Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic cats fed extruded, raw beef-based, and cooked beef-based diets

Abstract

The objectives of this study were to determine differences in apparent total tract energy and macronutrient digestibility, fecal and urine characteristics, and serum chemistry of domestic cats fed raw and cooked meat-based diets and extruded diet. Nine adult female domestic shorthair cats were utilized in a replicated 3 × 3 Latin square design. Dietary treatments included a high-protein extruded diet (EX; 57% CP), a raw beef-based diet (RB; 53% CP), and a cooked beef-based diet (CB; 52% CP). Cats were housed individually in metabolic cages and fed to maintain BW. The study consisted of three 21-d periods. Each period included diet adaptation during d 0 to 16; fecal and urine sample collections during d 17 to 20; and blood sample collection at d 21. Food intake was measured daily. Total feces and urine were collected for determination of nutrient digestibility. In addition, a fresh urine sample was collected from each cat for urinalysis, and a fresh fecal sample was collected from each cat for determination of DM percentage and ammonia, short-chain fatty acid (SCFA), and branched-chain fatty acid (BCFA) concentrations. All feces were scored after collection using a scale ranging from 1 (hard, dry pellets) to 5 (watery, liquid that can be poured). Blood was analyzed for serum metabolites. Apparent total tract DM, OM, CP, fat, and GE digestibilities were greater (P ≤ 0.05) in cats fed RB and CB than those fed EX. Total fecal SCFA concentrations did not differ among dietary treatments; however, molar ratios of SCFA were modified by diet, with cats fed RB and CB having an increased (P ≤ 0.05) proportion of fecal propionate and decreased (P ≤ 0.05) proportion of fecal butyrate compared with cats fed EX. Fecal concentrations of ammonia, isobutyrate, valerate, isovalerate, and total BCFA were greater (P ≤ 0.05) in cats fed EX compared with cats fed RB and CB. Our results indicated that cooking a raw meat diet does not alter apparent total tract energy and macronutrient digestibility and may also minimize risk of microbial contamination. Given the increasing popularity of feeding raw diets and the metabolic differences noted in this experiment, further research focused on the adequacy and safety of raw beef-based diets in domestic cats is justified.

Key bacterial families (Clostridiaceae, Erysipelotrichaceae and Bacteroidaceae) are related to the digestion of protein and energy in dogs

“…Apparent digestibility of energy and crude protein was also higher in dogs fed the meat diet. This is in agreement with previous studies in cats that have shown that both raw and cooked beef diets result in higher apparent total tract dry matter, crude protein, crude fat and gross energy digestibility compared to extruded (kibbled) diets (Kerr et al, 2012). …”

Effects of inulin or yeast cell-wall extract on nutrient digestibility, fecal fermentative end-product concentrations, and blood metabolite concentrations in adult dogs fed raw meat–based diets

“…Total tract apparent CP and fat digestibilities of the dogs in the present study were similar to findings of previous raw meat studies [2][3][4]35 in cats (CP digestibility, 92.9 to 93.9; fat digestibility, 93.9 to 95.5) performed in the same laboratory. The digestibility of raw meat is much greater than that typical of kibble.…”

“…34 When a nonfermentable fiber source was included in a raw diet for cats, low fecal consistency scores were observed (2.1/5; hard feces). 2 When a more fermentable fiber source was included in those diets, ideal fecal scores were observed (3/5; typical feces), suggesting a fermentable fiber source should be included in raw meat-based diets, particularly for cats prone to constipation. High dietary ash content of such diets may also contribute to hard, dry feces.…”

“…Reasons for feeding this type of diet include the lack of preservatives and possible improvement of feces, skin, or coat quality 1 as well as the high digestibility reported for domestic cats. [2][3][4] Conversely, consumption of raw meat-based diets can increase pathogen expoFructans are a group of fermentable carbohydrates classified as prebiotics. To qualify as a prebiotic, a compound must be resistant to gastric acidity, enzymatic hydrolysis, and gastrointestinal absorption (nondigestible); be fermented by cecal or colonic microflora; and selectively stimulate the growth or activity of bacteria that contribute to colonic and host health.…”

Salmonellosis impacts the proportions of faecal microbial populations in domestic cats fed 1–3-d-old chicks

“…poultry species can act as a reservoir for pathogenic Salmonella species without overt signs of infection) ( 20 ) . Although the diet samples tested herein were negative for Salmonella , Kerr et al ( 10 ) detected Salmonella in 1–3-d-old chicks obtained from the same supplier. Whole-prey diet items containing gut contents make it inevitable that the animals ingesting them will be exposed to foreign bacteria.…”