畜牧兽医学报2012，Vol.43Issue(12)：1904-1909,6.
用Wood模型拟合南方中国荷斯坦牛产奶量、乳脂率、乳蛋白率和体细胞评分及其效果分析
Lactation Curve Fittings of Wood's Nonlinear Model for Milk Yield, Milk Fat,Milk Protein and Somatic Cell Score for Chinese Holstein in Southern China
摘要
Abstract
This study aimed to reveal the variations of daily milk yield, milk fat percentage, milk protein percentage and somatic cell score (SCS) , and to establish the prediction models for these parameters in the lactation period for Chinese Holstein in southern China. A 33194-test-day dairy herd complete data from 5 Chinese Holstein dairy farms were collected in the southern China from first lactation to third lactation between 2008 to 2010 and fitted to nonlinear curve of test-day milk yield, milk fat percentage, milk protein percentage and SCS with the Wood's incomplete gamma function model. The curve of test-day milk yield for Chinese Holstein was the standard lactation curve, and the curves of milk fat percentage, milk protein percentage and SCS were the reversed standard lactation curve. The best fitness of the Wood's model occurred for milk protein percentage and daily milk yield with the lowest residual mean square, then following for milk fat percentage. The poor model fitness (R2≦0. 7) was observed for SCS which residual mean square was highest. Daily milk yield peak day was accompanied with occurrences of minimal milk protein andSCS in the estimated lactation model. The minimal milk fat percentage came at the latest time of 18th week to 21th week in lactation curve. The peak milk yield was 30. 4 kg ?d-1 for first-parity cows, but the persistence for maintaining high milk yield and low SCS were greater than those of second- and third- parity cows in the latter lactation period, and the maximal milk yields for second- and third-parity dairy cows were 35. 9 and 36. 2 kg ?d-1 , respectively. The persistence for keeping high milk fat percentage and milk protein percentage was greater for second-parity cows than those of first- and third-parity cows in the latter lactation period. The Wood's incomplete gamma function model was appropriate to predict the variation for test-day milk yield, milk fat percentage, milk protein percentage, and was not appropriate for SCS for Chinese Holstein dairy cows in southern China关键词
Wood模型/产奶量/乳成分/泌乳曲线/体细胞评分/南方中国荷斯坦牛Key words
Wood model/ milk yield/ milk composition/ lactation curve/ somatic cell score/ Chinese Holstein dairy cow分类
农业科技引用本文复制引用
毛永江,张美荣,许兆君,刘姗,张亚琴,陈丹,王杏龙,杨章平..用Wood模型拟合南方中国荷斯坦牛产奶量、乳脂率、乳蛋白率和体细胞评分及其效果分析[J].畜牧兽医学报,2012,43(12):1904-1909,6.基金项目
国家自然科学基金(31272407) （31272407）
江苏省苏北专项(BN2011016) （BN2011016）
江苏高校优势学科建设工程资助项目(PAPD) （PAPD）
扬州大学科技创新培育基金(2011CXJ059) （2011CXJ059）
