Variability of traits of growth and quality of pig carcass sides: Effect of the breed and sex

Abstract

Investigation of the phenotypic variability of traits of growth and carcass quality was carried out on 865 fatteners (394 female animals and 461 male castrated heads) originating from 29 sires (9 breeds-crossbreds: SL- Swedish Landrace, VJ- Large White, KL - Canadian Landrace, KJ - Canadian Yorkshire D - Duroc, KD - Canadian Duroc, H - Hempshire, Hempshire x Duroc, Pietrain x Duroc) and 197 dams ( pure breed, two and three breed crosses). Investigation included following traits: age at slaughtering (UK), body mass at slaughtering (TMK), daily gain of body mass during life cycle (ZDP), mass of warm carcass sides (MTP), daily gain of carcass sides (DPP) quantity and content of meat in carcass sides (UKMP, USMP - according to Regulations,1985), total mass and ratio of leg+shoulder+loin (UMFO, UFO). Obtained results were processed using several models (Harvey, 1990) which included sire breed, dam breed, sex, age at slaughtering or mass of warm carcass (regression effect). Traits TMK, MTP, ZDP and DPP were regressed to average age at slaughtering (UK=224 days), and remaining traits to average mass of warm carcass sides (MTP=91,98 kg) All investigated traits varied under the influence of sire breed (P<0,01), however not under the influence of dam breed except UKMP and USMP (P<0,05, table 2). Statistically highly significant differences were determined in regard to average values of all traits between female animals and male castrated heads (P<0,01). All traits of carcass quality dependen on the mass of warm carcass sides (P<0,01). Greater body mass at slaughtering and same average age was determined for offspring of boars of following breeds: KD - Canadian Duroc, KL - Canadian Landrace, D - Duroc and KJ - Canadian Yorkshire since their growth was more intensive compared to average values of al other investigated fatteners. Offspring of boars of SL - Swedish Landrace, KL - Canadian Landrace and KD Canadian Duroc breeds had more meat in warm carcass sides (42,14 to 43,37%) compared to the general average (41,95%) determined for all investigated pure breed fatteners, as well as two, three and four breed crosses. The lowest quantity and content of meat was determined for offspring of Large White boars (37,65 kg and 41,01%). Gilts had lower ZDP and DPP and higher UKMP, USMP, UMFO and UFO compared to male castrated heads (table 4).