THE use of dietary magnesium supplements for pigs is producing promising results in studies to improve the quality of WA pork, according to Agriculture WA researcher Darryl D'Souza. Dr D'Souza said research funded by the Pig Research and Development Corporation had shown magnesium supplements could improve pork quality by reducing drop loss from fresh pork, improving fresh pork colour and reducing the incidence of what was known as PSE pork. "Pre-slaughtering handling of pigs from farm to abattoir can greatly influence ultimate pork quality," Dr D'Souza said. "Short-term stress around the time of slaughter (such as the use of electric prodders, fighting and excessive noise) can lead to pale, soft, exudative (PSE) pork by stimulating the rate of immediate post-mortem glycogenolysis and acidification. "This means low pH values can be reached in the muscle, while the carcase temperature is still high." Dr D'Souza said the economic loss associated with PSE pork pork was estimated to cost the Australian pig industry about $24 million annually. "Consequenetly, considerable effort has been directed towards determining best practices for optimising pork quality," he said. Implementing best practices, such as modifying lairage and chiller facilities, was often difficult and expensive in a commmcerail situation. A less costly answer appeared to lie with the use of magnesium supplements in the diet. "Magnesium has a relaxant effect on skeletal muscle by antagonising calcium, which is required for stress hormone release," Dr D'Souza said. "This has led to the hypothesis that exogenous magnesium could reduce the effects of stress, and hence improve pork quality." Research to date has investiagted the influence of: ndietary magnesium supplement on pork quality; ndifferent sources of magnesium; ndifferent magnesium doses; and ndifferent magnesium supplmentation periods. Dr D'Souza said research results indicated a dose of 1.6 grams of elemental magnesium per pig day for two days prior to slaughter could maximise improvements in pork quality.