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

Abstract

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 2 broilers (14-d-old) or 1 pig (50-d-old) each were distributed into a 3x2 randomized factorial design with 3 pelleted diets (maize, barley, or oat-based) and the 2 species. Nutritional composition was equal for both species. Diets were fed for 10 days, then 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 on 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 to 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 utilization capacity is more related to its dietary source than to the species to which it is fed.