Utilization of energy and amino acids of spray-dried egg, plasma protein, and soybean meal by ducks

Spray-Dried Animal Plasma as a Multifaceted Ingredient in Pet Food

Plasma is a co-product from pork and beef obtained during the processing of animals for human consumption. The spray-drying process maintains the solubility of spray-dried animal plasma (SDAP) and its nutritional and functional properties, making this ingredient multifunctional in human and animal nutrition. In pet food, SDAP has been used in the production of wet foods (pates and chunks in gravy) as an emulsifying and binding agent, with the potential to replace hydrocolloids partially or totally, which have some negative implications for digestibility, fecal quality, and intestinal inflammation. From a nutritional point of view, SDAP has high digestibility and an amino acid profile compatible with high-quality ingredients, such as powdered eggs. Studies in companion animals, especially in cats, have shown that SDAP is an ingredient with high palatability. Despite the immunomodulatory, anti-inflammatory, prebiotic, and neuroprotective properties demonstrated in some animal models, there are still few publications demonstrating these effects in dogs and cats, which limits its use as a functional ingredient for these species. In this review, the potential use of SDAP in pet food, aspects related to the sustainability of this ingredient, and opportunities for studies in companion animals are discussed.

Quantification of secretory IgA and mucin excretion and their contributions to total endogenous amino acid losses in roosters that were fasted or precision-fed a nitrogen-free diet or various highly digestible protein sources

The objective of this study was to quantify total secretory IgA (sIgA) and mucin excretion via excreta in roosters fed diets containing highly digestible protein sources and to determine their proportional contributions to total endogenous amino acid (AA) losses. Precision-fed rooster assays with 24 h excreta collections were conducted using conventional White Leghorn roosters (4-8 roosters per treatment). In Experiment 1, roosters were fasted or precision-fed 30 g (crop intubation) of a nitrogen-free (NF) or semi-purified diet containing 10% casein. Roosters in Experiment 2 received a NF or semi-purified diet containing either 10% casein, 17% whole egg, 10% egg white, 9.8% soy protein isolate, 10.2% chicken breast meat, 11.2% spray-dried animal plasma (SDAP), or an AA mixture containing the same AA as casein. A Latin square design was used in Experiment 3, where roosters received NF or semi-purified diets containing either 10% casein, 17% whole egg, or 9.6% of a crystalline AA mixture to evaluate both diet and individual bird effects. In Experiment 1, mucin excretion did not differ (P > 0.05) among treatments; however, total sIgA excretion was lower for fasted birds, intermediate for the NF diet, and highest for casein (P < 0.05). Total endogenous AA losses (proportion of the total) from sIgA were higher for roosters fed casein, whereas mucin contributions were higher for fasted roosters (P < 0.05). In Experiment 2, sIgA excretion did not differ (P > 0.05) among treatments; however, mucin excretion was reduced for NF, whole egg, egg white, and chicken breast compared with casein and SDAP. In Experiment 3, sIgA and mucin excretion did not differ (P > 0.05) among treatments; however, sIgA excretion differed among individual roosters (7-27 mg/24 h; P < 0.05). Overall, fasting reduced sIgA excretion and sIgA and mucin excretion were affected by dietary protein source. Further, roosters excreted a substantial amount of sIgA, and sIgA and mucin were considerable contributors to total endogenous AA losses.

Metabolizable energy and amino acid digestibility in spray-dried animal plasma using broiler chick and precision-fed rooster assays

Four experiments were conducted to determine ME and amino acid (AA) digestibility of spray-dried animal plasma (SDAP) and soybean meal (SBM). The 48-h precision-fed adult rooster assay was used in 2 experiments; TMEn and standardized AA digestibility were determined using conventional and cecectomized roosters, respectively, 50 weeks of age and weighing approximately 2,200 g. Eight individually-caged roosters (4 per diet) were fasted for 26 h, then precision-fed 30 g of SDAP mixture (containing 50% corn) or SBM mixture (containing 50% corn). The TMEn and AA digestibility for SDAP and SBM were calculated by the difference procedure. The TMEn for SDAP was greater (P < 0.05) than SBM (3,743 and 2,669 kcal/kg DM, respectively). Similarly, mean AA digestibility of SDAP was greater (P < 0.05) than SBM (94 and 86%, respectively). Two assays were conducted using Ross male broilers to determine AMEn and apparent (AIAAD) and standardized (SIAAD) ileal AA digestibility of SDAP and SBM. A 3 × 2 factorial arrangement of treatments was used to determine AMEn; 126 chicks (6 replicate pens of 7 chicks) were fed a corn-SBM-based reference diet, a diet containing 30% SDAP, or a diet containing 30% SBM from d 7 to 10 and 18 to 21. A 2 × 2 factorial arrangement of treatments was used to determine AIAAD and SIAAD; 168 chicks (12 replicate pens of 7 chicks) were fed a semi-purified diet containing 25% SDAP or a semi-purified, isonitrogenous diet containing 41% SBM from d 7 to 10 and 18 to 21. The AMEn for SDAP was greater (P < 0.05) than SBM at d 10 (3,851 and 2,089 kcal/kg DM, respectively) and d 21 (4,239 and 2,849 kcal/kg DM, respectively). The second assay showed an increase (P < 0.05) in AIAAD and SIAAD for SDAP compared with SBM at d 10 (mean SIAAD for SDAP and SBM were 96% and 84%, respectively) and d 21 (97% and 87%, respectively). Regardless of assay or age, these results indicate SDAP is a highly digestible feed ingredient with high ME and AA digestibility.

Determination of metabolizable energy and amino acid digestibility in various hatchery byproducts for broiler chickens

The objective of the present experiment was to determine ME concentrations and amino acid (AA) digestibility in various hatchery byproducts (HBPs) for broiler chickens. In experiment 1, a total of forty 60-day-old female broiler chickens were allotted to 1 of 5 dietary treatments with 8 replicates and used to measure ME concentrations in HBPs. The basal diet was prepared to contain corn, soybean meal, corn oil, and other non-energy ingredients. Additional 4 experimental diets were prepared to contain 10% of infertile eggs (IFE), unhatched eggs (UHE), low-grade or dead chicks (LDC), and mixture (MIX; 55% IFE, 10% UHE, 10% LDC, and 25% hatched eggshells). In experiment 2, a total of seven hundred and sixteen 1-day-old mixed-sex broiler chickens (1:1 ratio of males and females) were allotted to 1 of 5 dietary treatments with 7 replicates per treatment and used to determine apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA in HBPs. The experimental diets consisted of a nitrogen-free diet and 4 diets containing IFE, UHE, LDC, or MIX as a sole source of AA. Results indicated that AME and AME_n values were greater (P < 0.05) for LDC than for IFE, which had greater (P < 0.05) AME and AME_n values for UHE and MIX. The AID and SID of most AA in LDC were greater (P < 0.05) than those in MIX, whereas IFE and UHE had intermediate AID and SID of those AA as compared to LDC and MIX. Average SID of essential AA in LDC was greater (P < 0.05) than in UHE and MIX, but the average SID of nonessential AA did not differ among 4 HBPs. In conclusion, LDC has the greatest ME concentrations and AA digestibility among 3 individual HBPs (IFE, UHE, and LDC). The mixture of HBPs has the least ME concentrations and AA digestibility in broiler chickens. The ME and AA digestibility of HBPs are likely affected by inclusion amounts of hatched eggshells. However, high concentrations of ME and available AA demonstrate that individual HBPs and their mixture are potential protein ingredients for broiler diets.

Digestibility of Amino Acids in Protein-Rich Feed Ingredients Originating from Animals, Peanut Flour, and Full-Fat Soybeans Fed to Pigs

Standardized ileal digestibility (SID) of amino acids (AA) in alternative protein sources for growing pigs was determined in this study. Diets containing egg albumen (EA), casein, blood meal (BM), and blood plasma meal (BPM) and a nitrogen-free diet (NFD) were fed to 20 barrows in a quadruplicate 5 × 2 incomplete Latin square design with two periods in experiment 1. The SID of AA was greater in casein than other ingredients (p < 0.05), except Pro. The SID of Arg, Ile, and Met was lower (p < 0.05) in EA than BM and BPM. The SID of Trp in BM was greater (p < 0.05) than EA but not different from BPM. In experiment 2, 20 pigs were fed diets containing peanut flour (PF) or full-fat soybeans (FFSB) or NFD in a randomized complete block design with body weight as a blocking factor but providing six observations for NFD. The SID of Arg, Ileu, Leu, Met, Phe, and Val was greater (p < 0.05) in PF than FFSB. The SID of Lys was greater (p < 0.05) in FFSB than PF. In summary, the test ingredients contain readily digestible AA and could serve as alternative protein sources for growing pigs.

Composition of amino acids and related nitrogenous nutrients in feedstuffs for animal diets

We analyzed the composition of amino acids (AAs) in oligopeptides, proteins, and the free pool, as well as creatine, agmatine, polyamines, carnosine, anserine, and glutathione, in animal- and plant-derived feedstuffs. Ingredients of animal origins were black soldier fly larvae meal (BSFM), chicken by-product meal, chicken visceral digest, feather meal, Menhaden fishmeal, Peruvian anchovy fishmeal, Southeast Asian fishmeal, spray-dried peptone from enzymes-treated porcine mucosal tissues, poultry by-product meal (pet-food grade), spray-dried poultry plasma, and spray-dried egg product. Ingredients of plant origins were algae spirulina meal, soybean meal, and soy protein concentrate. All animal-derived feedstuffs contained large amounts of all proteinogenic AAs (particularly glycine, proline, glutamate, leucine, lysine, and arginine) and key nonproteinogenic AAs (taurine and 4-hydroxyproline), as well as significant amounts of agmatine, polyamines, creatine, creatinine, creatine phosphate, and glutathione. These nitrogenous substances are essential to either DNA and protein syntheses in cells or energy metabolism in tissues (particularly the brain and skeletal muscle). Of note, chicken by-product meal, poultry by-product meal, and spray-dried poultry plasma contained large amounts of carnosine and anserine (potent antioxidants). Compared with most of the animal-derived feedstuffs, plant-derived feedstuffs contained much lower contents of glycine and proline, little 4-hydroxyproline, and no creatine, creatinine, creatine phosphate, carnosine or anserine. These results indicate the unique importance of animal-source feedstuffs in improving the feed efficiency, growth and health of animals (including fish and companion animals). Because soy protein concentrate is consumed by infants, children and adults, as are BSFM and algae for children and adults, our findings also have important implications for human nutrition.

The amino acid composition and protein quality of various egg, poultry meal by-products, and vegetable proteins used in the production of dog and cat diets

New protein ingredients are used to support pet food market growth and the development of new products while maintaining animal dietary needs. However, novel protein sources (e.g., spray-dried chicken, and (or) rice, pea, and potato protein concentrates) have limited data available regarding their protein quality. The objective of this study was to evaluate protein ingredients used in the pet food industry by laboratory analysis and a chick growth assay as a model. Following analysis for proximate and amino acid composition, chicks (six birds per pen with four pens per treatment) were fed experimental diets for 10 d. Diets contained 10% crude protein from each of the experimental protein sources (spray-dried egg-SDEG; spray-dried egg white-SDEW, spray-dried inedible whole egg-SDIE, chicken by-product meal-CBPM, chicken meal-CKML, low-temperature fluid bed air-dried chicken-LTCK, low-temperature and pressure fluid bed dried chicken-LTPC, spray-dried chicken-SDCK, whey protein concentrate-WPCT, corn gluten meal-CGML, corn protein concentrate-CPCT, potato protein isolate-PPIS, rice protein concentrate-RPCT, pea protein isolate-PEPI, soy protein isolate-SPIS, and soybean meal-SBML) along with an N-free diet (negative control). Chicks fed SDEG, SDIE, and LTPC had the highest protein efficiency ratio (PER; P < 0.0001; 5.18, 5.37, and 5.33, respectively), LTCK and SDCK were intermediate (4.54 and 4.79), and the CBPM and CKML were the lowest among the poultry proteins for EAA:NEAA, PER, and Lys availability. Among the vegetable proteins, PPIS and SBML had the highest PER values (3.60 and 3.48, P < 0.0001). In general, the chick PER method ranked the quality of animal protein sources higher than vegetable proteins, and these results were consistent with the EAA:NEAA ratio and Lys availability.

Apparent ileal digestibility of amino acids in feedstuffs for White Pekin ducks

The apparent ileal amino acid digestibility of 6 feedstuffs, namely corn, wheat, corn distillers dried grains with solubles, canola meal, soybean meal (SBM), and meat and bone meal (MBM) were determined for White Pekin ducks in a 5-d experiment. The feedstuffs served as the sole source of amino acids in semipurified diets composed of dextrose, soy oil, Solka Floc, minerals, and vitamins, with the exception of corn and wheat, in which both lacked dextrose. The ducks received a standard duck starter diet during the first 14 d posthatch. On d 14, ducks were sorted by weight and allocated to 6 dietary treatments in a randomized complete block design. Each assay diet was fed to 8 replicates (6 ducks/replicate) from d 14 to 19 posthatch. Birds were killed on d 19 and digesta from the terminal ileum were collected. Ileal N digestibility was highest (P < 0.01) in SBM (88.3%) and lowest in MBM (72.4%). Ileal digestibility for all of the amino acids was highest in SBM among the feedstuffs. Lysine digestibility was highest (P < 0.01) for SBM followed by canola meal, corn, wheat, MBM, and distillers dried grains with soluble; the values were 90.3, 79.0, 78.0, 76.8, 75.6, and 69.2%, respectively. Methionine digestibility in SBM was highest (P < 0.01), whereas MBM had the lowest digestibility value for methionine (78.4%). For threonine, SBM (84.0%) had the highest digestibility and corn (61.6%) had the lowest digestibility (P < 0.01), but there were no differences among other feedstuffs. Ileal tryptophan digestibility was between 78.9 (MBM) and 93.0% (SBM). In conclusion, the data from the current study show that there are considerable differences among feedstuffs in the digestibility of their amino acids for ducks. Therefore, it is important to take the digestible amino acid content of feedstuffs into account during feed formulation.