【摘要】 本文对奶牛最高日产奶量出现天数（X₁）、最高月产奶量（X₂）、90天产奶量（X₃）、最高日产奶量（X₄）及90天内泌乳均稳指数（X₅）等五个早期产奶性状进行了通径分析。结果确定:最高日产奶量出现天数、90天产奶量及90天内泌乳均稳指数是产奶量早期选择的重要性状。 同时,又对上述五个性状进行了逐步回归分析,得“最优回归”方程式为: y=314.86+5.77X₁+2.15X₃+44.44X₅。用此方程式预测奶牛一胎305天产奶量,其平均误差为5.1％,说明所选择的“最优回归”方程式具有一定的实用价值。更多还原

【Abstract】 In this study path analysis was carried out in number of days of producing maximum daily milk yield ( X, ),maximum monthly milk yield ( X2 ) , 90 days’ milk yield ( X3 ) , maximum daily milk yield ( X4 ) and average stable index of milk secretion within 90 days ( X5 ) 。The findings definitely show:the number of days of producing maximum daily milk yield, 90 days’ milk yield and average stable index of milk secretion within 90 days’ are important characters of the early selection of milk yield.IN the meantime we also made stepwise regression analysis of the above five characters, by which an ’optimum’ regression equation was found as follows:Y =314.86 + 5.77X1+2.15X3 + 44.44X3Using this equation to forecast 305 days’ milk yield of cows at first lactation shows, average error 5.1%, that the selected ’optimum’ regression equation is certainly of practical value.更多还原