Validation of an in vitro technique for determining ileal starch digestion of field peas (Pisum sativum) in pigs

The present study aimed to validate an in vitro enzymatic technique that estimates the coefficient of apparent ileal digestibility (CAID) of the starch and amino acids of eight varieties of field peas (Pisum sativum) in adult pigs. Eight adult pigs (132 ± 6.9 kg) with a ileal T-cannula were fed for seven days with a synthetic diet containing one of the field peas as the only protein source in an incomplete Latin Square design (n = 6 pigs/treatment). Ileal digesta were collected for the last three days of each period. The in vitro degree of starch hydrolysis of all pea samples was determined after a sequential hydrolysis carried out by pepsin (120 min) and a mixture of pancreatin, isomaltase and maltase (240 min). A high linear relationship was observed between the in vitro and in vivo starch digestion (Y = 1.12X − 0.052; adjusted r2 = 0.76, P<0.01, residual standard deviation = 0.51). The CAID of starch was negatively correlated with starch content (r = −0.71, P<0.05), but positively correlated with CAID of dry matter (r = 0.48, P<0.001). In conclusion, the in vitro technique used in this study as well as the pea composition can be used to predict in vivo ileal starch digestibility of peas in adult pigs.