Inclusion of wheat gluten as a protein source in diets for weaned pigs

The effect of substitution of fish meal (FM) by wheat gluten (WG) or hydrolysed wheat gluten (HG) in weaned pig diets was studied in two experimental periods. The tested protein sources were included at proportionally 0.10 and 0.06 in two diets formulated to meet pig requirements for weeks 0 to 2 and 3 to 5 after weaning, respectively. During each period, 5 lots of 5 weaned piglets ( 21 d old) per treatment were used to estimate growth, feed intake and nutrient digestibility. In addition, in the first period, one pig per replicate was slaughtered at the end of each phase in order to estimate ileal digestibility and pH, ammonia concentration and intestinal histology in different sections of the tract. There were no significant differences in daily growth, but the pigs consumed more of the FM diet than of the WG or HG diets on phase 3 - 5 ( 875, 807 and 827 g center dot d(-1); P < 0.10). Total apparent dry matter, organic matter and crude protein digestibility were higher with wheat gluten diets ( P < 0.001), but no differences were observed in ileal digestibility. However, ammonia concentration was higher in FM than WG in phase 0 - 2 ( P < 0.01). Overall villous height tended ( P = 0.10) to be higher with HG than FM. In conclusion, substitution of fish meal by wheat gluten in weaning pig diets does not affect growth up to 5 weeks after weaning. In addition, wheat gluten diets had higher apparent digestibility, maybe as a result of a reduced negative impact of weaning on enteric mucosa. There were no differences that might be attributed to the enhanced protein solubility of the hydrolysed wheat gluten.