Effects of enzyme-treated soy oligopeptide on intestinal health, feed preference, and growth performance in nursery pigs.

OBJECTIVE

The objective was to evaluate the effects of replacing soybean meal (SBM) with enzyme-treated soy oligopeptide (ESO) in nursery pig diets on intestinal health, growth performance, and feed preference.

METHODS

In Exp. 1, 128 pigs (average 5.2 kg) were housed in pens (4 pigs/pen), assigned to 4 diets supplemented with 0%, 1%, 2%, or 3% of ESO, and fed for 32 d. On d 32, blood, tissues, and mucosa from the duodenum and jejunum were collected. In Exp. 2, 24 pigs (average 6.2 kg) were assigned to 6 pens (4 pigs/pen). Each pen had two separate feeders containing two diets with 0% or 2% of ESO for 27 d.

RESULTS

Increasing dietary ESO tended to quadratically change serum tumor necrosis factor-α (p = 0.059; minimum at 1.6% of ESO) and duodenal villus height to crypt depth ratio (p = 0.062; maximum at 1.8% of ESO). Increasing dietary ESO linearly reduced feed intake both linearly and quadratically (p<0.05) during phase 2 (maximum at 0.9% of ESO). Increasing dietary ESO both linearly and quadratically changed (p<0.05) weight gain during phase 2 (maximum at 1.0% of ESO). Increasing dietary ESO linearly changed (p<0.05) and tended to quadratically change (p = 0.077) weight gain during the overall phase. Increasing dietary ESO tended to linearly change (p = 0.059) gain to feed ratio during phase 1 and quadratically change (p<0.05) gain to feed ratio during phase 2 (maximum at 1.4% of ESO). Feed preference of the diet containing 2% of ESO was negatively associated with post-weaning days (R2 = 0.542).

CONCLUSION

Gradually replacing SBM with ESO at levels from 1.4% to 1.8% enhanced intestinal health and gain to feed ratio, whereas exceeding 0.9% to 1.0% reduced feed intake and weight gain, suggesting that optimal level of ESO in nursery pig diets is 0.9%.