摘要
In a 2 × 2 factorial design, 24 newborn, crossbred (Bos indicus × Bos taurus) calves were distributed in 4 equal groups involving dietary treatments of prestarter diets with (FM) or without fish meal (NFM) in a faunated (F) or ciliate-free (D) ruminal environment to study the ruminal fermentative development in pre-and postweaning periods. Defaunation was achieved by rearing calves in isolation and its effect was studied after first appearance of ciliate protozoa (observed after 8 wk of age) in the faunated animals. Calves were fed colostrum for 24 h and whole milk until weaning at 8 wk of age. Ruminal content samples were collected on d 4, 1 wk, weekly to 8 wk, and then biweekly at 9, 11, and 13 wk of age. The samples were analyzed for fermentation products [pH, total volatile fatty acids (VFA) and ammonia N] and enzyme [carboxymethyl (CM) cellulase, xylanase, β-glucosidase, α-amylase, β-galactosidase, proteases, and urease] activities. Weekly feed intake increased with age, but was similar in both groups. Ruminal pH declined steadily during 0 to 4 wk of age and then stabilized. The total VFA concentration increased with the age. The ammonia N (mg/dL) concentration increased from 14.9 on d 4 to 32.4 at 4 wk, decreased to 17.6 at 8 wk, and then steadied during the postweaning period. Samples collected on d 4 had no fibrolytic activity. Xylanase (U/dL) appeared first (1 wk) followed by β-glucosidase (U/dL) and CM cellulase (U/dL), which increased steadily from a low of 4.69, 0.08, and 2.95 to 31.8 (6 wk), 5.92 (7 wk), and 19.8 (8 wk), respectively, and the concentrations showed nonsignificant alterations during postweaning periods. The concentration of α-amylase (U/dL) increased from 34.3 on d 4 to 87.2 at 8 wk, and then decreased to 56.6 (13 wk). β-Galactosidase increased up to 6 wk then decreased to trace level (0.20 U/dL) at 13 wk of age. The concentrations of proteases and urease reached a steady state after 1 wk of age. The effect of diet type on ruminal fermentation products and enzyme parameters was nonsignificant. However, a steady and proportional alteration in both parameters in response to dry feed intake with the advancement of age was seen in all calves. Defaunation increased total VFA (97.3 vs. 75.8 mM/L) and α-amylase activity (80.3 vs. 61.4 U/dL) and decreased ammonia N (16.4 vs. 21.1 mg/dL), whereas the effect on other parameters was nonsignificant. Ruminal fermentative changes responded to dry feed intake, but did not differ in response to animal protein in prestarter diet.
摘要译文
在2×2因子设计中，24个新生儿，（FM）或不含鱼粉（NFM）的预先饲喂日粮（F）或无环礁（D）瘤胃环境中研究瘤胃发酵前期和后期的发育。通过隔离饲养犊牛来实现失败，并且在栉孔扇贝原生动物（在8周龄后观察）出现后，研究其效果。犊牛喂养初乳24小时，全脂牛奶，直到8周龄断奶。在第4周，第1周，每周至第8周收集瘤胃内容物样品，然后在9,11和13周龄时双周收集瘤胃内容物样品。对样品进行发酵产物[pH，总挥发性脂肪酸（VFA）和氨氮]和酶[羧甲基（CM）纤维素酶，木聚糖酶，β-葡糖苷酶，α-淀粉酶，β-半乳糖苷酶，蛋白酶和脲酶]活性。每周采食量随着年龄增加而增加，但两组相似。 0至4周龄期间瘤胃pH稳定下降，然后趋于稳定。总的VFA浓度随着年龄而增加。氨氮（mg / dL）浓度从第4天的14.9上升到第4周的32.4，第8周时下降到17.6，然后在断奶期后稳定。在第4天收集的样品没有纤维蛋白溶解活性。木聚糖酶（U / dL）首先出现（1周），然后是β-葡萄糖苷酶（U / dL）和CM纤维素酶（U / dL），从4.69,0.08和2.95低点分别稳步上升到31.8（6周），5.92（7周）和19.8（8周）并且在断奶后期浓度显示无显着变化。在第8周时，α-淀粉酶的浓度（U / dL）从第4天的34.3上升到87.2，然后下降到56。6（13周）。 β-半乳糖苷酶增加至6周，然后在13周龄时降至痕量水平（0.20U / dL）。 1周后蛋白酶和脲酶的浓度达到稳定状态。饮食类型对瘤胃发酵产物和酶参数的影响不显着。然而，在所有的小牛中都观察到随着年龄的增长，干饲料摄入对两个参数的稳定和成比例的变化。 Defaunation增加总VFA（97.3对75。8 mM / L）和α-淀粉酶活性（80.3比61.4 U / dL）和氨氮（16.4比21.1 mg / dL）下降，而对其他参数的影响不显着。瘤胃发酵的变化对干饲料的摄入量有反应，但对于动物蛋白在prestarter饮食中的响应没有差异。
A.Sahoo;D.N.Kamra;N.N.Pathak;. Pre- and Postweaning Attributes in Faunated and Ciliate-Free Calves Fed Calf Starter With or Without Fish Meal[J]. Journal of Dairy Science, 2005,88(6): 2027-2036