Digital characteristics in commercial dairy herds fed metal-specific amino acid complexes.

Five commercial dairy herds in Central New York fed metal-specific amino acid complexes were selected to evaluate digital characteristics. During the first year (period 1), herds were evaluated by a specific procedure by one individual. Three herds were not supplemented and two herds were supplemented with zinc methionine. During the subsequent year (period 2) all herds were switched to a combination of zinc methionine, copper lysine, manganese methionine, and cobalt glucoheptonate and evaluated in the same way as during period 1. There was no effect of period on incidence of heel erosion and interdigital dermatitis. During period 2, there was a reduced incidence of double soling, white line separation, sole hemorrhages, sole ulcers, and papillomatous digital dermatitis, and the incidence of wall ridges tended to be reduced compared with period 1. There was no effect of period on the incidence of abaxial wall lesions, digital arthritis, or foot rot, although the overall incidence of these disorders was low. During period 2, when cows were fed a combination of complexed trace minerals, there was a general reduction in the incidence of digital disorders associated with the laminitis syndrome complex compared with period 1; however, other time-related differences existed that may confound interpretation.