In Journal of Animal Science, A.V. Weschenfelder of Agriculture and Agri-Food Canada and co-authors there and at Université Laval and University of Saskatchewan in Canada and Universitat Autònoma de Barcelona and PigCHAMP Pro Europa S.A. in Spain report a study aimed at evaluating the effects of trailer design on stress responses and meat quality traits of three different pig crosses. The three crosses used were: 50 per cent Pietrain breeding with halothane (HAL)Nn (50Nn); 50 per cent Pietrain breeding with HALNN (50NN); and 25 per cent Pietrain breeding with HALNN genotype (25NN).

Over a six-week period, pigs (120 pigs per crossbreed) were transported for seven hours in either a pot-belly (PB) or flat-deck (FD) trailer (10 pigs per crossbreed per trailer per week).

Temperature (T) and relative humidity (RH) were monitored in each trailer. Behaviours during loading and unloading, time to load and unload, and latency to rest in lairage were recorded, whereas a sub-population of pigs (four pigs per crossbreed per trailer per week) was equipped with gastro-intestinal tract (GIT) temperature monitors. Blood samples were collected at ex-sanguination for measurement of cortisol, creatine kinase (CK), lactate, haptoglobin and Pig-MAP concentrations. Meat quality data were collected at 24 hours post-mortem from the LM and semimembranosus (SM) and adductor (AD) muscles of all 360 pigs.

Greater T were recorded in the PB trailer during transportation (P=0.006) and unloading (P<0.001). Delta GIT temperature was greater (P=0.01) in pigs unloaded from the PB.

At loading, pigs tended to move backwards more (P=0.06) when loaded on the FD than the PB trailer.

At unloading, an interaction was found between trailer type and crossbreed type, with a greater (P<0.01) frequency of overlaps in 50NN and 25NN pigs and slips/falls in 50Nn and 50NN pigs from the FD than the PB trailer.

Cortisol concentrations at slaughter were greater (P=0.02) in pigs transported in the PB than FD trailer. Greater lactate concentrations were found in 50Nn and 50NN pigs (P=0.003) and greater CK concentrations (P<0.001) in 50Nn pigs.

As expected, 50Nn pigs produced leaner (P<0.001) carcasses, with greater (P=0.01) dressing percentages, as well as lower (P<0.001) ultimate pH values and greater (P<0.001) drip loss percentages in the LM and greater (P=0.002) drip losses and a paler colour (greater L* values, P=0.02) in the SM than 50NN pigs.

When used for long distance transportation under controlled conditions, the PB trailer produced no detrimental effects on animal welfare or pork quality. Pigs with 50 per cent Pietrain cross-breeding appear to be more responsive to transport stress, having the potential to produce acceptable carcass and pork quality, provided pigs are free of the HAL gene.

Reference

Weschenfelder A.V., S. Torrey, N. Devillers, T. Crowe, A. Bassols, Y. Saco, M. Piñeiro, L. Saucier and L. Faucitano. 2012. Effects of trailer design on animal welfare parameters and carcass and meat quality of three Pietrain crosses being transported over a long distance. J. Anim. Sci., 90(9):3220-3231. doi: 10.2527/jas.2012-4676

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March 2013