Читать книгу Bovine Reproduction - Группа авторов - Страница 215

Natural service typically utilizes bull to cow ratios of 1 : 15 to 1 : 50 [1]. The inability of the bull to breed in a single sire unit will always have a devastating effect on reproductive efficiency. Similarly, when a socially dominant bull in a multisire unit is unable to complete the copulatory act, the decrease in breeding efficiency may not be masked by the presence of additional subservient bulls. Although artificial insemination eliminates the requirement for coitus, most semen processed for the artificial insemination industry is collected by methods that mimic the copulatory act utilizing an artificial vagina (AV) as the bull mounts a teaser or phantom. While some impediments to the copulatory act may be overcome by the collection of semen using electroejaculation, others may not be easily managed.