Effects of dietary quillaja saponin and curcumin on the performance and immune status of weaned piglets1

The objective of this study was to determine whether dietary quillaja saponin and curcumin (extract of turmeric) can modify piglet immune status and performance immediately after weaning. Piglets (n = 192) were weaned at 29 ± 0.1 d and allocated to treatment (six replicates of eight pig per treatment) accounting for weight, litter, and gender, using a 2 × 2 factorial arrangement. Factors were diets with or without (as-fed basis) quillaja saponin (750 mg/kg during wk 1, 300 mg/kg during wk 2 to 3) and with or without dietary curcumin (200 mg/kg). Diets were fed ad libitum for 20 d after weaning. Feed intake was measured daily. Piglets were weighed at weaning, d 7, 14, and 20 after weaning. On each of d 6 and 20 after weaning, eight pigs per treatment were sacrificed for blood and tissue collection. Treatment had no effect on piglet growth. The ADFI and G:F were similar for all treatments between d 0 and 14 of the trial. Between d 15 and 20, ADFI and G:F were lower in quillaja-supplemented piglets (ADFI = 621 vs. 572 g/d; G:F = 0.75 vs. 0.85; P < 0.05). Serum immunoglobulin (Ig) G, IgA, interferon-γ, and C-reactive protein (CRP) did not differ among treatments on d 6 after weaning. On d 20, IgG and CRP were greater (P < 0.05) in saponin-supplemented pigs (IgG = 17.5 vs. 11.4 mg/mL; CRP = 26.98 vs. 12.5 mg/mL). Small intestine villus and crypt measurements did not differ among treatments on either d 6 or 20. Saponin supplementation during the postweaning period seemed to potentiate an immune response in the weaned piglet but had a detrimental effect on the utilization of feed. Dietary curcumin had no influence on any measured aspect of pig performance or immune status. [PUBLICATION ABSTRACT] Key Words: Curcumin, Growth, Immune response, Piglets, Quillaja