Effect of different levels of Yucca extract and antibiotic on growth performance, immune response and blood factors of broiler chickens

This experiment was designed to study the effects of feeding diets containing different levels of yucca extract and antibiotic on growth performance, blood parameters, immune system and ascites index. Three hundred and twelve, one-day old broiler chicks (Arian) were used in a completely randomized design with four treatments, consisting of three replications and 26 (male & female) chicks per pen. The treatments consisted of control (without supplementation), Yucca schidigera extract at 150 and 225 mg/kg, and virginiamycin at 15 mg/kg up to six weeks of age. Significant differences were found for feed intake, feed efficiency, and body weight gain in the studied treatments (p < 0.01). Immune responses, expressed as a primary and secondary antibody response to SRBC, were affected by treatments (p < 0.01). Treatment groups did not affect the weights of organs (p < 0.05). Effects of treatments on cholesterol, triglycerides, HDL and LDL levels, at 35 days of age, were significant on the parameters evaluated in different experimental groups (p < 0.01). The trends observed indicate that Yucca schidigera extract could have beneficial effects on broiler chicks performance.