Investigation of heritability and genetic correlations of milk traits in sheep

Abstract

Considering that total variability of milk traits in sheep within single population greatly depends on factors of genetic nature, objective of this paper was to investigate the trend of genetics parameters in populations raised in Pirot region, in order to create more efficient selection program in regard to milk production. Obtained and processed results of investigation have demonstrated that investigated traits occupy central heritability values. Degree of heritability for protein and fat had higher values in relation to other observed traits. Weak and negative genetic correlation is present between fat content and other traits whereas strong and positive correlation was determined for milk quantity and fat content and protein. Statistical analysis confirmed absence of significant differences between sheep of Pirot Pramenka breed and improved Pirot population. This research has also demonstrated that in selection of sheep in regard to milk traits and production special attention should be directed to importance of genetic parameters considering that with the increase of quantity of milk not only content of fat but also of protein are reduced, which can influence the economical efficiency on farm in system of payments for milk according to its quality.

U radu je izvršena analiza genetskih parametara važnijih osobina mlečnosti u populacijama pirotske pramenke i pirotske oplemenjene ovce. Dobijeni i obrađeni rezultati istraživanja su pokazali da ispitivane osobine imaju srednji nivo heritabiliteta, pri čemu su vrednosti stepena naslednosti za protein i mast veće u odnosu na ostala posmatrana svojstva, što se svakako mora imati u vidu prilikom kreiranja programa selekcije. Ustanovljena su pozitivna i negativna odstupanja u ispitivanim osobinama. Slaba i negativna korelacija prisutna je između sadržaja masti i drugih osobina dok je jaka i pozitivna povezanost utvrđena između količine mleka i količine masti. odnosno proteina. Ne postoje statistički značajne razlike između ovaca rase pirotska pramenka i pirotske oplemenjene populacije.