Effect of hot carcass weight on loin, ham, and belly quality from pigs sourced from a commercial processing facility

Authors: HARSH, B - University Of Illinois; ARKFELD, E - University Of Illinois; MOHRHAUSER, D - Smithfield Foods, Inc; King, David - Andy; Wheeler, Tommy; DILGER, A - University Of Illinois; Shackelford, Steven; BOLER, D - University Of Illinois

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2017
Publication Date: 11/9/2017
Publication URL: http://handle.nal.usda.gov/10113/5927848
Citation: Harsh, B.N., Arkfeld, E.K., Mohrhauser, D.A., King, D.A., Wheeler, T.L., Dilger, A.C., Shackelford, S.D., Boler, D.D. 2017. Effect of hot carcass weight on loin, ham, and belly quality from pigs sourced from a commercial processing facility. Journal of Animal Science. 95:4958-4970. http://doi:10.2527/jas2017.1674.

Interpretive Summary: The objective was to quantify the effect of marketing group on variability of pork quality. Since 1995 average weight of U.S pigs has increased nearly 15%. If this rate of increase continues, pork carcasses will weigh 104 kg by the year 2030, 111 kg by 2040, and 118 kg by 2050. Based on data from the present study, packers should not expect increasing weight to have detrimental effects on lean quality traits such as muscle pH, color, water-holding capacity, or tenderness. In contrast fat quality traits will likely improve. Bellies are projected to become thicker, more saturated in their fatty acid profile and therefore, firmer.

Technical Abstract: The objective was to determine the predictive abilities of HCW for loin, ham, and belly quality of 7,684 pigs with carcass weights ranging from 53.2 to 129.6 kg. Carcass composition, subjective loin quality, and ham face color were targeted on all carcasses, whereas in-plant instrumental loin color and belly quality were assessed on 52.0% and 47.5% of carcasses, respectively. Loin chop slice shear force (SSF), cured ham quality, and adipose iodine value (IV) were evaluated on at least 10% of the population. The slope of regression lines and coefficients of determination between HCW and quality traits were computed using PROC REG of SAS and considered significant at P = 0.05. As HCW increased, boneless loins became darker and redder, evidenced by lesser L* (ß1 = -0.0243, P < 0.001) and greater a* values (ß1 = 0.0106, P < 0.001); however, HCW only accounted for = 0.80% of variability in loin L* and a* values. Similarly, subjective loin color score (ß1 = 0.0024, P < 0.001) increased with increasing carcass weight, but subjective marbling score was not affected by HCW (ß1 = -0.0022, P = 0.06). After 20 d aging, HCW only explained 0.98% of variability in loin L* values (ß1 = -0.0287, P < 0.01). Heavier carcasses had lesser SSF values (ß1 = -0.1269, P < 0.001) of LM chops, although HCW only explained 4.46% of variability in SSF. Although heavier carcasses produced loins that exhibited lower ultimate pH values (ß1 = -0.0018, P < 0.001), HCW explained only 1.23% of the variability in ultimate loin pH. Interestingly, cook loss decreased (ß1 = -0.0521, P < 0.001) as HCW increased, with HCW accounting for 5.60% of the variability in cook loss. Heavier carcasses resulted in darker, redder ham face color (P < 0.001), but HCW only accounted for = 2.87% of variability in ham face L* values and 0.47% of variability in a* values. Heavier carcasses produced thicker and firmer bellies, with HCW accounting for 37.81% of variability in belly thickness (ß1 = 0.0272, P < 0.001), 20.35% of variability in subjective flop score (ß1 = 0.0406, P < 0.001), and 10.35% of the variability in IV (ß1 = -0.1263, P < 0.001). Overall, the proportion of variability in loin and ham quality explained by HCW was poor (= 5.60%) suggesting HCW is a poor predictor of primal quality of pigs within this weight range. Nonetheless, HCW was a moderate predictor of belly quality traits. The findings of this study suggest increasing HCW did not compromise loin, ham, or belly quality attributes.