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

Abstract

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.

Fermentation Characteristics of Several Carbohydrate Sources for Dog Diets Using theIn VitroGas Production Technique

“…solubility), but do not provide any information about their suitability for bacterial fermentation (de-Oliveira et al, 2011). Therefore, the combination of the chemical composition analysis with the in vitro gas production technique provides interesting complementary data about the ingredients.…”

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

“…This technical deficiency is proven in the evaluation of food for dogs and cats by the studying of Oliveira et al (2012) in which six dry dog foods and six dry cat foods were evaluated for fiber composition and digestibility, comparing a total dietary fiber, neutral and acid detergent fiber and crude fiber. The results demonstrated that crude fiber analysis did not correlate with any other method.…”

“…Based on laboratory results, the coefficient of total tract apparent digestibility of nutrients (CTTAD) of dry matter (DM), crude protein (CP), acid-hydrolyzed fat (AHF), organic matter (OM), nitrogen free extract (NFE), and gross energy (GE) were calculated according to the equation of Pond et al (1995).…”

Effect of soybean hulls on blood biochemical profiles and body condition of dogs

“…Dry commercial foods for companion animals contain significant amounts of carbohydrates and these are mostly digestible, like starch. The part that is not digestible, denominated non-starch polysaccharides, is usually classified as dietary fiber (De-Oliveira, 2011). Physiologically, fibers are conceptualized as corresponding to food components that resist degradation by mammalian enzymes (Fischer, 2011).…”

“…Diets with fibers are inserted into the animal feed according to their beneficial actions, such as control of various biochemical parameters in serum, i.e., glucose, triglycerides, and cholesterol (De-Oliveira, 2011). Studies show that dogs and cats that have their diet supplemented with different sources of fiber reduce postprandial blood glucose and cholesterol levels, and lose weight.…”