Weaning cattle and sheep to conserve feed and condition
Graziers are being urged to wean lambs and calves onto high-quality diets now to make the most of feed on offer and arrest falls in condition after summer storms stripped nutrition from standing feed across much of south-eastern Australia.
Elders livestock production manager Rob Inglis, who is based in Wagga Wagga, said stock were rapidly losing condition, particularly those with offspring at foot.
“The rain has washed a lot of the soluble carbohydrates out of the feed and there’s only just enough energy to maintain a dry cow or dry ewe, so any extra energy drain due to lactation is causing quite rapid body condition loss on the dam,” he said.
As well as taking a toll on breeders, Mr Inglis said the production of milk was a very inefficient way to feed young stock.
“If they’re at least 40 per cent of their adult weights, they really should be weaned, because it’s a waste of food to leave them on their dams at the moment,” he said.
A ewe and lamb together had a dry sheep equivalent (DSE) of about 3-3.5 but, once split, accounted for just 2 DSE. Similarly, a cow and calf set were 18 to 25 DSE but, once separated, each former pair amounted to just 12 DSE.
“Your stocking rate’s increased by about 20 to 30 per cent if you delay weaning,” he said.
Mr Inglis said earlier weaning also had real animal welfare and reproductive benefits.
“We know that it takes three times more feed to put weight on than it does to maintain it,” he said.
“The earlier you wean, the less time it takes to get females back into a condition score that gives them enough buffering to ensure that they have a lamb or a calf the following year.
“Preservation of the female looks after next year’s progeny.”
The impact of weather on the welfare of the weaners should also be considered, Mr Inglis said.
“Some people wait until the cattle are 300 kilograms and that might take them into February or March, when the weather’s really hot and feed is at its lowest point,” he said.
“If they only weight 160 to 200kg but it means you can do it in December or January, when the conditions may be less challenging, go early.
“And if you really have to wean during the hotter months, be careful to choose a week where the weather forecast is relatively benign.”
Mr Inglis said the weaning process needed to be carefully planned and begin with a 10-day introduction of a supplement before lambs or calves were yarded so their rumens could adapt to the new diet.
They needed a high-protein and high-energy diet during weaning that would maintain body scores and ensure the lifetime fertility of weaner females whose reproductive systems were still in development.
The yards needed to be big enough to allow 10 square metres per calf or 3m2 per lamb, he said, and separation of the mob into at least two groups by weight, so smaller animals were not bullied.
It was also an important time to ensure vaccinations, mineral status and drenching was all up to date.
“Obviously, weaning is a stressful event, so we need to minimise any other stress for their immune systems,” Mr Inglis said.
“Watch out for Bovine Respiratory Disease, which is the bane of most intensive cattle feeding systems.”
The symptoms of the disease include depression and loss of interest in surroundings, lethargy, droopy ears, discharge from the eyes, nose and mouth, as well as coughing and rapid shallow breathing.
Get in contact with your local Elders livestock production manager