The influence of the proportion of Duroc genes on growth, carcass and pork eating quality characteristics

Abstract

A study was carried out involving 721 pigs, comprising boars and gilts, with either 0, 0.25 , or 0.50 Duroc inclusion level, which were produced by mating Large White boars with Large White × British Landrace sows, Large White boars with Duroc × (Large White × British Landrace) sows, or Duroc boars with Large White × British Landrace sows, respectively. Animals were reared on one of seven different feeding regimens from 30 to 90 kg live weight. Tissue growth rates were determined using a triple sampling procedure based on a combination of full-side and ham joint dissection on subsamples of pigs (127 and 366 pigs, respectively) and P2 backfat thickness on the remainder. Initial body composition was determined at 30 kg on subsamples of the three genotypes. Daily food intakes increased with increasing Duroc inclusion but live-weight gains were similar for the three genotypes. Lean and fat growth rates and food conversion ratios were greatest for the 0·50 Duroc group, although the genotype differences were small. Killing-out proportions and P2 fat depths were higher for the 0.25 and 0·50 Duroc groups. The proportion of lean in the carcass was lower (P < 0·01) for 0·50 Duroc pigs. Japanese colour scores and EEL reflectance indicated that the longissimus muscle was darker for the 0·25 and 0·50 Duroc genotypes. Subcutaneous fat firmness scores and penetrometer readings taken in the mid back indicated softer fat for the 0 Duroc group. Intramuscular fat levels increased (P < 0·01) with increasing Duroc inclusion (10.4, 11.2, and 18·2 g/kg for the 0, 0.25, and 0.50 groups respectively). Cooked longissimus from pigs with 0·50 Duroc had a lower shear force and was judged to have a stronger pork odour and to be more tender and acceptable than that from the 0 Duroc group. The 0.25 Duroc group showed a small improvement in tenderness but a weaker pork odour and similar overall acceptability compared with the 0 Duroc group. This study suggests that the use of the Duroc in crossing systems in the United Kingdom will have limited impact on growth performance but that 0·50 Duroc inclusion will result in fatter carcasses, higher intramuscular fat levels and improved eating quality.

Sire breed comparisons for meat and eating quality traits in Australian pig populations

“…Progeny of LW sires had the leanest bellies and the highest LBP. Results comparing DU with LW for carcase weight and back fat in this study are consistent with breed contrasts for average daily gain and carcase fat reported in other studies (Johnson and Goodwin, 1995;Blanchard et al, 1999c). There was no comparable literature available for progeny of LR or DS sires.…”

“…In our study, meat from the faster growing females was no tenderer than meat from their male contemporaries, although females did have higher IMF and reduced CL. The study of Blanchard et al (1999c) also demonstrated that progeny of purebred Duroc sires had higher IMF levels and improved eating quality, but carcases were fatter, similar to the results found in this study. Slaughter progeny containing only 25% Duroc genes had IMF levels, marbling scores and subcutaneous fat levels more similar to progeny of LW (0% Duroc) than DU (50% Duroc) boars, implying that a 50% Duroc inclusion is required to obtain demonstrable differences between Duroc-infused sire breeds in meat and eating quality traits.…”

“…In a later trial at Stotfold, 721 slaughter pigs were used to evaluate the influence of growth rate, sex and the proportion of Duroc genes on pork eating quality (Blanchard et al, 1999a(Blanchard et al, , 1999b(Blanchard et al, and 1999c. In their study, rapid growth prior to slaughter was favourably associated with many sensory characteristics of pork, but relationships were generally weak (Blanchard et al, 1999a).…”

Influence of crossing Polish and foreign pig breeds on physicochemical traits of longissimus lumborum muscle

“…Having in mind maintenance of good quality slaughter material, each new fattener genotype obtained should be examined (1)(2)(3)(4)(5)(6). Quantitative and qualitative features of meat tissue determine consumption and technological usefulness of pork meat (1,7).…”

“…Having in mind maintenance of good quality slaughter material, each new fattener genotype obtained should be examined (1)(2)(3)(4)(5)(6). Quantitative and qualitative features of meat tissue determine consumption and technological usefulness of pork meat (1,7). The aim of this study was an assessment of the indices characterizing the longissimus lumborum muscle in fatteners that were the product of an application of various variants of commodity crossbreeding using 2 Polish and 2 foreign breeds.…”