longevity, length of productive life, effects, type traits, slovak simmental breed
Abstract
The aim of this study was to analyze the length of productive life in 118 646 dairy cows of the Slovak Simmental breed. The average length of productive life reached 1451 days (3.98 years). The recorded factors with most important impact to the length of productive life were: milk production at first lactation (F = 7736.88+++), year of culling (F = 4890.54) and the age at first calving (F = 2759.81). The length of productive life was significantly affected by reason of culling (F = 272.43) and the Sire (F = 53.43). The analysis of effects of exterior traits to the length of productive life was done in group of 6585 culled cows. From the main exterior traits the most important impact was recorded for body frame (F = 17.39+++), udder (F = 9.43+++) and feet and legs (F = 6.41+++). For more detail advisement was tested the influence of partial exterior traits. From the partial exterior traits the most significant effect to length of productive live had udder depth (F = 26.04+++), teats length (F = 18.49+++), teats thickness (F = 3.23+++) and teats placement (F = 3.31++). From partial traits of feet and legs the most significant effect to length of productive live had heel joint expression (F = 9.10+++) and foot (F = 5.47+++). Results from the present study confirmed the important influence of main and partial exterior type traits of Slovak Simmental breed on the productive life of cows.
