Influence of Combined Yeast-derived Zinc, Selenium and Chromium on Performance, Carcass Traits, Immune Response and Histomorphological Changes in Broiler Chickens

This study was carried out to assess the effects of dietary supplementation of yeast-based Zn, Se, and Cr on growth performance, carcass characteristics, immune response, and histomorphological changes in broiler chickens. A total of 1092 one-day-old unsexed broilers of Ross 308 strain were randomly allocated into two equal treatment groups (6 equal replicates/ group). Birds were fed the dietary treatments from day 1 to day 35 of age. The first group was fed a basal diet without yeast-based Zn, Se and Cr supplementation (control). The second group was fed a basal diet supplemented with 1.5 mg, 0.15 mg and 2 µg / kg diet of Zn, Se, and Cr, respectively. The yeast-based Zn, Se and Cr increased (P<0.05) the growth rate, carcass traits and improved feed conversion ratio compared to control. The antibody titer against avian influenza and the relative weight of bursa, thymus and spleen were increased (P < 0.05) in broilers supplemented with yeast-based Zn, Se, and Cr compared with the control. The intestinal villi height and crypt depth and bursa diameters were increased in broilers fed the yeast-based Zn, Se and Cr supplemented diet. In addition, there was an increase in the lymphocytic infiltration in the bursa and a decrease in germinal centers in the submucosal lymph nodules of the ileum of birds supplemented with yeast-based Zn, Se and Cr compared to the control. In conclusion, dietary supplementation of yeast-based Se, Cr, and Zn in combination could improve growth performance, carcass traits, immune responses and histo-morphological parameters in broiler chickens