Nutrient digestion efficiency: a comparison between broiler chickens and growing pigs fed maize, barley and oats-based diets with an emphasis on starch

We investigated the hypotheses that broilers and pigs have distinct starch digestion capacities and that different cereals could trigger diet–species interactions. Ten replicates of two broilers (14 d old) or one pig (50 d old) each were distributed into a 3 × 2 randomised factorial design with three pelleted diets (maize, barley or oat-based) and the two species. Nutritional composition was equal for both species. Diets were fed for 10 d, and then the pancreas and organs from the stomach region and small intestine were collected with contents. It was observed that both species were similarly efficient at digesting starch but differed in some digestive aspects. Broilers had higher ileal digestibility coefficients (P < 0·001) of DM (0·69) and crude protein (0·75) than pigs (0·66 and 0·67), presented a higher volume of particles < 0·1 mm in duodenal digesta (P < 0·001) and had a lower gizzard pH (3·68) than pig stomach (4·48; P < 0·05). Conversely, pigs had lower ileal viscosity (1·44 v. 2·77 cP; P < 0·05) and higher pancreatic lipase activity (27 v. 5·9 U/g of pancreas; P < 0·05) compared with broilers. In the jejunum, oat led to higher starch digestibility (0·96; P < 0·05) than maize and barley regardless of species. In the ileum, starch digestibility was higher for broilers fed oats (0·99) than broilers fed barley (0·94; P < 0·05), establishing that oats provided, in general, a superior starch availability. The results imply that starch utilisation capacity is more related to its dietary source than to the species to which it is fed.