Consequences of Transport Conditions on the Welfare of Slaughter Pigs with Different Health Status and RYR-1 Genotype.

This study assessed the influence of transport conditions on welfare indicators of slaughter pigs with different health status and RYR-1 genotype. The group of pigs, predominantly consisting of Nn (56.67%) and subclinically diseased (60.00%) individuals, that were exposed to short transportation (<30 min) at high loading density (~235 kg/m 2 ) had the highest slipping ( p < 0.0001), falling ( p = 0.0009), turning back ( p < 0.0001), reluctance to move ( p < 0.0001), panting ( p < 0.0001) and shivering ( p < 0.0001) frequencies at unloading. Subclinically diseased Nn pigs subjected to short transportation (<30 min) and high loading density (~235 kg/m 2 ) had the highest lactate ( p < 0.0001 and p < 0.0001), glucose ( p = 0.0450 and p = 0.0002), CK ( p < 0.0001 and p = 0.0010), LDH ( p < 0.0001 and p = 0.0484), AST ( p = 0.0208 and p = 0.0170), ALT ( p = 0.0500 and p = 0.00081), ceruloplasmin ( p = 0.0334 and p < 0.0001) and MDA ( p = 0.0048 and p < 0.0001) concentrations, but the lowest sodium ( p < 0.0001 and p < 0.0001), chloride ( p = 0.0001 and p = 0.0432), albumin ( p < 0.0090 and p < 0.0001), PON-1 ( p = 0.0122 and p = 0.0500) and GSH ( p = 0.0042 and p = 0.0340) levels, respectively. In the group consisting of of stress-resistant (100%) and predominantly healthy (60.00%) pigs subjected to short transportation (<30 min) at high loading density (~235 kg/m 2 ), none of the individuals showed irregular behavioural reactions during unloading. Healthy NN pigs that underwent short transportation (<30 min) at high loading density (~235 kg/m 2 ) had the lowest lactate ( p < 0.0001 and p < 0.0001), glucose ( p = 0.0450 and p = 0.0002), CK ( p < 0.0001 and p = 0.0010), LDH ( p < 0.0001 and p = 0.0484) and ceruloplasmin ( p = 0.0334 and p < 0.0001) levels, but the highest sodium ( p < 0.0001 and p < 0.0001) and chloride ( p = 0.0001 and p = 0.0432) concentrations, respectively. In conclusion, the most compromised welfare was recorded in subclinically diseased Nn pigs exposed to short transportation (<30 min) and high loading density (~235 kg/m 2 ), while under the same conditions, the welfare of healthy NN pigs was not compromised. Therefore, stress-carrier pigs with subclinical pathological lesions should not be considered fit for transportation, indicating that the health status and genotype are the key factors for optimising pig welfare.