Evaluation of Dry Matter Intake and Average Daily Gain Predicted by the Cornell Net Carbohydrate and Protein System in Crossbred Growing Bulls Kept in a Traditionally Confined Feeding System in China
Evaluation of Dry Matter Intake and Average Daily Gain Predicted by the Cornell Net Carbohydrate and Protein System in Crossbred Growing Bulls Kept in a Traditionally Confined Feeding System in China
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DOI：
10.5713/ajas.2010.10055
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发表时间：
2010-11-01
期刊：
影响因子：
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通讯作者：
Meng, Qingxiang
中科院分区：
文献类型：
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作者：
Du, Jinping;Liang, Yi;Meng, Qingxiang
为了评价康奈尔净碳水化合物和蛋白质系统预测的干物质采食量与平均日增重之间的一致性，进行了两个不同的动物试验，并对中国传统限制饲养系统中饲养的杂交生长公牛进行了实际观测。试验一选用45头西蒙杂交F1公牛，随机分成3个处理(T1-3)，每个处理15头。试验2选用60头利木辛×福州杂交F_2公牛，分成4个处理(T1-4)。所有的动物都被关在单独的牛栏里。每头公牛的日增重和日增重作为每个处理的平均值进行测量。收集了CNCPS模型所需的所有关于动物、环境、管理和饲料的数据，并为每个处理的动物生成了模型预测。随后，将模型预测的DMI和ADG与实际记录的结果进行比较。在试验1的三个处理中，93.3、80.0和73.3%的DMI平均偏差落在-0.4~0.4 kg/d的范围内；同样，在试验2的四个处理中，约86.7、73.3、73.3和80.0%的点落在相同的范围内。结果表明，该模型能较准确地预测中国地区传统限制饲养制度下杂交公牛的日增重。试验1中T1(p=0.06)和T2(p=0.09)以及试验2中T1(p=0.07)、T2(p=0.14)和T4(p=0.83)的ADG预测值和观测值之间没有显著差异，但试验1中T3(p<；0.01)和试验2中T3(p=0.04)的预测值和观测值之间存在显著差异。通过回归分析，DMI回归方程的截距为零(p<；0.01)，ADG的截距与零的截距相同(p=0.06)，而DMI和ADG的斜率与1有显著差异(p<；0.01)。此外，对于两个方差(DMI和ADG)的无偏估计，获得了较小的均方根误差(RMSE)值。因此，本研究结果表明，该模型能较好地估计中国地区传统限制饲养条件下杂交生长公牛的日增重和日增重。
Two separate animal trials were conducted to evaluate the coincidence of dry matter intake (DMI) and average daily gain (ADO) predicted by the Cornell Net Carbohydrate and Protein System (CNCPS) and observed actually in crossbred growing bulls kept in a traditionally confined feeding system in China. In Trial 1, 45 growing SimmentalxMongolia crossbred F1 bulls were assigned to three treatments (T1-3) with 15 animals in each treatment. Trial 2 was conducted with 60 LimousinxFuzhou crossbred F2 bulls allocated to 4 treatments (t1-4). All of the animals were confined in individual stalls. DMI and ADG for each bull were measured as a mean of each treatment. All of the data about animals, environment, management and feeds required by the CNCPS model were collected, and model predictions were generated for animals on each treatment. Subsequently, model-predicted DMI and ADG were compared with the actually recorded results. In the three treatments in Trial 1, 93.3, 80.0 and 73.3% of points fell within the range from -0.4 to 0.4 kg/d for DMI mean bias; similarly, in the four treatments in Trial 2, about 86.7, 73.3, 73.3 and 80.0% of points fell within the same range. These results indicate that the CNCPS model can accurately predict DMI of crossbred bulls in the traditionally confined feeding system in China. There were no significant differences between predicted and observed ADG for T1 (p = 0.06) and T2 (p = 0.09) in Trial 1, and for t1 (p = 0.07), t2 (p = 0.14) and t4 (p = 0.83) in Trial 2. However, significant differences between predicted and observed ADG values were observed for T3 in Trial 1 (p < 0.01) and for t3 in Trial 2 (p = 0.04). By regression analysis, a statistically different value of intercept from zero for the regression equation of DMI (p < 0.01) or an identical value of ADG (p = 0.06) were obtained, whereas the slopes were significantly different (p < 0.01) from unity for both DMI and ADG. Additionally, small root mean square error (RMSE) values were obtained for the unbiased estimator of the two variances (DMI and ADG). Thus, the present results indicated that the CNCPS model can give acceptable estimates of DMI and ADG of crossbred growing bulls kept in a traditionally confined feeding system in China.