Analysis of effects influencing length of productive life in Holstein cattle

PÁCHOVÁ, E. & DĚDKOVÁ, L. Vyhodnocení faktorů působících na dlouhověkost u holštýnských dojnic. Náš chov. 2004, roč. 63, č. 2, s. 20-21.
PÁCHOVÁ, Eva and DĚDKOVÁ, Ludmila. Analysis of effects influencing length of productive life in Holstein cattle. Náš chov, 2004, vol. 63(2), p. 20-21. ISSN 0027-8068.
Year2004
CathegoryPublication in specialized journals
Internal link4214.pdf
Abstract

The aim of the present study was to inform about longevity, its impact on economy of cattle breeding and the trends in foreign countries. It was described by survival analysis, Cox regression. Analyses were carried out using SAS and Survival Kit. Date set included 290 834 cows of Holstein breed. The analyzed factors were number of lactation and stadium of lactation (time dependent variables) and age at first calving, herd and culling reason (time independent variables). The model explained 58 % of the variability of the lenght of productive life (LPL) and all variables showed significant effects.