Preventing bearings in ewes will be at the forefront of sheep farmers' minds heading into lambing season.
Gore Vet South sheep and beef vet Donna Hamilton says while there is no silver bullet for preventing bearings, there are some steps farmers can take to reduce the risks.
“Identifying at-risk stock is a good place to start as a first step,” Hamilton says.
Ewes carrying multiples are especially at risk.
A ewe carrying triplets is eleven times more likely to prolapse than a ewe carrying a single, and a ewe with twins is five times more at risk.
Flatter paddocks also help reduce the risk with multiples, so Hamilton suggests keeping flatter paddocks for triplets and twins.
Access to salt in late gestation is a risk factor.
"If salt is fed, it is better not to do this late in pregnancy," Hamilton advised.
Feeding a crop with a higher water content late in pregnancy can also be problematic.
"Feeding swede crop late in pregnancy has been identified as a risk factor for bearings –the likely cause is high water content.
“On those type of crops ewes produce a lot more urine, and a full bladder increases pressure on the abdomen.”
Hamilton said the same probably applies to Fodderbeet, but feeding singles on these crops in late pregnancy is usually fine.
Some farmers also found disturbing stock while resting helped prevent bearings.
"One farmer we know uses his huntaway to run through the flock and get them moving.
"It encourages ewes to empty their bladders, which reduces intra-abdominal pressure," Hamilton said.
As well as the feed type, gorge feeding can cause issues.
"How crops are being fed is a factor.
"If ewes are in a gorge mentality, such as being on one-day breaks, they will feed more quickly and produce more gas in a short time which increases abdominal pressure.
"Four-day breaks, for example, would potentially lessen the risk."
Weight gain between mating and scanning is also a factor, as is shearing in the first half of pregnancy.
Some farmers have found that supplementing ewes with Vitamin D helped mitigate the risk.
"This is farmer-based evidence; there is no science behind it, but some farmers use it for bearing prevention and metabolic support.
"And they believe it's working," Hamilton said.
During a study conducted in 2000 and 2001, a number of things were identified as NOT associated with risk to bearings:
- Thin vs fat ewes at the end of pregnancy
- Weight gain or loss from scanning to lambing
- Ewe tail length
- Magnesium levels
- Amount of feed late pregnancy
- Shearing three months before mating or in the second half of pregnancy (protective)
If ewes have bearing issues, Hamilton recommends a hygienic approach to treatment.
"Using a mild disinfectant in water to clean the tissue and giving antibiotics will improve your success rate.
"Ensure you mark her as a cull, as she will likely have a bearing again next year.
"Consider the use of anti-inflammatories to improve discomfort and success of treatment."
by Claire Inkson