Evaluación del efecto de la somatropina bovina recombinante (rbTS) sobre parámetros reproductivos, de vacas sometidas al pastoreo en el cantón Cumandá de la provincia de Chimborazo.

Abstract

The aim of the present research was to evaluate the effects of recombinant bovine somatropin (rbTS) on reproductive parameters of cows grazing in the canton Cumandá, province of Chimborazo. We worked with 60 crossbred animals (Braman, Holstein, Brown Swiss crosses), subjected to extensive grazing production, without stabling and belonging to small dairy farmers; The cows of the control treatment did not receive a dose of hormone, were inseminated and their pregnancy was evaluated 60 days later; the cows corresponding to treatment 1, a dose of hormone (2 g) was applied at the moment of insemination and their pregnancy was diagnosed 60 days later; the animals corresponding to treatment 2, a dose (2 g) was applied at the moment of insemination and a second dose (2 g) 10 days after insemination, and their pregnancy was diagnosed 60 days after insemination. A completely randomized design was used, with 2 replicates for each treatment. The reproductive parameters of cows submitted to grazing in Cumandá canton are the percentage of conception of treatment 0 is 30.0 %; of treatment 1 30.0 % and of treatment 2 65.0 %; the days open are between 76.20, 78.65 and 69.15 for treatments 0, 1 and 2 respectively. The highest cost benefit was reported for treatment 2 with 1.33. It was concluded that the percentage of conception increased in female cattle that received two doses of somatotropin 65.0 % compared to the control treatment that did not use hormones 30.0 %. The use of somatotropin hormone is recommended because it improved conception percentage in female cattle subjected to grazing.