共轭亚油酸钙对奶牛产奶量和品质的影响

Effect of Adding Ca-CLA on Milk Yield and Quality of Lactating Cows

为研究共轭亚油酸钙对奶牛乳脂肪的影响,选取16头泌乳中期的奶牛饲喂不同日粮,分为对照组(基础日粮)、共轭亚油酸钙低剂量组(基础日粮+50 g/(头.d))、中剂量组(基础日粮+100 g/(头.d))、高剂量组(基础日粮+200 g/(头.d)),试验共进行14 d,分析乳产量和乳成分。结果表明,日粮中添加共轭亚油酸钙对奶牛的乳产量、乳蛋白和乳糖没有影响,但极显著降低了乳脂肪含量(P<0.01)。检测脂肪酸组成发现奶牛的中、短链脂肪酸(C6、C10、C12、C16)含量显著降低(P<0.05),而长链脂肪酸(C18、C18:1)的含量显著增加(P<0.05);发现添加共轭亚油酸钙显著降低了各种脂肪酸的产量。研究结果显示,奶牛饲料中添加共轭亚油酸钙能够降低乳脂率,改变脂肪酸的组成。

To investigate the effect of Ca-CLA on the milk yield and quality,sixteen lactating cows were selected and allocated randomly into 4 treatments,basal diet plus 0 g/d（control）,50 g/d（Low group）,100 g/d（medium group）and 200 g/d（high group）Ca-CLA for two weeks,then the milk yield and composition was analyzed.The results showed that the milk yield,protein content and lactose content had no difference among the 4 treatments,while the milk fat content was significantly reduced in Ca-CLA supplement groups（P0.01）,compared with the control.The gas-liquid chromatography analysis of FAME revealed that the fatty acid composition of milk was markedly altered by Ca-CLA treatments.Adding Ca-CLA in the diet of lactating cows decreased significantly the composition of short and midium chain fatty acids（C6,C10,C12 and C16）,but increased significantly the concentration of stearic（C18：0）and linoleic（C18：2）acids in milk fat（P0.05）.The yield of total milk fatty acid reduced significantly in the Ca-CLA supplement treatments.This suggested that the supplement of Ca-CLA in dietary resulted in the reduction of milk fat rate and the alternation of milk fatty acid composition.