A recent study from Cornell University analyzed the effect of prostaglandin treatment on prevalence of subclinical ketosis and fertility. In the study, 406 cows from five farms were evaluated for ketosis status and body condition at 21, 35 and 49 days in milk. During these visits blood samples were also taken to evaluate estrous cyclicity.
During each herd visit, cows with even number ear tags received 25 milligrams of prostaglandin and cows with odd number ear tags received a saline solution. The results were published in the September issue of the Journal of Dairy Science.
Researchers concluded that cows with subclinical ketosis:
Took longer to get pregnant when diagnosed at 35 days in milk, but not when identified with ketosis at 21 days in milk. The median days to pregnancy were delayed 30 and 40 days for cows classified as having subclinical ketosis at days 35 and 49 days in milk, respectively. Treatment with prostaglandin did not affect the prevalence of subclinical ketosis at days 35 and 49 or time to first artificial insemination.
Prostaglandin did improve conception rates in animals with poor body condition (less than 2.5).
It was concluded that prostaglandin did not influence subclinical ketosis or days to first service, but did improve conception rate and time to pregnancy in cows with low body condition scores.
Source: Journal of Dairy Science/DCRC