Authors : Cordova-Izquierdo , A. Diaz-Mart�nez , H. Garcia-Garcia , M.S. Cordova-Jimenez and C.A. Cordova-Jimenez
Abstract: In females bovine meat producers, to increase the efficiency of the artificial insemination it should be maximized the synchrony and fertility from the oestrus when manipulating the cycle of the oestrus. In this study the effectiveness of two programs of oestrus synchronization was evaluated by means of progesterone, for these 400 cows of the races were used Brahmin, Nellore and their cross, which were divided in two groups. To the group 1, with 200 animals, they were inserted the device intravaginal progesterone liberator (CIDR) with duration of 10 days, to the moment of the one implants 2 mg of stradiol benzoate it was applied (BE) i. m., the day 8 were applied 2 mL. of cloprostenol i. m., he/she retired the one it implants and at the 24 hrs it was applied 1mg. of BE, i. m. and they registered the cows that presented oestrus. To the group 2, with 200 animals, they were administered an it implants subcutaneous (crestar) on the external back of the right ear, it remained 10 days, to the moment of the one implants they were applied 2 mL. of norgestomet and stradiol valerate i. m., later on a day 10 when moving away the one implant, they were applied 1.2 mg of PMSG i. m. and they registered the cows that presented oestrus. The observation of oestrus behaviour was made at different hrs 30, 48 and 56. Later on, you proceeded to inseminate all the cows and after 3 months he/she was carried out the gestation diagnosis by means of rectal palpation. In cows with the treatment CIDR to the 56 hrs. it was bigger the presentation of oestrus signs in 38% and the gestation percentage was of 78.18%. With the treatment crestar, one can observe that the oestrus percentage to the 56 hrs. it was of 30% and that of gestation of 65.22%. The percentages of empty cows for CIDR were of 21.82% and crestar of 34.78% stops. In conclusion, under the conditions of this work, you can indicate that the best results, as for the oestrus presentation and percentage of gestations, were presented in the animals treaties with the device CIDR, incomparison with those to which were administered the one crestar implants.
Cordova-Izquierdo , A. Diaz-Mart�nez , H. Garcia-Garcia , M.S. Cordova-Jimenez and C.A. Cordova-Jimenez , 2006. Synchronization of the Oestrus in Bovine Females of Meat under Conditions of Tropic Humid Mexican. Journal of Animal and Veterinary Advances, 5: 322-324.