The effect of prostaglandin F2 alpha treatments in superovulated cattle on estrus response and embryo production.
Approximately 10% of cows in a commercial embryo transfer center that were superovulated for embryo production did not show estrus at the right time and therefore did not produce embryos. This problem was investigated by studying the effects of prostaglandin F2 alpha (PGF) treatment regime and dose rate on the superovulatory process. The cows in estrus following superovulation (96% vs. 86.6%), the % cleaved (62% vs. 51%) and the transferable embryo production (5.4 vs. 3.8) was increased when 50 mg. PGF was administered in three divided doses rather than in two doses. In a second experiment doses of 15 mg, 30 mg and 45 mg (each administered as three divided doses 6 hours apart) all produced the same estrus response (95.6, 97.9 and 95%) and production of transferable embryos (4.9, 3.6 and 4.6). Three-times-a-day PGF reduced the time interval from treatment to the onset of estrus, but the time from PGF to estrus was not correlated with embryo production.
Donaldson
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