Variability of linearly evaluated traits of type of simmental bull dams

Abstract

One of the important factors of successful milk production is group of secondary traits: health, longevity, type and milking traits. These traits have become increasingly significant. In order for productive life of cows used in production of milk to be as long and as successful as possible, special attention must be directed to traits of body type and constitution. In selection of cows into the category of bull dams all heads are measured - exterior traits, and evaluated linearly for traits of type or body frame, body muscular characteristics/muscularity, form (appearance) and udder according to Regulation on method of evaluation of traits of breeding livestock (Official journal of RS, No. 21,1996). The effects of rearing region and year of measuring, i.e. evaluating were analyzed in detail using the Least Squares Method (Harvey 1987). Average values of linear evaluations of investigated heads obtained by method of Least Squares were: body frame 7,85; muscularity 7,74; form 7,66; udder 7,62. The effect of region on linear evaluation was highly significant (P (lt) 0,01). Evaluation year also influenced highly significantly (P (lt) 0,01) obtained evaluation result for form, significantly (P (lt) 0,05) obtained evaluation result for body frame and muscularity, but no effect was established on evaluation result for udder.

Da bi produktivni život krava usmerenih za proizvodnju mleka bio što duži i uspešniji posebnu pažnju treba posvetiti osobinama tipa i konstitucije. Nedostaci u osobinama tipa dovode do slabije proizvodnje, lošeg zdravstvenog stanja i preranog isključenja krava iz stada. Uključivanje linearne ocene tipa u oceni priplodne vrednosti krava doprinosi pouzdanosti ocene priplodne vrednosti što se pozitivno odražava na ukupne efekte selekcije i uspešnosti proizvodnje. Pri izboru krava u kategoriju bikovskih majki sva grla su eksterijerno izmerene i linearno ocenjene za okvir, muskuloznost, formu (izgled) i vime u skladu sa Pravilnikom o načinu ispitivanja svojstava priplodne stoke (Službeni glasnik RS br. 21 iz 1996.godine). Na ispitivane linearne ocene detaljno su ispitani uticaji odgajivačkog područja i godine merenja, korišćenjem Metoda najmanjih kvadrata (Harvey 1987 ). Prosečne vrednosti linearne ocene ispitivanih grla dobijene metodom najmanjih kvadrata su: okvir grla 7,85; muskuloznost 7,74; forma 7,66; vime 7,62. Uticaj regiona na linearne ocene bio je vrlo značajan (P (lt) 0,01). Godina ocenjivanja je visoko značajno uticala (P (lt) 0,01) na ocenu forme, značajno (P (lt) 0,05) na ocenu okvira i muskuloznosti, a na ocenu vimena nije imala značaj.