Vztah mezi mlecnou uzitkovosti a vyskytem vybranych zdravotnich poruch dojnic ve sledovanych chovech v Dolnim Sasku.

Abstract

Associations between milk yield and lactation incidence of the most frequently occuring clinical diseases and health disorders of dairy cows were studied using logistic regression. data on 2197 lactations of 1074 Holstein-Friesian cows from 10 commercial herds in the federal state of Lower Saxony, which were engaged in the herd health program during the 1990s, were used for this purpose Individual milk yield in dairy cows was characterized by data on their current 305 day lactation, as well. Eight complexes of health disorders were tested, i. e. retained placenta, pathological discharges from genital organs, ovarian cysts, clinical mastitis, foot diseases, parturient paresis, clinical ketosis and abomasal displacement. Associations studied were evaluated using models for each of the disorders complex separately. In addition, other influences such as of individual herds, parity, season and other disorders complexes were also taken into consideration. In association of statistical significance between the milk yield during the current lactation and the lactation incidence of the tested disorders complexes we evaluated their possible affection by differences in primiparous individuals on the one hand and delay conception or discarding the dairy cow from reproduction on the other. In this study it is proved marked association between the previous lactation milk yield and the lactation incidence of retained placenta, mastitis and parturient paresis. The results also indicate possible association between the previous lactation milk yield and the occurence of ketosis and abomasal displacement. We also found association between the current lactation milk yield and lactation incidence of ovarian cysts and foot diseases. There were found no associations between the milk yield and the lactation incidence of pathological discharges from genital organs. The influence of parity on the lactation incidence was proved in most disorders complexes evaluated using various models. The models created make it also possible to present the influence of the milk yield and parity on the lactation incidence of individual disorders complexes. The limiting conditions of individual types of models are discussed, as well.Summary in EnglishAvailable from STL, Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi