Between and within-lactation repeatabilities for hoof lesions in Canadian Holsteins

• Published in: Journal of animal science 2016-10, Vol.94, p.179-180
• Main Authors: Malchiodi, F, Christen, A M, Kelton, D F, Schenkel, F S, Miglior, F
• Format: Article
• Language: English
• Subjects: Animal lactation; Animal models; Animals; Breeding; Cattle; Coefficients; Dermatitis; Environmental effects; Hemorrhage; Hoof; Hyperplasia; Lactation; Lesions; Parameter estimation; Pedigree; Reproducibility; Studies; Toe; Touch screens
• ISSN: 0021-8812; 1525-3163

This study aimed to estimate genetic parameters and between and within-lactation repeatabilities for hoof lesions, considering the hoof lesions as binary traits or as categorical traits, using a severity score. Hoof lesions were recorded by 23 hoof trimmers during the routine trimming activity in 365 herds located in Alberta, British Columbia, and Ontario from 2009 to 2012. The hoof trimmers were trained to use a rugged touchscreen computerized lesion recording system. The lesions included in the analysis were: digital dermatitis, interdigital dermatitis, interdigital hyperplasia, sole hemorrhage, sole ulcer, toe ulcer, and white line lesion. Hoof lesions were coded as binary traits (0; 1), where 1 was assigned to the presence of a lesion in any claw or leg or as categorical traits, using a severity score from 0 to 3, where 0 was assigned to the absence of a lesion, 1 to less severe lesions, 2 to moderately severe lesions, and 3 to more severe lesions. The edited dataset contained 107,933 observations from 53,654 animals. The final pedigree file contained 196,899 animals and included 7 past generations. Hoof lesions were analyzed with univariate animal models using the average information-restricted maximum likelihood procedure in the DMU package. Two different permanent environmental effects were included to separate between-lactation permanent environmental effects from within-lactation permanent environmental effects when multiple lactations per cow occurred. For most lesions, affected cows showed higher proportion of moderate severe cases. Sole hemorrhage and white line diseases had very similar proportion of less severe and moderate severe cases (45.8% and 41.1%; 43.4% and 40.7%, respectively). Most of the cows affected by interdigital dermatitis showed less severe lesions (75.6%), and only 1.2% of affected cows showed more severe cases of interdigital dermatitis. Heritabilities ranged from 0.005 (for toe ulcer) to 0.07 (for digital dermatitis). Heritabilities estimated considering the presence or absence of the lesion, or using a severity scale, were very similar. Repeatabilities were low to moderate, both between and within-lactation. However, they were 3- to 90-fold larger than the heritabilities. The most repeatable lesion was toe ulcer, which showed a within-lactation repeatability coefficient of 0.45, and a between-lactation repeatability coefficient of 0.36. Sole hemorrhage showed the lowest coefficients (0.10, for both within and between-lacta