The SLICK Gene in Holstein Cattle Improves Thermotolerance

By: Colleen Larson

Regional Dairy Extension Agent, Okeechobee County

Colleen with SLICK gene dairy cow.
Colleen with SLICK gene dairy cow.

The SLICK gene is a mutation in a prolactin receptor that causes animals to have shorter hair. In the 1980’s Florida dairy farmers and UF Animal Scientists found that breeding Holstein cows to Senepol semen resulted in some offspring with slick haircoats. The University of Florida dairy unit and animal science researchers have developed homozygous SLICK bulls for commercial use. Research is ongoing to determine the thermotolerance benefits of the SLICK gene.

Want to learn more? Watch February Ona Highlight that featured Colleen giving this presentation. Run time is 36.29 minutes. You can also access it directly on YouTube here:

Colleen  is a regional dairy extension agent in Okeechobee, FL. If you have questions, you can reach her at


Andrea Dunlap, Educational Media/Communication Coordinator at the UF/IFAS Range Cattle Research and Education Center (RCREC)
Posted: February 22, 2022

Category: Agriculture, Livestock

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