The effect of Pregnant Mare Serum Gonadotrophin (PMSG) and GnRH injection on weaning to oestrus interval and litter size of artificially inseminated sows

Abstract

This experiment was carried out to investigate the effect of exogenous pregnant mare serum Gonadotrophin (PMSG) and Gonadotrophin-releasing hormone (GnRH) on weaned sows bred by artificial insemination. Chilled semen at 24 hours after the onset of standing heat was used for the experiment. In the treatment group (experiment 1), sows (n = 32) were injected with 500 IU of PMSG at weaning and 50 μg of GnRH injection was given at the time of insemination. As the control, sows (n = 33) were inseminated without giving any hormones. Weaning to estrus interval, conception rate and litter size were recorded. Results were analyzed using the Minitab Statistical Software version 14, 2010. The means were compared using the Student’s t-test. Results revealed that in group 1, the PMSG treated sows had significantly (p<0.05) lower mean interval from weaning to estrus compared to that of the control group (4.7 ± 0.51 and 20.15 ± 0.81 respectively). The mean litter size of PMSG-treated Durock sows was significantly lower compared to that of the control group (4.3 ± 4.3 and 8.7 ± 0.9), while the conception rate in the treated group was significantly higher (76.6 %;p<0.05) compared to that of the control group (39.3%). Tropical Agricultural Research Vol. 24 (3): 270-278 (2013

Keywords

• gonadotrophin, oestrus interval, litter size, sows