Studies On Influence Factor Of Milk Yield And Lactation Rules Of Yili Horse In Xinjiang

In this study,60 mares of 3rd and 4th parity Yili horses were selected as samples from Kala Su farm of Xinjiang Yili. The research was designed to predict milking capacity by the best fitting model of lactation curves and milk yield of 150 days of the regression equation.7200 lactation records were collected and measured to build the database,4 mathematical models ?including the Gaussian model, Inverse quadratic polynomial model, Cubic model and Six polynomial model? of were used to fit lactation curves of 3 kinds of day interval and 4 time points by MATLAB 2014 software. Analyzed difference of Parameter Value and fit on different fitting curve. SPSS 18.0 software was used to analyze the correlation between 150 days regulated milk yield with 11:00,13:00,15:00, and 17:00 time'milk yield and the highest daily milk yield. Multiple linear correlation and regression model was built. The result showed the cubic model was the ideal lactation curves model of Yili mares, through the daily milk yield and different time's milk yield could accurately predict the whole lactation milk yield. Which were provided scientific support for the evaluation of the lactation performance of Yili mares, and provided basic data and theoretical basis for the dairy breeding early work of diary horse.The significant results are as follows:1. The regular pattern changes of different time's milk yield in a single dayBy fitting lactation curve of 4 time points milk yield in a single day single day of 3rd and4th parities Yili mares. The result showed that milk yield of Yili mares at 15 o'clock was significant higher than 13 o'clock,17 o'clock,11 o'clock, P< 0.01. The cubic model was ideal fitting model for lactation curve of 4 time points fitting results on 3rd and4th parity of Yili mares,11:00 fitness were 0.8021,0.9408,13:00 fitness were 0.8384,0.7906,15:00 fitness were 0.7653,0.6802,17:00 fitness were 0.7038,0.7051. which showed different times'milk yield of Yili mares has the specific regularity during a milking day.2. The fitting effect of the full amount of milk that fit by different interval day's milk during the whole lactationBy fitting 3 kinds day interval lactation curve of the whole lactation milk, and analyzing difference of the parameter value and fitness on different fitting curve. The result showed the models were significant effect on the fitness, the parameter b and c of lactation curve were at P< 0.01, on the a parameter of lactation curve was at P< 0.05. The day interval and parity showed no significant effect on the fitness, the parameter a, b and c. The cubic model was the best fitting model for lactation curve of 3 kinds of day interval fitting results on 3rd and 4th parity of Yili horse,0 day interval fitness were 0.8021,0.9408,10 days interval fitness were0.8384,0.7906,30 days interval fitness were 0.7653,0.6802, the fitting effect of 30 day interval was the best than others, On the basis of fitting cubic model on the 0 day interval, calculated the regulate coefficient between 60 days to 150 days, and the 150 days regulated milk yield, which provided theoretical support for selection criteria of lactation curve.3. The correlation and regression of different lactation characters milk yield with the 150 days regulated milk yieldThe SPSS 18.0 software was used to analyze the correlation between the 150 days regulated milk yield with 11:00,13:00,15:00,17:00 time'milk yield and the highest daily milk yield. Multiple linear correlation and regression model was built. Y=137.321+191.447X₁+1543.476X₂+72.426X₃-538.223X₄-0.932X₅. This equation was used to calculate other dairy breeds horses 150d full of milk, which provided technical methods for cultivating the high milk yielding of dairy horse, evaluating lactation performance, it also provided theoretical basis for breeding the dairy horse.