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

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.