甘蔗渣作为粗饲料对奶牛生产性能、养分消化和采食行为的影响

文章旨在评价甘蔗渣作为粗饲料对泌乳奶牛采食量、消化率、采食行为、泌乳量、乳成分及微生物蛋白合成等方面的影响。试验选择10头初始体重为(450±25.6)kg,泌乳天数为(143.7±30.7)d的杂交奶牛为研究对象,试验采用5×5拉丁方设计,饲喂周期为5个21 d(1~14 d为适应期,15~21 d为数据采集期)。试验日粮分为对照日粮、45%、50%、55%和60%甘蔗渣日粮。结果:对照组与45%和50%甘蔗渣组干物质、有机物、总可消化养分摄入量、干物质和有机物消化率无显著差异(P>0.05),而55%和60%甘蔗渣组干物质和有机物消化率最低(P<0.05)。甘蔗渣组与对照组对中性洗涤纤维摄入量和表观消化率的影响具有显著差异(P<0.05),其中45%甘蔗渣组奶牛的非纤维碳水化合物摄入量和消化率与对照组相似(P>0.05)。日粮甘蔗渣添加水平对营养物质的摄入量和消化率呈显著线性降低(P<0.05)。60%甘蔗渣组较对照组显著降低了奶牛反刍时间,显著提高空闲时间(P<0.05)。奶牛的反刍时间、反刍和采食效率随日粮甘蔗渣添加水平的升高显著线性降低(P<0.05),而空闲时间随饲粮中甘蔗渣含量的增加线性增加(P<0.05)。结论:日粮添加甘蔗渣降低了奶牛日产奶量,但添加水平为45%~50%时可以使奶牛泌乳量达到12 kg/d。

Effects of bagasse as roughage on performance,nutrient digestion and feeding behavior of dairy cattle

The aim of this study was to evaluate the effects of bagasse as roughage on feed intake,digestibility,feeding behavior,milk production,milk composition and microbial protein synthesis of lactating dairy cows.Ten hybrid cows with initial weight of(450±25.6)kg and lactation days of(143.7±30.7)d were selected as research objects.The 5×5 Latin square design was adopted in the experiment,and the feeding cycle was 521-d(1~14 d for the adaptation period and 15~21 d for the data collection period).The experimental diets were divided into control diets,45,50,55 and 60%bagasse diets.Results:there were no significant difference in dry matter,organic matter,total digestible nutrient intake,dry matter and organic matter digestibility between control group and 45 and 50%bagasse group(P>0.05),while dry matter and organic matter digestibility between 55 and 60%bagasse group was the lowest(P<0.05).The influence of bagasse group and control group on neutral washing fiber intake and apparent digestibility was significantly different(P<0.05),among which the non-fiber carbohydrate intake and digestibility of 45%bagasse group was similar to that of control group(P>0.05).There was a significant linear decrease in nutrient intake and digestibility(P<0.05).Compared with control group,60%bagasse group significantly reduced ruminant time and significantly increased idle time(P<0.05).The ruminant time,ruminant and feeding efficiency of dairy cows decreased linearly with the increase of dietary bagasse content(P<0.05),while the idle time increased linearly with the increase of dietary bagasse content(P<0.05).In conclusion,the addition of bagasse reduced the daily milk yield of dairy cows,but the lactation of dairy cows could reach 12 kg/d at the addition level of 45-50%bagasse.