Analyse von Gesundheitsmerkmalen in verschiedenen Prüfabschnitten des Nachkommentests auf Station bei Deutschen Fleckviehbullen
Title of the paper:
Analysis of health traits in different lifetime classes in stationary progeny tested German Fleckvieh bulls
The objective of this study was to analyse systematic environmental and genetic effects on the incidence and number of treatments due to bronchopneumonia and other diseases for five different age groups in German Fleckvieh bulls. The data set contained 1775 male calves kept under identical housing and management conditions from the age of about 25–50 days to 450 days for a stationary progeny test in growth and carcass traits. The age groups distinguished were from day 10–75 (1), 76–100 (2), 101–150 (3), 151–200 (4) and > 200 (5) of age. Fixed environmental effects tested for significance in generalized or general linear models were barn at entry, age at entry, region of origin, season of entry, diagnosis of bronchopneumonia at entry, test group within year of entry and weight at entry. Heritabilities were estimated in linear multivariate animal models using Residual Maximum Likelihood (REML). The multivariately estimated heritabilities for the incidence of bronchopneumonia were between h 2 = 0.22 (first age group) and h 2 = 0.07 (fourth age group). The DEMPSTER and LERNER (1950) transformation resulted in estimates of h 2 = 0.34 for the first and h 2 = 0.13 for the fourth age group. The additive genetic correlations varied from r g = −0.76 (2nd–5th age group) to r g = 0.78 (1st–3rd age group). The lowest value of the residual correlation was r e= −0.05 (1st–4th age group) and the highest value was r e = 0.16 (4th–5th age group). The multivariately estimated heritabilities for the number of treatments due to bronchopneumonia were highest in the first age group with h 2 = 0.29 and lowest in the fourth age group with h 2 = 0.08. The additive genetic correlations ranged between r g = 0.64 (1st –3rd age group) and r g = −0.33 (2nd–5th age group). The residual correlations were between r e = −0.11 (1st–3rd age group) and r e = 0.33 (4th–5th age group). Genetic differences among animals in resistance to bronchopneumonia are expressed most clearly in the lifetime period between day 40 and 150.