Artificial insemination of beef cattle

A system for the artificial insemination fo beef cattle was described. The system involved preparation of the cattle and facilities, visual oestrous detection twice a day, drafting each morning and insemination of oestrous cows twice a day. The AI program was evaluated during the course of the program and at pregnancy test 35 to 90 days after the end of the insemination period. The insemination period was from 25 to 60 days depending on efficiency, with programs from 25 to 35 days being favoured. Results for 12218 first inseminations (65.9%) and 2222 second inseminations (57.8%) in 56 AI programs compared favourably with results in dairy AI. Pregnancy rates in lactating cows (70.5%) were significantly higher than in nonlactating cows and heifers (66.1%). Overall efficiency of well-managed AI programs were represented by 63% of cows put into a program becoming pregnant in a 29-day insemination period. Seventy-two per cent of the cows put into the program were inseminated yielding an 88% pregnancy rate. The efficiency of visual oestrous detection was 95% but this estimate did not include false positives. Efficiency of AI programs were effected by management, nutrition, infection, inseminators, facilities and the origin and type of cattle put into a program. Environmental factors such as handling, stress and thunderstorms did not effect efficiency except via a nutritional effect.