Effect of Dietary Fiber and Genetic Strain on the Performance and Energy Balance of Broiler Chickens

The experiment was conducted to evaluate the effect of dietary fiber on the performance and energy balance of broiler chickens of a fast-growing strain (Cobb500) and a slow-growing strain (Label Rokens during the period of 1 one to 42 days of used In total, 360 male broilers (240 fast-grorain and 120 slow-grtrain) were, housed in collective cages. A completely randomized experimental dewith in a 3x2 factorial arrangement was applied, consisting of three groups of birds (slow-growing - SG; fast-growing fed ad libitum - FGAL; and fast-growing pair-fed with SG broilers - FGPF) and two iso-protein dis (a 3100 kcal ME/kg low-fiber diet and a 2800 kcal ME/kg high-fiber diet- Hwith containing 14% wheat bran and 4% oat hulls). Dietary fiber level did not affect feed intake (FI); however, it resulted in lower weight gain (WG) and worse feed conversion ratio (FCR) (p <= 0.001) in birds fed the HFD diet due to its lower energy content. The FGPF group presented higher WG than SG and better FCR (p <= 0.001), indicating that fast-growing birds present better performance than SG broilers, even under restricted feed intake. The SG group retained more energy relative to body weight (p <= 0.001), which is associated to higher body fat retention in this strain (p <= 0.001). The slow-growing strain did not present better use of high-fiber diet than fast-growing strain as expected.