Rough hair coat has long been associated with Tall Fescue toxicosis, a condition in cattle that consume endophyte infected tall fescue.  This fungus produces toxins that decrease production and make rough hair coats in cattle that consume infected fescue.  All cattle tend to get rougher hair coats in late winter, but ny April to early May, hair coats should have slacked off.  Cattle that are well suited to their environment suffer less stress.  One of the greatest environmental challenges for beef producers is heat stress.  This is especially true where relatively high humidity levels intensify hot temperatures in which cattle must cope to remain comfortable and productive.  Recent research has shown that hair shedding scores are an easy and effective way to measure cattle's ability to cope with heat stress.  Also data suggest that cattle that shed their hair coat early have a greater genetic ability to tolerate tall fescue, the predominant forage in Ky.  With this theory in mind, this agent has set up an on farm trial with a 200 cow herd with Dr. Les Anderson, Extension Beef Specialist to evaluate the cattle's ability to shed hair coats and it's implications on animal performance.  Data will be collected in a two-three year study.

Hair shedding scores are simply a visual appraisal of the extent of hair shedding and are reported on a 1 to 5 scale.  A score of 5 indicates an animal that retains it's complete winter coat and exhibits no evidence of shedding.  At the other end of the scoring scale, a score of 1 is given when cattle have completely shed their their winter hair coat and exhibit a slick summer hair coat.  The amount of the winter coat shed by Mid-May is an effective predictor of a cows ability to cope with heat stress.  Earlier shedding can be an indication of improved productivity and adaptation to the production environment.  Regardless, calves from cows that shed their winter hair coat weigh more at weaning, with some estimates as large as 24 pounds.  

Early research has found that the heritability of hair shedding has been estimated to be approximately 0.35, meaning that 35% of the variation in hair shedding is due to genetic differences.  Although a hair shedding genetic prediction (i.e, Hair Shedding Expected Progeny Difference) would be the preferres method to select for increased hair shedding, these predictions are not yet available.  But producers can still make improvements, although at a slower rate, using selection on actual hair shedding scores