日粮添加不同来源脂肪酸对奶牛脂质代谢及激素水平的影响

Effect of Supplementing Different Sources of Fatty Acids on Lipid Metabolism and Endocrine Response of Mid-Lactating Holstein Cows

研究日粮中添加不同来源脂肪酸对泌乳中期奶牛脂质代谢及激素水平的影响。选择36头泌乳中期中国荷斯坦奶牛,采用随机区组设计,按照产奶量、胎次及泌乳日龄将奶牛分为对照组、中短链脂肪酸(SMC-FA)组和长链脂肪酸(LCFA)组。对照组饲喂基础日粮,SMCFA组和LCFA组分别在基础日粮的基础上添加400g/d SMCFA和400 g/d LCFA,正试期为56 d。结果显示,LCFA组奶牛血清中非酯化脂肪酸的含量显著高于对照组(P<0.05),其余组间差异不显著(P>0.05);血清中胆固醇的含量在SMCFA和LCFA组均有增加的趋势,但未达到显著水平(P>0.05);胰岛素样生长因子的含量在SMCFA组显著降低(P<0.05),其余组间没有显著差异(P>0.05);添加LCFA或SMCFA对奶牛血清中三酰甘油、高密度脂蛋白、低密度脂蛋白、生长激素及胰岛素均没有显著影响(P>0.05)。结果表明日粮中添加SMCFA对泌乳中期奶牛脂质代谢有一定的负面影响。

To investigate the effect of supplementing different sources of fatty acids on lipid metabolism and endocrine response of mid-lactating Holstein cows, thirty -six Chinese Holstein cows were divided into three groups according to random block design with milk yield, DIM and parity. The animals were fed with diets contained 0 g/d, 400 g/d short and medium chain fatty acids（SMCFA） and 400 g/d long chain fatty acids（LCFA） for groupl （con- trol）, group2 and group3, respectively. The experiment lasted 56 days. Results showed that ： 1 ） the non -esterified fatty acids concentration in serum was higher in group 3 than in group 2 ;2）supplementation of SMCFA and LCFA tended to increase the concentration of cholesterol ;3 ） the concentration of serum insulin - like growth factor was declined in group 2,while no difference was detected between other groups ;4）there were no differences among the groups in the concentrations of serum triglyceride, high - density lipoprotein, low - density lipoprotein, growth hormone and insulin. It was concluded that supplemental SMCFA may have some negative function on lipid metabolism in dairy cows.