Influence of supplemental protein source and feeding frequency on rumen fermentation and performance in dairy cows.
Influence of supplemental protein source and feeding frequency on rumen fermentation and performance in dairy cows.
复制标题
补充蛋白质来源和饲喂频率对奶牛瘤胃发酵和生产性能的影响。
DOI：
10.3168/jds.s0022-0302(94)77073-9
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发表时间：
1994
影响因子：
3.5
通讯作者：
R. McQueen
中科院分区：
文献类型：
--
作者：
P. H. Robinson;R. McQueen
试验选用泌乳早期经产荷斯坦奶牛，饲喂47%（DM）苜蓿和梯牧草青贮饲料与53%大麦和玉米精料的基础混合日粮，每天2次，在1630和0600 h自由采食。两种对瘤胃蛋白水解的抗性不同的补充蛋白质源以9%的总蛋白质在1730和0700 h时每天两餐或在1730、2130、0200、0700和1200 h时每天五餐饲喂。该研究是4 × 4拉丁方设计，具有6个区组，每组4头奶牛，其中一个区组的奶牛安装有瘤胃套管。DM、OM、NDF和CP的摄入量不受治疗的影响。然而，每天补充五餐的奶牛往往在下午和上午喂食后更快地消耗混合日粮。产奶量及其蛋白质、脂肪和乳糖含量也不受处理的影响。平均瘤胃pH值较高，丙酸浓度较低，补充五餐的奶牛，但昼夜模式没有受到影响。丙酸和瘤胃氨态氮浓度较低的奶牛补充更耐蛋白质来源，但是，瘤胃VFA，以及可溶性和肽态氮浓度，没有受到影响的类型的补充蛋白质。结果不支持同步瘤胃释放的能量和N的整体奶牛生产的好处，而是支持以前的研究，可溶性蛋白质或肽N，或两者，可以作为一个池，提供N微生物生长的时候，氨N浓度很低的一天。
Multiparous Holstein cows in early lactation were fed a basal mixed ration of 47% (DM) alfalfa and timothy silage and 53% barley and corn concentrate twice daily for ad libitum intake at 1630 and 0600 h. Two supplemental protein sources that differed in their resistance to rumen proteolysis were fed at 9% of total DMI in either two meals per day at 1730 and 0700 h or five meals per day at 1730, 2130, 0200, 0700, and 1200 h. The study was a 4 x 4 Latin square design with six blocks of 4 cows in which one block of cows was fitted with rumen cannulas. Intakes of DM, OM, NDF, and CP were not influenced by treatments. However, cows supplemented with five meals a day tended to consume the mixed ration more rapidly after both the p.m. and a.m. feedings. Milk yield and its content of protein, fat, and lactose also were not influenced by treatments. Average rumen pH was higher, and propionate concentrations were lower, for cows supplemented with five meals, but diurnal patterns were not influenced. Propionate and rumen ammonia N concentrations were lower for cows supplemented with the more resistant protein source; however, rumen VFA, as well as soluble and peptide N concentrations, were not influenced by the type of supplemental protein. Results do not support benefits of synchronized rumen release of energy and N to overall cow production, but rather support previous research that soluble protein or peptide N, or both, may act as a pool to provide N for microbial growth at times of the day when ammonia N concentrations are very low.