Ester Peeters

Influence of provision of toys during transport and lairage on stress responses and meat quality of pigs

Transport and accompanying mixing of pigs causes fights among pigs and stress resulting in decreased welfare and reduced meat quality. This study investigates the effect of toys available during transport and lairage on behaviour, stress responses, and meat quality of slaughter pigs. Cross-bred (Pietrain×Hypor) pigs (109·1±10·1 kg) were allocated to one of three treatments during transport and lairage: 1) no toys (control) 2) rubber toys and 3) balls. The rubber toy consisted of two fixed rubber sticks; the plastic ball was filled with pieces of maize, which became available for the pigs in small amounts by manipulating the ball. Per group of 11 pigs, two toys were provided. Totally, divided over 4 replicates, 144 pigs were involved, of which 72 were used for blood sampling and meat quality measurements. Five minutes scans during lairage revealed that treatment did not affect the percentage of pigs that lay ( P =0·20), stood ( P =0·83) or sat ( P =0·12) and that in almost all scans at least one pigs was manipulating a ball, compared with half of the scans in which at least one animal was manipulating a rubber toy ( P =0·02). However both toys resulted in a lower incidence of shoulder lesions compared with the control group ( P =0·06; 31·1% and 28·9% of the pigs for the rubber toys and balls respectively, versus 51·1% for the control group). Blood sampling at sticking showed that pigs with the balls during transport and lairage tended to have lower cortisol concentrations ( P =0·07) than pigs with the rubber toys. Also, a decrease in plasma lactate concentration was observed for these pigs in comparison with the control group ( P =0·08), and a higher pH of the m. longissimus dorsi 45 min post mortem for the pigs with the balls was found than for the pigs with the rubber toys ( P =0·01). These results indicate that enrichment of compartments during transport and lairage with balls reduced glycolysis in muscle resulting in a lower lactate production and a slower pH decline. The pH 45 min post mortem of the m. biceps femoris and the pH, electrical conductivity, colour, and water-holding capacity of the loin 48 h post mortem were not affected by treatment. In conclusion, environmental enrichment with toys during transport and lairage can decrease shoulder lesions and lower the pH decline 45 min post mortem , especially by provision of plastic balls filled with maize.

Head current during and blood splashes after electrical stunning in relation to characteristics of the pig's body.

In order to evaluate electrical stunning in relation to the incidence of blood splashes, meat quality and carcass quality parameters, 2035 pigs, heterozygous for the halothane gene, were observed during slaughter at a commercial slaughterhouse. The head current during electrical stunning is significantly higher (P<0.01) in gilts with a lower live weight (P<0.0001) or cold carcass weight (P<0.0001) and a higher lean meat percentage (P<0.0001). Also the incidence of blood splashes in the ham is significantly higher in gilts (P<0.0001) with a higher lean meat percentage (P=0.0028; odds ratio=1.11), a lower live weight (P=0.003; odds ratio=0.98) and a lower type number (P=0.0074; odds ratio=0.64). For barrows, no significant parameters were revealed. These results suggest that the variability in incidence of blood splashes can be explained by the variability of current density depending both on sex and body characteristics. Thus, electrical stunning can be improved by providing an energy level, based on the body characteristics of the pig.