Cattle can be bred to sweat more so they will be affected less by heat, therefore growing bigger and being more productive, new research has shown.

A new paper published in the Journal of Animal Science and Biotechnology is based on a study of the genetic sweat gland characteristics of cattle and how these can be used to manage the impact of climate change on livestock.

It used 2,401 Brangus (a cross between Brahman and American Angus) cattle from two commercial farms in Florida.

The paper states that heat stress in subtropical regions is a major limiting factor in beef cattle production systems, with around $369m being lost annually due to reduced performance.

Heat stress causes numerous issues, it added, including reduced feed intake and decreased production levels.

Genetics

Precise genetic characteristics that contribute to an animal’s ability to manage heat stress were calculated from skin biopsies.

All animals were genotyped and software was used to estimate genetic parameters. A significant amount of genetic variation was found.

The results indicate that both Brahman and Angus genetics contribute positively to sweat gland traits.

“Understanding and utilising genetic traits that confer better heat tolerance is a proactive approach to managing the impacts of climate change on livestock farming,” the paper said.

Tropical locations

Approximately 45% of beef cattle operations in the US are located in tropical and subtropical locations in the south and southeastern states.

In these environments, cattle compensate for hotter conditions through eating smaller meals and shifting feed intake to cooler parts of the day.

Feed intake has been reported to decline when temperatures reach 25°C to 27°C.

“Traits related to sweating competence are important to an animal’s ability to tolerate hot and humid conditions, with heat-adapted cattle capable of increasing sweating rapidly as soon as the skin temperature begins to rise,” it said.

Management strategies such as providing shade, fans and water are widely used in the US dairy industry to reduce heat stress, but these are costly and difficult to implement in beef cattle operations due to the extensive nature of the production system.