The Analysis Of Lactation Curve And Milk Yield Correction Coefficient Formulation On Three Varieties Of Cattle In Xinjiang

In order to investigate the lactation curves law of Xinjiang three varieties of cattle and the correctionfactor for the development of the305-day milk yield Xinjiang Holstein cows and Simmental. This study selectedfrom Hutubi cattle farm from2004to2008Holstein cows and Simmental individual yields registration records,collected13,326lactation records of1,364Holstein cows,675Simmental cows6,059lactation records and964Xinjiang Brown cattle29,991lactation records. Wood incomplete gamma function model, Nelder inversepolynomial, polynomial regression (six) were selected Ali-Schaeffer model and the the Wilmink model ofXinjiang Holstein cows and Simmental lactation curve fit to select the best fitting model, and develop a moreaccurate correction factor of milk yield for the Xinjiang Holstein cows and Simmental. In order to analyze theimpact of the three varieties of Xinjiang dairy cow lactation curve fit model parameters, as well as the comparativeanalysis of three cattle lactation curves for lactation capacity,This selection SAS8.1software fit and modelparameters of lactation curve analysis of the different models, parity and varieties, and three cattle lactation curveand lactation characteristic parameters were analyzed.Ali-Schaeffer model Hutubi cattle farm the best Holstein cow lactation curve model ideal effect on thevarious parities lactation curve fitting, R~2above0.9, the polynomial regression model (six)in Hutubi the cattlefarm Simmental best lactation curve model, the various parities lactation curve fitting are ideal, R~2above0.9,Different models fitting lactation curve fit of R~2, the model parameters a, d have a very significant impact,Different parity, varieties a significant impact on the the lactation curve fit R~2Xinjiang Holstein cows in thevarious parities peak milk volume than Simmental and Xinjiang Brown cattle, Xinjiang brown milk sustainabilitywere higher than in addition to the first parity Holstein cows and Simmental.In this study, based on the optimal model calculations of the two lactating cows Xinjiang Holstein cowsand Simmental305-day milk yield correction factor for the farm cows can more accurately predict the future305-day milk yield andobjective appraisal of the individual and the Hutubi cattle Holstein cattle genetic evaluationand provides a basis for the future Holstein milk yield research.Model have a very significant impact on thelactation curve fit, parity and varieties have a significant impact on the lactation curve fit, the three cattle lactationcurve law is basically the same, each parity305-day cumulative milk yield Xinjiang chargeStan cows wassignificantly higher than Simmental, Simmental higher than Xinjiang Brown cattle (the difference between theoverall parity: HST-XMT2690.7XMT-HN1114.1, the HST–HN3804.8).