The Inclusion Effect of Premix Additive in Joper Chicken Feed on The Morphological Body Size Characteristics

This research aimed to evaluate the inclusion effect of premix as a feed additive on the morphological characteristics of Joper chickens. The study used 192 Joper chickens reared from 21 to 56 days old. A Completely Randomized Design (CRD) with four treatments (T0: without premix, T1: 0.2% premix, T2: 0.3% premix, and T3: 0.4% premix) and six replications was applied. Observed variables included chest circumference, femur length, tibia length, shank length, and shank circumference. Data were analyzed using ANOVA and Duncan's Multiple Range Test for significant differences. Results showed that premix addition did not significantly affect all parameters (P>0.05), although improvements were observed in T1 and T2. The highest average values were found in T1 for shank length (86.46 mm) and shank circumference (4.13 cm), T2 for chest circumference (24.77 cm) and tibia length (114.29 mm), and T3 for femur length (83.70 mm). It can be concluded that premix addition does not significantly affect the body morphology of Joper chickens. Tibia length can serve as the best indicator in estimating body weight. Further studies are needed to evaluate long-term premix effects under different rearing conditions.