Efeito da aplicação de eCG ou hCG 7 dias após a IATF no desenvolvimento das estruturas ovarianas e nas taxas de prenhez de vacas de corte
Wecker, FábioXavier Thedy, DiegoVarella Gonsioroski, AndressaBatista Souza Borges, João
Background: The early embryo development is affected by the progesterone concentration, especially on the fi rst weeks after conception. Its well known that the size and weight of corpus luteum (CL) is positive correlated with higher progesterone production. The use of treatments that increase luteal function in different periods after fi xed timed insemination (FTAI) has been tested recently, aiming better embryo survival rates and pregnancy establishment. The objective of this experiment was evaluate the effect of treatment with hCG or eCG 7 days after FTAI on the development of the CL, follicle growth and pregnancy rate in beef cows.Materials, Methods & Results: Two hundred and nineteen Brangus cows were synchronized to FTAI using intravaginal implants containing 1g of progesterone for 8 days and injecting 2 mg of estradiol benzoate (EB), on the fi rst day of treatment. All cows received 150 mcg of D-Cloprostenol, i.m., on Day 8 and 24 h after, 1 mg of EB, i.m. The timed AI were done 52-56 h after the implant removal. Seven days after the AI the cows were randomly assigned in 3 different groups according the treatment. hCG (n = 40) receiving 1500 IU of hCG, i.m.; eCG (n = 41) injection of 400 IU of eCG, i.m., and Control (n = 138). The ultrasonographic examinations were done on days 0, 7 and 12 to determine the presence and diameter of follicles, area of CL on the subgr
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