Evaluación de dos programas de superovulación en vacas lecheras.

Abstract

This research was carried out to evalúate two programs of múltiple ovulation in milk cows. It was made ¡n different milk farms in the Sierra Centro of Ecuador. It was evaluated the effect of the múltiple ovulation in milk cows of different breed based on intravaginal devices implants of Progesterone (P4) Bobine Intravaginal Device (BID) + Estradiol Benzoate (EB) and the application or not of Gonadotropin- releasing hormone (GnRH) during the lst Artificial Insemination (Al), in 24 milk cows of breed (54.17 % Brown Swiss, 25.00 % 20.83 % Holstein Friesian and Jersey), being each on of them an experimental unit and distributed under a Completely Randomized Design (CRD). The experimental results were subjected to an descriptive statistical analysis with Chi- squared (X2 ) and t'studen tests, to compare the effect of treatments. Determining that the múltiple ovulation programs used showed statistically similardata. However, cows which receiving GnRH showed numerically greater number of over ovulated animals (91.67 % vs. 83.33 %), higher total amount of collected structures (10.73 + 7.00 vs. 8.40 + 4.14 per cow) and viable embryos (9.36 + 6.09 vs 7.10 + 3.54 per cow), corresponding to 87.30 % and 84.50 % respectively. The cows breed had a direct influence on the parameters evaluated. It is concluded that the application of GnRH after the lst IA, each viable embryo cost $ 54.47, while without GnRH, was $ 71.58. Livesotck farmers who wish to have animals with high genetic valué in terms of milk production it is recomended to cause múltiple ovulation in milk cows with intravaginal implants of P4 (BID) + EB and the GnRH application in the first artificial insemination to improve quantity and quality of embryos production.