MAGNESIUM AND CALCIUM LEVELS IN BLOOD-PLA SMA OF PIGS OF DIFFERENT BREEDS AND FITNESS

Magnesium and calcium levels in the plasma of twelve sows each of the breeds Large White und Pietrain were determined, and the effect of a s imulated short-term stress by application of ACTH was investigated. Th e average Mg2+ concentrations amounted to 0,66 mmol/l (1,60 mg/dl) in Large White and to 0,60 mmol/l (1,47 mg/dl) in Pietrain. This means a significant difference. Average Ca2+ concentrations of 2,60 mmol/l (10 ,42 mg/dl) were found in Large White and 2,58 mmol/l (10,36 mg/dl) in Pietrain. Short-term stress causes a decrease of the plasma calcium le vel within 30 minutes after test starting. The effect on the plasma ma gnesium was different in the two breeds, which might be an indicator f or constitutional traits. The results are discussed with emphasis on t he problems arising for delineating normal values and for the comparis on of breeds in the continuously rising efforts for hybrid breeding. I ndications of protection against stress by magnesium supplemented feed are outlined.