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

作　　者：毛永江[1] 张美荣[1] 许兆君[1] 刘姗[1] 张亚琴[1] 陈丹[1] 王杏龙[1] 杨章平[1] 

机构地区：[1]扬州大学动物科学与技术学院,扬州225009

出　　处：《畜牧兽医学报》2012年第12期1904-1909,共6页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家自然科学基金(31272407);江苏省苏北专项(BN2011016);江苏高校优势学科建设工程资助项目(PAPD);扬州大学科技创新培育基金(2011CXJ059)

摘　　要：旨在了解南方中国荷斯坦牛测定日产奶量、乳脂率、乳蛋白率和体细胞评分(Somatic cell score,SCS)变化趋势,并进行准确预测。利用Wood模型对南方5个大中型奶牛场(2008-2010年1～3胎)中国荷斯坦牛的33 194条测定日产奶量、乳脂率、乳蛋白率和SCS数据进行曲线拟合。结果表明,测定日产奶量为标准泌乳曲线,乳脂率、乳蛋白率和SCS变化与标准泌乳曲线正好相反。Wood模型对乳蛋白率和产奶量变化曲线拟合度最高,各胎次拟合度均为0.99,误差均方也较低;其次为乳脂率,各胎次拟合度均为0.98,而对SCS的拟合度最低,均在0.7以下,同时误差均方也最大。各胎次产奶高峰日出现的时间与乳蛋白率和SCS最低值出现的时间相近,而最低乳脂率出现的时间较晚。一胎牛高峰产奶量相对较低(30.4kg.d-1),但泌乳后期泌乳持续力及维持低SCS能力较强;二胎和三胎牛高峰产奶量较大,分别为35.9和36.2kg.d-1,二胎奶牛在泌乳后期同时维持高乳脂率和乳蛋白率的能力较强。Wood模型适合于南方中国荷斯坦牛测定日产奶量、乳脂率、乳蛋白率变化曲线的拟合分析,而不适合于SCS的拟合分析。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 percent- age and daily milk yield with the lowest residual mean square, then following for milk fat percent- age. 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 sec- ond- 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

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 

分 类 号：S823[农业科学—畜牧学] Q348[农业科学—畜牧兽医]