Efeito do estradiol associado ao progestágeno sobre a taxa de sincronização do estro, de ovulação e prenhez em vacas zebuínas lactantes no pós-parto / Effect of estradiol plus progestagen on estrus and ovulation synchronization, and pregnancy rates in zebu lactating cows at postpartum

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The objective of this research was to evaluate the effect of estradiol benzoate plus CIDR on estrus and ovulation synchronization and pregnancy rates in zebu lactating cows at postpartum. Two hundred and twenty six zebu cows, were randomly assigned to three different treatments: MN (n=77) - cows were submitted to a breeding season of 21 days, cows of the T1 (n=70) received an intravaginal progesterone device (CIDR) and an injection of estradiol benzoate (EB) (day 0 of treatment). On day 7, the CIDRs were removed and the animals received an injection of a PGF2α. The cows were inseminated 12 hours after estrus detection. Females of the T2 (n=79) received the same protocol as T1, but plus another injection of EB on day 8 and were inseminated at 56 hours after the CIDR implant removal. The estrus induction rates for the treatments T1 and T2 were 96.7 and 100.0% respectively. The pregnancy rates were respectively 42.9, 18.3 and 42.7% for the MN, T1 and T2 groups. The progesterone plasma concentration were 11.71 ng/mL (day 0) and 8.87 ng/mL (day 7). The body condition score (BCS) did not affect pregnancy rates. Estradiol benzoate injected 24 hours after progestágeno removal gave a better response for lactating beef cows at post-partum.

ASSUNTO(S)

sincronização do estro ovulação estradiol benzoate benzoato de estradiol bovino estrus synchronization ovulation reproducao animal pregnancy rates taxa de prenhez bovine

ACESSO AO ARTIGO

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