Effects of feeding birdsfoot trefoil hay on neutral detergent fiber digestion, nitrogen utilization efficiency, and lactational performance by dairy cows
Effects of feeding birdsfoot trefoil hay on neutral detergent fiber digestion, nitrogen utilization efficiency, and lactational performance by dairy cows
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DOI：
10.3168/jds.2015-9348
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发表时间：
2015-11-01
影响因子：
3.5
通讯作者：
MacAdam, J. W.
中科院分区：
文献类型：
--
作者：
Christensen, R. G.;Yang, S. Y.;MacAdam, J. W.
本试验旨在研究雀蹄草干草型日粮与苜蓿干草型日粮对泌乳中期奶牛氮利用率、瘤胃发酵和泌乳性能的影响。9头经产泌乳荷斯坦奶牛（产奶131 +/- 22.6 d），其中3头经瘤胃瘘管，采用3 × 3拉丁方重复设计饲喂3种试验日粮，3个阶段为14 d适应期和7 d数据和样品收集期。在方格内，将奶牛随机分配至以下日粮：苜蓿干草基日粮（AHT）、苜蓿和鸟足三叶草干草基日粮（ABT）和鸟足三叶草干草基日粮（BT）。干物质和粗蛋白质的摄入量相似的治疗，而ABT和BT饮食导致减少纤维摄入量相比，AHT。与ART和ABT相比，饲喂BT倾向于增加中性洗涤剂纤维消化率。奶牛食用ABT或BT日粮，产奶量有增加的趋势。牛奶真蛋白质浓度和产量更大的奶牛消费ABT相对于那些喂养的艺术。总挥发性脂肪酸的浓度往往增加的奶牛喂养BT相比，那些喂养的艺术和ABT。在全混合日粮中饲喂三叶草会导致乙酸盐比例下降，但会增加丙酸盐比例，从而导致乙酸盐/丙酸盐比例下降。而氨-N的浓度是相似的治疗，牛提供BT表现出更大的微生物蛋白质产量相对于那些喂养ART和ABT。饲喂三叶草日粮的奶牛比饲喂AHT的奶牛分泌更多的乳氮，从而提高了奶牛对乳氮的利用效率。由于饲喂鸟足三叶草干草的积极作用归因于增强中性洗涤纤维消化，因此，它可以取代苜蓿干草在高饲草奶牛日粮中，同时提高氮利用效率和保持泌乳性能相比，苜蓿干草。
This experiment was conducted to determine effects of feeding birdsfoot trefoil hay-based diets in comparison with an alfalfa hay-based diet on N utilization efficiency, ruminal fermentation, and lactational performance by mid-lactation dairy cows. Nine multiparous lactating Holstein cows (131 +/- 22.6 d in milk), 3 of which were rumen fistulated, were fed 3 experimental diets in a replicated 3 x 3 Latin square design with 3 periods of 14 d of adaptation and 7 d of data and sample collection. Within squares, cows were randomly assigned to diets as follows: alfalfa hay-based diet (AHT), alfalfa and birdsfoot trefoil hay-based diet (ABT), and birdsfoot trefoil hay-based diet (BT). Intakes of dry matter and crude protein were similar across treatments, whereas ABT and BT diets resulted in decreased fiber intake compared with AHT. Feeding BT tended to increase neutral detergent fiber digestibility compared with ART and ABT. Milk yield tended to increase for cows consuming ABT or BT diets. Milk true protein concentration and yield were greater for cows consuming ABT relative to those fed ART. Concentration of total volatile fatty acids tended to increase by cows fed BT compared with those fed ART and ABT. Feeding birdsfoot trefoil hay in a total mixed ration resulted in a tendency to decrease acetate proportion, but it tended to increase propionate proportion, leading to a tendency to decrease acetate-to-propionate ratio. Whereas concentration of ammonia-N was similar across treatments, cows offered BT exhibited greater microbial protein yield relative to those fed ART and ABT. Cows offered birdsfoot trefoil hay diets secreted more milk N than AHT, resulting in improved N utilization efficiency for milk N. The positive effects due to feeding birdsfoot trefoil hay were attributed to enhanced neutral detergent fiber digestion, and thus it could replace alfalfa hay in high-forage dairy diets while improving N utilization efficiencies and maintaining lactational performance compared with alfalfa hay.