Effects of gonadothrophin-releasing hormone and bovine somatotrophin on hormone profiles and ovarian function in postpartum beef cows

Abstract

Reproductive efficiency in beef cows is limited by the length of the postpartum anoestrous period wich in turn is controlled by pituitary gonadotrophins and gonadal steroids and/or ptoteins. The first aim of this study was to elucidate the role of LH pulses in the development of ovarian activity in postpartum beefcows, specially to determine whether or not the normal, relatively slow processo f folicular development could be accelarated in cows in low body condition (BC) with pulses of gonadotrophin-releasing hormone (GnRH). The second aim was to determine the role of metabolic hormones and in particular growth hormone (GH) in ovarian follicle development in cows.