微生物制剂对奶牛泌乳性能和乳品质的影响

Effects of Microbial Preparation on Milking Performance and Milk Quality

为考察微生物制剂对奶牛泌乳性能和乳品质的影响，选用胎次相同、试验前产奶天数基本相似的黑白花奶牛30头，每组15头，试验奶牛分别饲喂基础日粮（100％）、基础日粮99．5％＋微生物制剂0．5％的日粮，试验总计为90天。试验结果表明：试验组产奶量降幅相对对照组产奶量降幅减少7％；试验1期Ⅰ组比Ⅱ组头·日平均产奶量多1．16kg，差异显著（P〈0．05）；Ⅰ组试验1期的头·日平均产奶量也比试前增加了1．05kg，差异显著（P〈0．05）；而Ⅱ组试验1期平均前后无多大变化。试验2期30天（原来的Ⅰ组改为对照组，Ⅱ组改为试验组），试验2期头·日平均产奶量Ⅱ组比Ⅰ组多1．80kg，差异显著（P〈0．05）；纵向观察，Ⅰ组2期比1期下降1．17kg，Ⅱ组上升1．79kg，差异显著（P〈0．05）；而牛奶的成分除脂肪含量比对照组降低了2．34％外，乳密度、乳蛋白和全乳固体均高于对照组，分别增加了0．68％，10．18％，8．32％。结果表明：在奶牛日粮中添加微生物制剂，可增强奶牛抗热应激能力，改善其泌乳性能，并可提高牛乳中的乳密度、乳蛋白和全乳固体的比例，改善乳品质。

An experiment was conducted to study the effect of microbial preparation on milking performance and milk quality of cows. 30 Holstein cows having the same parity and similar milking duration prior to the test were selected and divided into 2 groups （ 15 heads per group）. During the 90 days test duration, one group was fed with basal diets （ 100% ） and the other with 99.5% basal diets in addition to 0.5% microbial preparation. Test results showed that milking performance decrease range of the test group decreased by 7%. There were 1.16 kg average milk yield （AMY） increased in Test group I more than in group Ⅱ during Phasel （P 〈 0.05）, and there were 1.05 kg average milk yield increased Ⅲ Test group I than before（P 〈0.05）. However, there were no changes of milking performance for Group Ⅱ during Phasel. Test 2 lasted for 30 days （during this test, the original group Ⅰ was regarded as the control group, and Group Ⅱ became the test group）. The results showed that AMY increased by 1.80kg in group Ⅱ more than the group Ⅰ （P 〈0.05）. Longitudinal observations showed that there was 1.17kg AMY decreased in Phase 2 compared to Phasel of group Ⅰ. However, there were 1. 79kg AMY increased in group Ⅱ （ P 〈 0.05 ）. Milk fat content of experiment group was lower than that of control group, and other ingredients such as milk density, protein and milk solids increased by 0.68% ,10.18% ,8. 32% more than that of control group respectively. The results showed that the dairy diet added with microbial preparation can strengthen cow＇s resistance to thermal stress, improve milking performance and milk quality, and increase density, proportion of protein and solids in milk.