Taking heat stress out of cows
With the advent of climate change, dairy farmers could expect to be dealing with more days where their cows are suffering from heat stress.
As temperatures soar, farmers are being urged to review feed plans and consider what supplements could help reduce the impact of heat stress on their cows.
Heat stress not only impacts a cow's milk production, but the resulting loss of body condition can have a detrimental and longer-term flow on effect.
"If cows lose body condition now, it can potentially affect them throughout the remainder of the season as they play catch-up before calving and into the next season's mating," says GrainCorp technical support manager, Glen McFarlane. "In-calf cows under stress and under fed at this time of year can reabsorb the foetus. Body condition loss now will come at a cost later when you need to put it back on."
Dairy cows are generally comfortable between four and 20 degrees Celsius. But as soon as the temperature rises, cows use a lot more energy, generating heat as they digest their feed, which makes them run hotter.
McFarlane says there are some simple things farmers can do to combat heat stress and maintain cows' energy levels.
"I'd suggest reviewing your feed plan so you're using more feed in the cooler part of the day and feeding concentrates as it gets hotter in the afternoon.
"Using supplements like molasses, salt and Levucell SC can also improve dry matter intake and fibre digestion. They are ideal for complementing a good nutrition programme and maintaining good production over the summer months.
"Molasses provides energy, while salt helps cows regulate their temperature. Products like Levucell SC make fibre digestion easier, reducing the amount of heat produced by the cow.
"Reviewing your cows' diet to ensure they're not eating too much feed that is high in neutral detergent fibre (NDF) is important as these feeds take a lot more energy to break down."
He also encourages farmers to spend time looking at their cows' breathing to assess if heat stress is an issue.
"A good visual assessment for heat stress is to take note of how many breaths they take in 10 seconds. Around seven breaths is good, but if it's closer to 10, the cow is likely suffering from heat stress."
Cows suffering from heat stress may also stand around rather than grazing or may be slow in walking to the milking shed. McFarlane says these indicators are often seen before heat stress impacts milk production levels.
Along with reviewing feed plans and supplements, McFarlane reminds farmers to keep doing the basics well.
"Make sure there is plenty of shade for animals, including at the milking shed, and using sprinklers together with fans in the shed.
"You could also consider shifting milking times to avoid cows standing in the shed during the hottest parts of the day."
He encourages farmers to contact their feed company if they have questions about managing heat stress and what supplements could help maintain cows' body condition and minimise production loss.
Foot and Mouth Disease outbreaks could have a detrimental impact on any country's rural sector, as seen in the United Kingdom's 2000 outbreak that saw the compulsory slaughter of over six million animals.
The Ministry for the Environment is joining as a national award sponsor in the Ballance Farm Environment Awards (BFEA from next year).
Kiwis are wasting less of their food than they were two years ago, and this has been enough to push New Zealand’s total household food waste bill lower, the 2025 Rabobank KiwiHarvest Food Waste survey has found.
OPINION: Sir Lockwood Smith has clearly and succinctly defined what academic freedom is all about, the boundaries around it and the responsibility that goes with this privilege.
DairyNZ says its plantain programme continues to deliver promising results, with new data confirming that modest levels of plantain in pastures reduce nitrogen leaching, offering farmers a practical, science-backed tool to meet environmental goals.
'Common sense' cuts to government red tape will make it easier for New Zealand to deliver safe food to more markets.