EFFECTS OF CHROMIUM ON THE GROWTH AND IMMUNOLOGICAL RESPONSE OF BROILER CHICKENS

Abstract

The objective of the study was to determine the effects of varying levels of chromium picolinate (CrPic) on the growth performance and mineral retention of chickens during a 35-day experiment. A total of 180 broilers were randomly allocated into 0 (control), 500 ppb (μg kg-1) Cr and 3000 ppb Cr groups with 6 replicates (10 birds/pen). Thirty-six birds were then subjected to the metabolic experiment. The results of the study revealed that there were no significant differences in average body weight gain between groups, but feed conversion ratio (FCR) in 3000 ppb group was better than control group during 1-21 days. The carcass yielded slightly lower than control after being given high concentrations of chromium picolinate. Retention ratio of Zn, Fe, Mn, Ca, and P were significantly (p<0.05) increased in the 500 ppb Cr group. The addition of CrPic caused the mineral concentrations in the livers to increase. It also decreased the H/L and heterophils ratio and increased lymphocytes. The chickens did not exhibit the Newcastle disease antibody titer. However, the added CrPic improved the retention of zinc, Fe Ca, and Cr in the liver.