Rates of hoof growth and wear in Holstein cattle.

Rates of hoof growth and wear were recorded on 223 Holstein cows in two herds during 20 mo. Herd 1 was mainly on pasture or dirt lots, and herd 2 was completely or partially confined in a new freestall facility. Growth and wear were measured on both dorsal and lateral surfaces of front and rear outside claws. Lateral measurements were taken 1 cm in front of the junction of wall and heel. No differences were detected in rates of hoof growth for various places on the dorsal wall. Herd effects influenced rates of growth and wear. Cow differences were not significant for hoof growth but were for a few wear rates. Monthly rates of dorsal hoof growth during first lactation were 6.04 mm for front claws and 6.58 mm for rear claws. Corresponding monthly wear rates were 5.78 and 6.11 mm, respectively. Wear rates on front and rear claws decreased with advancing stage of lactation. Front hooves grew and wore less than rear hooves. Lateral walls grew faster and wore more than dorsal walls on both front and rear hooves. Cows completely confined had higher rates of hoof growth and wear than cows on pasture. Rates of growth and wear were lowest during winter and highest during spring and summer.