Studies on Growth of Pelon Mexicano Pigs: Effect of Rearing Conditions on Carcass Traits and Meat Quality

A 2x2 factorial arrangement was used for evaluating carcass traits and meat quality of 22 Yorkshire x Landrace (YL) and 13 Pelon Mexicano (PM) castrate male and female pigs 63 days old which were allotted at random during 16 weeks into 2 rearing systems consisting of total (15 and 7 pigs) or partial confinement (7 and 6 pigs). Partial confinement included rearing animals outdoors in a grass prairie (Brachiaria brizantha) from 9-16 h. There were no significant differences (p<0.05) for the interaction rearing system x genotype in any measurement conducted throughout this experiment. Highly significant (p<0.001) differences between genotypes was encountered for carcass yield and primary cuts adjusted to slaughter weight as covariable. However, carcass yield expressed as percentage of slaughter weight only tended (p<0.103) to favour YL pigs. Differences between rearing systems were less marked, with better carcass traits in either totally confined YL animals or partially confined PM pigs. The genotype effect was at least significantly (p<0.01) different in all measurements indicating a higher fat content in carcasses of PM pigs, when compared to YL animals. Length of some reservoir digestive organs were significantly (p<0.001) higher in PM than in YL pigs. There were no significant differences (p>0.05) in meat quality indices, including meat pH, water holding capacity, color and marbling. It is considered that a total or partial confinement, consisting on daily grazing outdoors, rearing system, has less influence on carcass traits in pigs when Pelon Mexicano and Yorkshire x Landrace pigs are compared.