Effects of increasing levels of curcumin on growth performance and immune response of nursery pigs

Abstract Text: Curcumin (CUR), a curcuminoid in turmeric, has antimicrobial and anti-inflammatory properties that may be beneficial to pigs.  Two experiments (Exp.) were conducted to determine the effect of increasing levels of CUR on growth performance and immune response.  Pigs were weaned at 21 d, blocked by BW, and allotted randomly to dietary treatments (trts) in a randomized complete block design (RCBD).  Each experiment utilized corn-soybean meal based diets with a 4-phase feeding program.  Growth performance was calculated for d 0-21 and 0-42.  Exp. 1 (6 reps/trt) used 168 pigs (6.2 kg) with the following trts:  carbadox (55 mg/kg; AB), 12, 23, and 46 mg/kg of CUR.  Exp. 2 (7 reps/trt) used 112 pigs (6.0 kg) with the following trts: carbadox (55 mg/kg; AB), 46, 93, and 186 mg/kg of CUR.  On d 20, selected pigs were challenged with an E. coli lipopolysaccharide (LPS).  Rectal temperatures (RT) were measured and blood collected for analysis of tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) at h 0 and 3, 6, 12, and 24 h post-injection (PI).  Data were analyzed as a RCBD using a GLM/Mixed procedure.  In Exp. 1, there were no differences (P>0.10) in growth performance for d 0-21.  Curcumin did not affect (P>0.10) ADG, but decreased ADFI and improved G:F (P<0.08) for d 0-42 compared to the AB.  As CUR increased, ADFI decreased and G:F increased (P<0.08; quad).  In Exp. 2, ADG (P=0.09; quad) and ADFI decreased (P=0.009; linear) as CUR increased for d 0-21.  Compared to the AB, CUR decreased (P=0.03) ADFI.  For d 0-42, CUR decreased (P<0.06; linear) ADG and G:F; and decreased (P<0.04) ADG and G:F compared to AB.  For the LPS challenge in Exp. 1, there was a numerical decrease in TNF- α at hr 3 PI followed by a decrease (P=0.05; quad) in CRP at h 6 PI as CUR increased.  For Exp. 2, increasing CUR decreased (P<0.07; linear) RT at h 0 and h 3 PI.  As CUR increased, TNF-α tended (P=0.09; linear) to increase at h 6 PI.  However, CUR decreased (P<0.10; linear) CRP at h 0 and h 3, 6, and 24 PI.  Compared to the AB, CUR decreased (P<0.03) CRP at h 0 and h 3 and 6 PI.  When data were combined for both experiments, the optimum response in growth performance and immune response was between 46-93 mg/kg of CUR.

Keywords: curcumin, growth performance, immune response