摘要
用4头装有瘤胃瘘管和十二指肠双筒T形瘘管的黑白花公犊,研究颗粒精料对复胃消化代谢的影响。试验分粉状精料期(Ⅰ期)和颗粒精料期(Ⅱ期)。两期精料成分和量完全相同。粗料为青草,计量自由采食。试验结果表明:Ⅱ期与Ⅰ期相比,平均每kg体重青草采食量和干物质摄入量分别提高了42.97％(P<0.01)和57.35％(P<0.01);复胃纤维素、干物质和有机质消化率分别提高了7.94％(P<0.01),13.03％(P<0.01)和10.61％(P<0.05);瘤胃总挥发性脂肪酸浓度变化不明显(P>0.05)。但乙酸(C_2)百分比升高(P<0.01),丙酸(C_3)和戊酸(C_5)百分比降低(P<0.01),C_2/C_3升高(P<0.01),丁酸(C_4)变化不明显(P>0.05)。两期氨氮浓度无明显差异(P<0.05);瘤胃液平均pH由6.46升到6.67(P<0.01)。Ⅱ期十二指肠食糜流量增加了18.20％(P<0.01);食糜总蛋白、总徽生物蛋白、过瘤胃蛋白和非氨氮量分别提高了26.02％(P<0.01),38.28％(P<0.05),30.63％(P<0.01)和24.66(P<0.01).结果表明颗粒精料能促进犊牛粗饲料采食量,提高复胃纤维素消化率,改变瘤胃发酵类型,减少饲料蛋白在瘤胃的分解,增大进入十二指肠食糜量和非氨氮,从而提高了饲料蛋白和纤维素的利用效率。
Four Holstein-Friesian Bull Calves with ruminal and duodenal cunnulas were used to evaluate the effects of pelleted concentrate on ruminal digestion and metabolism. Feeding trial was divided into two periods. At the First one, calves were fed powder concontrate and second one, fed pelleted concontrate. The two forms of concentrate are in the same quility and ingredients. The amount of herbage fed to calves was libitum but scaled daily. The results were as follows: In the second period, the amount of herbage intake and its dry matter by calves per kilogram of B.W. increased by 42.97% (P<0.01) and 57.35% (P<0.01) respectivily; The digestibilities of cellulose, dry matter and organic matter in the complicated stomach increased by 7.94% (P<0.01), 13.03% (P<0.01) and 10.61% (P<0.05) respectively. The change of the total volatile fatty acid in the ruminai fluid was not significant, but the molar percentage of acetate increased (P<0.01), propionate and valerate declined (P<0.01); butyrate had no difference between two periods (P>0.05). The acetate to propionate ratio (A/P) increased (P<0.01). The ammonia concentration in rumen was not affected significantly (P>0.05). The mean pH of ruminai fluid was higher in the second period (P<0.01). The amount of digesta flow to duodenum increased by 18.20% (P<0.01). Total nitrogen, total microbial protein, non-ammoniac nitrogen and by pass protein in digesta increased by 26.20% (P<0.01), 38.28% (P<0.05), 21.83% (P<0.01) and 30.63% (P<0.01) respectively. When the pelleted concentrate was fed to the calves, because of its promoting roughage intake, changing the reminal fermentation pattern, decreasing decomposition in ruminai protein of concentrate and increasing the amount of digesta flow to duodenum, the utility efficiency of the feed was increased.
关键词
牛
公犊
消化
代谢
精料
颗粒饲料
fistula
calf
pelleted concentrate
cellulose digestibility
by pass protein
non—ammoniac nitrogen
