Heat production, eating behavior and milk yield of lactating cows fed two rations differing in roughage content and digestibility under heat load conditions
Heat production, eating behavior and milk yield of lactating cows fed two rations differing in roughage content and digestibility under heat load conditions
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热负荷条件下饲喂粗饲料含量和消化率不同的两种日粮的泌乳牛的产热量、采食行为和产奶量
DOI：
10.1016/j.livsci.2008.03.012
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
J. Miron
中科院分区：
文献类型：
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作者：
G. Adin;R. Solomon;E. Shoshani;I. Flamenbaum;M. Nikbachat;E. Yosef;A. Zenou;I. Halachmi;A. Shamay;A. Brosh;S. Mabjeesh;J. Miron
本研究旨在探讨饲喂粗饲料含量和干物质体外消化率不同的两种全混合日粮（TMR）对泌乳奶牛呼吸频率、体温、摄食行为和能量平衡的影响。测定了热负荷条件下奶牛代谢能摄入在产热（HP）和存留能（RE）之间的分配。将42头泌乳奶牛分为两个相似的亚组，每组21头，分别饲喂含有18%粗饲料中性洗涤纤维（NDF）的对照（CON）日粮或含有12%粗饲料NDF并使用大豆壳作为部分小麦青贮饲料添加剂的实验（EXP）TMR。CON和EXP TMR的体外干物质消化率分别为75.3%和78.6%（P<0.05）。EXP饮食降低了奶牛的直肠温度和呼吸频率，同时与CON饲喂的奶牛相比，每天的进餐次数增加了32.7%，并且这些进餐的持续时间更短，进食速度更快。与CON组相比，EXP组的总DM摄入量从19.6增加到21.5 kg/头/d，产奶量从32.3增加到34.6 kg，能量校正产奶量从30.9增加到32.2 kg。与CON组相比，饲喂EXP TMR的奶牛在牛奶和身体组织中的RE增加，但饮食对测量的HP没有影响，两组中保持相似（121与127 MJ/奶牛/d）。两个饮食组的MEI（MEI=RE+HP）和MEI用于RE生产的效率相似。
The objective of this study was to measure the effect of feeding two total mixed rations (TMRs), differing in their roughage content and in vitro dry matter digestibility, on the respiratory rate, body temperature, eating behavior and energy balance of lactating cows. The partitioning of metabolizable energy intake (MEI) between heat production (HP) and retained energy (RE) of cows held under heat load conditions was measured. Forty-two lactating cows were divided into two similar sub-groups, each of 21 animals, and were fed either a control (CON) ration containing 18% roughage neutral detergent fiber (NDF) or an experimental (EXP) TMR that contained 12% roughage NDF and used soy hulls as partial wheat silage replacer. The in vitro DM digestibility of the CON and EXP TMRs was 75.3 and 78.6%, respectively (P<0.05). The EXP diet reduced rectal temperature and respiratory rate of the cows while increasing their number of meals per day by 32.7% as compared with the CON fed cows, and these meals were shorter in duration and were eaten faster. The EXP diet increased total DM intake from 19.6 to 21.5 kg/cow/d, milk yield from 32.3 to 34.6 kg, and yield of energy corrected milk from 30.9 to 32.2 kg, as compared with the CON group. Cows fed the EXP TMR had increased RE in milk and body tissue, as compared with the CON group, but the diets had no effect on the measured HP that was maintained similar (121 vs. 127 MJ/cow/d) in the two groups. The measured MEI (MEI=RE+HP) and the efficiency of MEI utilization for RE production, were similar in the two dietary groups.