Evaluation of plant and meat based dog foods by In-vitro and In-vivo digestibility techniques

A study was conducted to evaluate dog foods using in-vitro and in-vivo digestibility techniques. Four commercially available adult maintenance type canine diets, viz., vegetable (V), chicken and vegetable (CV), meat and vegetable (MV) and meat and rice (MR) based diets, were selected. In-vitro digestibility was achieved by incubating the food samples with enzymes (pepsin, amylase, and pancreatin) to simulate digestion in the stomach and small intestine. The residue was subjected to an in-vitro gas production technique to simulate the hindgut fermentation. The gas production over a period of 24 hours was recorded. Twelve adult mongrel dogs of comparable body weight were selected and divided into four groups equally. A five-day in-vivo digestion trial was carried out at the end of the four-week feeding trial. The chemical composition of all four diets was comparable. In both in-vitro and in-vivo digestibility trials the diet V showed less digestibility of all the nutrients except crude fibre. There was no significant difference in dry matter and organic matter digestibility between in-vitro and in-vivo techniques. However, there was a significant (P≤0.05) difference in the digestibility of crude protein, crude fibre, ether extract and nitrogen free extract. Diet V showed the highest fermentation and gas production rate compared to CV, MV, and MR diets. Body weight (BW) and body condition score (BCS) was observed during feeding trial. Although all experimental diets were maintenance type, the mean average daily gain (g) in BW of 7.92, 8.57, 8.63 and 8.93 for V, CV, MV and MR, respectively, was observed. The BCS of less than an ideal score was observed in all the experimental groups. Higher gas production, faecal score and number of defecations was observed in animals receiving diet V. Therefore, it was concluded that the animal protein-based diets (CV, MV and MR) are better than the plant protein-based diet (V) for feeding of dogs.