The effects of mixing, transport and duration of lairage on carcass characteristics in commercial bacon weight pigs

Abstract

AbstractOn arrival at the factory commercial crossbred pigs were subjected to various treatments: (i) penned in producer lots; (ii) mixed with pigs from another producer and (iii) mixed and subjected to an additional transport of 1‐1.5h duration. Groups of pigs were killed on the day of arrival or after overnight lairage. Carcass parameters including pH1 (pH 45 min post mortem) and pHu (pH 20 h post mortem) values of the Longissimus dorsi (LD) and adductor muscles were taken post mortem. Mixing and transport had no statistically significant effect on any of the carcass parameters measured, although overnight lairage resulted in significant decreases in hot carcass weight, killing‐out percentage and liver weight. The incidence of carcasses classified as pale soft and exudative [PSE (muscles with a pH1 of 5.9 or less)] or dark firm dry [DFD (muscles with a pHu of 6.2 or greater)] was high after both normal and overnight lairage. pH1 and pHu values of the LD and adductor muscles were not significantly affected by mixing or transport. Statistically significant differences in the incidence of DFD between treatment groups were observed. In general the incidence of DFD increased more after overnight lairage in pigs penned in producer lots, than in pigs penned in mixed producer lots.