5 January 1996

Cystic ovary surge

CYSTIC ovaries in dairy cattle are up by 50% across the country, according to to the UK vet disease profile.

Bucks-based vet Ian Baker says: "Normally 2-5% cows show cystic ovaries but in some herds up to 15% are affected."

The disease is a hormonal dysfunction that leads to large cysts forming on the ovaries. Two types of cyst produce either oestrogen, causing a continuing oestrus, or progesterone which suppresses the cows reproductive cycle.

"Though treatment has a rapid effect, it can be some time before cystic ovaries are suspected, delaying the animals getting in calf and lengthening the calving interval.

"Ultrasound techniques are helping vets make more accurate diagnoses of cystic ovaries but in order to spot the disease as quickly as possible producers should keep accurate fertility records," he says.

ADASs Bruce Cottrill adds that the exact cause of cystic ovaries is unknown. But suggestions are that it is genetic, appearing more frequently in high yielders.

"Stress could also be a factor as well as nutritional imbalances."