While many sheep farmers might think that lambing just once a year is enough, Professor Steve Morris of Massey University in New Zealand, is keen to have ewes lambing all year round.
He does acknowledge though that the poor lamb prices will hardly provide incentive for sheep farmers to do this.
The three-year project investigated a system of using five breeding periods each year to produce lambs every 73 days. Funded by Meat and Wool New Zealand and the C Alma Baker Trust, the trial was run on a University farmlet.
A flock of 506 mixed-age ewes was split to form a conventional and accelerated lambing group; half the ewes high fertility composites and half medium fertility Romneys.
Some ewes in high-fertility flock were able to sustain15 pregnancies over three years in the accelerated trial, producing 26 per cent more lambweight than the traditionally lambed ewes. Professor Morris says, however, that the decision on whether to pursue accelerated lambing is based on the economics.
“The project was proof of a concept set up in 2003 when prices were good and people were thinking about increasing production. Now prices have come back down industry may not be so keen, although people are interested in production in the early part of the year when prices are high.”
The cost of producing an out-of-season lamb was found to be $0.50/kg of weaned lamb more than the conventional system. Professor Morris found feed demand to be only slightly higher for the accelerated flock each year, but that demand was spread more.
“In the trial, almost 70 per cent of the highly fertile ewes in the accelerated system got pregnant at each mating, not matching the almost 100 per cent in the once-a-year ewes but potentially earning more income.
“The extra lamb weight produced brought in another $234/hectare in our trial,” Professor Morris says.
As well as proving the accelerated lambing concept, Professor Morris says the trial was a great opportunity to integrate scientists from different parts of the University.
“We had frequent discussion groups up there with plant scientists because people had to grow forage out of season to feed the sheep, statisticians, vet science people and others from farm management