Estimation of phenotypic and genetic trends of the growth traits in Lipska and Svrljig sheep

Abstract

Some phenotypic and genetic trends on growth traits of lambs are observed. The research implicated lambs of two local breeds of sheep: Lipska (LP) and Svrljig (SV). All lambs were weighed for the first time at birth (BWB), and thereafter, regularly in two-week intervals. On the basis of the results during weighing the body weight (BW) were adjusted to the average age: 30 (BW30), 60 (BW60) and 90 days (BW90). Results of the effect of genotype on growth showed a significant effect on the growth traits. Sex of lambs had a significant effect at birth and very significant effect at 30 days, but had no significant effect on weight at 60 (BW60) and 90 (BW90) days. Birth type had significant effect on the body weight from birth to weaning and the highest body weights were recorded in singles. Phenotypic correlations were positive and very highly significant between the growth traits. Genetic correlations were significant, but not between all observed ages of lambs.

Važniji fenotipski i genetski trendovi osobina porasta jagnjadi su ispitivani. Istraživanje je obuhvatilo jaganjce dveju lokalnih rasa ovaca: Lipska (LP) i Svrliška (SV). Sva jagnjad su merena prvi put na rođenju (BVB) i nakon toga redovno na dve nedelje. Na osnovu rezultata merenja telesne težine (BW) su prilagođene prosečnoj starosti 30 (BW30), 60 (BW60) i 90 dana (BW90). Rezultati uticaja genotipa na rast su pokazali vrlo značajan uticaj. Pol jagnjadi ima značajan efekat na rođenju i veoma značajan efekat sa 30 dana, ali nije imao značajan uticaj na masu sa 60 (BW60) i 90 (BW90) dana. Tip rođenja ima značajan uticaj na telesnu masu od rođenja do zalučenja, a veće mase su zabeležene kod jedinaca. Fenotipske korelacije su pozitivne i vrlo visoko značajne između osobina prirasta. Genetske korelacija bile su značajne, ali ne i između svih posmatranih perioda uzrasta jagnjadi.