Viabilidade técnica de parto gemelar em fêmeas da raça Nelore

Abstract

The experiment was development at the JR farm in the period from 01 May 2007 to 07 February 2008. 93 Nellore cows were used, where ten animals from embryo donors and 83 recipients. The donor cows were synchronized with the insertion of an implant and four days after the animals were superovulated with 250 IU of FSH and the recipients cows were inseminated at fixed time on the same day from donors. Seven days after insemination the embryos were collected from donors and transfers in 83 recipients cows. The pregnancy rate was 75.50% (63/83), of which 58.73% (37/63) were to single birth, 34.92% (22/63) were twin birth and 6.35% of birth were triple birth (4/63). There was no difference among the abortions rate, stillborn rate, retained placenta rate and dystocia rate in females that calved 01, 02 or 03 calves, but the rate of rejection of the calf by the cow was higher (p <0.05) from birth triple (100%), double (50%) and single (0.0%). The length of pregnancy was lower (p <0.05) in animals from birth triple and double compared to animals from birth simple (272.76, 277.45 and 282.05 days, respectively), the birth weight, weight at three months of age, weight at seven months old were higher (p <0.05) for the delivery of simple animals (28.53, 115.63 and 195.01 kg) compared to animals from birth double (22.30, 97.31 and 168.52 kg respectively) having no difference in average daily weight gain between the third and seventh months of age.