Growth Performance, Carcass Characteristics and Economic Viability of Broiler Chickens Fed Partial Levels of Comfrey Leaf Meal ( Symphytum Officinale )

This study evaluated the effects of partially replacing soybean meal (SBM) with comfrey leaf meal (CLM) on the growth performance, carcass characteristics, and economic viability of broiler chickens. Fresh Symphytum officinale leaves were harvested, shade-dried, and milled to produce CLM. Four pelleted experimental diets were formulated to contain 0% (control), 4%, 8%, and 12% CLM inclusion levels. A total of 240 day-old Cobb 500 broiler chicks were brooded for 14 days, after which the birds were randomly assigned to four dietary treatments with three replicates of 20 birds per replicate in a completely randomized design. Growth performance, carcass traits, and economic parameters were evaluated during the growing-finishing phase. Final body weight, average daily gain (ADG), and average daily feed intake (ADFI) were significantly reduced (P<0.05) in birds fed 4%, 8%, and 12% CLM compared to the control. Final body weights were 2245.40 g, 2119.06 g, 1833.96 g, and 1485.57 g for 0%, 4%, 8%, and 12% inclusion levels, respectively. Corresponding ADG values were 66.26, 61.30, 51.30, and 38.30 g/bird/day, while ADFI values were 149.86, 148.00, 143.76, and 139.79 g/bird/day, respectively. Feed conversion ratio did not differ between 0% and 4% CLM (P>0.05) but was significantly poorer at higher inclusion levels. Slaughter weight differed significantly among treatments (P<0.05), whereas dressing percentage and organ weights were not significantly affected (P>0.05). Economic analysis indicated that 4% CLM inclusion produced the most favorable cost differential (160.96 TSH/kg gain) and relative cost reduction (5.90%) compared to the control. These findings suggest that partial replacement of SBM with CLM at 4% inclusion level maintains acceptable performance and carcass traits while improving economic efficiency, whereas higher inclusion levels negatively affect broiler performance.