Effect of Betaine on the Regulation of the Lipid Metabolism in Laying Hen

The experiment was conducted to investigate the effects of betaine on lipid metabolism of laying hens. 1 600 ISA brown laying hens of 20 weeks of age were alloted randomly into 4 groups each with 4 replicates of 100 layers, the layers were given a corn-soybean basal diet with 0,400,600 and 800 mg/kg betaine respectirely. Results indicated that supplementation of 600 mg/kg betaine significantly improved lay performance, and increased egg production 8.67 % ( P ＜ 0.04), decreased feed/egg ratio by 9.02 % ( P ＜ 0.03) compared with control, but there were no significant differences in egg weight and feed intake. It was found that supplementation of 600 mg/kg betaine decreased weights of abdominal fat by 19.63 % (P ＜ 0.02)and 22.35%(P＜0.02), and decreased liver fat by 8.52%(P＜0.05) and 16.28%(P＜0.01) in 50 and 70 weeks of age respectively. Compared with control, in 70 weeks of age, activity of LPL in abdominal fat was decreased by 44.83% (P ＜ 0.01), HSL activity in abdominal fat increased by 50.0% (P ＜ 0.02), and MDH activity in liver was decreased by 28.74% (P＜0.03). Supplementation of 600 betaine increased levels of T3 by 43.29%( P ＜ 0.05) and 43.95 % ( P ＜ 0.02) in 50 and 70 weeks of age respectively, and increased the concentration of cAMP in hypothalamus and anterior pituitary by 59.89% ( P ＜ 0.01) and 24.03% ( P ＜ 0.05) respectively in 70 weeks of age. The concentration of serum gluclose (GLU) , FFA and phospholipid were increased by 44.50% (P＜0.03), 19.66%(P＜0.03) and 71.66% (P＜0.01) in 50 weeks of age. The concentration of serum gluclose (GLU), FFA and phospholipid were increased by 16.25% ( P ＜ 0.05), 22.51% ( P ＜ 0.02) and 22.42%(P＜0.01) in 70 weeks of age.