This study aimed to evaluate the effects of dietary tryptophan supplementation on growth performance, skin lesions, and blood parameters in weaned piglets. A total of 144 piglets (Landrace × Yorkshire × Duroc; initial BW: 6.63±0.21 kg) were randomly assigned to one of three dietary treatments, with six replicates of eight pigs each for 28 days. The treatments included a control diet (CON), a diet supplemented with 0.10 % tryptophan (T1), and a diet with 0.20% tryptophan (T2). Growth performance was assessed by measuring average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Skin lesions were scored on days 14 and 28, and blood samples were collected at the end of each phase for analysis of growth hormone, cortisol, and serotonin levels. Results indicated that tryptophan supplementation improved ADG and G:F compared with the control, particularly in the T2 group. Skin lesion scores were lower in the tryptophan supplemented groups, suggesting reduced aggression. Furthermore, blood serotonin levels tended to increase and cortisol levels showed a decreasing trend in tryptophan-supplemented groups, suggesting potential stress mitigation. These findings suggest that dietary tryptophan supplementation can enhance performance and welfare in weaned piglets under stress.

This experiment was conducted to investigate effect of brine mineral water (BMW) on growth performance and properties of blood in weaning pigs. Treatments allotted were 0% (general water), 2%, 3% and 5% BMW. In growth trial, a total of 36 weaning pig barrows [(Landrace×Yorkshire)×Duroc] weaned after 21 days with an average initial weight of 5.38±0.89 kg were used. Each treatment had 3 replications of 3 pigs per pen in a randomized complete block design. Weaning pigs were investigated for growth performance, complete blood corpuscle count and blood biochemical assay. In results, growth performance of 2% and 3% treatment groups were significantly higher than other groups (p<0.05). In addition, high density lipoprotein cholesterol was significantly (p<0.05) higher in 2% group than other treatment groups. On the other hand, mean corpuscular volume of supplement of BMW treatment groups were significantly (p<0.05) increased than control. Therefore, this study suggests that supplementation of BMW could improve growth performance and level of red blood cell in weaning pigs.