Genetic Analysis of Several Economically Important Disease Traits in German Holstein Cows
In the present study several disease categories were analysed. Data recording ends after 50, 100, or 300 days in milk. Furthermore, the impact of increasing numbers of daughters per sire (improved genetic structure of the data) was examined and genetic correlations between disease categories were estimated. Diseases were clustered into fertility diseases, udder diseases, metabolic diseases, and claw and leg diseases. In addition, all diseases were analysed simultaneously. Frequencies of the disease categories were moderately high and vary between 7% and 78%. The most frequent disease categories were fertility diseases and udder diseases. Heritabilities for all diseases varied between 0.03 and 0.05, and were 0.02 to 0.05 for fertility diseases, 0.06 to 0.08 for udder diseases, 0.08 to 0.16 for metabolic diseases, and 0.01 to 0.03 for claw and leg diseases, respectively. The genetic correlation between disease categories ranged from – 0.18 to 0.82.