The Effects of Different Levels of Crude Protein and Energy on Growth Performance Parameters and Economic Viability of Tanbro Chickens in Tanzania

This study evaluated the effects of varying crude protein (CP) and metabolizable energy (ME) levels on growth performance and economic viability of Tanbro chickens. A total of 200-day-old chicks were brooded for 26 days and randomly allotted to four dietary treatments (T0-T3) in a completely randomized design, with four replicates of 12 birds each. Diets were formulated separately for growing (G) and finisher (F) phases. T0-G was a commercial control diet (T0-G: 2959 kcal/kg ME, 19.6% CP; T0-F 3068 kcal/kg ME, 19.3% CP). T1-G contained 2978 kcal/kg ME, 20.12% CP), T1-F had (3018.8 kcal/kg ME, 18.29% CP). T2-G (2567.68 kcal/kg ME and 20.06% CP) while T2-F had (2741.17 kcal/kg ME and 16.1% CP) and T3-G: had (ME, 2583.84 kcal/kg &, 18.64%CP); T3F (ME, 2661.04 kcal/kg &, 14.77%CP). Dietary crude protein and metabolizable energy levels significantly affected the growth performance of Tanbro chickens during grower and finisher phases. During the grower phase, birds fed T0-G exhibited significantly (P < 0.001) higher body weight (1327.0 g), body weight gain and (67.1 g/day), compared to other treatments. Feed conversion ratio (FCR) in grower phase was also significantly affected (P = 0.0001), with T1-G showing better efficiency (2.4), than T2-G and T3-G. Likewise, final body weight and body weight gain were significantly influenced by dietary treatments. Birds on T1-F achieved the higher final BW (1984.5 g) and weight gain (59.3 g/day), than other tested diets. Feed intake and FCR differed significantly (P < 0.0001), with the highest intake observed in T2-F (156.2g) while T1-F showing better FCR compared to other testable diets (2.5). Economically, T1-F yielded the highest cost advantage, with a differential gain of 1005.27 TSH and a relative cost per kilogram of weight gain representing 23% of the control diet. These findings highlight the need for balanced diet formulation tailored to breed, the growth stage and production goals, especially in resource-limited production settings.