Kentucky’s high temperatures and humidity can greatly impact herd health. Cows often show decreased conception rates, decreased duration and intensity of estrus, decreased calf birth weight, and increased early embryo mortality when experiencing heat stress. Cattle suffering from heat stress spend less time grazing and consume less feed, which means lower gains, decreased milk production, and lower overall performance.

Signs of Heat Stress

• Slobbering
• High respiratory rate (panting)
• Open mouth breathing
• Lack of coordination
• Trembling
• Increased water intake with reduced feed intake
• Increased respiration rate (90 breaths per minute)
• Milk production and gains are reduced as feed intake decreases. 

Solutions to Heat Stress

• Providing shade can reduce heat loads on cattle up to 30%.
• Shade from trees is ideal, but may not be available in many situations. Providing artificial shade is an effective substitute.
• Turning livestock into pastures without shade during the evening and night is a simple strategy to reduce heat stress. Typically these cattle are in a temperature-controlled barn during the day or on pasture with shade.
• Providing cool drinking water at all times to maintain performance. This can be done by increasing circulation of water in tanks or preventing direct sunlight to water in tanks.

Types of Shade

• Natural - The least expensive type of shade would be existing trees. Though they are good at blocking incoming solar radiation and the leaves help cool surrounding air, they are not always where you need them. Congregating cattle can cause areas of intense erosion and reduce effective utilization of pasture. In order to prevent this problem rotate cattle from tree-lined areas with natural shade and provide other shading methods.
• Permanent - Shade that is provided by barns or sheds. In a grazing system, permanent shade in pastures is costly and least efficient.
• Portable - Another way to provide shade to your animals and utilize pasture is using portable shade systems. These structures can be built from pipe and welded into a frame. Shade cloths, which block 80% of the sun, cover these structures. They are easily moved and relocated within your pasture.

Categories: 
Summer
Grazing Considerations