The bearings bugbear

11-08-2010 | Not Specified

How to reduce the incidence of bearings remains an unanswered question. Balclutha veterinarian John Smart says there's still no silver bullet to the problem.

"It's a multi-variable problem with no easy solution, and what might work on one property might not work on another," he says.

He did trials and research into the problem as part of South Otago Monitor Farm programme from 2005 to 2007 and found nothing conclusive, although feast/famine feeding with a shorter grass rotation in later pregnancy could be a contributing factor. Blood testing of ewes before and immediately after bearing problems showed nothing of significance.

"Magnesium and calcium levels do fall after it happens but that's probably as a result rather than the cause of the problem."

His advice based on his own South Otago experience and subsequent trials as part of a Sustainable Farming Fund (SFF) project is to reduce shift times and graze ewes on bigger feed breaks.

The SFF project , "No More Bearings", compared feed management on three high-performance sheep farms. Ewes were split into two management groups of at least 650 and shifted every one to two days or four days from mating until scanning.

They were then brought back together until lambing and treated similarly using winter crops if applicable.

Overall the farmers had lower incidence of bearing problems relative to property history, and there was a slight trend to fewer bearing problems with ewes shifted every four days.

The study concludes that farmers still have a lot to learn about feed management of ewes during pregnancy and staving off bearing problems requires farmers to: know ewe liveweights (average and range) to determine maintenance rations; know ewe Body Condition Scores (average and range); and use "formal" rather than "informal" feed planning.

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