Sheep consultant and educator Jason Trompf is urging sheep producers to move away from pregnancy scanning for wet-dry, or pregnancy only, and instead focus on multiple pregnancies.
Dr Trompf said by wet-dry scanning, or not scanning at all, sheep producers would be treating ewes with contempt.
‘‘More than 3000 producers have participated in Lifetime Ewe Management and the producers that have adopted scanning for twins and differential management have lifted their whole farm weaning by 15 per cent,’’ he said.
‘‘The break even costs on every extra lamb is 15 per cent lower than the producer benignly feeding all ewes.
‘‘There are farms consistently scanning 135 per cent and marking 110 per cent lambs in Merinos. It requires attention to detail but the pay-offs are profound.’’
Ideally, pregnancy scanning should be carried out at day 75 to 80 on a five-week joining (40 days after ram removal).
‘‘Don’t scan and leave the ewes boxed together then separate singles and twins at pre-lambing inoculation or drenching, as the opportunity for differential management of singles and twins to drive ewe and lamb survival is reduced,’’ Dr Trompf said.
‘‘Once a ewe drops in body condition score she partitions less resources to the developing foetus, then birth-weight drops which is the key for twin lamb survival.
‘‘Overall, the keys that drive lamb survival are birth-weight, body composition (muscle and positive fat) and privacy (in the lambing paddock).’’
Dr Trompf said a doubling of non-Merino or first-cross ewe numbers and the advent of self-replacing meat flocks from 2008 onwards accounted for almost half of the gains in marking.
‘‘People used to say the prime lamb industry is reliant on Merino genes but the only Merino genes that will make the grade in the prime lamb industry will be those that are good enough,’’ he said.
‘‘We are no longer reliant on first-cross ewes — less than 10 per cent of the ewes nationally are Merinos joined to Border Leicester rams.
‘‘Only 40 per cent of the ewe lambs born in Australia are pure Merino so we are effectively ending up with a self-replacing meat flock and a Merino industry.’’
To boost lamb survival, Dr Trompf suggested using measurable practices including pasture assessment, condition scoring ewes, scanning for multiples, differentially managing ewes based on nutritional requirements, preparing energy budgets and quantifying lamb losses.