The effect of biotin and zinc supplementation on dairy cow hoof health and milk quality

The objective of this field study was to evaluate the effect of biotin and zinc sulphate (ZnSO4) supplementation on hoof health and milk quality in lactating dairy cows. Clinically lame (n = 31) and healthy (n = 28) cows were selected on the basis of locomotion scores (LS), and were randomly assigned to either the 'treatment group' [clinically lame treatment (CLT) = 17 and healthy treatment (HT) = 15; supplemented with 1 g of 2% biotin and 4 g of ZnSO4 daily for 4 mo] or the 'control group' [clinically lame control (CLC) = 14 and healthy control (HC) = 13]. Locomotion scores, body condition scores, and milk quality and yield were estimated before and after the end of the study. Also, hoof trimming was undertaken before and after the supplementation period, and claw lesions were observed for type and severity. Sole thickness (ST) was measured by ultrasonography in some of the back claws in treatment and control cows. Data were analyzed using likelihood ratio Chi-square and paired t tests. At the end of the study, there was a significant improvement in the LS (P<0.001); heel horn erosion score (P<0.05); overgrown sole score (P<0.001); and sole haemorrhage score (P<0.01) in the CLT cows. Some of these lesion scores deteriorated in the HC cows. Sole thickness increased in the CLT cows (P<0.05), whereas it decreased in the CLC cows (P<0.05). The milk somatic cell count (SCC) decreased (P<0.05), whereas milk yield (P<0.001) and fat content (P<0.05) increased in the CLT cows. A significant decline in the average SCC (P<0.05) in the HT was also observed. We concluded that concurrent supplementation with biotin and ZnSO4 seems to be beneficial for correction and prevention of claw lesions, as well as improvement of milk quantity and quality in clinically lame dairy cows.