Possible Relationships Between the Physical Conditions of Cattle and the Occurrence of Structural Modifications of Their Coat Hair

The study investigated the effects of vitamin A deficiency, various diseases, and pregnancy on the structure of coat hair in Japanese black cattle and Holstein cows. It was found that when vitamin A levels were significantly reduced to about half of the minimum adequacy level of 20 μg/dL, there was interference in the self-assembly of keratin fibrils, indicating a change in hair structure due to vitamin A deficiency. Additionally, structural modifications were observed in the keratin fibers of cattle with chronic renal failure. Pregnant cows exhibited stronger hair than non-pregnant ones at the same diameter, suggesting that pregnancy may enhance hair formation despite potential increases in cortisol. X-ray diffraction measurements also showed structural changes in the coat hair of non-pregnant cows with inferior tensile properties. The study concludes that vitamin A deficiency can alter hair structure, while pregnancy seems to support regular hair formation, implying that hair can act as an indicator of health status in cattle.