Effects of magnesium supplementation during preslaughter period in finisher`s diet on pork quality

Abstract

This experiment was conducted to evaluate the beneficial effects of various sources of magnesium on pork quality in finishing pigs. Treatments contained 1) Control (basal diet), 2) Magnesium sulphate supplementation (basal diet + MgSO4 0.12%), 3) Magnesium chloride supplementation (basal diet + MgCl2 0.12%), 4) Magnesium oxide supplementation (basal diet + MgO 0.12%) and 5) Magnesium gluconate supplementation (basal diet + Mg-glu 0.12%), respectively. The experimental diet and water fed ad libitum 5 days pre-slaughter period. There was no significant difference in growth performance. A treatment fed MgSO4 showed higher muscle glycogen concentration than other treatments (p＜0.01). No significant difference in muscle pH was observed, however, hunter L value (40 min of post-mortem) of control group was lower than that of MgO or Mg-glu treatments significantly (p＜0.05). And Hunter L* value (24 hr, post-mortem) in control group and MgSO4 treatments were lower than that of MgO and Mg-glu treatment significantly (p＜0.05). Hunter a* value of Mg-glu addition at 18 hr post-mortem were higher than control, MgSO4 and MgCl2 treatments (p＜0.05). Hunter b* value at 18 hr of postmortem in control and MgSO4 treatment was lower than MgO and Mg-glu treatments (p＜0.05). And b* value at 24 hr post-mortem of control group and MgSO4 treatment were lower than MgO, MgCl2 and Mg-glu treatments significantly (p＜0.05). Although there were no differences among treatments on blood cortisol, it seemed that MgSO4 incorporation was effective on reducing stress response during rearing stage. No significant differences were found among treatments on TBARS value. However, the value was the lowest in Mg-glu treatment (7 day, post-mortem). The value of TBARS in pork were generally increased by storage time but it was maintained low level when pigs were fed Mg regardless of sources.