During these long summer days one of the dilemmas facing area farmers is heat stressed cattle. Robert Seay, Agriculture Extension Agent with the University of Arkansas, offered a few suggestions for farmers whose cattle are exposed to problems caused by heat stress. Seay said, "Heat stress can affect the milk cattle produce and the function of their bodies. If the herd is heat stressed their consumption drops and there is no way to maintain a good body gauge."
Seay added that heat doesn't effect the energy requirement of cattle exactly, but cattle aren't able to spend enough time grazing. He explained if they cannot pasture as long they will fail to meet the energy demanded of them to milk their calves and to maintain their body. "If cattle are heat stressed they lose the ability to produce sufficient milk for their growing calf and it also effects their ability to rebreed," Seay said.
When cattle lose the ability to produce sufficient milk for their growing calf there are significant economic setbacks for farmers to consider. Ideally, a cow should calve each year, but if the mother cow is not producing enough milk the weight of the calf is in jeopardy.
Also, Seay touted Arkansas' quality genes in cattle. However, heat stressed cattle do not capture the best traits that they could receive.
Heat stress occurs mostly during the summer months. The high temperatures of June and July are considered out of ideal range for cattle. Ideally, the temperatures of late March and early April are the best for cattle. However, April is a difficult month in another way – that is when fescue begins to develop in the pasture.
Despite the fact that there are a variety of toxins in the environment that affect animals, fescue growth contributes to the internal heat stress in cattle, whereas temperature and humidity affect the external heat stress. Endophyte fescue elevates body temperature in the cattle due to the release of toxins in the cow's system.
"The best way to manage fescue is to try to dilute it with crab grass, orchard grass or clover. If the farmer can come up with new forages that will grow and compete with the fescue it will give the cattle something to sustain them without jeopardizing their milk/weight," said Seay.
Another one of Seay's concerns is that farmers do not consider the toxins when evaluating their cattle. They attribute a limp, for example, to a cow getting caught in the wire when it could be fescue foot.
Farmers are faced with the question on how to eliminate heat stress in their cattle in order to receive the strongest productivity from their herd. Seay stressed that farmers should be cautious of letting their cattle cool off in standing water. Aside from reducing time the cow is grazing or the calf is nursing, another big concern here is water quality. Everyone is familiar with the debate as to whether or not farmers should fence their cattle out of the water. Seay said fencing the cattle is more of a question of annual expense. He believes that if a farmer loses their fence due to external forces such as wind, flood, etc, then they are also incurring an added expense. Seay suggested an alternative to water: "One of the best ways to eliminate heat stress is to install supplemental shading where the cattle are maintained, such as portable shields."
