Synchronization of ovulation in beef herds: Improved conception rate after and interrupted course of progesterone administratio

Author: J.F.W. Grosskopf
Year: 1974
Issue: 1
Volume: 4
Page: 61 - 65

The oestrous cycles of cows and/or heifers were synchronized in six herds by the intramuscular administration of progesterone. In order to exclude those cows that were in the latter third of their cycles at the onset of treatment, the herds were first presynchronized by four 48-hourly injections of 50 mg of progesterone in propylene glycol and after an interval of eight days, treatment was resumed by giving them 6 more such 48-hourly injections. Conception figures varying from 69 to 86 %were attained in 4 of the 6 trials during the synchronized oestrus. These compare favourably with normal first insemination figures uncomplicated by synchronization and represent a marked improvement on The average figure of 47% (36 to 58%) previously experienced after synchronization with progesterone.


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