Reduced Protein Digestibility and Growth Performance Due to Feeding Lentil-based Diets to Weaned Pigs Can Be Ameliorated by Including Benzoic Acid

Lentil is a pulse grain that can serve as alternative dietary energy and protein source for pigs but may have lower nutrient digestibility. Inclusion of organic acids such as benzoic acid (BA) may enhance energy and protein digestibility and thereby increase nutrient utilization and growth performance of weaned pigs. The objective of the present study was to test the effect of BA inclusion in diets with or without lentil fed to weaned pigs. In a randomized complete block design, 192 pigs (initial body weight [BW], 8.8 kg) housed with 4 pigs/pen were fed 4 wheat-canola expeller-soybean meal diets with or without red lentil (Lens culinaris) in substitution of wheat grain at 20% for phase 1 (day 0–14) and at 30% for phase 2 (day 14–28), with or without 0.5% BA (VevoVitall®, dsm-firmenich) for 12 replicate blocks per treatment starting 1 week after weaning at 21 days of age. Diets were formulated to provide 10.25 and 10.16 MJ net energy (NE)/kg and 1.32 and 1.22 g standardized ileal digestible lysine/MJ NE for phase 1 (steam-pelleted) and phase 2 (mash), respectively. Data were analyzed as a 2 × 2 factorial arrangement using PROC GLIMMIX of SAS. Lentil inclusion decreased (P < 0.05) diet apparent total tract digestibility (ATTD) of dry matter (DM) and gross energy (GE) by 1% for phases 1 and 2 and diet ATTD of crude protein (CP) by 3% for phase 1. Dietary BA inclusion increased (P < 0.05) diet ATTD of DM and GE by 1% for phases 1 and 2 and diet ATTD of CP by 3% (78.7 vs. 81.3%) for phase 1. For phase 2, BA inclusion increased (P < 0.05) ATTD of CP for diets without lentil by 4% (78.7 vs. 81.8%) but not for diets with lentil. Feeding lentil decreased (P < 0.05) average daily feed intake (ADFI) by 8%, average daily gain (ADG) by 11%, and gain-to-feed (G:F) by 4% for diets without BA. Dietary BA increased (P < 0.05) ADFI by 11%, ADG by 18%, and G:F by 6%. Feeding lentil decreased (P < 0.05) final BW by 0.7 kg whereas dietary BA increased (P < 0.05) final BW by 1.4 kg. In conclusion, 0.5% dietary BA inclusion increased energy and protein digestibility and growth performance of weaned pigs fed diets containing red lentil.