The effect of paragenetic factors on longevity traits of simmental cows

Abstract

The effect of paragenetic factors on longevity traits was investigated in Simmental cows housed at the "Zlatiborski Suvati" farm. The effect of the lactation number, the calving season and the age at first insemination on longevity traits such as the age at culling, the length of productive life the total number of milking days and the utilization index was examined. The general average (m), according to the model, for the age at culling, the length of productive life, the total number of milking days and the utilization index was 3496.31 days, 2637.14 days, 2000.43 days and 72.42 % respectively. The effect of the total number of lactations on all the longevity traits was very highly significant (P lt 0.001), whereas the calving season statistically very significantly affected only the age at culling (P lt 0.01). The age at first insemination had a very highly significant effect on the age at culling and the cow utilization index (P lt 0.001).

Uticaj paragenetskih faktora na osobine dugovečnosti ispitivan je kod 143 krave simentalske rase sa farme "Zlatiborski suvati". Na ispoljenost osobina dugovečnosti, kao što su uzrast pri izlučenju, dužina produktivnog života ukupan broj muznih dana i indeks iskorišćavanja, ispitivan je uticaj broja laktacija, sezone telenja i uzrasta pri prvoj oplodnji. Opšti prosek (m), po modelu, za uzrast pri izlučenju iznosio je 3496.31 dan, dužinu produktivnog života 2637.14 dana, ukupan broj muznih dana 2000.43 i indeks iskorišćavanja 72.42%. Uticaj broja laktacija na sve osobine dugovečnosti bio je vrlo visoko značajan (P lt 0.001), dok je sezona telenja statistički vrlo značajno uticala samo na uzrast pri izlučenju (P lt 0.01). Uzrast pri prvoj oplodnji vrlo visoko značajno uticao je na uzrast pri izlučenju i indeks iskorišćavanja krava (P lt 0.001).