Controlled trial demonstrates that higher dietary trypsin inhibitor levels impair gut integrity and growth in nursery pigs, suggesting tight limits are necessary in weaner feed.
Key Points
To evaluate the effects of increasing dietary trypsin inhibitor concentrations from raw soybeans on growth performance, intestinal morphology, inflammatory responses, and fermentation in nursery pigs.
A total of 120 newly weaned piglets (initial body weight 5.16 ± 1.03 kg; 18.1 ± 1.48 days of age) were allotted to 5 dietary treatments in 6 replicates with 4 pigs per pen for a 28-day trial.
Pigs received diets containing graded trypsin inhibitor levels (1.5, 3.1, 4.8, 6.4, and 8.0 TIU/mg) achieved via raw soybean inclusion, followed by blood, intestinal mucosa, digesta, and fecal collections at day 28.
Increasing dietary trypsin inhibitor levels linearly decreased final body weight, average daily gain, average daily feed intake, and gain-to-feed ratio while increasing diarrhea incidence up to day 21 (P < 0.05).
Inflammatory and oxidative markers deteriorated with higher trypsin inhibitor levels, showing linear increases in jejunal and ileal interleukin-8 (P < 0.05), ileal interferon-γ (P < 0.05), and ileal protein carbonyls (P < 0.05), alongside decreased jejunal catalase (P < 0.05).
Villus height-to-crypt depth ratios in the duodenum and ileum linearly decreased (P < 0.05), and fecal acetate and total short-chain fatty acid concentrations linearly declined (P < 0.05).