The effect of eCG and/or FSH on reproductive parameters of Zandi ewes

Document Type : Research Paper

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Abstract

    This study was conducted to evaluate the effect of two gonadotropins, eCG and FSH, separately or together on reproductive parameters of Zandi ewes. The ewes (n=135), during breeding season, were synchronized using CIDR and randomly assigned to 8 treatment groups. The control group (n=36) received no treatment. The ewes in eCG group (n=20) recieved an im injection of 400 IU eCG at the time of CIDR removal. In addition to eCG injection at CIDR removal, the groups eCG+FSH/0h (n=15), eCG+FSH/12h (n=10) and eCG+FSH/24h (n=14) ewes were injected 10 mg of FSH at 0, 12 and 24 h after CIDR removal, respectively. The ewes in group FSH/0h (n=15), FSH/12h (n=10) and FSH/24h administrated one dose of FSH at the time of CIDR removal 0, 12 and 24 h after CIDR removal, respectively. All ewes were artificially inseminated using fresh semen of Zandi ram in 48 h following CIDR removal. After parturition, the reproductive parameters of ewes and birth weight were recorded. The reproductive parameters were analysed using the ProcGenmod and the data of birth weight analysed by ProcGLM in SAS 9.1. The highest lambing rate was obtained in the group FSH/24 (80%) which it was not significantly different (P > 0.05) with control (52.8%) and eCG (55%) groups. Moreover, the highest fecundity rate was achieved in FSH/24 group (86%), which was higher (P <0.05) than control (52.8%) and eCG (55%) groups. The highest litter size occurred in eCG+FSH/24h group (1.4%), which was not significantly different (P > 0.05) compared to other groups. The data of birth weight also didn’t show significant differences (P > 0.05) between the treatment groups. The result of current research showed that an injection of FSH at 24 h after CIDR removal can be more effective on the reproductive parameters of Zandi ewes during breeding season.

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