Effect of the proportion of Duroc genes in crosses with Large White and Landrace pigs on the characteristics of seasoned Parma ham

Abstract

The aim of this study was to estimate the linear and quadratic effects of the proportion of Duroc genes on the characteristics of seasoned Parma hams by means of a covariance model. The study was carried out on 167 pigs (87 castrated males, 80 females) from different crosses among Duroc (D), Large White (LW) and Landrace (L) breeds, slaughtered at 300 d of age (live weight 170 kg). All pigs were raised under similar conditions. The curing period was 380 days. The proportion of Duroc genes was 0% (LWxL; n. 33), 25% [(LWx(DxL); n. 31 and Lx(DxLW); n. 35)] and 50% [Dx(LWx(LWxL)); n. 68]. The increase in the proportion of Duroc genes had a positive linear effect (P<0.01) and a negative quadratic effect (P=0.01) on the yield of deboned ham while ham fat thickness decreased linearly (P=0.07) and increased quadratically (P<0.01). A higher proportion of Duroc genes was also linearly associated with a lower lightness (P<0.01) and a less yellow color (P=0.09) of the biceps femoris muscle; positive quadratic coefficients have been shown for lightness (P<0.01), yellowness (P=0.01) and hue (P=0.03). The chemical composition of the semitendinosus muscle featured a linear increase in moisture (P<0.01) and decrease in fat (P=0.03) and non protein nitrogen (P=0.01) content, in addition to significant quadratic effects with an increase in the proportion of Duroc genes. In conclusion, crossbreeding with the Duroc breed (up to 50%) makes it possible to obtain positive quality characteristics of cured Parma ham.

Use of multivariate analysis to evaluate genetic groups of pigs for dry-cured ham production

“…The differences in the ham traits of the Duroc and Large White breeds observed in this study are in agreement with the results obtained by Schivazappa et al (2002), Bosi and Russo (2004) and Sabbioni et al (2004). Furthermore, some studies have reported significant differences among the ham of animals of the Duroc and Large White breeds in the quantity of ham after deboning, such that Duroc breed animals gave the highest yields (Franci et al, 1997;Sabbioni et al, 2004).…”

“…Sabbioni et al (2004) observed differences in ham weight between 50% Duroc and Large White  Landrace animals in the 160-170 kg harvest weight range. Thus, the hypothesis may be considered that the data structure, specifically in the set of ham measurements harvested at 160 kg (limited number of WIWI and no DUDU genetic group), influenced the results obtained.…”

“…Furthermore, some studies have reported significant differences among the ham of animals of the Duroc and Large White breeds in the quantity of ham after deboning, such that Duroc breed animals gave the highest yields (Franci et al, 1997;Sabbioni et al, 2004).…”

“…Peloso et al (2010) working with the same data in a univariate analysis concluded that apart from the Durocs, a second option within the genetic groups studied is the DULA group. Thus, using multivariate analysis we could recommend 50% Duroc animals for dry-cured ham production because several studies have shown that the Duroc breed presents favorable traits in its raw ham that are important in the curing process, such as the ham's inner and outer layer fat thickness, pH and intramuscular fat (Bosi and Russo, 2004;Candek-Potokar et al, 2002;Sabbioni et al, 2004;Schivazappa et al, 2002).…”

“…Traits related to product acceptance include fat cover thickness, intramuscular fat quantity and muscle and fat coloring (Candek-Potokar et al, 2002). Sabbioni et al (2004) recommended that ham for dry-cured ham production should have a high percentage of intramuscular fat and a fat thickness greater than 8 mm.…”