Effects of abomasal starch infusion on body condition, nutrient digestibility, mRNA abundance of hepatic and subcutaneous adipose in lactating dairy cows

An experiment was performed to assess the effects of starch infusion on the nutrient digestibility, mRNA abundance of gluconeogenesis and lipid metabolism in mid-lactating cows. Four multiparous Holstein cows fitted with permanent ruminal cannulas were arranged into a complete 4×4 Latin squares, abomasally infused starch solution at 0, 800, 1600, and 2400 g/d for 15 days. Compared with control, starch digestibility was improved by starch infusion of 1600 g/d (P<0.05). No difference was detected in body weight and BCS (P>0.05). Liver PEPCK-C mRNA abundance in 1600 g/d starch infusion was significantly (P<0.05) higher than control and 2400 g/d starch group. GLUT-4mRNA (P=0.12) tended to increase quadratically; the maximum abundance was in 800 g/d infusion group; however, the minimum PPAR-gamma abundance was in 1600 g/d starch infusion group (P=0.10). Overall, abomasally supplementation of different degrees of starch to mid-lactating cows could certainly be carried down to the intestine directly to ameliorate energy supplies, and therefore, transport to the subcutaneous adipose stored as lipid.