CAJ | 학술논문

本试验旨在研究热应激条件下不同代谢葡萄糖水平的饲粮对奶牛生产性能和生理指标的影响。选择胎次、泌乳天数、产奶量、体重相近的健康泌乳荷斯坦奶牛16头，随机分为4组，每组4头，试验1～4组分别饲喂代谢葡萄糖水平为121．31、109．70、99．27和89．55 g / kg 的试验饲粮。试验共计42 d，其中预试期14 d，正试期28 d。结果表明，直肠温度和呼吸频率全期平均值分别以试验2组和试验3组最低，显著低于其他各组（ P＜0．05）。各时间点，试验3组采食量和产奶量都高于其他各组，全期平均值显著高于其他各组（ P＜0．05）。乳脂率、乳蛋白率和乳干物质率的全期平均值均为试验3组显著高于其他各组（P＜0．05），乳糖率则为试验1组显著高于其他各组（P＜0．05）。以上结果表明，荷斯坦奶牛饲粮代谢葡萄糖水平的改变可以调节热应激奶牛的生产性能和生理指标；本试验条件下，饲粮代谢葡萄糖水平为99．27 g / kg 时效果最好，提高了奶牛的产奶量和采食量。
본시험지재연구열응격조건하불동대사포도당수평적사량대내우생산성능화생리지표적영향。선택태차、비유천수、산내량、체중상근적건강비유하사탄내우16두，수궤분위4조，매조4두，시험1～4조분별사위대사포도당수평위121．31、109．70、99．27화89．55 g / kg 적시험사량。시험공계42 d，기중예시기14 d，정시기28 d。결과표명，직장온도화호흡빈솔전기평균치분별이시험2조화시험3조최저，현저저우기타각조（ P＜0．05）。각시간점，시험3조채식량화산내량도고우기타각조，전기평균치현저고우기타각조（ P＜0．05）。유지솔、유단백솔화유간물질솔적전기평균치균위시험3조현저고우기타각조（P＜0．05），유당솔칙위시험1조현저고우기타각조（P＜0．05）。이상결과표명，하사탄내우사량대사포도당수평적개변가이조절열응격내우적생산성능화생리지표；본시험조건하，사량대사포도당수평위99．27 g / kg 시효과최호，제고료내우적산내량화채식량。
This experiment was conducted to study the effects of dietary metabolizable glucose(MG)level on performance and physiological indices of dairy cows under heat stress. Sixteen healthy Holstein cows with simi-lar parity,days in lactation,milk yield and body weight were randomly divided into four groups with four cows in each group. Cows in test groups 1 to 4 were fed experimental diets containing 121.31,109.70,99.27 and 89.55 g / kg MG,respectively. The experiment lasted for 42 days,including a 14-day pre-experiment peri-od and a 28-day experiment period. The results showed as follows:rectal temperature and respiratory rate of dairy cows(the means during whole period)reached the lowest in test groups 2 and 3,respectively,and were both significantly lower than those in the other groups(P<0.05). At different time point,feed intake and milk yield of dairy cows in test group 3 were all higher than those of the other groups,and the means during whole period were significantly higher than those in the other groups( P <0.05). Milk fat,milk protein,milk dry matter milk percentages(the means during whole period)in test group 3 were significantly higher than those in the other groups(P<0.05),and lactose percentage in test group 1 was significantly higher than that in the oth-er groups(P<0.05). In conclusion,the change of dietary MG level can affect performance and physiological indices of dairy cows under heat stress;under conditions in the present study,the optimal level is 99.27 g / kg, which can improve feed intake and milk yield.