EFFECT OF DIETARY SUPPLEMENTATION OF CHROMIUM AND ZINC ON PERFORMANCE, SERUM BIOCHEMICAL PARAMETERS, CARCASS DEVELOPMENT, AND INTESTINAL MICROFLORA BALANCE IN BROILER CHICKENS REARED UNDER HEAT STRESS

The present study evaluates the effect of dietary chromium and zinc (Cr-Zn) supplementation on performance, serum biochemical parameters, carcass development and intestinal microflora of broilers reared under high heat stress (HS). An experiment was carried out on 60 Ross 308 broiler chickens, assigned to two experimental groups (C and Cr-Zn) with 30 chickens/group and maintained under high heat stress (32 degrees C). Compared to the control diet (C), the experimental diet included the addition of a premix with 20 mg chromium picolinate +2.5 g Zn/kg premix (Cr-Zn). Dietary Cr-Zn did not affect the performance and serum biochemical parameters of broiler chickens reared under HS conditions. The use of Cr-Zn in broiler diet led to a significant reduction of Enterobacteriaceae, E. coli, staphylococci in the caecal and intestinal content. Both in the caecum and in the intestinal contents of Cr-Zn broiler chickens, the number of lactobacilli was significantly higher than in the C broilers. The combination of Zn and Cr in broiler feeding has a positive impact on maintaining the balance of intestinal microflora during heat stress