At the Sheep Forum to be held in the Graham Centre, Wagga Wagga, on Friday 8 July, sheep producers will hear from industry experts speaking about research priorities and the sheep industry strategic plan (2015-2020) and what this means for future research and development and marketing initiatives for the industry; worm control and sheep management to reduce the onset of resistance across the region and the impact of worms on sheep.
Other topics include whole farm modelling work looking at the long-term impacts on productivity and gross margins of sheep enterprises, and managing flocks based on scanning results and feeding to meet body condition score targets; research on lamb growth rates from grazing hard-seeded pasture legumes as an alternative to sub clover, and findings from a recent project looking at issues relating to maintaining sub clover in pastures.
Dr Susan Robertson will provide practical advice on management strategies to improve lamb survival, while Lockhart producer Tim Westblade will talk about his own experiences and management to improve lamb survival on-farm.
On average 20 percent of lambs born will die, with 90 percent of deaths occurring during or within seven days of birth. This represents a large income loss for producers, and may be perceived as a welfare issue.
The major cause of death for lambs varies between properties and seasons, but starvation, mismothering, exposure and difficult births are generally the largest causes.
So which lambs are most at risk? Lambs born as multiples (twins 30 percent mortality) compared to singles (10 percent mortality), merino rather than crossbred lambs, and lambs born to maiden ewes – maidens have 10 percent lower survival rates than mature ewes.
“Ewe nutrition is the most important factor influencing lamb survival,” Dr Susan Robertson said.
“Optimum nutrition minimises difficulties during birth, improves maternal behaviour, allows ewes to provide sufficient colostrum and milk, and allows ewes to stay on the birth site longer to bond with the lamb, reducing mismothering.”
Ewes gain weight and maintain condition during late pregnancy with adequate nutrition. Avoid having fat ewes (condition score 4) at lambing as this increases the risk of pregnancy toxaemia and lambing difficulty.
“The month of lambing effects both the likelihood of adequate pasture being available for the ewe and the risk of poor weather causing either heat or cold stress to new-born lambs. The month of lambing also influences the number of ewes able to be carried by the association between feed supply and demand, and hence the potential number of lambs born,” said Dr Robertson.
“Shelter that reduces wind speed can increase lamb survival in cold, windy weather, but will be ineffective in mild weather.”
“Consider the cost of creating shelter against the value of potential increased production. Where possible use natural, existing shelter,” Dr Robertson said.
Lambing twin-bearing ewes in separate paddocks to singles does not appear to increase lamb survival. But separation may improve survival if it allows preferential management, as twin bearing ewes can be placed in more sheltered paddocks or where better feed is available.
Dr Robertson advises against lambing mature and maiden ewes in the same paddock, as research suggests this can reduce the survival of lambs from maiden ewes by 10 percent.
“Genetics also plays an important role. Avoid buying rams with high birthweight Australian Sheep Breeding Values or blocky shoulders as this can result in increased lambing difficulties,” Dr Robertson said.
- Visit www.trybooking.com.au/LLRC to register.
- For further details please contact Toni Nugent, Industry Partnerships and Communications Manager, Graham Centre for Agricultural Innovation on mobile 0418 974 775.
