Comparison of different dietary magnesium supplements on pork quality

Forty-eight crossbred (Large White x Landrace) boars were used to compare t he effect of dietary magnesium aspartate (MgAsp), magnesium sulphate (MgSO4 ) and magnesium chloride (MgCl2) on muscle glycogenolysis and pork quality. The pigs were fed finisher feed supplemented with either MgAsp, MgSO4 and MgCl2 for 5 days prior to slaughter. At the abattoir, all pigs received 15 electric shocks from an electric goad 5 min prior to slaughter. Pigs fed th e diet supplemented with MgSO4 had the highest plasma Mg concentrations at slaughter in comparison with pigs fed the MgAsp and MgCl2 supplemented diet s. There were no differences in plasma adrenaline and noradrenaline concent rations at slaughter between the different diets. Pigs fed the Mg diets had higher muscle glycogen concentrations in the Longissimus thoracis (LT) mus cle at 5 min and at 40 min (except MgCl2) post-slaughter compared to pigs f ed the control diet. Also pigs fed the Mg diets had lower muscle lactic aci d concentrations in the LT at 5 min post-slaughter and lower drip loss at 2 4 hr post-slaughter compared to pigs fed the control diet. These results in dicate that cheaper magnesium sources, MgSO4 and MgCl2, are as efficacious as MgAsp in reducing drip loss and improving pork quality. (C) 1998 Elsevie r Science Ltd. All rights reserved.