8 June 2001

Litter size mystery

VARIABLE litter size and high return rates have been a problem on pig units for the past year.

But apart from a possible link with poor weather, reasons are difficult to identify, according to Beds-based vet David Chennells.

"There is tremendous variability in conception rates and although averages are lower than I would like to see, some farms are doing well."

Poor weather last year and early this year may be to blame, exerting its effect on stock and staff, says Mr Chennels.

"Particularly on outdoor units, staff were dealing with cold, wet weather and appalling ground conditions last year. But even on indoor units, conditions were dull and dark which can have a depressive effect on people, compromising efficiency."

Although AI use has increased, this is not to blame for reduced fertility, he says. "Some units are obtaining fantastic results using AI.

"There may be a slight advantage to on-farm semen collection because it is fresher and more concentrated. But some units using purchased semen are doing well."

Taking time to discuss what you are doing, when and why will help address fertility problems. "Stockmen training other stockmen can pass on bad as well as good habits. There is also a tendency for complacency to creep in over time," he warns &#42