Increasing the use of AI in suckler herds.

End of Project ReportReproductive efficiency is a major factor affecting production and economic efficiency of beef herds. For herds using artificial insemination (AI) heat detection rate and calving rate are the two major determinants of compactness of calving and ultimately the calving-to-calving interval. Heat detection is a time consuming repetitive chore that must be carried out up to 5-times each day for as long as AI is used. Heat detection rate, usually measured as submission rate, is hugely variable from herd-toherd but for most herds only between 40% and 70% of cows that exhibit heat are actually detected by the stockman. Despite an increased understanding of the endocrine control of the oestrous cycle the goal of fixed-time insemination is not yet consistently achievable in either cows or heifers treated at different stages of the oestrous cycle and in different physiological states. The overall objective of the this project was to develop an improved cost effective hormonal method to control the time of ovulation to allow beef cows be bred by AI without the need for heat detection. A total of 3 studies were carried out and the results are summarised in this report.Department of Agriculture, Food and the Marin