New research into Merino weaning shows that while liveweight at weaning is important, growth rate is critical.
Senior wool research scientist with the Victorian Department of Primary Industries, Dr Ralph Behrendt says management targets are emerging from the Sheep CRC's research work across Australia, which can lift weaning success and long-term weaner performance.
"These include managing nutrition, liveweights, supplementary feeding, parasites, the 'weaner tail' and the overall weaning environment," Dr Behrendt said.
"Adequately addressing these will result in improved weaner survival, a younger flock age structure, extra surplus sheep sales and increased value of wool sales from the younger sheep in the flock."
By improving weaning performance, it's been estimated the Australian sheep industry could gain $100 million per year.
"Our analysis suggests that increasing weaning numbers by 4pc would improve farm profit by $1.20–$2.20 per weaner, across a range of sheep enterprises," he said.
Dr Angus Campbell, veterinary researcher with the Mackinnon Project, Melbourne University, said success over the first year post-weaning is strongly associated with liveweight and weight gain.
"Liveweight is a big driver of survival, starting at weaning and going right through to 12 months of age or more," he said.
"However, while liveweight at weaning is important, growth rate is critical.
"Data shows that average growth rate is even more strongly associated with mortality risk than weaning weight.
"Producers can look at management options such as drafting-off the lightweight tail of weaners for differential management and feeding."
He says Sheep CRC survey work shows that only 14pc of Australian farmers draft-off the weaner flock 'tail' some time over summer.
"This should be done at weaning – not when nutritional stress begins," Dr Campbell said.
"Regardless of the average weight of the mob at weaning, the lightest 20pc of weaners are over three times more likely to experience illthrift than weaners from the middle 20pc of weaning weights."
Dr Campbell said targeted supplementary feeding, especially during the summer months, that modestly increase liveweight and average growth rate across the flock are likely to cost-effectively improve weaner performance.
