Effect of a Salt-Block Containing Biotin on Serum Biotin Concentration and Prevention of Hoof Diseases in Dairy Cows

Introduction 
Biotin is recognized as an essential nutrient for the formation of hoof, and it promotes the keratin for production of hardened substances in hoof cells. It is suggested that in dairy cow exhibiting hoof diseases, these biotin concentration in blood is lower than normal cattle, and decreased biotin intake from fed diet also biotin production in rumen. There are many reports to evaluate the effect of biotin supplement to dairy cattle, but no report to evaluate the effect of salt-block containing biotin. In this study, we investigate the preventive effect for hoof disease, salt-block containing biotin were fed to dairy cows ad-libitum for one year, and we examined serum biotin concentration and prevention of hoof diseases. 

Materials and methods  
We used a total of 217 dairy cows (11 farms) of tie-stall form, which were raised in the four prefectures of the Tohoku district (Akita, Fukushima, Yamagata and Miyagi). Serum concentration of biotin and incidence of hoof diseases, such as sole ulcer, sole erosion, sole hemorrhage, white line disease and others, were examined in the cows administered a salt-blocks containing biotin (300 mg / kg and 100 m g/ kg, HBFB and LBFB). As a control, commercially available biotin-free and selenium-containing salt- block (SE) was used. These salt-blocks were served ad-libitum through one year. The serum biotin concentration was measured according to the commercially available biotin assay ELA kit. Each veterinarian observed the presence of hoof lesions based on the Guidelines for Agricultural Mutual Aid at the time of hoof trimming in the start of study and one year after administration. […]