泌乳奶牛采食、反刍、逍遥行为和日粮纤维性物质表观消化率对比分析

为了对比不同泌乳阶段奶牛的采食、反刍、逍遥行为和日粮营养物质表观消化率,选择体重、胎次相近的8头健康荷斯坦泌乳奶牛,其中,4头处于泌乳盛期(泌乳盛期组),4头处于泌乳后期(泌乳后期组),进行了采食行为观察和消化试验,两组奶牛预饲期20 d,正试期15 d。结果表明,泌乳盛期组奶牛每天的干物质采食量为21.2 kg,极显著高于泌乳后期组的14.1 kg(P<0.01),但两组奶牛的采食时间和采食次数无显著差异(P>0.05),泌乳盛期组奶牛每千克DM采食的时间也极显著低于泌乳后期组奶牛(P<0.01);一昼夜总反刍时间泌乳盛期组奶牛极显著低于泌乳后期组(P<0.01),每千克DMI需反刍时间泌乳盛期组奶牛极显著低于泌乳后期组(P<0.01)。泌乳盛期组奶牛躺卧、走动和站立时间与泌乳后期组奶牛相比无显著差异(P>0.05)。泌乳盛期组奶牛日粮中NDF和ADF的表观消化率极显著低于泌乳后期组(P<0.01),两组奶牛NDF的表观消化率分别为55.8%、67.8%,ADF的表观消化率分别为44.2%、60.7%。

Comparison of Feeding,Rumination,Idleness Behavior and Apparent Digestibility of Dietary Fibrous Nutrients in Dairy Cows at Different Lactation Stages

The objectives of this study were to characterize the feeding,rumination and idleness behavior and nutrient apparent digestibility at different lactation stages in dairy cows.Eight lactating cows with similar body weight and parity were selected in this experiment.Four cows were in the high lactation stage and four cows were in the late lactation stage.All cows were fed for 20 days in preliminary trial period and 15 days in the formal trial period.The results showed that the daily intake of dairy cows in the high lactation period was 21.2 kg DM,which was significantly higher than that in the late lactation period (14.1 kg DM,P<0.01).While there was no significant difference in the intake time and frequency between the two groups (P>0.05),the intake time per kilogram of DM of dairy cows in the high lactation period was significantly lower than that in the late lactation period (P<0.01).The total daily rumination time was significantly lower in high lactation group than in late lactation group (P<0.01),and the rumination time per kilogram of DMI was significantly lower in high lactation group than in late lactation group (P<0.01).There was no significant difference in lying,walking and standing duration between the two groups (P>0.05).The apparent digestibility of dietary NDF and ADF of dairy cows in high lactation period was significantly lower than in the late lactation period (P<0.01).The apparent digestibility of NDF for the dairy cows in high and late lactation period was 55.8% and 67.8%,respectively,and the apparent digestibility of ADF for the dairy cows in high and late lactation period was 44.2% and 60.7%,respectively.