Effects of Low-Protein Diet Supplemented with Tryptophan, Pyridoxine and Niacin on Feed Intake and Growth Performance of Weaning Piglets

This study aimed to investigate the effects of dietary tryptophan (Trp), pyridoxine and niacin supplementation on feed intake and growth performance of weaning pigs fed low-protein diet. A total of 42 day-old crossbred (Landrace×Yorkshire×Duroc) of weaned female pigs were reared under seven dietary treatments. Treatments were 1) corn-soybean meal diet, 2) pyridoxine + niacin, 3) pyridoxine, 4) niacin, 5) 0.30% synthetic Trp + pyridoxine + niacin, 6) 0.30% synthetic Trp + pyridoxine and 7) 0.30% synthetic Trp + niacin. The experimental results indicated no significant difference (p>0.05) in feed intake for pigs fed the experimental diets. However, pigs fed the synthetic Trp + pyridoxine diet tended to have better feed intake among dietary treatments, followed by synthetic Trp + niacin diet. Overall (wk 1 to 8), pigs consuming supplemental Trp diets had better weight gain and feed efficiency than without Trp supplemental pigs (p<0.01). In conclusion, supplementation of Trp in combination with pyridoxine or niacin in weaning pigs diets greatly improve growth performance than only supplementing Trp alone in low crude protein diet.