Utilização de protocolos de sincronização de estros com inseminação artificial em tempo fixo (IATF) nos municípios de Cerro Corá e Currais Novos - RN.

Abstract

Use of estrus synchronization protocols with fixed-time artificial insemination (FTAI) in the municipalities of Cerro Corá and Currais Novos - RN. The aim of this study was to evaluate the efficiency of three different protocols in Fixed Time Artificial Insemination (TAI) for crossbred Holstein x Gir and crossbred Holstein x Sind. A total of 30 animals, 20 cows and 10 heifers, aged 5 to 9 years and 2.5 to 3 years respectively, with body condition score between 2 and 3.5 were used. The animals were divided into three groups. Group 1 (G1) and 2 (G2) consists of 10 cows each and Group 3 (G3) for 10 heifers. The protocol G1 consisted of 100 mg of gonadotropin-releasing hormone (GnRH) on day 0 at 18 hours, 500 mg of prostaglandin F2α (PGF2α), day 7, 100 mg of GnRH on day 9. The insemination was performed on the 10th day at 19 hours. In protocol G2 on day 0 was implanted a device intravaginal progesterone releasing 1g and were applied four mg of estradiol cypionate (ECP) IM, at 16 o'clock, on the 8th day there was removal of implants and application of 2mL of PGF²α α and 400 IU of equine chorionic gonadotropin (eCG) IM; application on the 10th day of 2mL of GnRH IM and on the 11th at 8 o'clock insemination was performed. In protocol G3 on day 0 was implanted a device intravaginal progesterone releasing 1g and IM applied four mg of estradiol cypionate (ECP) on the 9th day there was removal of implants and application of 2mL of PGF2α intramuscularly, in the 11th day application of 2mL of GnRH intramuscularly at day 12 and females were inseminated 23 hours after application of GnRH. There was no difference between treatments in both groups. The three protocols developed in this work can be used to aid in reproduction of cattle.