Advances in bovine theriogenology in New Zealand. 2. Breeding management and technologies for improved reproduction

Abstract

The importance of submission rates (SR) on conception patterns in dairy herds during a short artificial breeding (AB) programme was first reported in 1973. Subsequent research has focussed on achieving 3-week SRs of 90% through improved detection of oestrus utilising tailpainting and vasectomised bulls fitted with chin-ball harnesses. Despite nutritional limitations of spring pasture as a sole diet, conception rates to first insemination of 65% have been recorded in cycling cows in many trials. Anovulatory anoestrus (AA) has become a major factor compromising SRs as well as reducing average conception rates and herd in-calf rates by 4-7 weeks after the planned start of mating (PSM). Whole he..