摘要
选用4头安装永久瘤胃瘘管和十二指肠瘘管的泌乳奶牛(体重为483 kg±21 kg,泌乳日龄为175 d±6 d),研究4种日粮,分别为30∶70CW(粗料由羊草组成)、30∶70CCA(粗料为玉米青贮+苜蓿+羊草混合型)、50∶50CCA、65∶35CCA日粮对泌乳奶牛瘤胃内pH、NH3 N浓度、VFA的动态变化及奶牛生产性能的影响。试验采用4×4拉丁方设计,每期23 d。结果表明,精粗比为65∶35CCA日粮条件下奶牛瘤胃内pH显著低于其它组(P<0 01), 65∶35CCA及50∶50CCA日粮组瘤胃内NH3 N浓度显著高于精粗比30∶70 日粮组(P<0 01),瘤胃内乙酸浓度随精料比例的提高而降低(P= 0 10),丙酸浓度、丁酸浓度及乙酸/丙酸比例差异均为极显著(P<0 01);在不同精粗比日粮条件下,乳脂率差异显著(P<0 01),以30∶70CCA组为最高;产奶量、乳蛋白率及非乳脂固形物含量均呈极显著差异(P<0 01),均以高精料组65∶35CCA组为最高。
Effects of forage to concentrate ratio on dynamic changes of pH, NH_3-N concentration, VFA pattern of rumen fermentation were studied. Four Holstein cows with rumenal cannula in mid lactation were used in 4×4 Latin square design experiment with 23 d each period. Dietary forage to concentrate ratios were 30∶70CW(forage was composed of Chinese wildrye,CW), 30∶70CCA(forage was composed of corn silage, Chinese wildrye and alfalfa, blend), 50∶50CCA and 65∶35CCA, respectively. The results indicated there were significant changes in pH value and ammonia N concentration (P<0.05), acetate tended to be higher in 30∶70CW (P=0.10), acetate to propionate ratio and butyrate concentration in the rumen were significantly different (P<0.01). Milk fat percentages were significant different (P<0.01), highest in 30∶70(blend); Milk yield, protein percentages, and solid non-fat (SNF) contents were significantly different (P<0.01).
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
2005年第6期569-573,共5页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
基金
"十五"国家重大科技专项(2002BA518A02)
