University of Waikato research reveals 2050 drought threats
New research could help farmers prepare for a future where summer rainfall is increasingly unpredictable and where drought risk is rising, no matter what.
Current NIWA soil moisture deficit maps show soil moisture levels are significantly below historical averages across the upper North Island, parts of the Waikato, Taranaki, Manawatū, the North Island’s East Coast, Marlborough, Canterbury and Otago.
“Ongoing dry weather can be stressful for farmers,” says DairyNZ’s strategy and investment leader, Dr Bruce Thorrold.
“Planning ahead for how to respond if the dry conditions continue will allow farmers to consider their options and provide confidence about having a plan in place.
“The use of supplements needs careful consideration, taking into account the costs and benefits, including to cow health.”
Farmers looking at using supplementary feed to fill a feed deficit should consider a number of issues to ensure it is used profitably:
• calculate the maximum supplement price that is affordable (including additional costs associated with supplement use), while still achieving performance goals
• manage the amount of supplementary feed used to achieve post-grazing residuals of seven clicks (1500 kg of dry matter per hectare) or less on the rising plate meter, to ensure minimal substitution of pasture
• reduce feed demand by reviewing stocking rates and moving unwanted stock off-farm.
“Heat stress has a real impact on cows and it is one of the key factors affecting milk production, but farmers can take steps to manage this,” says Thorrold.
When temperatures are over 21C and humidity is over 70 percent, Friesians and crossbreeds begin to feed less, and milk production reduces. In Jerseys, production losses only occur when temperatures rise to 25C or more.
To help keep cows comfortable in warm weather, farmers can:
• ensure ample water is available to cows both day and night by checking flow rates to water troughs are high. Lactating cows need 100 litres per cow per day
• provide shade. Many farmers also use sprinklers and fans in dairy sheds to cool cows
• avoid giving high fibre feed to cows during the daytime, as it increases heat load
• change milking times to avoid the heat of the day. Moving to once-a-day milking or three milkings over two days is worth considering as an option.
“Farming through dry conditions does create uncertainty which can be stressful for everyone on a farm,” says Thorrold.
“Take care of yourself and your team by planning for everyone to have regular time off to help you farm through a difficult time.”
