engleski

Phenotypic trends for the mass, height at withers and chest depth of one year old Simmental bulls in performance test from 1975 to 1995.

Since the first Croatian cattle-breeding program dating from 1973 (Juric et al., 1973), for the Simmental cattle, growth traits have been tested with the performance test (Station in Varazdin). Although there are several studies related to growth traits and body size no systematic analysis of the realized genetic gain nor the evaluation of the breeding program has been taken in the past 28 years. During the last decades economic situation was more favourable at the meat type while selected bulls (mainly imported) were mainly of dairy type. The aim of this paper was to set up phenotypic trends for the traits (mass, height at withers and chest depth) and thus to analyze the type of cattle (meat versus dairy type) Simmental breed in Croatia is going toward in the period of 21 years (from 1975 to 1995). The analysis was related to the measurements of the one-yearold bulls (around 1000) from the Performance test station Varazdin. Significant negative linear regression coefficients were obtained for the mass (b = -0.928, RZ = 0.026) as well as for the chest depth (b = -0.091, RZ = 0.078) while there was significant positive regression coefficient for the height at wither (b = 0.064, RZ = 0.078) for the models where season was considered as a fixed effect. Very similar estimates were obtained in the models without season as a fixed effect. The obtained estimates suggest that Simmental population was moving more toward dairy type. However, explained variation in the model was low and the models with included genetic factors would be necessary to confirm obtained trends.

Cattle ; bulls ; breeds ; Simmental ; fenotipe

nije evidentirano