Guava fibre characterization and effects on digestibility, fermentation products, gastrointestinal transit time and palatability of dry diets for dogs

The use of fruit fibres as a way of reusing industrial waste is attractive and necessary, increasing the efficiency and reducing the environmental impact of the industry. This study characterized guava fibre as a fibrous ingredient and evaluated its effects when included in extruded diets for dogs on nutrient digestibility, faecal traits, fermentation products, gastrointestinal transit time and palatability. Four diets were formulated: CO (control diet, no fibrous ingredients added), GF3 (3% guava fibre), GF6 (6% guava fibre) and GF12 (12% guava fibre). The guava fibre was added to diets in replacement of maize, with small adjustments in the other ingredients to ensure similar contents of protein and fat. The diets were fed to 24 adult Beagle dogs (6 per diet) during 15 days for adaptation followed by 15 days for assessment of digestibility, fermentation end products and gastrointestinal transit time. The palatability of G6 and G12 treatments was evaluated against the CO by the two-pan test. Results were compared by analysis of variance and polynomial contrasts according to the guava fibre inclusion level (p < 0.05). The addition of guava fibre did not change nutrient intake except for the increase on dietary fibre (p < 0.001). Fibre inclusion resulted in a quadratic reduction in total tract apparent digestibility for dry matter, organic matter, crude protein and crude energy (p < 0.001), and on the metabolizable energy content of the foods (p < 0.001). Guava fibre addition did not change the faecal concentration of ammonia, lactic acid, faecal pH and branched chain fatty acids but it decreased acetic and propionic acids concentration (p < 0.01). The inclusion of 12% guava fibre did result in a faster transit time (p = 0.046) compared to the control diet. Guava fibre can be characterized as a novel insoluble non-fermentable fibre source that could be safely used in levels up to 12% in canine extruded diets.

Hydrolysed poultry byproduct meal in extruded diets for cats

Hydrolysed proteins have been shown to be potential ingredients in cat diets due to their high digestibility, presence of bioactive peptides, and relatively low antigenicity. The effects of the substitution of conventional low ash poultry byproduct meal (PBM) with hydrolysed poultry byproduct meal (HPM) as a protein source were evaluated in extruded cat diets. Five diets with similar nutrient contents were formulated: a control (CO) diet based on PBM and 4 diets with different inclusions of HPM (5%, 10%, 20%, and 30%, on an as-fed basis) replacing PBM as the protein source. The total tract apparent digestibility (CTTAD) of nutrients, faecal characteristics and microbial fermentation products, urine production and pH, nitrogen balance and urea renal excretion were evaluated using 30 healthy cats (15 males and 15 females; 4.18 ± 0.86 kg; 4.17 ± 1.38 years old), with 6 cats per diet in a complete randomised block design. When significant differences were found with the F test, the effects were evaluated by polynomial contrasts according to HPM inclusion (p < 0.05). The CTTADs of DM (89 ± 0.41%), CP (90 ± 0.36%), fat (93 ± 0.41%) and gross energy (90 ± 0.33%) were similar among treatments (p > 0.05). The faecal production, score, short-chain fatty acids and ammonia concentration were similar among treatments (p > 0.05). Isobutyric, isovaleric, valeric, and total branched-chain fatty acid contents increased quadratically (p < 0.05), with the highest level in the faeces of cats fed the diet with 20% HPM. Lactate concentration in faeces increased linearly with the inclusion of HPM (p < 0.05). Urine characteristics and urea renal excretion did not differ among treatments (p > 0.05). At 10% inclusion, HPM tended to increase the nitrogen retention of cats (p = 0.083), which may reflect the higher tryptophan, methionine, lysine, and available lysine contents of HPM in comparison to PBM. The inclusion of up to 30% HPM can be considered in cat formulations without affecting nutrient digestibility or faecal and urine characteristics. HPM tended to increase nitrogen retention and increased branched-chain fatty acids in faeces, aspects which deserves further studies.

Effect of Citrus Pellet on Extrusion Parameters, Kibble Macrostructure, Starch Cooking and In Vitro Digestibility of Dog Foods

Fiber supplemented extruded foods are produced by pet food companies to help with several specific health conditions. The fiber material, however, is difficult to incorporate efficiently into dry kibble diets for dogs. The aim of the study was to evaluate the influence of citrus pulp pellet (CPP), the solid waste part of the production of orange juice characterized by a good proportion of soluble and fermentable fiber, on extrusion traits, kibble macrostructure, starch gelatinization and in vitro digestibility of dog foods. A control formula (CO) was developed for dogs. CPP was added to CO at different inclusion levels: 5%, 10%, 15% and 20%. Foods were extruded in a single screw extruder using two different die diameters (d_d): 5 mm and 7 mm. CPP inclusion with 5 mm d_d did not affect bulk and piece density and resulted in a lower impact on kibble expansion; It also resulted in greater starch gelatinization and kibble expansion compared to the 7 mm d_d configuration (p < 0.01). In addition to the nutritional implications, recycling and proper uses of this material exemplified in the present study by the exploration of CPP as a fiber source to dogs, this method can improve sustainable agriculture by transforming low-quality materials into high-quality foods.

Effect of orange fibre on nutrient digestibility and fermentation products in faeces of cats fed kibble diets

The aim of the present study was to compare orange fibre, beet pulp and inulin as fibre sources for cats. A control diet (CON) was formulated without inclusion of a fibre source. Further experimental diets were also based on diet CON but were supplemented with 1% orange fibre (diet 1%OF); 3% orange fibre (diet 3%OF); 3% beet pulp (diet 3%BP) or 1% inulin (diet 1%IN). Forty cats were used in a randomised block design (4 blocks of 10 cats, 2 animals per food in each block, totalling 8 animals per treatment). Each block lasted 20 d, with 10 d of adaptation, 10 d of faecal collection for digestibility as well as evaluation of pH-value and fermentation products. The digestibility of dry matter, organic matter, crude protein, ether extract, starch and gross energy did not vary between diets. In diet 1%OF, dietary fibre revealed a greater digestibility than in diet CON (p < 0.05). Faecal production was higher in cats fed diets 3%OF and 3%BP than in those fed diet 1%IN (p < 0.05). Faecal concentrations of acetate and total short-chain fatty acids were higher for cats fed diet 3%BP than for those fed diets 1%IN and CON (p < 0.05), while diets 1%OF and 3%OF showed intermediate results. Faecal propionate concentration was higher for cats fed diet 3%BP, intermediate for diets 1%OF, 3%OF and 1%IN and lower for animals fed diet CON (p < 0.05). Compared with diets CON and 1%IN, the faecal concentration of tyramine was higher for cats fed diet 3%OF (p < 0.05). Orange fibre was fermentable; up to 3% inclusion it did not interfere with the digestibility of nutrients, faecal score and faecal moisture content, and promoted the formation of short-chain fatty acids and tyramine by the intestinal microbiota, with possible effects on intestinal function.

Effects of thermal energy on extrusion characteristics, digestibility and palatability of a dry pet food for cats

The influence of specific thermal energy (STE) applications on extruder preconditioner was evaluated in a dry food for cats. In the first study, six STE applications were tested with mass temperatures of 45°C, 55°C, 65°C, 75°C, 85°C and 95°C. The extrusion parameters, starch gelatinization and kibble formation were evaluated. Diets were given to cats to evaluate digestibility, faecal characteristics and palatability. In the second experiment, three treatments were compared: low STE-a preconditioner temperature of 45°C (_L STE); high STE-a preconditioner temperature of 95°C (_H STE); high STE (preconditioner temperature of 95°C) combined with an increase in the mass flow rate to obtain a motor amperage similar to that of the _L STE (_H STE_flow ). Data were analysed by polynomial contrasts (Experiment 1) or Tukey's test (Experiment 2; p < 0.05). An increase in STE reduced motor amperage, mass pressure and specific mechanical energy (SME) implementation (p < 0.001) and increased total specific energy (TSE) and mass temperature (p < 0.01). The increase in STE induced greater kibble expansion and starch gelatinization (p < 0.001). No changes in apparent nutrient digestibility or faeces characteristics were observed (p > 0.05). Lower STE and starch gelatinization induced higher butyrate and total volatile fatty acid (VFA) contents in faeces (p < 0.01). Cats showed greatest preference for the formulation with the highest STE (p < 0.01). In the second experiment, when the motor amperage was increased in the _H STE_flow treatment to a value similar to that of the _L STE, the mass flow rate increased 40%, and the electric energy consumption remained unchanged (p < 0.001), with gains observed for efficiency and cost. In conclusion, STE application is important for sufficient TSE implementation, enhancing kibble expansion, starch gelatinization, cat preferences for food, extruder productivity and reducing SME application. Foods with lower starch gelatinization lead to increased VFA in faeces, with possible implications for gut health.

Orange fibre effects on nutrient digestibility, fermentation products in faeces and digesta mean retention time in dogs

Fermentable fibres are used in commercial dog food to promote intestinal health by providing substrates for better metabolic activity of the gut microbiota. Brazil is the world's largest producer of oranges, from which it is possible to obtain fibre with a relevant soluble fraction. The present study compared the effects of two inclusions of orange fibre (1% and 3%, on as fed basis) with a negative control (without addition of fibre source) and two positive controls, beet pulp (3%) and purified inulin (1%), totalling five extruded diets for dogs. The experiment followed a randomised block design with 4 blocks of 10 dogs, 2 dogs per food in each block, totalling 8 dogs per diet. The apparent total tract nutrient digestibility was determined by total faecal collection. Faecal pH and fermentation product content were also measured. The digesta mean retention time (DMRT) was evaluated using plastic markers. The inclusion of a 3% fibre source in diets with 3% orange fibre and beet pulp reduced DM, OM, and energy digestibility (p < 0.05). Diets with 3% orange fibre, beet pulp and 1% inulin presented lower crude protein digestibility than the control (p < 0.05). Dietary fibre digestibility was higher for orange fibre-supplemented diets than inulin (p < 0.05). Beet pulp and 3% orange fibre inclusions resulted in increased moisture content in the faeces of dogs (p < 0.05) but did not alter DMRT. Total short-chain fatty acids were higher than the control in the faeces of dogs fed both orange fibre levels and the beet pulp-supplemented diet (p < 0.05), and the inulin diet-fed dogs presented intermediate values. Butyrate was higher in the faeces of dogs fed the diets supplemented with 1% and 3% orange fibre (p < 0.05), and similar values to the control were observed for beet pulp- and inulin-fed animals. Thus, it was concluded that orange fibre presented higher apparent total tract dietary fibre digestibility than beet pulp and had a fermentation profile in the colon that promoted the generation of butyrate, an effect not observed for inulin and beet pulp.

Influence of type of starch and feeding management on glycaemic control in diabetic dogs

The present study evaluated the effects of two diets with different starch sources and two feeding methods on the glycaemic control in dogs with diabetes mellitus. The diets had similar nutrient contents (40% starch and 16% dietary fibre), one formulated with 46% of broken rice and the other with 42% sorghum and 10% lentils (as-fed). Ten client-owned diabetic dogs were fed with each diet for 2 months, in a crossover design. Five dogs received NPH human insulin and food every 12 h (feeding method 1), and the other five received insulin every 12 h but were fed three times a day (feeding method 2). In feeding method 2, morning insulin was higher than the evening dose and dogs received the second meal after 4 to 5 h of the morning insulin and meal. Parameters evaluated included insulin dosage, 12- and 8-h glycaemic curves, complete blood count, biochemical profile and urinalysis. Glycaemic curves were analysed by ANOVA with repeated measures. Glycaemic control parameters (fasting, mean, minimum and maximum glycaemia and serum fructosamine) and glucose area under the curve (AUC) were calculated and analysed by paired t test (p < 0.05). In feeding method 1, dogs fed the sorghum-based diet presented lower mean (p = 0.04) and minimum blood glucose concentrations (p = 0.03), and a tendency to lower maximum blood glucose (p = 0.06) and glucose AUC (p = 0.08) than when fed the rice-based diet. When food was provided twice a day, the ingestion of the rice-based diet resulted in higher post-prandial glucose response than the diet with sorghum and lentil. In feeding method 2, there was no effect of diet on the assessed parameters (p > 0.05). No differences in insulin dosage were observed between groups or feeding methods (p > 0.05). Providing two meals a day followed by insulin administration associated with the sorghum- and lentil-based diet improved glycaemic control in diabetic dogs.

328 Targeting food formulation considering nutrient intake

Since the last publication of NRC (2006), dog and cat nutritionists have a good starting point to formulate pet food, once the Committee included the “recommended allowances” (RA) in the nutrient requirement tables, both expressed per dry matter (DM) or food metabolizable energy (ME). According to the Committee, the RA means “…where applicable, includes a safety factor for nutrients with uncertain bioavailability.” This is certainly important for many situations, but does not solve all concerns related to achieve a complete nutrient supply for a specific individual. This presentation will discuss the implications of the wide diversity of animals’ energy requirements, and consequently food and nutrient consumption that dogs and cats may experience along their life cycle and housing conditions. Thus, Diet Diversity, or products with diverse energy and nutrient densities, is important to drive veterinarians and nutritionists to the better food selection to fulfill nutrient requirements of specific individuals. Although data from NRC (2006) based on food ME correct distortions of DM intake related to available energy content of diets, this approach does not correct for the diversity of energy requirement among individuals, as well known for dogs (Bermingham et al., 2014) and cats (Bermingham et al., 2010). The problem is reinforced by the value assumed by NRC (2006) to estimate energy intake in adult dogs (130k cal/kg 0.75/day) and cats (100k cal/kg 0.67/day), far distant from the real energy expenditure of several (maybe most) home-living animals. A meta-analysis study showed that the NRC (2006) equation quite substantially overestimated energy requirements and food intake for cats under 4.5 kg of BW. House-living dogs (Thes et al., 2016) may need only 98k cal (per kg 0.75/day) when in ideal body condition to keep BW constant, while 120k cal when lean, and 86k cal when obese. The substantial variation among individuals is also important; considering the obese dogs group, for example, the 25% quartile value was lower (62k cal) than the 75% quartile (105k cal), showing that to achieve the adequate nutrient intake for obese animals with low energy requirement might be a challenge, due to the low DM intake (Thes et al., 2016). Based on the clinical experience of the presenter, managing a clinical nutrition service inside a teaching veterinary hospital, and a research experience with energy metabolism of cats and dogs, the presentation will explore the implications of energy requirements on nutrient intake, and how to better address NRC standards in practical formulations.

Modelling of sulphur amino acid requirements and nitrogen endogenous losses in kittens

The objective of this study was to estimate the sulphur amino acid (methionine + cystine) requirements and nitrogen endogenous losses in kittens aged 150 to 240 d. Thirty-six cats were distributed in six treatments (six cats per treatment) consisting of different concentrations of methionine + cystine (M + C): T1, 6.5 g/kg; T2, 8.8 g/kg; T3, 11.3 g/kg; T4, 13.6 g/kg; T5, 16.0 g/kg; and control, 6.5 g/kg. Diets were formulated by serial dilution of T5 (a diet relatively deficient in M + C but containing high protein concentrations) with a minimal nitrogen diet (MND). Thus, crude protein and amino acid concentrations in diets T1-T5 decreased by the same factor. The control diet was the T1 diet supplemented with adequate concentrations of M + C (6.5 g/kg; 8.8 g/kg; 11.3 g/kg; 13.6 g/kg and 16.0 g/kg). All diets were based on ingredients commonly used in extruded cat diets. Digestibility assays were performed for the determination of nitrogen balance. Nitrogen intake (NI) and nitrogen excretion (NEX) results data were fitted with an exponential equation to estimate nitrogen maintenance requirement (NMR), theoretical maximum for daily nitrogen retention (NR_maxT), and protein quality (b). M + C requirements were calculated from the limiting amino acid intake (LAAI) equation assuming a nitrogen retention of 45 to 65% NR_maxT. The NMR of kittens aged 150, 195, and 240 d was estimated at 595, 559, and 455 mg/kg body weight (BW)^0.67 per day, respectively, and M + C requirements were estimated at 517, 664, and 301 mg/kg BW^0.67 per day, respectively.

Active fractions of mannoproteins derived from yeast cell wall stimulate innate and acquired immunity of adult and elderly dogs

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Aging can promote changes in the immune system in dogs.

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Nutritional intervention in older dogs aims to increase lifespan.

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The yeast cell wall comprises β-(1,3)-D-glucan, β-(1,6)-D-glucan and mannoproteins.

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Elderly dogs when compared to adult dogs had lower absolute T and B lymphocyte counts.

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Mannoproteins stimulated acquired and innate immune responses in adult and elderly dogs.

Nutritional intervention in older dogs aims to increase lifespan and improve life quality as well as delay the development of diseases related to ageing. It is believed that active fractions of mannoproteins (AFMs) obtained through extraction and fractionation of yeast cell walls (Saccharomyces cerevisiae) may beneficially modulate the immune system. However, studies that have evaluated this component and the effects of ageing on the immune system of dogs are scarce. This study aimed to evaluate the immunological effects of AFMs in adult and elderly dogs. Three extruded iso-nutrient experimental diets were formulated: without addition of AFM (T0); with AFM at 400 mg/kg (T400); and with AFM at 800 mg/kg (T800). Thirty-six beagle dogs were used, and six experimental treatments, resulting in combinations of age (adult and elderly) and diet (T0, T400, and T800), were evaluated. On days zero, 14, and 28, blood samples were obtained for leucocyte phenotyping and phagocytosis assays. On days zero and 28, a lymphoproliferation test, quantification of reactive oxygen (H₂O₂) and nitrogen (NO) intermediate production, evaluation of faecal immunoglobulin A (IgA) content, and a delayed cutaneous hypersensitivity test (DCHT) were performed. Statistical analyses were performed with SAS software. Repeated measure variance analyses were performed, and means were compared by the Tukey test. Values of P ≤ 0.05 were considered significant, and values of P ≤ 0.10 were considered tendencies. Dogs fed T400 tended to have higher neutrophilic phagocytic activity than dogs fed T800 (P = 0.073). Regarding reactive oxygen intermediates, bacterial lipopolysaccharide (LPS)-stimulated neutrophils from animals that were fed T400 had a tendency to produce more H₂O₂ than those from animals fed the control diet (P = 0.093). Elderly dogs, when compared to adult dogs, had lower absolute T and B lymphocyte counts, lower auxiliary T lymphocyte counts, and higher cytotoxic T lymphocyte counts (P < 0.05). A significant effect of diet, age, and time with saline inoculation was noted for the DCHT. There was no effect of diet or age on faecal IgA content in dogs. This study suggests beneficial effects of mannoproteins on the specific and nonspecific immune responses in adult and elderly dogs.

Effects of the solubility of yeast cell wall preparations on their potential prebiotic properties in dogs

Derivatives of yeast cell wall (YCW) have been studied for their potential prebiotic effects. Recently, new purified and soluble preparations have been developed in an attempt to increase their biological actions. Two YCW preparations, one conventional and another with higher solubility of the mannan oligosaccharide fraction, were evaluated on dogs. One food formulation was used, divided into the following treatments: CON-control, without yeast cell wall addition; YCW-addition of 0.3% of a conventional yeas cell wall extract; YCWs-addition of 0.3% of a yeast cell wall extract with high mannan oligosaccharide solubility. Twenty-four beagle dogs were used, eight per food, distributed on a block design. Blocks lasted 32 days, and TNF-a, IL-6, IL-10, ex vivo production of hydrogen peroxide and nitric oxide by peripheral neutrophils and monocytes, phagocytic index, and fecal IgA were evaluated at the beginning and end of each period. Additionally, nutrient digestibility, feces production and quality, and fermentation products were quantified. The results were evaluated by analysis of variance and compared using the Tukey test (P<0.05), using the basal immunological parameters as a covariate. The inclusion of YCWs reduced fat digestibility (P<0.05), increased the concentration of butyrate and putrescine, and reduced lactate in feces (P<0.05), showing that mannan oligosaccharide solubilization resulted in higher fermentation of this compound and altered the metabolism of the gut microbiota. Lower IL-6 on serum was verified for dogs fed the YCWs diet (P<0.05), suggesting a reduction in the inflammatory activity of dogs. Higher phagocytic index was verified for peripheral monocytes after the intake of the YCW food, suggesting better innate immunity. In conclusion, the solubilization of the mannooligosaccharide fraction alters its interaction with gut microbiota and biological actions in animals, although both yeast cell wall preparations exhibited prebiotic effects on dogs.

Male and female cats have different regional body compositions and energy requirements for weight loss and weight maintenance

Body composition and energy requirements are different between males and females in several species, and both interfere with weight loss. The aim of this study was to compare the total and regional body composition and energy requirements in obese male (n = 8) and female (n = 8) cats, during weight loss and weight maintenance over 17 subsequent weeks after regimen. The total and regional (thoracic and pelvic limbs, and trunk) body composition was assessed by dual-energy X-ray absorptiometry (DXA). Females exhibited a higher fat mass (FM) than males (p < 0.05), and the trunk was the site with greater fat accumulation regardless of gender. A 23.0 ± 2.8% reduction in body weight was followed by a 50.3 ± 9.4% and a 37.0 ± 8.9% reduction in fat in the trunk region in males and females respectively. Lean mass (LM) mobilization was also increased in the trunk (p < 0.05), and the loss of LM was associated with a reduction in bone mass. The energy intake to achieve the same rate of weight loss was 12.9 ± 3.4% higher in males (p < 0.05). The cats exhibited a gradual increase in energy requirements to maintain their body weight after weight loss (p < 0.05). It was concluded that obese cats mainly accumulate fat in the trunk. The reduction in lean mass after the regimen also occurred in the trunk, with no modifications in the skeletal muscle mass of the limbs. Neutered male cats have higher energy requirements than neutered females, and gender should be considered during obesity management in cats.

Effects of Passive Immunization by Anti-Gingipain IgY on the Oral Health of Cats Fed Kibble Diets

Porphyromonas gulae is one of the key microorganisms in biofilm dysbiosis that leads to periodontal disease, a prevalent disease in cats. Gingipains are proteases secreted that promote the disruption of cell adhesion and the differentiation of osteoclasts. The use of anti-gingipain immunoglobulin Y (IgY-GP) has emerged as a promising alternative to conventional prevention and treatment methods. The aim of this study was to evaluate the efficacy of IgY-GP on different parameters related to oral health in cats. Twenty adult mixed-breed cats were divided into 2 groups of 10 cats fed with 2 extruded diets differing only by coating. The control group received a coating of 4 g/kg of powdered egg and the test group received a coating of 4 g/kg of IgY-GP. The experiment followed a crossover design with 2 periods, each lasting 40 days with a washout period of 30 days. The evaluated parameters were plaque, calculus, gingivitis index, and percentage of Porphyromonas gingivalis of the oral cavity (%PG-OC) at baseline and after 40 days of diet consumption. All cats remained healthy throughout the study and no adverse reactions or side effects were observed. After 40 days of IgY-GP consumption, the plaque index was significantly lower compared to the baseline ( P = .0133). There were no significant changes in calculus index, gingivitis index, and %PG-OC between groups after 40 days ( P > .05). The consumption of IgY-GP reduces plaque accumulation, which may lead to an improvement in the oral health of adult cats.

Effects of dietary yeast cell wall on faecal bacteria and fermentation products in adult cats

This study evaluated the effects of increasing concentrations of spray-dried yeast cell wall (YCW) in diets for healthy adult cats on apparent nutrient digestibility and on bacterial composition and fermentation products in the stool. Fourteen cats with an average weight of 4.40 ± 1.05 kg and an average age of 6.2 ± 0.54 years were used and assigned to treatments in an unbalanced randomized block design (by experimental period) with two blocks and three or four cats per diet in each block. Treatments included: control (0% YCW), 0.2% YCW, 0.4% YCW and 0.6% YCW, totalling seven animals per experimental diet. We found that YCW did not affect body weight, nutrient and food intake, faecal production, faecal score, faecal pH or urine output (p > .05). Regarding faecal bacteria, we observed a linear reduction in Clostridium perfringens, a quadratic reduction in Escherichia coli, and linear increases in Bifidobacterium spp. and Lactobacillus spp. (p < .05) with the inclusion of YCW. Regarding the faecal short-chain fatty acid profile, butyrate, valerate, total biogenic amines, putrescine, cadaverine and histamine increased linearly (p < .05) with the inclusion of YCW. It was concluded that in healthy adult cats, consumption of YCW modulates the faecal bacterial populations, with an increased presence of beneficial bacteria and a reduction in some potentially pathogenic bacteria. It was concluded that YCW modulated the levels of fermentation products. There was an increase in fermentation products coming from carbohydrate metabolism, an important effect that can potentially benefit the intestinal health of cats. The consumption of YCW also increased the fermentation of nitrogen compounds, which have not yet been defined as deleterious or beneficial. The fermentability of carbohydrates and nitrogen compounds may be associated. Therefore, YCW may cause rapid fermentation of both classes of compounds by enhancing the fermentability of one class.

Processing traits and digestibility of extruded dog foods with soy protein concentrate

Soya bean protein concentrate (SPC) with two particle sizes were evaluated on extrusion parameters, kibble formation, digestibility and palatability of dog foods. Eight diets were extruded: PBM-control diet based on poultry by-product meal (PBM); GM-a diet in which corn gluten meal (GM) replaced 45% of the diet protein; cSPC15%, cSPC30% and cSPC45%-diets in which SPC of coarse particle size (600 μm) replaced 15%, 30% and 45% of the diet protein; and sSPC15%, sSPC30% and sSPC45%-diets in which SPC of small particle size (200 μm) replaced 15%, 30% and 45% of the diet protein. The digestibility of nutrients was evaluated for the PBM, GM, cSPC45% and sSPC45% diets, using six dogs per food. The PBM, GM and cSPC45% diets were compared for palatability. Data were submitted for analysis of variance, and the means were compared by polynomial contrasts or Tukey's test (p < .05). The cSPC increased the specific mechanical energy (SME) application, extrusion temperature and pressure linearly, resulting in lower kibble density and higher expansion and starch gelatinization (SG) (p < .01). When comparing the PBM, GM, cSPC45% and sSPC45% diets, higher SME, extrusion temperature and pressure, SG and kibble expansion were verified for the cSPC45% diet (p < .05). The DM, fat and crude protein digestibility were similar among diets. Faecal pH, ammonia and lactate did not differ, demonstrating that the removal of oligosaccharides and soluble non-starch polysaccharides of SPC produces an ingredient with mostly non-fermentable fibre. Dogs preferred the PBM to the GM diet (p < .05), but consumed the PBM and cSPC45% foods equally. In conclusion, SPC exhibited good extrusion functionality, favouring kibble expansion and SG, with high digestibility, similar to that of PBM. The removal of soluble compounds from soya beans resulted in an ingredient with low fermentable fibre content, which did not alter faecal formation or characteristics.

Beet pulp intake and hairball faecal excretion in mixed-breed shorthaired cats

Hairball formation may induce vomiting and intestinal obstruction in predisposed cats. Some insoluble fibres as sugarcane fibre and cellulose can prevent hairball formation. The aim of this study was to evaluate the effect of beet pulp consumption, a moderate soluble and fermentable fibre source, on faecal trichobezoars excretion in adult shorthaired cats fed kibble diets. Eighteen mixed-breed shorthaired cats and three extruded diets were used as follows: a basal diet without added fibre source (PB0-8.8% dietary fibre); BP8-8% inclusion of beet pulp (17.5% of dietary fibre); BP16-16% inclusion of beet pulp (23.8% of dietary fibre). The cats were fed during 31 days and faeces quantitatively collected during three periods of 3 days each (from days 3-5; 15-17; 26-28). Gastrointestinal transit time was determined in the last 3 days of study (from days 29-31). The trichobezoars were separated from faeces, collected, dried and washed in ether for complete removal of all faecal material. The results were submitted to repeated-measure analysis of variance and means evaluated by polynomial contrast (p < 0.05). Beet pulp increased faecal production (p < 0.001) and reduced gastrointestinal transit time (p = 0.003). No alterations were found on trichobezoar faecal excretion, both as considered in number per cat per day of mg per cat per day (p > 0.05). Beet pulp intake did not reduce the number or the size of hairballs eliminated via faeces of shorthaired cats.

Effect of the addition of papain enzyme on digestive parameters and palatability of extruded diets for dogs

As fontes comuns de proteína utilizadas na fabricação de rações para cães são oriundas de coprodutos, os quais podem apresentar digestibilidade reduzida de acordo com a fonte. Este estudo avaliou os efeitos da adição da enzima papaína em dietas secas e extrusadas na palatabilidade, digestibilidade dos nutrientes, qualidade e produção fecal de cães adultos. Uma dieta foi formulada contendo farinha de vísceras de frango, farinha de carne e ossos e farinha de penas hidrolisadas como fontes proteicas. Esta foi posteriormente dividida em três dietas isonutrientes: controle negativo (CN) sem adição da enzima; adição de 855.000 UI de papaína por quilograma de ração (EZ1); e adição de 2.280.000 UI de papaína por quiilograma de ração (EZ2), ambas adições feitas antes da extrusão. O experimento seguiu delineamento em blocos casualizados, com dois blocos de nove animais (três animais por tratamento em cada bloco), totalizando 18 cães, e seis repetições por tratamento. Os dados obtidos foram submetidos a análise de variância, com as médias dos três tratamentos comparadas por contrastes polinomiais (P < 0,05). Não foram verificadas diferenças nos coeficientes de digestibilidade aparente dos nutrientes ou mesmo alterações na palatabilidade, pH e produção de fezes entre os tratamentos com diferentes inclusões de enzima (P > 0,05). Apenas o escore fecal reduziu com o aumento da adição da enzima (P < 0,05).

The effect of age and carbohydrate and protein sources on digestibility, fecal microbiota, fermentation products, fecal IgA, and immunological blood parameters in dogs

The present study compared the effects of diets formulated with fibers of different fermentability and protein sources of animal or vegetable origins on old and adult dogs. The experiment was organized in a 3 (diets) × 2 (ages) factorial arrangement, totaling 6 treatments. Thirty-six Beagle dogs were used (18 old dogs [10.2 ± 1.0 yr] and 18 young adult dogs [2.6 ± 0.9 yr]), with 6 dogs per treatment. Three diets with similar compositions were used: a nonfermentable insoluble fiber source (sugarcane fiber) and chicken byproduct meal (nonfermentable fiber [NFF] diet), a fermentable fiber source (beet pulp) and chicken byproduct meal (fermentable fiber [FF] diet), and soybean meal as a protein and fiber source (soybean meal [SM] diet). Data were evaluated using the MIXED procedure and considering the effects and interactions of block, animal, diets, and age. Means were compared using Tukey's test ( < 0.05). Age × diet interactions were evaluated when < 0.1. Old dogs had a reduced coefficient of total tract apparent digestibility of DM, which was explained by the age and diet interaction of CP and fat digestibility that was lower for old than for adult dogs fed the FF diet ( < 0.05). The SM diet obtained higher DM, OM, CP, and fiber digestibility compared with the NFF diet ( < 0.05). The feces of dogs fed the NFF diet had increased DM content ( < 0.05). The short-chain fatty acids (SCFA) did not change by age group and were higher for dogs fed the FF and SM diets compared with dogs fed the NFF diet ( < 0.05). An age and diet interaction was observed for lactate and was increased in the feces of old dogs compared with adult dogs fed the FF diet ( < 0.05). Fecal putrescine, cadaverine, and spermine were increased for old dogs compared with adult dogs ( < 0.05), and the spermidine fecal concentration was increased for dogs fed the SM diet regardless of age ( < 0.05). Old dogs had reduced peripheral T and B lymphocytes ( < 0.05). An age and diet interaction was observed for fecal IgA ( < 0.001). Adult dogs fed the SM diet had increased IgA in feces compared with animals fed the NFF and FF diets ( < 0.05). However, for old dogs, both the FF and SM diets induced increased IgA compared with the NFF diet ( < 0.05). In conclusion, beet pulp may reduce digestibility and induce increased lactate in the feces of old dogs. The protein and oligosaccharides of soybean meal are digestible by dogs, induce the production of SCFA and spermidine, and increase fecal IgA. Old dogs had increased putrecine, cadaverine, and spermine fecal concentrations.

Effect of resistant starch on the intestinal health of old dogs: fermentation products and histological features of the intestinal mucosa

The effects of resistant starch (RS) intake on nutrient digestibility, microbial fermentation products, faecal IgA, faecal pH, and histological features of the intestinal mucosa of old dogs were evaluated. The same formulation was extruded in two different conditions: one to obtain elevated starch cooking degree with low RS content (0.21%) and the other lower starch cooking with high RS content (1.46%). Eight geriatric Beagles (11.5 ± 0.38 years old) were fed each diet for 61 days in a crossover design. Food intake, nutrient digestibility, fermentation products, faecal pH, and faecal IgA were examined via variance analysis. Histological results of intestinal biopsies were assessed via Wilcoxon test for paired data. The morphometric characteristics of large intestine crypts were evaluated via paired t tests (p < .05). Protein, fat, and energy digestibilities were higher for the low-RS diet (p < .05). Dogs receiving the high-RS diet had lower faecal pH and higher values for propionate, butyrate, total volatile fatty acids, and lactate (p < .05). No differences between diets were found in the histological parameters of the gut mucosa, and only a tendency for deeper crypts in the descending colon was observed for dogs fed the high-RS diet (p = .083). The intake of a corn-based kibble diet manufactured with coarse ground raw material and low starch gelatinization to obtain 1.4% of RS affected microbial fermentation products and faecal pH and tended to increase crypt depth in the descending colon of old dogs.

The Effects of Fiber Inclusion on Pet Food Sensory Characteristics and Palatability

The objectives of this study were to determine (a) the influence of fiber on the sensory characteristics of dry dog foods; (b) differences of coated and uncoated kibbles for aroma and flavor characteristics; (c) palatability of these dry dog foods; and (d) potential associations between palatability and sensory attributes. A total of eight fiber treatments were manufactured: a control (no fiber addition), guava fiber (3%, 6%, and 12%), sugar cane fiber (9%; large and small particle size), and wheat bran fiber (32%; large and small particle size). The results indicated significant effects of fibers on both flavor and texture properties of the samples. Bitter taste and iron and stale aftertaste were examples of flavor attributes that differed with treatment, with highest intensity observed for 12% guava fiber and small particle size sugar cane fiber treatments. Fracturability and initial crispness attributes were lowest for the sugar cane fiber treatments. Flavor of all treatments changed after coating with a palatant, increasing in toasted, brothy, and grainy attributes. The coating also had a masking effect on aroma attributes such as stale, flavor attributes such as iron and bitter taste, and appearance attributes such as porosity. Palatability testing results indicated that the control treatment was preferred over the sugar cane or the wheat bran treatment. The treatment with large sugarcane fiber particles was preferred over the treatment with small particles, while both of the wheat bran treatments were eaten at a similar level. Descriptive sensory analysis data, especially textural attributes, were useful in pinpointing the underlying characteristics and were considered to be reasons that may influence palatability of dog foods manufactured with inclusion of different fibers.

Enzyme effects on extruded diets for dogs with soybean meal as a substitute for poultry by-product meal

The effects of exogenous enzymes supplementation on kibble diets for dogs formulated with soybean meal (SBM) as a substitute for poultry by-product meal (PM) was investigated on nutrient digestibility, fermentation products formation, post-prandial urea response and selected faecal bacteria counts. Two kibble diets with similar compositions were used in two trials: PM-based diet (28.9% of PM; soybean hulls as a fibre source) and SBM-based diet (29.9% of SBM). In experiment 1, the SBM diet was divided into three diets: SBM-0, without enzyme addition; SBM-1, covered after extrusion with 7500 U protease/kg and 45 U cellulase/kg; and SBM-2, covered with 15,000 U protease/kg and 90 U cellulase/kg. In experiment 2, the SBM diet was divided into three diets: SBM-0; SBM-1, covered with 140 U protease/kg; 8 U cellulase/kg, 800 U pectinase/kg, 60 U phytase/kg, 40 U betaglucanase/kg and 20 U xylanase/kg; and SMB-2, covered with 700 U protease/kg, 40 U cellulase/kg, 4000 U pectinase/kg, 300 U phytase/kg, 200 U betaglucanase/kg and 100 U xylanase/kg. Each experiment followed a block design with six dogs per diet. Data were submitted to analysis of variance and means compared by orthogonal and polynomial contrasts (p < 0.05). In both experiments, nutrients and energy digestibility did not differ between diets (p > 0.05). SBM consumption resulted in increased faecal moisture and production (p < 0.05), without effect on faecal score. Higher concentration of propionate, acetate and lactate, and lower ammonia and pH were found in the faeces of dogs fed SBM (p < 0.05). Higher post-prandial urea was verified in dogs fed SBM (p < 0.05). In experiment 2, the addition of enzymes increased faecal concentration of propionate, acetate and total short-chain fatty acid (p < 0.05) and tended to reduce post-prandial urea concentration (p = 0.06). Although with similar digestibility, SBM shows a worse utilization of absorbed amino acids than the PM. Soybean oligosaccharides can beneficially change gut fermentation product formation. Enzymes can increase the gut fermentation activity and improve the SBM proteic value.

Fiber fermentability effects on energy and macronutrient digestibility, fecal traits, postprandial metabolite responses, and colon histology of overweight cats

Considering the different potential benefits of divergent fiber ingredients, the effect of 3 fiber sources on energy and macronutrient digestibility, fermentation product formation, postprandial metabolite responses, and colon histology of overweight cats (Felis catus) fed kibble diets was compared. Twenty-four healthy adult cats were assigned in a complete randomized block design to 2 groups of 12 animals, and 3 animals from each group were fed 1 of 4 of the following kibble diets: control (CO; 11.5% dietary fiber), beet pulp (BP; 26% dietary fiber), wheat bran (WB; 24% dietary fiber), and sugarcane fiber (SF; 28% dietary fiber). Digestibility was measured by the total collection of feces. After 16 d of diet adaptation and an overnight period without food, blood glucose, cholesterol, and triglyceride postprandial responses were evaluated for 16 h after continued exposure to food. On d 20, colon biopsies of the cats were collected under general anesthesia. Fiber addition reduced food energy and nutrient digestibility. Of all the fiber sources, SF had the least dietary fiber digestibility (P < 0.05), causing the largest reduction of dietary energy digestibility (P < 0.05). The greater fermentability of BP resulted in reduced fecal DM and pH, greater fecal production [g/(cat × d); as-is], and greater fecal concentration of acetate, propionate, and lactate (P < 0.05). For most fecal variables, WB was intermediate between BP and SF, and SF was similar to the control diet except for an increased fecal DM and firmer feces production for the SF diet (P < 0.05). Postprandial evaluations indicated reduced mean glucose concentration and area under the glucose curve in cats fed the SF diet (P < 0.05). Colon mucosa thickness, crypt area, lamina propria area, goblet cell area, crypt mean size, and crypt in bifurcation did not vary among the diets. According to the fiber solubility and fermentation rates, fiber sources can induce different physiological responses in cats, reduce energy digestibility, and favor glucose metabolism (SF), or improve gut health (BP).

INTER-RELAÇÃO ENTRE BALANÇO CÁTION-ANIÔNICO DO ALIMENTO E O pH URINÁRIO DE GATOS

Estudos para o desenvolvimento de formulações de alimentos para animais de companhia buscam componentes essenciais à manutenção da vida de forma saudável, bem como segurança de produtos, incorporando nestes, elementos capazes de prevenir os riscos de determinados distúrbios metabólicos associados à dieta. Desordens do trato urinário felino, em destaque as urolitíases, apresentam alta incidência na casuística clínica. Estudos associam fatores dietéticos como ingredientes, digestibilidade e composição química, a alteração do volume, pH e densidade da urina e conseqüente indução a formação de urólitos. Uma correlação altamente significativa entre a composição mineral da dieta e o pH urinário de gatos começa a ser estudada, utilizando a associação entre o balanço catiônico-aniônico da dieta (BCAD) e a regulação do equilíbrio ácido-base do organismo. O BCAD pode ser definido como a diferença entre os cátions e ânions fixos totais presentes na dieta, ferramenta importante para estimar o pH urinário e determinar a faixa de pH que o alimento utilizado favorece, podendo assim associar o desencadeamento e a prevenção de urólitos de estruvita e oxalato de cálcio no trato urinário de felinos. Diante disso a presente revisão teve como objetivo apontar associações entre a dieta e o reflexo desta no pH urinário de gatos e, conseqüentemente, no desenvolvimento de desordens do trato urinário, caracterizadas por formação de concreções macroscópicas, assim como descrever a  metodologia do BCAD para estimação deste pH e prevenção de doenças, melhorando a qualidade de vida dos gatos.

Digestibility for dogs and cats of meat and bone meal processed at two different temperature and pressure levels*

This study evaluated the effect of two rendering processes applied to meat and bone meal (MBM) production, associated or not with extrusion, by measuring diet apparent total tract digestibility of dogs and cats, and true digestibility of amino acids (AA) by cecectomized roosters. Four diets were evaluated, with the main protein source as follows: conventional and extruded MBM; high temperature and pressure (HPT; 135 °C, 3 bar, 20 min) and extruded MBM; conventional non-extruded MBM; HPT non-extruded MBM. Nutrient digestibility and food metabolizable energy content were evaluated with dogs and cats by the method of total collection of faeces. True AA digestibility was evaluated by a precision-fed assay with cecectomized roosters. The evaluated MBM had high-ash content. The HPT process of MBM increased the digestibility of crude protein of the diets by cats, and the true digestibility of several AA by cecectomized roosters. The extrusion process did not modify the apparent total tract nutrient digestibility of MBM by dogs and their amino acid digestibility by roosters, but increased the digestibility of the dietary protein by cats. Dogs fed HPT MBM presented a higher urea post-prandial response, suggesting reductions in bioavailability and protein synthesis from absorbed AA.

Fibre analysis and fibre digestibility in pet foods--a comparison of total dietary fibre, neutral and acid detergent fibre and crude fibre

Six dry dog foods and six dry cat foods with different carbohydrate sources were investigated in digestion trials. Food and faecal samples were analysed for CF, TDF and starch. In dogs, also neutral detergent fibre (aNDFom) and acid detergent fibre (ADFom) were analysed. N-free extract (NfE) was calculated for CF, and similarly for all other fibre analyses. Linear regressions were calculated between fibre intake and faecal fibre excretion. True digestibility was calculated from the regression coefficients [true digestibility in % = (1 - regression coefficient)*100], with the intercept of the equation representing excretion of material of non-food origin. Crude fibre analyses gave the lowest values, and TDF the highest, while ADFom and aNDFom were in between. Variation between diets was lowest in CF and highest in TDF. Total dietary fibre, aNDFom and ADFom in food were positively correlated. Crude fibre in food did not correlate with any other method. The NfE analogue for TDF was closest to the starch content. Methods of fibre analyses in faeces did not agree very well with each other. Crude fibre had the lowest apparent digestibility, followed by ADFom, TDF and aNDFom. For all fibre analyses, there was a significant correlation between fibre intake and faecal fibre excretion. True digestibility was close to zero for CF, with a high uniformity in both species. In dogs, true digestibility of aNDFom was 53%, of ADFom 26% and of TDF 37%; in cats, true digestibility of TDF was 31%. Except for CF, the intercept of the regression equations suggest that faecal excretion of some material of non-food origin is analysed as fibre. A combination of TDF and CF analyses might give good information on the content of total (TDF), unfermentable (CF) and partially fermentable fibre (TDF-CF) in pet foods.

DIGESTIBILIDADE DE UMA DIETA CASEIRA E DOIS ALIMENTOS COMERCIAIS, ECONÔMICO E SUPER-PRÊMIO, PARA CÃES

Foram comparados os coeficientes de digestibilidade aparente (CDA) e a qualidade dasfezes de cães alimentados com uma dieta caseira e dois alimentos comerciais, econômicoe super-prêmio. Seis cães adultos foram distribuídos em delineamento quadrado latinoduplo (3 x 3), com três tratamentos e três períodos, totalizando seis repetições portratamento. As médias foram comparadas pelo teste Tukey. A dieta caseira apresentou osmaiores CDA, não diferindo apenas do CDA do extrato etéreo ácido do alimento superprêmio.O alimento econômico foi o menos digestível, gerando o maior resíduo fecal. Oteor de matéria seca das fezes dos cães alimentados com a dieta caseira foi menor emrelação aos cães recebendo os alimentos econômico e super-prêmio, os quais nãodiferiram entre si. O escore fecal variou pouco entre os tratamentos, mantendo-se dentrodo considerado ideal. A dieta caseira pode ser uma alternativa na alimentação de cães.

Protein requirements for Blue-fronted Amazon (Amazona aestiva) growth

The objective of this study was to evaluate the protein requirements for hand-rearing Blue-fronted Amazon parrots (Amazona aestiva). Forty hatchlings were fed semi-purified diets containing one of four (as-fed basis) protein levels: 13%, 18%, 23% and 28%. The experiment was carried out in a randomized block design with the initial weight of the nestling as the blocking factor and 10 parrots per protein level. Regression analysis was used to determine relationships between protein level and biometric measurements. The data indicated that 13% crude protein supported nestling growth with 18% being the minimum tested level required for maximum development. The optimal protein concentration for maximum weight gain was 24.4% (p = 0.08; r(2) = 0.25), tail length 23.7% (p = 0.09; r(2) = 0.19), wing length 23.0% (p = 0.07; r(2) = 0.17), tarsus length 21.3% (p = 0.06; r(2) = 0.10) and tarsus width 21.4% (p = 0.07; r(2) = 0.09). Tarsus measurements were larger in males (p < 0.05), indicating that sex must be considered when studying developing psittacines. These results were obtained using a highly digestible protein and a diet with moderate metabolizable energy levels.

Influência do teor de água e da digestibilidade de alimentos industrializados sobre o balanço hídrico de gatas

A modificação dietética tem sido estudada e empregada no controle e prevenção da Doença do Trato Urinário Inferior dos Felinos. Este trabalho estudou a influência do teor de água e da digestibilidade das rações sobre a ingestão, excreção urinária e excreção fecal de água. Utilizaram-se 10 gatas adultas castradas, alojadas em gaiolas metabólicas.Testaram-se quatro tratamentos: ração enlatada; seca super-premium; seca econômica e seca econômica acrescida de 50% de água. Determinou-se a ingestão de água via alimento e bebedouro, a excreção de água via fezes e urina e o coeficiente de digestibilidade das rações. Foi empregado um quadrado latino com repetições no tempo. Os resultados foram avaliados por análise de variância seguido pelo teste de Tukey para a comparação de médias e a Correlação de Pearson para se verificar a associação entre variáveis (p<0,05). O consumo de ração enlatada proporcionou uma maior ingestão total de água e uma maior excreção de urina, que apresentou menor densidade. Os gatos compensaram a maior ingestão de água alimentar bebendo menos água. Quanto menor a ingestão de matéria seca e maior a digestibilidade do alimento, menor a excreção fecal de água, pois as rações secas de baixa e alta digestibilidade obtiveram, respectivamente, relação excreção de urina:excreção de água fecal de 0,7:1 e 1,6:1. A ingestão de gordura apresentou correlação positiva com o volume urinário. Rações de maior digestibilidade promovem menor perda fecal de água, mas somente a ração enlatada (alta relação água:matéria seca) proporcionou maiores ingestão total de água e volume urinário.

Estudo etiológico e epidemiológico da "doença da vaca caída"

Objetivo: Investigar a etiologia e o panorama epidemiológico da "doença da vaca caída" em bovinos atendidos no Hospital Veterinário "Governador Laudo Natel" da Faculdade de Ciências Agrárias e Veterinárias da Universidade Estadual Paulista (FCAV/UNESP), Campus de Jaboticabal, Jaboticabal, SP. Material e Método: Procedeu-se ao exame clínico, avaliação neurológica, colheita de soro sangüíneo e líquido rumenal para a detecção de toxina botulínica, líquido cefalorraquidiano para diagnóstico de encefalites, exame necroscópico, exame histopatológico do cérebro e o diagnóstico de raiva. Caracterizou-se o manejo, tipo de exploração zootécnica, nutrição, sanidade e colheu-se dados epidemiológicos dos surtos. Resultados: Foram incluídas 24 fazendas e 29 animais. O inquérito epidemiológico totalizou 7.261 bovinos, sendo l43 doentes gerando uma taxa de morbidade geral de 2% (2,6% dentre novilhas, 2,2%dentre vacas, 1,7% dentre garrotes e 0,6% dentre bois), 40% dos animais acometidos foram garrotes, seguidos pelas vacas (28%) e novilhas (27%). A taxa de morbidade variou entre propriedades (0,14% a 57,5%) com letal idade próxima à 100%. Empregavam sal comum misturado ao sal mineral 57% das propriedades e 30% destas sal mineral completo comercial, a quantidade fornecida foi considerada inadequada em 54%. Predominaram pastos de Braquiaria sp em manejo extensivo sem adubação. Apenas dois proprietários referiram osteofagia, apesar de 45% dos pastos apresentarem ossadas. Os bovinos apresentaram-se em decúbito externo-abdominal ou lateral, 40% com diminuição do tônus da língua e 80% com diminuição do tônus e ausência de movimentos de cauda. Dentre os diagnósticos que puderam ser firmados verificou-se as seguintes freqüências de ocorrência: 3,4% de polioencefalomalácia; 3,4% de raiva; 10,3% de encefalite; 3,4% de falência de órgãos; 41,4% de botulismo; 38, I% idiopáticos, pois os animais não apresentaram sinais ou alterações que permitissem um diagnóstico conclusivo. Conclusões: Conclui-se que se trata de doença de etiologia multifatorial e cujo panorama epidemiológico necessita de investigações mais abrangentes, a fim de se estabelecer métodos de controle mais eficientes.

Prototheca sp. outbreak of bovine mastitis

Prototheca sp., a colourless algae, is quite common in dairy environments, particularly in wet areas contaminated with manure. The main purpose of this paper is to describe an outbreak of clinical bovine mastitis in an 86-cow dairy herd in the State of Säo Paulo, Brazil. Prototheca sp., an achlorophyllous algae, were isolated on blood agar (incubated for 24 h at 37 degrees C) from 11 quarters of seven lactating Holstein cows, and from one quarter of a cow at the end of the dry period. Treatments were applied, but there was only a microbiological cure, not a functional one. Diagnosis of Prototheca sp. in any of the cows in the herd indicates a herd problem. Infected animals usually have markedly reduced milk production and granulomatous changes often occur in the mammary gland. All sources of contact between the teat ends and drainage water or damp areas should be corrected. An all-out effort for strict sanitation, including during milking, should be made so that the teat ends will not become contaminated.

Bovine mastitis due to algae of the genus Prototheca

Protothecosis was described in many animals, with bovine mastitis being the main form. The increasing number of isolations of Prototheca spp. from bovine mastitis cases indicates the need of a detailed evaluation of this problem. Besides this, these algae do not respond to treatment with the antimicrobians most frequently applied, leading to elimination of the affected animals, as the best method to control the disease. In two dairy farms in the State of São Paulo, Brazil, a total of 155 lactating cows and 52 dry cows were examined. Milk samples were aseptically collected from lactating cows with clinical or subclinical mastitis. From dry cows, secretion samples from all quarters were collected. All samples were then taken to microbiological exams. At dairy farm 1, Prototheca spp. was isolated from 14.95% milk samples from lactating cows, (all of them cases of subclinical mastitis), and from 8.06% samples from dry cows. At dairy farm 2, Prototheca spp. was isolated from 5.1% milk samples and there were ten cases of clinical mastitis due to this agent. Although clinical mastitis has been considered the main form of occurrence of this pathology until now, it is important to consider Prototheca spp. as subclinical mastitis pathogen. Prototheca zopfii was the main specie isolated. In this study a high rate of intramammarian infections, as clinical or subclinical mastitis during lactation as well as in dry period, was observed, high lighting the importance of suitable diagnosis, so that control and preventive measures can be implemented to avoid dissemination of the agent.