appearance, texture, and heating characteristics of wet pet foods

Many wet pet foods include carbohydrate ingredients that enhance viscosity for container filling or provide structure after processing. These gums and gels can cause differences in commercial sterilization as well as visible changes in product quality. Therefore, the objective was to determine the effect of different gums and gelling carbohydrates on the appearance, texture, and thermal processing metrics of wet pet foods. Treatments were added to a chicken-based formula as 1% dextrose (NH), 0.5% guar gum and 0.5% dextrose (GG), 0.5% guar gum and 0.5% kappa carrageenan (KCGG), 0.5% guar gum and 0.5% locust bean gum (LBGGG), or 0.5% guar gum and 0.5% xanthan gum (XGGG). Batters were analyzed for pH, water activity, and consistency with a Bostwick consistometer as a crude indication of viscosity. Thermocouples were placed in cans to measure cold-spot temperatures for Fo and cook-value calculations. Replicate batches (n = 3) included each treatment and were commercially sterilized in a still retort at 121 ℃ and 144.79 kPa. Can vacuum and product color (colorimetry) were measured after cans cooled to ambient temperatures. Treatments were analyzed as a 1-way ANOVA with batch as a blocking factor. Means were separated by Fisher’s LSD using statistical analysis software (GLIMMIX; SAS 9.4). Batter consistency thickened (P &lt; 0.05) with increasing levels of gums and gelling carbohydrates. Batter pH, batter water activity, and can vacuum were not different (P &gt; 0.05) among treatments (averaging 5.94, 0.990, and -12.9 kPa, respectively). The NH treatment accumulated the greatest (P &lt; 0.05) Fo and cook values during the cook cycle compared to all other treatments. The NH and GG treatments were more (P &lt; 0.05) red and yellow than KCGG, LBGGG, and XGGG. Gums and gelling carbohydrates influenced the rate of heat penetration of the foods, likely due to the differences in batter consistency, and affected product color and physical characteristics.

PSXI-30 Descriptive sensory evaluation of rotary molded sorghum-based dog treats supplemented with soluble animal protein

Treats are food products given to dogs to strengthen bonds between owners and pets. Most treats on the market are made of wheat, mostly because of gluten binding properties. While sorghum lacks gluten, soluble animal proteins could be used as binders instead. The objective of this study was to evaluate appearance, aroma, flavor, texture/mouthfeel, and aftertaste of rotary-molded dog treats made with white (WS) or red (RS) whole sorghum flours. The sorghum biscuits were prepared with spray-dried plasma (SDP), gelatin (GL), egg protein (EP), or no protein (NC). All were compared to a positive control made with whole wheat flour (WF-GTN). The trained sensory panel identified 27 attributes. The products were evaluated on a scale from 0 to 15, using a consensus approach. A Principal Component Analysis (PCA) with XLSTAT Statistical Software and radar plots were created to visualize correlations between treatments and attributes. Brown and surface cracks were the most differentiating attributes: RS and WS biscuits with SDP or EP resulted in a darker appearance (10.0–14.0), while NC biscuits had more surface cracks (10.0–12.0). Aroma attributes did not vary significantly among samples, except for the overall intensity that was higher for RS-EP (7.0). Grainy was the main flavor and aftertaste, ranging from 4.0–7.0. Other flavors such as cardboard, leavening, starchy, and toasted were perceived in less proportion (2.0–4.0). Initial crispness, hardness, and fracturability were more pronounced in EP treatments (11.0–14.5). All biscuits had less hardness, less cohesiveness of mass, and more particle residuals when compared to the control WF-GTN. This work indicated that formulation had a bigger effect on texture and product appearance rather than flavor, aroma, or aftertaste. These results can be used as insights for pet owners’ interpretation and as preliminary data to describe dog preferences, which may complement instrumental analyses.

Evaluation of faba beans as an ingredient in dog diets: apparent total tract digestibility of extruded diets with graded levels of dehulled faba beans (Vicia faba L.) by dogs

The growing pet food market is continuously in search for novel ingredients. Legumes such as faba beans (FB) are increasing in popularity and are known to benefit human health, but little is known about their use in pet foods. The objective of this study was to determine the effect of dehulled FB utilization by dogs. Experimental diets were extruded with 0%, 10%, 20%, and 30% FB inclusion (FB0, FB10, FB20, and FB30, respectively). Beagle dogs (n = 12) were fed the diets for 9-d adaptation with 5-d total fecal collection in a replicated 4 × 4 Latin square design. Apparent total tract digestibility (ATTD) was determined by external marker Cr₂O₃. At the culmination of each period, blood samples were collected from brachial venipuncture for complete blood count and blood chemistry. Palatability was determined with a 2-bowl test (n = 20). Means of blood parameters were separated by multivariate analysis of variance (MANOVA) with the aid of statistical software (SAS v9.4). Contrasts and least square means of fecal parameters and ATTD were computed. Significance level was considered to be α = 0.05. Dogs ate all food on offer and maintained body weight. There was no difference (P > 0.05) among treatments (FB10, FB20, and FB30) and the control (FB0) relative to food intake, fecal output (“as is” basis), and fecal score, but feces were softer when dogs were fed the treatments (P = 0.031) and there was a linear increase (P = 0.011) in defecation frequency (stools/day) when FB increased in the diets. Dry matter, organic matter, and crude protein digestibilities were slightly higher when dogs were fed the control diet (P < 0.05) compared with the FB diets. All blood and serum chemistry parameters were similar among treatments and within the reference ranges. Dogs preferred the control diet relative to the 10% and 30% FB diets, but the 20% FB preference was similar to the control. Dogs remained healthy, maintained body weight and no adverse health events were observed during the study. Dehulled FB are a suitable ingredient for dog foods, but concentrations should not exceed 20% to avoid reduction in palatability and stool quality.

Use of Medium Chain Fatty Acids To Mitigate Salmonella Typhimurium (ATCC 14028) on Dry Pet Food Kibbles

ABSTRACT

This study evaluated the antimicrobial effects of medium chain fatty acids (MCFAs) against Salmonella Typhimurium (ATCC 14028) when used on dry dog food kibbles. The MIC of three MCFAs, caproic (C6), caprylic (C8), and capric (C10), was determined using the broth micro- and macrodilution assay technique. Using canola oil as a fat coating, the efficacy of each MCFA was then tested on dry dog food kibbles at 37°C for up to 5 h. The MIC was found to be 0.3125, 0.3125, and 0.625% for C6, C8, and C10, respectively. When the MCFAs were tested on fat-coated dry kibbles, all three MCFAs reduced (P ≤ 0.05) Salmonella levels by >4.5 log after 5 h when the Salmonella recovery from a no-treatment control was ∼6.4 log. At each evaluation time point, the three treatments were effective in reducing (P ≤ 0.05) Salmonella loads. No countable colonies of Salmonella were detected at 4 h when the combination of C6+C8 was used on the kibbles (P ≤ 0.05), whereas with the C6+C10 combination, the Salmonella colonies were not detectable between 2 and 4 h after treatments (P ≤ 0.05). Different combinations of C8 and C10 caused Salmonella to drop to a nondetectable limit (1 CFU/g) between 1 and 5 h after treatment (P ≤ 0.05). This study suggests that the use of MCFAs during kibble coating may mitigate postprocessing Salmonella recontamination on dry dog food kibbles.

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Effects of different carbohydrate sources on taurine status in healthy Beagle dogs

This study evaluated the effects of a grain-based (GB) and grain-free (GF) diet on protein utilization and taurine status in healthy Beagle dogs. Two practical dog diets sufficient in crude protein, sulfur amino acids, and taurine content were formulated with the same ingredients with exception of the carbohydrate sources. The GB contained sorghum, millet, and spelt while potatoes, peas, and tapioca starch were used in the GF. A total of 12 Beagle dogs were used in a completely randomized design with six replicates per treatment. The study consisted of an adaptation period of 2 wk followed by an experimental period of 28 d in which GB and GF were fed to the dogs. At the end of the adaptation period and every 2 wk after it (day 0, day 14, day 28), markers of taurine metabolism were analyzed in whole blood (taurine), plasma (taurine, methionine, and cystine), urine (taurine:creatinine), and fresh fecal samples (primary and secondary bile acids). Fecal samples were collected during the last 6 d of experimental period for digestibly assessment using titanium dioxide as an external marker. Taurine markers and digestibility data were analyzed in a repeated measures model and one-way ANOVA, respectively, using PROC GLIMMIX in SAS (version 9.4). Apparent crude protein digestibility was not affected by treatment, but dogs fed GF diet had lower apparent organic matter digestibility compared with those fed GB (P < 0.05). Greater plasma taurine concentrations were observed at days 14 and 28 compared with day 0; wherein dogs fed GF exhibited greater increase compared to those fed GB (P < 0.05). Whole blood taurine concentrations, plasma methionine concentrations, and urinary taurine:creatinine were also greater at days 14 and 28 compared with day 0 (P < 0.05), but no effect of diet was observed. Total bile acid excretion was similar between GF and GB groups, but dogs fed GF excreted a higher proportion of primary bile acids compared with those fed GB (25.49% vs. 12.09% at day 28, respectively). In summary, overall taurine status was not affected by dietary treatments, however, our results suggest that the higher content of oligosaccharides and soluble fibers in the GF diet may alter the composition of the fecal bile acid pool.

Starch characterization of commercial extruded dry pet foods

Starches provide an effective energy source for dogs and cats and can affect health according to its inclusion and extent of digestion. The starch fraction that escapes small intestine (SI) digestion is called resistant starch (RS) and is desirable due to its prebiotic function. Starch is not an essential nutrient for dogs and cats and thus is not reported on commercial pet food labels. Hence, the objective of this work was to characterize starches in commercial pet foods. The top five pet food companies by sales were selected to represent U.S. pet foods, which were divided into four strata with a sampling frame of 654 foods: dog grain based (372 foods), dog grain free (71 foods), cat grain based (175 foods), and cat grain free (38 foods). Five random foods within each stratum were purchased (20 total). Starch analyses (total starch, resistant starch, and starch cook), as well as nutrient analyses were conducted on all foods. Total starch, RS, and starch cook means were compared using a two-group Z-test on dog vs. cat and grain-based (GB) vs. grain-free (GF) diets, and differences were considered significant at a P < 0.05. Total starch was higher (P < 0.05) in dog than cat food, and starch cook was greater (P < 0.05) in GF diets. A regression analysis showed that nitrogen-free extract was a good predictor of total starch. Resistant starch was low and not different among groups. A post hoc test showed that a total sample size of at least 28 diets per group would be required to detect differences in RS between GF and GB diets, if one exists.

Organic matter disappearance and production of short- and branched-chain fatty acids from selected fiber sources used in pet foods by a canine in vitro fermentation model1

Dietary fibers can influence a dog’s overall health, but high concentrations of soluble dietary fibers can cause soft stools. An in vitro model could be useful to predict the rate fibers are fermented once they reach the colon. Pet food companies are constantly searching for new ingredients to differentiate their products from competitors. Miscanthus grass (MG), pea fiber (PF), and sorghum bran (SB) are novel fiber sources that could be alternatives to standards like cellulose (CE) and beet pulp (BP). The objectives of the study were to determine the effects of fiber source on organic matter disappearance (OMD), estimated organic matter disappearance (EOMD), and fermentation end-product concentrations using an in vitro fermentation procedure and dog fecal inoculum. Total dietary fiber (TDF) residues from MG, CE, BP, PF, and SB were fermented in vitro with buffered dog feces. Fecal samples were collected and maintained in anaerobic conditions until the dilution and inoculation. Test tubes containing the fibrous substrates were incubated for 4, 8, and 12 h at 39 °C. Short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), OMD, and EOMD were determined for each fiber source and time point. Beet pulp had the highest OMD, EOMD, and SCFA production of all tested fiber sources (38.6% OMD, 26.2% EOMD, 2.72 mmol SCFA/g of substrate). Sorghum bran led to greater concentrations of BCFA (59.86 µmol/g of substrate) and intermediate OMD and EOMD compared to the other tested fibers. Cellulose and MG were poorly fermented with the lowest OMD, EOMD, SCFA, and BCFA compared to other fibers. In conclusion, MG could be used as an insoluble minimally fermentable replacement fiber for CE in dog foods.

Effect of fiber source and particle size on chick performance and nutrient utilization

The addition of fiber in chick feeds is known to dilute nutrients; as a result, this may reduce nutrient digestibility and performance. However, recent studies suggest that moderate inclusion of insoluble fibers (2 to 3%) may stimulate gizzard development, which could result in better nutrient utilization and chick growth. The previous fiber sources evaluated were subject to wide fluctuation in their nutritional and chemical composition due to variation in processing. Miscanthus giganteus is a C4 grass purposefully grown for its fiber content which has a consistent fiber composition compared to food process residues. The objectives of this study were to determine the effect of dietary fiber source and particle size on day-old chick performance and nutrient digestibility. Day-old chicks (8 chicks per cage, 5 cages per treatment) were fed diets containing 3% of either sepiolite (SEP), cellulose (CEL), coarse beet pulp (BP), fine BP, coarse Miscanthus grass (MG), and fine MG. At the end of days 7, 14, and 21, chicks and experimental diets were weighed to compute average daily gain and feed intake. In addition, excreta from the previous 48 h of each data capture point was collected to determine nutrient digestibility. In general, chicks fed diets containing fiber consumed more feed, gained more weight, and had better feed conversion rate than birds fed the SEP diet. Particle size of the fiber had no effect on chick performance; however, nutrient utilization was higher (P < 0.05) for chicks fed coarse fiber particles compared to these fed fine fiber particles. Birds fed diets containing MG performed similar to chicks fed CEL (P > 0.05), but digestibility coefficients of birds fed BP diets were generally higher than chicks fed MG diets. In conclusion, chicks performed better with fiber in their diet and MG was comparable to CEL.

The effects of diets varying in fibre sources on nutrient utilization, stool quality and hairball management in cats

Pet food companies use fibrous ingredients in cat foods to aid weight and hairball management. Miscanthus grass could be an alternative novel fibre source for cat foods. The objectives of this work were to determine the effects of Miscanthus grass as a fibre source on nutrient utilization, stool quality and hairball management in cats. Dry extruded cat foods (average chemical composition; digestibility trial: 94.54% dry matter-DM, 34.47% crude protein-CP, 11.67% crude fat, 7.06% ash and 13.04% total dietary fibre-TDF; and hairball trial: 94.88% DM, 34.60% CP, 11.30% crude fat, 7.02% ash and 9.77% TDF) were fed to 12 cats for a 9-day (digestibility trial) or 16-day (hairball trial) adaptation period followed by a 5-day total faecal collection period. Digestibility trial was performed as a replicated Latin square design, and the hairball trial was performed as a switchback design. In general, the cats fed the beet pulp diet (BPD) had higher DM, organic matter, gross energy and TDF digestibility than cats fed Miscanthus grass (MGD) or cellulose (CED) diet (p < .05). However, CP digestibility was lower for cats fed BPD (82.1 vs. 84.7 and 85.1%, respectively, for BPD, MGD and CED). These differences could be due to the differences in dietary fibre content and(or) composition. Faecal scores were lower for cats fed BPD (2.84) compared with MGD (3.32) and CED (3.21; p < .05). No effects due to fibre were reported on the faecal hairball variables, with the exception of less total hair weight and hair clumps per gram of dry faeces for cats fed Miscanthus grass (MGH) compared with control diet (COH; p < .05). In conclusion, Miscanthus grass could be used as an alternative ingredient to cellulose in cat diets.

235 Awardee Talk - Processing considerations for the pet food industry

The US is the largest pet food market in the world and produces approximately 8.5 MMT of pet food annually. Most of this is processed or cooked in some manner and fortified to be nutritionally complete with a need to assure more than 40 nutrients are met with each bite. To overlook this can lead to poor product performance, rejection by consumers, animal health issues, and recalls. Whether we consider baking, canning or extrusion, this food is subjected to some form of particle size reduction, conveyance, mixing and shear, cooking and drying process to agglomerate ingredients, provide texture and palatability, improve nutrient utilization, control spoilage, or eliminate pathogen contamination. Many of the raw ingredients are processed in similar fashion. While many benefits can be attributed to these processes, essential nutrients can be lost, utilization can be affected, unintentional compounds can be produced, shelf-keeping quality can be shortened, and sensory attributes can be altered. The objective of this review is to provide insight into significant issues that are currently being researched or should be addressed in future research. Examples from research from a variety of areas will be provided along with a discussion of mechanisms, formulation strategies, and process modifications which should be considered in order to ameliorate unintended alternations of foods intended for companion animals. Research relevant to amino acids, fatty acids, vitamins, and starch will be discussed, along with work demonstrating the impact on shelf-life, sensory qualities, and performance of pet foods.