Effect of eCG and laparoscopic insemination on reproductive performance in F1 (Damara x Merino) ewes

Abstract

Forty five F1 (Damara x Merino) ewes with 123 +/- 27.6 days post partum were used to evaluate two differents dosage of equine chorionic gonadotropin (eCG) plus laparoscopic insemination (IL) and its effect on oestrus presentation, fertility and prolificacy percentages under conditions of humid tropic conditions. To synchronize oestrus ewes were treated with controlled internal drug release (CIDR) devices containing 0.3 g of progesterone for 12 d. Ewes were assigned randomly to three treatments: T1. CIDR plus natural mating

T2. CIDR plus 150 Ul of eCG and IL to 42-46 h at the moment of the CIDR removal with semen of Damara male

T3. CIDR plus 300 Ul of eCG and IL to 42-46 h at the moment of the CIDR removal with semen of Damara male. Fertility percentages to synchronized oestrus were 40

40 and 46.6% for T1, T2 y T3 respectively, no showing differences (P > 0.05) among them. Prolificacy percentages showed differences (P < 0.05) among treatments being 100

100 and 133.3% to T1, T2 and T3. These results will permit to do adjustments in future studies on the synchronization programs methodology of oestrus and laparoscopic insemination to fixed time with frozen semen, with the objective to improve the reproductive performance of F1 (Damara x Merino) ewes under conditions of humid tropical climate in Mexico.