Potential benefits of yeast Saccharomyces and their derivatives in dogs and cats: a review.

Yeast Saccharomyces and its derivatives have been largely used in livestock and poultry nutrition for their potential positive impact on growth, performance, and general health. Originally included in animal diets as a source of protein, yeasts can also offer a wide range of by-products with interesting bioactive compounds that would confer uses beyond nutrition. Although its supplementation in livestock, poultry and even in humans is well documented, the available body of literature on the use of yeast and its derivatives in companion animals' food, mainly dogs and cats' diets, is still developing. Despite this, gut microbiota modulation, immune system enhancement or decreasing of potentially pathogenic microorganisms have been reported in pets when using these products, highlighting their possible role as probiotics, prebiotics, and postbiotics. This review attempts to provide the reader with a comprehensive on the effects of Saccharomyces and its derivatives in pets and the possible mechanisms that confer their functional properties.

Fine cassava fibre utilization as a dietary fibre source for dogs: Effects on kibble characteristics, diet digestibility and palatability, faecal metabolites and microbiota.

The objective was to evaluate through three experiments the effects of a fine cassava fibre (CA: 106 µm) on kibble characteristics, coefficients of total tract apparent digestibility (CTTAD) of macronutrients, diet palatability and faecal metabolites and microbiota of dogs. Dietary treatments consisted of a control diet (CO), without an added fibre source and with 4.3% total dietary fibre (TDF), and a diet with 9.6% CA (106 µm), with 8.4% TDF. Experiment I evaluated the physical characteristics of the kibbles. The palatability test was evaluated in experiment II, which compared the diets CO versus CA. In experiment III, 12 adult dogs were randomly assigned to one of the two dietary treatments for 15 days, totalling six replicates/treatment, to assess the CTTAD of macronutrients; faecal characteristics, faecal metabolites and microbiota. The expansion index, kibble size and friability of diets with CA were higher than the CO (p < 0.05). Additionally, the CA diet presented higher palatability than the CO (p < 0.05) but did not affect CTTAD except for those of fibre (p > 0.05). Moreover, a greater faecal concentration of acetate, butyrate and total short-chain fatty acids (SCFA) and a lower faecal concentration of phenol, indole and isobutyrate were observed in dogs fed the CA diet (p < 0.05). Dogs fed with the CA diet presented a greater bacterial diversity and richness and a greater abundance of genera considered to be beneficial for gut health, such as Blautia, Faecalibacterium and Fusobacterium when compared to the CO group (p < 0.05). The inclusion of 9.6% of a fine CA improves the expansion of kibbles and diet palatability without affecting most of the CTTAD of nutrients. Besides, it improves the production of some SCFA and modulates the faecal microbiota of dogs.

Evaluation of postprandial glycemic response in rats (Wistar) fed with different starch sources.

The consumption of readily digestible starch sources, such as corn, can negatively impact endocrine disorders related to hyperglycaemia in predisposing animals. In this sense, starch sources containing slowly digestible and resistant fractions can assist glycemic control. The present study analyzed the postprandial glycemic response and blood variables of rats fed with four extruded diets containing corn, brown rice, sweet potato and pea as the main starch source. Thirty-two male Wistar rats (90 days old) were divided into groups of eight animals each. The rats received one of the experimental diets for 30 days according to a completely randomised design. The glycemia was measured on the 29th and 30th days. The glycemia measured on the 29th day was analyzed at 0, 30, 60, 120 and 240 min after oral administration of 50% glucose solution. On the 30th day, the same protocol was repeated after providing 3 g of the experimental diet for each animal to obtain the glycemic curve. After the euthanasia on the 30th day, 7 ml of blood was collected via cardiac puncture for glycated haemoglobin (HBA1c), triglycerides, cholesterol, and aspartate and alanine aminotransferases analysis. Diets with pea and sweet potato provided lower glycemic index, average and maximum glycemia, and glycemic increment in relation to the other starch sources (p < 0.05). Animals fed with the corn diet had higher serum concentrations of triglycerides and HBA1c than the other treatments (p < 0.05). Results demonstrated that pea and sweet potato are interesting starch sources for the control of metabolic disorders related to glycemia.

Effects of two dietary fiber levels on nutrient digestibility and intestinal fermentation products in captive brown howler monkeys (Alouatta guariba).

Herbivorous primates present a selective consumption profile and morphological adaptations to use the fibrous fraction of their diets. Brown howler monkeys (Alouatta guariba) are generalist herbivores; however, when kept under human care, they usually receive diets rich in fruits and with insufficient amounts of fiber. Thus, the objective of this study was to evaluate the effects of two levels of neutral detergent fiber (NDF) in howlers on apparent total tract digestibility coefficients (ATTDC), fecal consistency, and intestinal fermentation products. A group of 26 adult howler monkeys, 13 males and 13 females, were fed two diets formulated to have 33% or 40% NDF for 11 days, according to a randomized block design (N = 26). The block factor was the enclosures with one, two, or three individuals (each enclosure corresponded to an experimental unit), totaling in eight replicates per treatment. There were no differences in dry matter and nutrients intake between treatments (p > 0.05). The diet with 33% NDF resulted in higher (p < 0.05) ATTDC of crude protein and crude energy. However, lower fecal concentrations of short-chain fatty acids (SCFA) and dry matter were observed in the treatment with 33% NDF in contrast to the 40% NDF group (p < 0.05). We recommend the inclusion of higher fiber levels (40% NDF) in the diet of howler monkeys since there is evidence of greater production of SCFA and improvement in fecal consistency.

Endogenous fat losses and true and apparent fat digestibility in adult and growing dogs fed diets containing poultry offal fat.

The objective of this study was to evaluate the coefficient of total tract apparent digestibility (CTTAD) of dietary nutrients, endogenous fat loss (EFL), dietary metabolizable energy (ME) content, coefficient of true digestibility (CTD) of fat and faecal parameters of dogs. A total of 16 puppies and 8 adult dogs were distributed according to a double Latin square experimental design. A basal diet was formulated, to which increasing levels (60, 120 and 180 g/kg) of poultry offal fat oil were added. EFL was estimated using hyperbolic and linear regression as a function of LW/day and dry matter (DM) intake, respectively, and the CTD of fat was calculated. The CTTAD of acid-hydrolysis ether extract (AHEE) and ME content increased as dietary poultry offal fat level increased both in adult dogs and in puppies (p < .05). The CTTAD of DM and crude protein were higher in adult dogs than in puppies. EFL was estimated by hyperbolic regression as y = 98.1094 - 13.6202/x and y = 99.1280 - 26.1366/x, where y = CTTAD of AHEE (%) and x = AHEE intake/kg BW, for adult dogs and puppies, respectively, which yielded EFL values of 138 and 262 mg AHEE per kg BW per day for adult dogs and puppies respectively. The EFL estimated by linear regression was 7.89 g and 8.97 g/kg DM intake for adult dogs and puppies respectively. The CTD estimated by both methodologies was higher in puppies than in adults (p < .05). Lower faecal DM and score, and higher ammonia production were obtained in puppies than adult dogs (p < .05). The results indicate good fat utilization and that fat digestibility is underestimated, as the CTTAD of AHEE does not take into account EFL, particularly at low-fat inclusion levels and in growing dogs, which have greater EFL than adult dogs.

Body condition of dogs fed diets containing soya hulls.

Obesity is a growing problem in dogs. Therefore, there is an increasing need of foods for obese dogs with high-fibre content to dilute energies and to reduce energy absorption. Soya hulls are cheap and are widely available as a fibre source. We aimed at evaluating the body condition of dogs fed diets containing 0 % soya hulls (0SH) or 16 % soya hulls (16SH) in replacement of maize. Twelve adult dogs, with 11·3 (se 1·6) kg average body weight (BW), 4·1 (se 0·1) years old and body condition score (BCS) between 4 and 7, were completely randomised assigned (six per treatment) and were fed the 0SH diet according to their maintenance energy requirements or the same amount in grams (g/kg BW(0·75)) of the 16SH diet once daily for 56 d. The animals were evaluated on days 0 and 57 for BW, BCS (1, very thin to 9, obese), subcutaneous fat thickness in the L7 vertebra using ultrasound (L7), canine BMI (CBMI) and body fat (BF). Data were analysed by the Student's t test and Kruskal-Wallis test (P < 0·05). The change (final - initial) in BW (-0·58 v. -0·49 kg), BCS (-1 v. -1), L7 (-2 v. 0·35 mm), CBMI (-0·85 v. -0·63 kg/m(2)) and BF (-5·0 v. -5·4 %) of dogs fed the 0SH and 16SH diets, respectively, were not different (P > 0·05). The 16SH diet, with 11·4 % restriction in metabolisable energy, did not change the BCS of adult dogs. Further studies evaluating the supply of soya hulls only to overweight/obese dogs should to be carried out, because these dogs may respond differently than the group evaluated, which had a BCS between 4 and 7 (ideal to overweight).

Effect of feeding frequency of a diet containing soya hulls on the food intake and behaviour of dogs.

Dietary fibre may promote satiety and reduce energy consumption per gram of food. Associated with feeding management, dietary fibre may contribute to reduce anxiety in dogs submitted to food restriction to lose weight. The objective of the present study was to evaluate the food intake and the behaviour of dogs fed diets without soya hulls (0SH) or with soya hulls (16SH) once (1×) or twice (2×) daily. Eight adult Beagle dogs, with 11·3 (se 1·6) kg body weight (BW), 4·1 (se 0·1) years of age and body condition score between 4 and 7, were distributed in 4 × 4 Latin square design (n 8/treatment, 5 d/period) in a 2 × 2 factorial arrangement (0SH v. 16SH; 1× v. 2×). Food allowance was 50 % in excess of the daily metabolisable energy (ME) requirements; food residues were weighed. The behavioural test consisted in continuously observations for 24 h, using the scanning sampling technique (observations every 10 min). General behaviours, such as sleeping, barking, standing and others were recorded. Food intake in g/kg BW(0·75) per d of 0SH and 16SH was not different (P > 0·05). However, dogs fed the 0SH diet presented higher (P > 0·05) energy intake (kJ/kg BW(0·75) per d; P < 0·05) compared with those fed the 16SH diet. Dogs fed 2× daily had higher intake, both in g and in kJ, compared with those fed 1 × , independently of diet. There was no interaction between diets and feeding frequency (P > 0·05). No behavioural differences were observed (P > 0·05). The diet containing 16SH, despite reducing ME intake, did not restrict food intake (in g). Dogs fed 1× per d had lower food intake, possibly due to gastric capacity limitation.