Key points
- Only 10pc of cows milking for five lactations or more
- Older cows produce more milk
- Reproductive failure and disease key reasons
RETAINING the best performing older dairy cows without the increased risk of illness or reproduction failure that can come with age is the aim of new research.
This would mean fewer heifers entering a herd, ensuring that those retained as replacements were truly superior genetics.
Dairy herd managers would have more choice about the animals they milked, reared and bred.
Retaining more older cows could see milk production lift 16 per cent, while providing farmers with 8pc more calves or heifers to sell.
This also opens the door to an expanded dairy-beef income stream, while working to reduce the dairy industry's environmental footprint.
This is the future of Australia's dairy industry and its possible thanks to DairyUp - a new collaborative NSW industry research, development, and extension program.
Adj. Prof. Ian Lean shared the potential of the "geriatric cow" as part of the online Dairy Research Foundation 2021 Symposium in November highlighting the work of DairyUp.
The managing director of livestock consulting firm Scibus, Adj. 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," Adj. 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 cross-bred steers and heifer sales, a chance for income diversification."
With only 10pc of cows milking for five lactations or more, dairy herds are now younger.
Adj. Prof. Lean said this was potentially robbing farmers of production and costing money.
He blamed disease and reproduction failure for this industry trend.
A first-lactation heifer, even if she's smoking-hot, will only produce around 85pc of third-lactation cows.
- Adj Prof Ian Lean
"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 85pc 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 would also reduce costs.
Cost reduction opportunities include rearing fewer replacements and less time and money spent treating sick animals.
Adj. 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.
Some initial findings from the research includes:
- 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 17pc cent less likely to become pregnant on any given day over the mating period and is 64pc 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 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.
Want to read more stories like this?
Sign up below to receive our e-newsletter delivered fresh to your email in-box twice a week.
