大麦粉替代不同比例玉米对奶牛生产性能的影响

选取泌乳天数、体重、产奶量相近的荷斯坦高产泌乳牛340头,随机分为试验组和对照组两组,每组170头。试验时间共28d,对照组全期饲喂全混合配方日粮(TMR),试验组分四阶段进行,每阶段7d,分别饲喂以10%、20%、30%、40%粉碎大麦粉替代玉米的TMR。结果发现:随着大麦粉替代玉米比例的增加,试验组采食量呈现下降趋势,其中30%、40%替代期采食量极显著低于对照组(P<0.01);与对照组相比,大麦粉替代不同比例玉米对奶牛产奶量影响不一致,20%、30%替代期产奶量增加0.4、0.3kg/d,10%、40%替代期分别下降0.6、0.7kg/d,但差异均不显著(P>0.05);试验组10%、40%替代期乳脂率极显著高于对照组(P<0.01),而20%、30%替代期乳脂率与对照组差异不显著(P>0.05);试验组10%替代期乳蛋白率极显著高于对照组(P<0.01),而30%、40%替代期显著低于对照组(P<0.05),20%替代期乳蛋白率较对照组下降0.012个百分点,但差异不显著(P>0.05)。综上所述,饲粮中用大麦粉替代20%比例的玉米饲喂奶牛,在不影响采食量、乳脂率、乳蛋白率情况下可提升产奶量并降低饲养成本,从而提高经济效益,为最佳替代比例。

Effect of Barley Flour Replacing Different Ratios of Corn on theProduction Performance of Dairy Cows

The experiment intends to use barley flour in the diet to replace different proportions of corn to feed high-yielding dairy cows. Totally 340 Holstein high-yielding dairy cows with similar lactation days, body weight and milk yield were randomly divided into two groups, a test group and a control group, each with 170 heads. Each group consists of 4 phases. Each phase of the trial is 7 days. The control group was fed Total Mixed TMR diet for the whole period, and the test group was fed with crushed barley flour instead of 10%(Phase 1), 20%(Phase 2), 30%(Phase 3), and 40%(Phase 4) corn TMR formula diets in each phase.The amount of other feeds is the same as the control group. Results showed that compared with the control group, the feed intake of the test group showed a downward trend with the increase of the ratio of barley flour instead of corn,the feed intake at the replacement rate of 30% and 40% were significantly lower than those of the control group(P<0.01). Compared with the control group, the yield during the replacement rate of 20% and 30% of the test group increased by 0.4 kg and 0.3 kg, and the yield during the replacement period of 10% and 40% decreased by 0.6 and 0.7 kg respectively, but the difference was not significant(P>0.05). The milk fat of the test group was significantly higher than the control group at the replacement rate of 10%and 40%(P<0.01), while the milk fat at the replacement rate of 20% and 30% decreased by 0.014% and increased by 0.002% compared with the control group. The differences were not significant(P>0.05). The protein level of the test group with a replacement rate of 10% was significantly higher than that of the control group(P<0.01), while the replacement rates of 30% and 40%were significantly lower than those of the control group(P<0.05). When the replacement rate was 20%, the protein level dropped by 0.012 point compared with the control group, but the difference was not significant(P>0.05). In summary,without affecting feed intake, milk fat percentage and milk protein, feeding cows with barley flour instead of 20% corn in the diet can increase milk yield and reduce feeding costs,and improve economic efficiency, so it is the best replacement ratio.