Finding value in older cows
New research shows that holding onto mature-aged cows in dairy herds could increase milk production — and it’s not a point that is lost on Katunga farmer David Beer.
He has 13-year-old Holsteins in his herd and is holding on to them, simply because they are producing so well.
Like many other dairy farmers, Mr Beer holds no prejudice against the age of the cow if she can continue to make a contribution.
One of the 13-year-olds is producing 32 litres In her current lactation and is coming close to a lifetime total of 100,000 litres.
“She’s not very attractive, but she is holding her own with production.”
Mr Beer said one of the biggest challenges for older cows was fertility, and when they didn’t get in-calf for successive years they would be moved out.
He and wife Sue run a 170-head herd on 128 hectares of pasture with 6kg/day of supplementary feed in the bail.
At Stanhope, farmer Craig Emmett lost a great cow from his herd earlier this year, at the age of 17.
“She was a beautiful type,” Mr Emmett said of the Jersey.
“She just kept on getting in-calf.
“She calved in February and was looking good. But she developed toxic mastitis and died within 24 hours. It was a shame; she was a ripper.”
Adjunct Professor Ian Lean shared the potential of the ‘geriatric cow’ as part of the online Dairy Research Foundation 2021 Symposium highlighting the work of Dairy UP.
Dairy UP is a new collaborative body established in NSW for industry research, development and extension.
The managing director of livestock consulting firm Scibus, Prof Lean is leading a team researching the ability to predict and prevent disease in dairy herds.
The aim of this work is to reduce the ‘wastage’ of old cows, while enhancing the potential to improve production and reproduction.
This work will draw on a dataset of more than 36,000 cows, with detailed health and production data, from more than 13 studies across Australia, Canada and the United States.
“Farmers will be able to be more selective about what animals they retain because they won’t have to bring as many replacements through, because this work is controlling the risk of removal,” Prof Lean said.
“It can be a game-changer and if it’s used with sexed semen and beef then there’s the opportunity to get crossbred steers and heifer sales, a chance for income diversification.”
With only 10 per cent of cows milking for five lactations or more, dairy herds are now younger.
Prof Lean said this was potentially robbing farmers of production and costing money.
He blamed disease and reproduction failure for this industry trend.
“The idea that dairy farmers are getting paid very well for older (cull) cows, and then bringing in potentially new genetics, that just doesn’t add up,” he said.
“A first lactation heifer, even if she’s smoking-hot, will only produce around 85 per cent of third lactation cows.”
Working towards reducing disease and other factors that result in the culling of an older cow would not only result in a consistently higher yielding herd, but this would also reduce costs.
Cost reduction opportunities include rearing fewer replacements and less time and money spent treating sick animals.
Prof Lean said this research would take the 36,000-cow dataset and break it down by age to quantify the risk factor for illness and reproduction failure.
Researchers would drill down to an individual cow level searching for the key risk factors.
RESEARCH HAS FOUND
Cows that have had five or more calves are 2.5 times less likely to be mated than cows that have had one calf.
A cow that’s had five or more calves is 17 per cent less likely to become pregnant on any given day over the mating period and is 64 per cent less likely to become pregnant during a lactation.
Both low and high producing mature cows are at a greater risk of reproductive failure.
The odds of milk fever greatly increased as a cow had more calves, suggesting “profound differences” in metabolism with increased lactations.
Cows that have had three calves are 3.5 times more likely to contract milk fever, if they’d had four calves this increased to 8.6 times, and they are 20.2 times more likely if they’d had five or more calves.
The risk of retained placenta, mastitis, lameness and ketosis increased with the number of calves a cow had.
Heifers calving for the first time had a greater risk of dystocia, metritis and endometritis.
Source: Prof Ian Lean, Dairy Research Foundation 2021 Symposium