An unprecedented combination of soaring temperatures and prolonged drought is pushing the island’s dairy herds into critical heat stress, forcing cows to divert energy from milk production to temperature regulation, the president of the Dairy and Beef Producers Association has warned. As climate change intensifies extreme weather events across global agricultural sectors, industry head McDonald Stevenson is calling for urgent, proactive changes across the sector to buffer the dairy industry from the worst impacts of the ongoing scorching heatwave.
Stevenson emphasizes that while milk yields have dropped measurably due to heat stress, current consumer milk supplies remain secure for the time being. This unexpected stability stems largely from two key factors: the seasonal rhythm of dairy production and rapid adaptive steps taken by farmers already. The island’s traditional calving season, which runs through December to build up supply for the holiday shopping period, is already well underway. This natural cycle has increased the number of cows entering lactation, which has offset lower individual yields and kept overall production volumes steady.
The physiological toll of the persistent heatwave on cattle is far more severe than many outside the industry recognize, Stevenson explains. Daily temperatures regularly climb above 90 degrees Fahrenheit, and Stevenson notes that cows begin to experience harmful heat stress once temperatures hit just 70 to 80 degrees Fahrenheit—far lower than the threshold at which humans feel significant discomfort. Unlike human handlers, bovines are extremely sensitive to even small temperature increases, and the relentless heat offers little reprieve: high daytime temperatures often carry over into warm nights, leaving cows no chance to cool down and recover.
This constant thermal strain directly cuts into milk output, as the energy cows would normally use to produce milk is rerouted to basic thermoregulation and biological survival. When an animal’s entire biological system is focused on staying cool, reduced productivity is an unavoidable outcome. The heatwave is not just impacting dairy cattle, Stevenson adds; even livestock traditionally considered tolerant of warm climates are struggling. Sheep, which are often assumed to handle high heat well, are now spending peak midday hours clustered in shade rather than grazing, a clear sign of widespread thermal stress across all grazing herds.
To address these growing climate-driven challenges, Stevenson is pushing for sweeping, systemic changes to livestock infrastructure. He stresses that simply acknowledging the reality of climate change is not enough—immediate on-the-ground action is required to protect herds and preserve production. “If we really want to make a difference, we need to concentrate heavily on housing. Housing is critical for any animal,” he says.
Adequate shade and active cooling systems are no longer optional upgrades for dairy farms, they are an absolute necessity, Stevenson argues. He is calling on producers to construct purpose-built cattle housing with naturally ventilated, open-roof designs that allow air to flow freely through enclosures, alongside adding mechanical cooling tools such as sprinkler systems that actively wet cattle to lower their body temperatures.
In addition to infrastructure overhauls, Stevenson is advocating for a shift in breeding strategy, urging producers to prioritize domestic breeding of locally acclimatized cattle over importing foreign herds. Despite previous imports in 2020 and 2024, he argues that bringing in cattle from other regions carries unacceptable risks, including major biosecurity threats and difficulty acclimatizing to the island’s hotter, drier new climate pattern. “I don’t like the idea that we have to import cows because when you bring cows, you bring something with them — some little bug all the time,” Stevenson says. He adds that imported cattle struggle to adapt to the island’s current extreme heat, making local breeding the only safe, sustainable path forward. Most farmers have already shifted their focus to raising more locally bred heifers, he notes, building a steady pipeline of heat-adapted milk-producing cattle for the future.
Beyond the direct threat of heat stress to cattle, Stevenson highlights a second, growing crisis: the devastating impact of the prolonged dry spell on pasture growth. High-quality fresh grass is a foundational input for healthy, productive dairy cows, and the ongoing lack of rain has severely stunted grass growth across the island. While brief, scattered showers have triggered temporary sprouting, the immediate return of scorching temperatures kills off the new growth almost immediately. Soils remain cracked and depleted of deep moisture, and Stevenson warns that if significant sustained rainfall does not arrive soon, the island’s agricultural sector could face a critical livestock feed shortage by the end of 2025.
To prepare for this potential feed gap, Stevenson advises farmers to adopt a flexible, opportunistic approach to forage management. Instead of waiting for grass to reach its ideal harvest height, he urges producers to cut and store whatever usable forage is available immediately. “If you sit and say: ‘Oh, I can wait for it to grow another three inches,’ with the heat, it comes in scorching the grass all the time, so you’re not getting the growth,” he explains. Cutting and storing existing forage now will at minimum build a baseline feed reserve, he says, and also clears pastures to make space for fresh new growth when rain eventually arrives, which is expected in October.