Improving the Reproductive Efficiency of Dairy Cattle through Genetic Selection

摘要: Abstract Achieving pregnancy in high-producing dairy cows a timely and cost-effective manner is one of today's greatest management challenges. Fertility highly influenced by environmental factors, but significant genetic differences exist both male (service sire) female (daughter) fertility. The first challenge improving fertility through selection data collection, because an inverse relationship exists between quantity quality. Rough measures, such as calving interval, are available for all multiparous milk-recorded cows. Insemination (and, hence, nonreturn rates) perhaps half the population, while examination roughly quarter population. Detailed regarding technician, type breeding (standing or synchronized), so on from selected herds, milk progesterone limited to experimental studies. Statistical modeling also challenge, linear models inappropriate binary traits, continuous traits badly skewed frequently censored. Threshold can be used data, survival (failure time) may more effectively fit complex nature factors that influence them. This paper describes 2 potential approaches analysis based detailed reproductive advanced statistical methodology. large-scale threshold model uses veterinarian-confirmed conception rates, second in-depth failure time properly accounts censoring among were culled failed conceive. former approach analyses service sire fertility, latter evaluation management, well improvement daughter