Location: Location not imported yet.Title: Estimation of genetic parameters and transmitting ability for Minnesota Johne’s milk ELISA test) Author
Submitted to: Journal of Dairy Science
Publication Type: Abstract only
Publication Acceptance Date: 3/5/2009
Publication Date: 7/12/2009
Citation: Attalla, S.A., Seykora, A.J., Cole, J.B., Heins, B.J. 2009. Estimation of genetic parameters and transmitting ability for Minnesota Johne’s milk ELISA test. Journal of Dairy Science. 92(E-Suppl. 1):20(abstr. M56). Interpretive Summary:
Technical Abstract: A total number of 45,907 results for Johne’s Milk ELISA test were received from Minnesota DHIA, of which 40,177 records were from herds with at least one positive Johne’s cow. Pedigree information was available for 19,304 Holstein cows from AIPL USDA representing 22,694 total records. Milk ELISA optical density was transformed using a natural logarithm (lnOD). Heritability, repeatability, and breeding values for lnOD were estimated fitting a linear animal model. Variables for statistical analysis were the fixed effects of test date, and age at test day and lab control OD were covariables. Herd, animal, and permanent environmental effects were random effects in the model. All fixed effects were highly significant (P < 0.001). Heritability of linOD was 0.06 ± 0.01, while repeatability was 0.34 ± 0.02. The correlations between the breeding values of linOD for 108 Holstein AI sires that had at least 30 daughters in this study and their corresponding USDA PTAs for milk, fat, protein, productive life (PL), daughter pregnancy rate (DPR) and Net Merit (NM) were calculated. The correlations between lnOD breeding values and corresponding PTAs were: milk (0.01); fat (-0.05); protein (0.0); PL (-0.26); DPR (-0.21); SCS (0.19); and NM (-0.26). These correlations suggest that selection for PL, DPR, SCS and NM could improve the resistance of Holstein cattle against Johnes disease.