Abstract
A primiparous infertile Holstein-Friesian cow was imported from Canada and inseminated 19 times for the past 2 years. Its ovarian function was monitored successively by measuring its serum progesterone level. After one full estrous cycle was detected, 800μgof an analog of prostaglandin F2α (ONo-1052) was administered intramuscularly (i.m.) on day 12 of the estrous cycle. The cow was inseminated 3 days later. Insemination was repeated twice thereafter. On each occasion the cow was treated with bovine APG (Hypohorin), 400KE, or fertirelin acetate (an analog of LHRH), 200μg. No services were successful. During the last estrous cycle, LH-RH was injected on day 2 and ONo-1052 i.m. on day 17. The cow was inseminated at the induced estrus and treated with APG on day 2, when it conceived.
