VASECTOMISED rams are being used to fine-tune a lambing operation in Western Victoria to a three week period.
The program has tightened the breeding season by about two weeks at Tim and Georgie Leeming's Pigeon Ponds property by "teasing" non-cycling ewes to ovulate early prior to being joined with fertile rams.
The Leeming's prime lamb operation, which is complimented by the Paradoo Prime stud, runs across 1350hectares and has undergone a major expansion program in the past five years through a stringent lambing program, land acquisition and a productive pasture focus.
The Leeming's purchased a neighbouring 880ha property four years ago and have enabled stocking numbers to lift from 3,000 to 6,500 breeding ewes.
One aspect of their success is lamb survival of the Coopworth composite breeding flock.
The 6500 head flock has two defined lambing periods of three weeks in July and four weeks in August, which Tim said was to allow for more accurate feed allocation to ewes at late pregnancy and lactation.
"There are big benefits to feed allocation with more targeted feeding for the ewes that need it most," he said.
"We have a nice tight group of lambs which has resulted in better effectiveness with animal health because of the more accurate nutrition management of the mother."
Lambs can be weaned down to nine weeks of age for a tight lambing which Tim said allowed him to "pull the trigger on the weaning date" and focus on the ewes health.
"Weaning is all about the ewe - we want her to get back in lamb next year so we need to avoid her getting light in condition by getting the lambs off her as early as possible," he said.
Extended joinings can exacerbate huge differences in energy required to ewes that are lambing in the last week as opposed to the first week of lambing.
"This puts the farmer under pressure to allocate enough feed, have good animal health controls and has less of a tail end of ewes and more consistent weight-gains of lambs," he said.
In dry years, the Leeming's alter their weaning age to nine weeks which Tim said ensured there was green grass for the ewes to return to condition.
"We always get fixated on the lambs conditions but the ewe is the dollar figure for the next five years so rather than looking at the here and the now we need to be more long-term," he said.
"Weaning early can be a cheap option because a milking ewe uses two to three times more energy than a dry sheep so it is a way to save grass and put condition back on ewes that also ensures her fertility in the following year."
The flock is pregnancy scanned for twins and singles and managed separately.
From 2008, genetic selection has been aimed at "designing our own sheep" which has focused on maintaining growth while improving genetic fat and muscle in our ewes.
"The industry got too lean and too big," he said.
"Now we want to moderate sheep that grow well with more genetic fat and muscle so instead of having ewes up to 75kg, our modern is around 61-63kg with a (Condition Score) CS3.
"When lambs are born in different conditions it is their genetic fat that makes them survive."
The genetic development has been linked to the Leeming's use of Australia Estimated Breeding Values (AEBV) and seen lamb survival steady at 85-95per cent.
Ewes flock is kept below five-years of age to accelerate greater genetic gain while keeping ewes robust.
"Your next generation of ewe lambs are far greater," Tim said.
The farm currently is aiming for a 14 dry sheep equivalent (DSE) per hectare.
Their goal to drought-proof the new property has been strengthened through the installation of 65kilometres of paddock and laneway fencing and 12km of water systems, including 30 troughs, and sown 450ha of improved pastures - phalaris, sub-clover and perennial ryegrass.
The Leeming's subdivided the tableland country, sloped country and fenced off streams and riparian areas across the average 620millimetres rainfall property which has helped lamb survival.
"This is highly important when we want to provide them with more shelter and feed on offer, we know we can get a greater weaning percent by doing so and fencing was the only way we could do that," Tim said.
He said mob sizes of a maximum of 150 head for twin bearing ewes and 300 for singles improved mismothering issues and allowed ewe condition scores to be maintained through tailored nutrition.
"The biggest killer of lambs is exposure which can be heightened by poor birthweight and mismothering," Tim said.
"We address this by maintaining ewes to a CS3 by supplementary feeding from January through to May with grain.
"We spend from $7-9 per head per ewe per year with grain because it is more efficient and accurate to feed the flock of 8000 sheep twice a week."
This year, Tim said they would be feeding sheep for an extra four to five weeks because of the dry season they've been dealt.