Immune competence and serum parameters in commercial broiler chickens fed graded levels of organic and inorganic chromium

Chromium (Cr), a trace mineral in commercial poultry nutrition has greater role in stress reduction and immunity enhancement. The present study was designed to evaluate the immune status and serum profile of the broilers fed graded levels of organic (Cr- picolinate) and inorganic (Cr-chloride) Cr. Experimental treatments were comprised of one corn-soybean based diet without supplemental Cr and designed as control diet (CD). To this CD, organic Cr at 300 (T₁), 600 (T₂), 900 (T₃), 1200 (T₄) and 1500 (T₅) and inorganic Cr at 300 (T₆), 600 (T₇), 900 (T₈), 1200 (T₉) and 1500 (T₁₀) ig per kg diet were added, comprising a total of 11 dietary treatments with eight replicates of five chicks each. Duration of the experimental period was six weeks. Blood samples for serum biochemical analysis were collected during 28^th and 42^nd of age. Dietary Cr did not influence the relative weight of thymus, spleen and bursa, when the birds were sacrificed on 42^nd day of age. Supplementation of chromium in the form of either organic or inorganic had increased (P<0.05) the humoral immune response against ND virus and decreased (P<0.05) the in-vivo cell mediated immune response. Serum concentration of glucose and cholesterol were decreased and the triglyceride concentration increased. From the results, it was concluded that supplementation of Cr @ 300 ig per kg diet either as organic or inorganic source improved the immune response and glucose utilization in broilers.