摘要
In a replicated 3 × 3 Latin square experiment, six heifers (443 ± 6.1 kg) fed a 61% barley grain:39% alfalfa silage diet (DM basis) were given intraruminal doses of powdered Yucca schidigera (YS). Doses of 0 (control), 20, or 60 g/d were given at 0800 daily. Ruminal content was sampled 0, 2, 4, and 6 h after dosing. Acidity, concentrations of reducing sugars, free amino acids, and peptides in the rumen were not affected (P > .05) by YS. Relative to control, ruminal ammonia concentration was reduced (P < .05) 2 h after YS dosing. Ruminal propionate concentration was increased (P < .05) by YS. Protozoal numbers in the rumen were lower (P < .05) with YS than without. Yucca did not affect (P > .05) rate or extent of in situ DM degradability. Fibrolytic, amylolytic, and proteolytic activities in ruminal contents were similar among treatments (P > .05). Dry matter intake, apparent digestibilities of DM, NDF, and CP, nitrogen balance, and microbial protein synthesis in the rumen were not affected (P > .05) by treatment. The effect of YS on ruminal ammonia concentration likely resulted from a decreased concentration of protozoa and, presumably, from ammonia binding by YS. The effect on ruminal propionate was probably a result of a selective inhibitory effect of YS on rumen microbial species.
摘要译文
在重复的3×3拉丁方实验中，给6头小母牛（443±6.1公斤）饲喂61％大麦籽粒：39％苜蓿青贮饲料（DM基础），进行了intracinalinal剂量的丝兰灰粉蚧（YS）。0（对照），20或60g / d的剂量在每日0800给予。给药后0,2,4和6小时取瘤胃内容物。酸度，还原糖浓度，游离氨基酸，并且YS对瘤胃中的肽没有影响（P 0.05）。相对于对照，YS给药后2小时瘤胃氨浓度降低（P 0.05）。YS增加瘤胃丙酸盐浓度（P 0.05）。 YS的原生动物数量比没有的低（P 0.05）。丝兰没有影响（P。05）原位DM降解率的速率或程度。瘤胃内容物中的纤维溶解，淀粉分解和蛋白水解活性在处理之间相似（P .05）。干物质摄入量，DM，NDF和CP的表观消化率，氮平衡和微生物蛋白质合成在瘤胃中不受影响（P 0.05）。YS对瘤胃氨浓度的影响可能是由于原生动物浓度降低以及可能由YS与氨的结合所致。对瘤胃丙酸盐的影响可能是YS对瘤胃微生物物种的选择性抑制作用的结果。
Alexander N. Hristov;Timothy A. McAllister;Fred H. Van Herk;K.-J. Cheng;C. Jamie Newbold;Peter R. Cheeke. Effect of Yucca schidigera on ruminal fermentation and nutrient digestion in heifers[J]. Journal of Animal Science, 1999,77(9): 2554–2563