The effect of dietary supplementation with the natural carotenoids curcumin and lutein on broiler pigmentation and immunity

Abstract

The objective of this study was to compare the effects of supplementation with 2 carotenoids, curcumin and lutein, on pigmentation and immunity in lipopolysaccharide (LPS)-stimulated broiler chicks. Two hundred forty 1-d-old Arbor Acres broilers were randomly distributed into 3 dietary treatment groups: a basal diet without carotenoid supplementation (control), a basal diet supplemented with 200 mg/kg of curcumin (CRM), or a basal diet supplemented with 200 mg/kg of lutein (LTN) for 42 d. The birds were vaccinated against Newcastle disease (ND) and avian influenza on d 10. At 16, 18, and 20 d of age, half of the chicks in each group were injected in the abdominal region with either LPS (250 mg/kg of BW) or an equal volume of 0.9% NaCl. The intensity of the shank skin color (Roche color fan score) and the b* (yellow) values of the breasts and thighs were highest in lutein-supplemented broilers, followed by curcumin-supplemented and control broilers, whereas the a* (red) value of the thigh muscle was highest in curcumin-supplemented LPS-induced birds. At 42 d, the relative weight of the abdominal fat was lowest in the CRM-supplemented group, followed by the LTN-supplemented and control groups; the spleen weight was lower in the non-LPS-induced LTN-supplemented group than the LPS-induced control group. The ND and avian influenza titers were significantly higher in the CRM-supplemented group than in the other groups at 20 d; at 30 d, the ND titer was significantly higher in the LPS-induced LTN group. Supplementation with curcumin significantly promoted B and T lymphocyte proliferation in both LPS- and non-LPS-induced birds at 21 d. Curcumin also promoted B lymphocyte proliferation in non-LPS-induced birds at 42 d. Curcumin significantly reduced alanine aminotransferase and aspartate aminotransferase activities at 42 d in non-LPS-treated birds, whereas lutein significantly increased the activities of these enzymes in LPS-induced birds. Both carotenoids significantly lowered lipid oxidation in the liver of supplemented birds. Thus, in broiler chickens, lutein-supplemented birds exhibited better pigmentation efficiency, whereas curcumin-supplemented birds exhibited improved immune responses.