Effect of selected factors on the lenght of productive life of cows

Abstract

Effect of some selected factors on length of productive life was analyzed in 181001 culled cows of Holstein breed and in 114020 culled cows of Slovak Simmental breed. In both the breeds the most important factor was the sire (F = 65.36 +++ in Holstein breed vs. F = 53.43 +++ Slovak Simmental breed) and then the effect of ram (F = 49.29 +++ in Holstein breed vs. F = 26.32 +++ in Slovak Simmental breed). The factors of milk production at first lactation (F = 30215.0 +++) and breeding group (F = 3195.74 +++) affirm direction of selection for intensive increase of milk production in the Holstein breed. The milk production at first lactation was important factor in case of the cows of Slovak Simmental breed too (F = 7736 +++). The least significant effects to the length of productive life of cows was recorded in the age at first calving (F =454.61 +++ in Holstein vs. F = 2759.81 +++ in Slovak Simmental breed) and the year of culling (F = 4004.61 +++ in Holstein vs. F = 26.32 +++ in Slovak Simmental breed). This study confirms that the most important factors affecting the length of productive life in Holstein and Slovak Simmental breeds of cows are the sire, farm and milk production.