Superovulation in cattle with PMSG or a horse anterior pituitary extract (HAP)

Abstract

Forty Friesian x Zebu crossbred animals were used to compare the superovulatory effect of PMSG with a horse anterior pituitary extract (HAP). Half the animals were injected with 2000 UI of PMSG, and the other half received a daily injection during three consecutive days of 70 mg of HAP; 48 hours after the first injection all animals received 25 mg of prostaglandin F2a. All animals were inseminated with frozen-thawed semen from the same bull 12 and 24 hours after oestrus detection and subjected to non surgical embryo recovery 7 days after oestrus. At the time of embryo recovery the length, width and height of the ovaries were registered to estimate the ovarian volume. Embryos recovered were classified morphologically. Mean ovarian volume was 382.6 vs 204 cm³, mean number of ova collected was 4.3 vs 4.2 and mean number of transferable embryos was 1.2 vs 2.4 for animals treated with PMSG and HAP respectively. There were no statistically significant differences (P > 0.05) between the treatments for any of the parameters registered.