PRODUCTION OF HETEROSIS IN THREE AND FOUR CROSSBREADING OF PIGS

Provedena istraživanja odnose se na proučavanje efekta dvorasnog, trorasnog i četverorsanog križaanja nerastova rase Durok (D), Hempšir (H) i F1 (H x D), s krmačama F1( ŠL x VJ) u odnosu na čiste rase Švedski Landras (SL) i Veliki Jorkšir (VJ) i to na važnija reprodukcijska i tovna svojstva te svojstva kvalitete polutki krmača i nerastova. Heterozis majke i oca kao i indivdue manifestirao se u očekivanoj razini kod pojedinih svojstava. Nerastovi F1 (HxD) bili su superiorniji količinom sperme u odnosu na svoje vršnjake čiste rase, snažnije su konstitucije s izraženijim libidom i agresivnošću kontaktu s plotkinjama. Ove značajke daju im značajnu prednost u odnosu na nerastove čiste rase Durok i naročito Hempšir.The investigations involved the study of the effect of two, three and four crossbreedings of _the Durok (D), Hampshire (H) and F1, (HxD) boars wtth the F1, (SL xVJ) sows in relation to the pure breed Swedish Landras (SL) and Big Yorkshire (VJ) including important reproduction and fattening traits and the halves quality of sows and boars. The level of heterosis of mother and father as well as an individual was as expected in particular traits. Boars F1 (HxD) were superior in the amount of sperm when compared with the same age of a pure breed, they had stronger constitution, a more pronounced libido and aggression in contact with the sows. These characteristics give them a more significant adventage in relation to the boars of the pure breeds Durok and particularly Hampshir