Effects of Ferulic Acid Supplementation on Growth Performance, Carcass Traits and Histochemical Characteristics of Muscle Fibers in Finishing Pigs

SIMPLE SUMMARY: Different compounds with potential phytogenic activity are being studied in the feeding of monogastrics and ruminants. The present study evaluated the effect of ferulic acid (FA) dietary supplementation on the growth performance, carcass quality and histochemical characteristics of the Longissimus thoracis muscle from finishing pigs. The growth performance, carcass quality, histomorphometric characteristics, and histochemical characteristics of skeletal muscle were affected by FA supplementation. The addition of FA on diet improved average daily gain, 12th rib fat depth and Longissimus muscle area in the same way as ractopamine treatment. Histochemical analysis indicated that FA treatment induces a shift in muscle fiber, a lower cross-sectional area, and a greater number of muscle fibers per area. The findings indicate that ferulic acid supplementation without extra-lysine can replace the use of ractopamine as a growth promoter in finishing pigs. ABSTRACT: FA dietary supplementation on the growth performance, carcass traits and histochemical characteristics of the Longissimus thoracis muscle from finishing pigs was investigated. Four hundred and twenty pigs were used in this study, and 105 animals (with five replicate pens and 21 pigs per pen) were assigned to one of four treatments: basal diet (BD) without additives (C−); BD + 10 ppm ractopamine hydrochloride + 0.97% lysine (C+); BD + 25 ppm of FA (FA); and BD + 25 ppm of FA + 0.97% lysine (FA-Lys). Dietary supplementation with FA or ractopamine increased both the average daily gain (14%) and loin muscle area (19%), while fat deposition decreased by 53%, in comparison with C− (p < 0.05). The growth performance of pigs treated with FA was similar to those of ractopamine (p > 0.05). The histochemical analysis showed that FA and C+ treatments induced a shift in muscle fiber types: from fast fibers to intermediate (alkaline ATPase) and from oxidative to glycolytic fibers. Muscle tissues from animals treated with FA or ractopamine had a lower cross-sectional area and a greater number of muscle fibers per area (p < 0.05). Findings regarding growth performance and carcass traits indicate that FA supplementation at 25 ppm without extra-lysine can replace the use of ractopamine as a growth promoter in finishing pigs.