Comparison of jejunal digestive enzyme activities, expression of nutrient transporter genes, and apparent fecal digestibility in weaned piglets fed diets with varied sources of fiber

The objective of this study was to evaluate the effect of different fiber sources on jejunal digestive and absorptive physiology in weaned piglets. One hundred weaned piglets were allotted according to body weight, gender and litter to four dietary treatments. Each treatment was replicated in 5 pens of 5 pigs each. The experimental diets contained 10% of a fiber source: wheat bran (WB), maize fiber (MF), soyabean fiber (SF), or pea fiber (PF). Piglets were fed ad libitum for 30 d. Reduced villus height and villus height-to-crypt depth ratio (P < 0.05) were observed in pigs fed diet MF compared with pigs fed diet WB. In the mid-jejunal mucosa, lower activities of sucrase (P < 0.05) were found in pigs fed diets MF and SF compared with WB. In mid-jejunal digesta, inclusion of SF and PF decreased the activities of trypsin and lipase (P < 0.05) compared with inclusion of WB. Supplementation with PF resulted in higher facilitated glucose transporter 2 (P < 0.05) and lower excitatory amino acid carrier 1 mRNA levels compared with supplementing WB. The apparent faecal digestibility of gross energy, dry matter, organic matter, neutral detergent fiber and acid detergent fiber declined in the following order: diet SF > PF > MF > WB. Our study indicates that SF and PF could promote apparent faecal digestibility in piglets, but this is not accompanied by better jejunal morphology or digestive enzyme activities as compared with WB.