Evaluation of the effects of a contract breeding program on reproductive efficiency in Ohio dairy herds.

摘要

A significant problem facing modern dairy herds in Ohio and the rest of the United States is reproductive inefficiency, which leads to economic losses to dairy producers. The research herein discusses a variety of issues related to reproductive efficiency of dairy herds in three distinct sections. The first section of this dissertation discusses factors that can affect reproductive performance and a systematic approach to troubleshooting reproductive inefficiencies. The second session addresses economic losses associated with reproductive inefficiency and describes a modeling approach for estimating losses. The third section evaluates the utility of a reproductive management program offered to Ohio dairies, with respect to reproductive as well as economic outcomes.;Although it is accepted that reproductive inefficiency is costly to dairy producers, loss estimates vary. Variability in estimates arises because of the conditions under which they are evaluated. Another aspect of this research has been the development of a spreadsheet-based model to be used for estimating economic effects of changes in reproductive performance under specific situations. It is shown that the magnitude of economic effects are sensitive to market prices faced by dairy producers as well as the herd's current level of reproductive performance.;A very common management problem limiting reproductive efficiency in Ohio dairies is the failure to efficiently and accurately detect estrus. In other words, many cows are not being selected for insemination in a timely manner following calving. A major challenge facing modern dairy producers is that they are unable to devote adequate time and resources to estrus detection activities. Numerous estrus detection aids have been developed and used in a variety of settings. A novel approach currently being offered to Ohio dairies is for producers to contract estrus detection activities and breeding decisions to outside parties. Under this arrangement, it is hoped that greater numbers of cows will be selected for insemination, thus improving reproductive performance. (Abstract shortened by UMI.).