真胃灌注不同水平淀粉对泌乳奶牛生产性能和代谢参数的影响

Effects of Graded Abomasal Starch Infusion on Performanc and Metabolism Parameters in Lactating Dairy Cows

试验旨在研究灌注不同水平淀粉对奶牛泌乳性能、血液代谢和葡萄糖耐受能力的影响。选用带有永久性瘤胃瘘管的荷斯坦二胎奶牛4头,采用4×4拉丁方设计,分别真胃灌注0、800、1 600、2 400 g/d淀粉,试验期为16 d。结果表明:随着真胃灌注淀粉量的增加,奶牛的消化能(P=0.08)和泌乳净能摄入量(P=0.05)呈线性增加或有线性增加的趋势,血浆葡萄糖含量呈二次曲线下降(P=0.08),1 600 g/d灌注量时血浆葡萄糖含量(60.50 mg/d L)最低。血浆非酯化脂肪酸含量的降低(P=0.04)表明体脂动员的减少。真胃灌注淀粉的奶牛对葡萄糖有更好的耐受能力,淀粉灌注组的葡萄糖峰浓度(P=0.12)呈二次曲线上升,800 g/d灌注组的胰岛素清除速率显著高于2 400 g/d灌注组(P=0.02)。以上结果说明,额外的能量供应没有改善奶牛的泌乳性能,但是非酯化脂肪酸浓度的降低和葡萄糖耐受力的增加都表明了能量储存的可能性。

An experiment was performed to assess the effects of graded starch infusion on lactation performance, plasma metabolism and glucose tolerance test in lactating cows. Four multiparous Holstein cows fitted with permanent ruminal cannulas were arranged into a complete 4 × 4 Latin squares, infused starch abomasally of 0, 800, 1 600, 2 400 g/d for 16 days. With the increase of starch infusion, DE intake （P=0.08） and NEL intake （P=0.05） was or tended to increase linearly. Plasma glucose content tended to decrease quadratically （P=0.08） after starch was infused for 16 days, the lowest glucose （60.50 mg/dL） occurred in 1 600 g/d starch. The decrease in plasma NEFA concentration （P=0.04） indicated decline in mobilization of adipose reserves and stimulation of lipid anabolism. Cows with starch infusion abomasally can tolerate glucose better. The glucose peak concentration of starch infusion groups were quadratic higher （P=-0.12）, insulin clearance rate in 800 g/d infusion group was the highest, significantly higher than that of group 2 400 g/d（P= 0.02）. Results indicated that the extry energy supply had no effect on lactation performance, however, decrease in NEFA concentrations and increase in glucose tolerance were indicators of tissue energy retention in lactating cows.