The impact of glycine and glutamate, as components of glutathione precursors, on the productivity, digestive performance and blood profile of weaning pigs

The impact of glycine and glutamate, as components of glutathione (GSH) precursors, was studied as a factor in determining the growth rate of weaning pigs, their digestion of nutrient supplements and their blood concentration levels. There were 180 crossbred weaning pigs with an average body weight (BW) of 7.94 ± 1.53 kg (five pigs per pen [two barrows and three gilts]; nine pens per treatment) that were randomly assigned to one of four diets. We used a basal diet as the control, TRT1 as the treatment with 0.10% precursor of GSH, TRT2 as the treatment with 0.20% precursor of GSH and TRT3 as the treatment with 0.30% precursor of GSH. The BW of weaning pigs exhibited a linear increase on days 7 (p < 0.001), 21 (p < 0.001) and 42 (p < 0.009) following the supplementation with the GSH precursor. Supplementation with GSH precursor led to a consistent and gradual increase in average daily gain (ADG) on days 8–21, 22–42 and overall, as indicated by a significant linear trend (p < 0.05). G: F was linearly increased (p < 0.05) on days 22–42 and overall with the increment in the precursor of GSH supplementation. However, GSH precursor supplementation did not have any impact on nutrient digestibility and blood profile in the treatment group. In summary, the administration of GSH precursor improved BW, ADG and G: F ratio while not affecting nutrient digestibility or blood profile.