Genetic parameters for carcass composition and pork quality estimated in a commercial production chain1

Abstract

Breeding goals in pigs are subject to change and are directed much more toward retail carcass yield and meat quality because of the high economic value of these traits. The objective of this study was to estimate genetic parameters of growth, carcass, and meat quality traits. Carcass components included ham and loin weights as primal cuts, which were further dissected into boneless subprimal cuts. Meat quality traits included pH, drip loss, purge, firmness, and color and marbling of both ham and loin. Phenotypic measurements were collected on a commercial crossbred pig population (n = 1,855). Genetic parameters were estimated using REML procedures applied to a bivariate animal model. Heritability estimates for carcass traits varied from 0.29 to 0.51, with 0.39 and 0.51 for the boneless subprimals of ham and loin, respectively. Heritability estimates for meat quality traits ranged from 0.08 to 0.28, with low estimates for the water holding capacity traits and higher values for the color traits: Minolta b*(0.14), L* (0.15), a* (0.24), and Japanese color scale (0.25). Heritability estimates differed for marbling of ham (0.14) and loin (0.31). Neither backfat nor ADG was correlated with loin depth (r(g) = 0.0), and their mutual genetic correlation was 0.27. Loin primal was moderately correlated with ham primal (r(g) = 0.31) and more strongly correlated with boneless ham (r(g) = 0.58). Backfat was negatively correlated with (sub)primal cut values. Average daily gain was unfavorably correlated with subprimals and with most meat quality characteristics measured. Genetic correlations among the color measurements and water-holding capacity traits were high (average r(g) = 0.70), except for Minolta a* (average r(g) = 0.17). The estimated genetic parameters indicate that meat quality and valuable cut yields can be improved by genetic selection. The estimated genetic parameters make it possible to predict the response to selection on performance, carcass, and meat quality traits and to design an effective breeding strategy fitting pricing systems based on retail carcass and quality characteristics.

Genetic parameters of meat quality traits in two pig breeds measured by rapid methods

“…The Duroc estimate was similar to the highest values reported in earlier studies (Hermesch et al, 2000a;Suzuki et al, 2005;van Wijk et al, 2005), while the Landrace estimate was much higher. Common to the study reporting the highest heritability (Hermesch et al, 2000a) and our study was a fixed effect for all the animals tested at the same time, which had a large effect on the heritability estimate in our study (in spite of good routines for calibration).…”

“…For pH measurements in different muscles, the estimated heritabilities ranged from low to moderately high. Heritability estimates for ultimate pH in LD in the literature were also low (Hermesch et al, 2000a;Kadarmideen et al, 2004;van Wijk et al, 2005). These literature estimates were for Landrace and Large White and compare, as expected, better than our estimates for Landrace than for Duroc.…”

“…In addition, heritabilities estimated for marbling were lower in two studies using marbling as a method for measuring IMF (Sonesson et al, 1998;van Wijk et al, 2005). In a preliminary analysis in this study, IMF predicted by NIR was found to have higher heritability estimates, compared with IMF predicted by chemical analysis.…”

“…Common to the study reporting the highest heritability (Hermesch et al, 2000a) and our study was a fixed effect for all the animals tested at the same time, which had a large effect on the heritability estimate in our study (in spite of good routines for calibration). The estimated heritabilities for the a* and b* values in LD were moderately high, between the estimates of Sonesson et al (1998) andvan Wijk et al (2005).…”

“…Our results are in agreement with heritability estimates for drip loss published by Hovenier et al (1992), who used a filter paper method, and also with those of de Vries et al (1994) and Hermesch et al (2000a), who both used a bag method. Lower heritability estimates were found by Suzuki et al (2005), who used loin chops hanging from a wire in specimen cases, and by van Wijk et al (2005), who used a method similar to the EZ-DripLoss method. All methods for the determination of drip loss are relatively sensitive to variations in operator and procedure.…”