Correlation Analysis Of Body Size And Weight As Well As Udder Traits And Milk Yield In Crossbred Buffalo Cows

Buffalo is one of the most potential for development and the development value of dairy cattle by internationally recognized. However, the low milk yield and low fecundity has seriously restricted the development of dairy buffalo industry. Dairy cow breeding practice proof that appearance and breast traits have directly or indirectly influential to milk production and reproductive performance in dairy buffalo, for buffalo is like ordinary holstein cows with similar relationship needs further study. So study the relationship in body size and udder traits and milk performance of buffalo cows. It is important for breeding to improve buffalo milk production.This study through the investigation, field observation, measurement, recorded calving buffalo body size, body weight and udder traits data, and record milk yield (corrected to the first child305d milk production) data. By the buffalo body size, weight, udder traits with first child305d milk yield relationship in order to find the most closely related indicators for buffalo breeding selection; logistic growth curve model fitting breast growth and development, clearly buffalo breast growth and development of the law, to provide the basis for the daily feeding and management; Regression model is used to evaluate the breeding value.1Determination of the adult buffalo body size, body weight, breast traits and milk yieldHybrid buffalo adult body size, body weight, breast traits and milk production are as follows:Body height:136.41±3.46cm, Body length:146.94±5.12cm, Chest girth:218.42±10.16cm, Cannon Circumference:27.05±2.38cm, Pin bone width:22.56±2.62cm, Breech width:40.92±3.55cm, Weight:640.00±58.20kg,Rump length:37.79±3.20cm, Breech end:113.91±4.35cm, Waist angle width:59.23±2.90cm, Rump high:140.65±3.68cm, Average teat length:6.43±1.21cm, Teat uniformity:0.14±0.15, The spacing of teat before and after:8.79±1.06cm, The spacing of teat left and right:10.01±1.90cm, Teat cross pitch:13.43±2.11cm, The teat surrounded area:86.17±19.87cm2, The first child305d milk yield:896.38±311.96kg.2Buffalo udder growth and development patternsHybrid buffalo’s udder in early (3years old to4years old) growth relatively fast growth, achieve the inflection point at about3years old, this period is also the beginning of buffalo and pregnancy period, even some early heifers primiparous period. And then, although udder growth and development have a growing trend after4years old, but the growth rate tends to slow, basically have stopped growing. 3The correlation analysis and path analysis of the adult buffalo body size, body weight, udder traits and milk yieldThrough the correlation analysis and path analysis, we found that, hybrid buffalo each body size, body weight and udder traits has different degrees of relevance, and milk production also has a certain correlation. The first child305d milk yield with Circumference X3, The spacing of teats before and after X12, The spacing of teats left and right X13, The teat surrounded area X15, Teat uniformity X17was moderate or strong positive correlation, the strongest correlation (r=0.5489); circumference with hip-side width, rump length was moderate or strong negative correlation, and other traits showed a weak correlation. The milk yield is directly related to the amount of the six traits:The spacing of teats before and after (0.3557), Teat uniformity (0.2599), The spacing of teats left and right (0.2572), Pin bone width (-0.2201), Chest girth (0.2174),Cannon Circumference(0.1954). These results show that, influence on the maximum milk yield is udder traits, followed are Cannon Circumference and Pin bone width these body traits, effect of body weight on milk production is very small; Although the correlation of chest and milk production of small, but its on milk yield has a direct influence.4The establishment of the optimal regression equation in the adult buffalo body size, body weight, udder traits and milk yieldBased on the above information, Through the analysis of the body length, weight, udder traits and the first305d milk yield, the multiple regression equation:Y=-685.93-8.98X1-10.61X2+24.02X3-28.69X-0.04X5+102.18X12+41.28X13+27.23X14-2.37X15+540.46X16+0.99X6-0.52X7+6.62X8+6.41X9-0.20X10+7.09X1(R=0.78, R2=0.61, P<0.01)According to the regression equation of the optimization principle, establish the optimal regression equation is:Y=-572.66+40.47*Cannon Circumference+84.26*The spacing of teat before and after+40.78*The teat surrounded area-38.12*Pin bone width (R=0.73, R2=0.53, P<0.01)...