Dietary amylose and amylopectin ratio and resistant starch content affects plasma glucose, lactic acid, hormone levels and protein synthesis in splanchnic tissues

Abstract

Experiments were conducted to determine the effects of feeding different starch sources on piglets. Four diets were formulated with maize, brown rice, sticky rice and Hi-Maize 1043 as starch sources, with resistant starch (RS) contents of 2.3%, 0.9%, 0.0%, 20.6%, and amylose and amylopectin ratio of 0.23%, 0.21%, 0.18%, 0.06% respectively. Fifty-six pigs weaned at 28 days of age were randomly assigned to one of the four diets. In Exp. 1, six piglets in each group were fitted with an indwelling jugular catheter. After 25 days of feeding trial, venous blood samples were obtained at time zero and every 1 h for 4 h. In Exp. 2, the remaining piglets were used to determine the effects of different starch sources on the fractional synthesis rate (FSR). The results indicated that feeding the Hi-Maize 1043 diet decreased (p < 0.05) plasma contents of glucose, insulin, lactic acid and T(3), while sticky rice increased plasma contents of glucose and insulin. The insulin contents in piglets fed the sticky rice diet was 69.2 microIU/ml at 1 h post-feeding which was highest among the starch diets. The FSR in the pancreas, spleen, duodenum, jejunum, ileum and colon in the corn group were much higher (p < 0.05) than that in the sticky rice group. These results suggest that RS is potentially beneficial for improving insulin sensitivity in young pigs and that the ratio of amylose and amylopectin have significantly effects on the FSR in splanchnic tissues in weaned piglets. Another finding of this study indicated maize with a ratio of amylose and amylopectin of 0.23 has the best starch sources for pig production.