Reproductive performance and dairy heifer management in large herds in Canterbury: A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science (Hons)

Abstract

An investigative survey was undertaken in the Canterbury area to assess current management practices, and the reproductive results being achieved in the rearing of first calf heifers in large herds. Ten farmers were involved in the survey, from Temuka to Southbridge. The survey and analysis highlights that there is large variation in the reproductive performance being achieved between farms, in both pregnancy rate and calving spread. The farmers involved in the survey were more concerned with calving spread than pregnancy rate. There was equally diverse variation in the different management practices carried out across farms. Distinct patterns of management were identified that contributed to the level of reproductive performance being achieved, with feeding management and heifer growth rates being paramount. Following the identification of the management practices that resulted in the best reproductive performance, a financial analysis was conducted to assess: (a) costs involved in the production of heifer replacements and (b) the financial benefits of good management practices. This analysis identified a potential net gain of $71 heifer through good management practices which improved reproductive performance and production. The results of this investigative survey align with both the historical and contemporary literature on the topic, and form the basis for further research.