PIG WELFARE AND CARCASS QUALITY - A COMPARISON OF THE INFLUENCE OF SLAUGHTER HANDLING SYSTEMS AT 2 ABATTOIRS

Pigs from four farms (two producing 'easy' and two 'difficult to handl e) pigs) were slaughtered at two abattoirs, each with two slaughter ha ndling systems, so that 25 pigs of each behavioural type were slaughte red by all four handling systems on each day; there were 16 replicates (3200 pigs) in total. The pigs at abattoir X were electrically stunne d, either in a floor pen holding five pigs or in a race-restrainer. At abattoir Y the pigs were stunned either in a floor pen holding five p igs or in a dip-lift carbon dioxide stunner. The following measurement s were made: hot carcase weight and backfat thickness at P2, degree of rigor mortis 35 minutes post mortem, skin blemish, pH and muscle refl ectance in the m longissimus dorsi at 60 minutes and 18 hours post mor tem, and pH and muscle reflectance in the m adductor at 18 hours post mortem. At abattoir X, the pigs slaughtered in the race-restrainer had heavier carcases (74.0 kg vs 73.0 kg, P<0.05), developed rigor mortis more rapidly (8.1 mm vs 7.3 mm, P<0.01), had more skin blemish (2.8 v s 2.7, P<0.01), paler m longissimus dorsi muscles after one hour (15.7 vs 13.9, P<0.01) and 18 hours (27.8 vs 26.6, P<0.05), and paler m add uctor muscles (24.5 vs 22.7, P<0.001) after 18 hours. At abattoir Y, t he pigs handled through the floor pen system had more skin blemish (2. 7 vs 2.6, P<0.05) and a tendency to develop rigor mortis more quickly (6.11 vs 5.32, P = 0089). These results show that, under commercial co nditions, the design of slaughter handling systems can have a signific ant effect on ante mortem stress of pigs and on the quality of their m eat.