Hristov A N, Price W J, Shafii B
Department of Animal and Veterinary Science, College of Agricultural and Life Sciences, University of Idaho, Moscow 83844, USA.
J Dairy Sci. 2004 Jul;87(7):2184-96. doi: 10.3168/jds.S0022-0302(04)70039-9.
This meta-analysis was undertaken to determine the impact of dietary components on dry matter intake (DMI), milk yield (MY), and milk protein yield (MPY) in Holstein dairy cows. Diets (n=846) from 256 feeding trials published in Volumes 73 through 83 of the Journal of Dairy Science were evaluated for nutrient composition using 2 diet evaluation models: CPM Dairy (a computer program based on the principles of the Cornell Net Carbohydrate and Protein System) and NRC (2001). Data were analyzed with and without the effect of stage of lactation as a dummy variable (<100 d in milk or > or =100 d in milk). A mixed model regression analysis was used to completely investigate the potential relationships among composition variables and DMI, MY, and MPY. Protein and carbohydrate fractions were the main components within the DMI models, and DMI played a dominant role in estimating MY and MPY. Inclusion of stage of lactation substantially improved the MY models but did not affect model fits or residual structure for DMI and MPY.
本荟萃分析旨在确定日粮成分对荷斯坦奶牛干物质采食量（DMI）、产奶量（MY）和乳蛋白产量（MPY）的影响。利用两种日粮评估模型：CPM Dairy（一种基于康奈尔净碳水化合物和蛋白质系统原理的计算机程序）和NRC（2001），对发表于《乳品科学杂志》第73卷至83卷的256项饲养试验中的日粮（n = 846）进行营养成分评估。分析数据时，将泌乳阶段作为虚拟变量（产奶期<100天或≥100天），分别考虑其有无影响。采用混合模型回归分析全面研究成分变量与DMI、MY和MPY之间的潜在关系。蛋白质和碳水化合物组分是DMI模型中的主要成分，且DMI在估算MY和MPY方面起主导作用。纳入泌乳阶段显著改善了MY模型，但对DMI和MPY的模型拟合或残差结构没有影响。
