Effects of different amylose/amylopectin ratio combination diets in the early and late stages on growth performance and dynamic changes of glycolipid metabolism of growing geese.

This study evaluated the effects of varying dietary amylose/amylopectin ratios (AR) during starter (1-28 d) and grower (29-63 d) phases on growth performance, nutrient metabolism, and related molecular mechanisms in Jiangnan White geese. A total of 330 one-day-old male goslings were allocated to six groups in a 2 × 3 factorial design: two starter AR diets (0.34 or 0.46) and three grower AR diets (0.34, 0.46, or 0.58). The results showed that serum glucose increased post-prandially across all groups, with an increase at 120 min in the AR0.34/0.34 group (P < 0.05). Triglycerides (TG) decreased post-feeding in AR0.34/0.34, AR0.34/0.46, and AR0.46/0.46 groups (P < 0.05), while total cholesterol (TCHO) and high-density lipoprotein (HDL) increased in AR0.46/0.46 and AR0.46/0.58 groups (P < 0.05). Fasting insulin levels were elevated in AR0.34/0.46, AR0.34/0.58, and AR0.46/0.34 groups, whereas glucagon increased in AR0.46/0.46 and AR0.46/0.58 groups (P < 0.05). Liver glycogen content increased post-feeding in most groups, except AR0.34/0.34 and AR0.46/0.46. Pancreatic α-amylase activity decreased in AR0.46/0.58 at 120 min post-feeding, while jejunal α-amylase fluctuated temporally (P < 0.05). Gene expression analysis revealed dynamic regulation of glucose-6-phosphatase catalytic subunit 1 (G-6-PC-1), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS) postprandially, with higher fasting G-6-PC-1 and ACC expression in AR0.34/0.34 (P < 0.05). Results indicate that higher AR in the grower phase enhances postprandial glucose and lipid mobilization, modulates hormonal responses, and influences glycogen dynamics and starch-digesting enzyme activity. These findings suggest that amylose/amylopectin ratios differentially regulate glucose and lipid metabolism in geese, with implications for optimizing dietary formulations to improve nutrient utilization during distinct growth stages.