The Use of Milk Progesterone Samples for Complete Herd Oestrous Control

Abstract

The most common cause of poor reproductive performance in the dairy herd is poor heat detection. It is impossible to separate heat detection from conception rate as accurate timing of service is certainly a requirement for the successful use of Artificial insemination. However many workers have shown that heat detection is much more closely related to reproductive performance than is conception rate.^1,2

Milk Progesterone Assays have been used for over 20 years to asses the stage of oestrous cycle in cattle.³ The first widespread application was for pregnancy diagnosis due to the fact that the method was by Radioimmunoassay (RIA) which involved centralised testing and a necessary time lag between sampling and results . The development of Enzyme-Immunoassay (EIA or ELISA systems) opened up the practical application of on site or "cow-side" testing and results.

Use of the test for pregnancy diagnosis severely restricted the potential of the test as the accuracy was often poor. Use for the detection of oestrous and timing of insemination has brought many revolutionary changes.5 This paper examines a complete system of applying the test for oestrous detection and insemination in a commercial dairy herd and the implications for routine veterinary fertility visits.