THE EFFECT OF GRADED-LEVELS OF MELATONIN ON PERFORMANCE AND GASTRIC-ULCERS IN PIGS

Graded concentrations of dietary melatonin were fed to examine the eff ects on performance and gastric ulcers in pigs. Four levels of melaton in, 0, 2.5, 5, and 10 mg kg(-1), were fed in a finely ground, corn-whe at based diet (578 +/- 1.89 mu m), designed to induce gastric ulcers, to 64 Yorkshire barrows and gilts between 22.2 +/- 2.0 and 102.5 +/- 4 .3 kg. At postmortem, ulcers were scored from 0 (no ulcer) to 3 (sever e ulcer). Volume, percent moisture, pH; and bile acid concentration of the stomach digesta were determined. Melatonin supplementation was as sociated with a decreasing severity of ulcers (P < 0.05). There were n o differences in average daily gain between melatonin treatments; alth ough 10 mg kg(-1) diet caused a reduction in feed intake. Bile acid co ncentration in the stomach digesta was highest in pigs receiving the c ontrol diet without melatonin (P < 0.05) and was increased with increa sing ulcer severity (P < 0.05).