Abstract :
Four economic nutritional models including a constant calorie-nutrient ratio (C-E:P), a variable calorie-protein ratio (V-E:Pg), a constant protein-amino acid ratio (DBP) and a variable calorie-protein ratio for the finisher period (V-E:Pd) were compared in terms of relative performance, economic nutrient requirements and profitability based on relative performance expressed as a function of nutrients, relative or real prices of feedstuffs and broilers and maximum profit feed formulation. The relative body weight or feed intake in response to nutrient contents tended to increase or decrease respectively with particular differences for each model. The economic nutrient requirements were different for each model such as 3.139 Mcal/kg for C-E:P, 2.968 Mcal/kg and 20.7% of protein for V-E:Pg model, 22.44% of protein for DBP model, 3.167 Mcal/kg for V-E:Pd and 3.134 Mcal/kg for C-E:P-3.15 model. As the price of broilers or corn increased, the energy or protein content was increased for C-E:P, V-E:Pg and DBP models except the energy level of V-E:Pg model. However, as the Soybean Meal (SBM) or poultry oil price increased, the energy or protein content was reduced for the three models indicated above except the energy level of V-E:Pg model. Energy levels of the V-E:Pd model were kept almost constant as the broiler or ingredient price raised. Under relative price of feedstuffs and broilers the best profits depended on the model used, being more economical when the broiler or corn price increased for the C-E:P or DBP models respectively. The best profitability using real price of broiler, corn or SBM for twelve months came from the C-E:P model followed by the DBP model. From the two models, V-E:Pd and C-E:P-3.15 models, the V-E:Pd model had the best benefit but with a narrow range of growth response and economic conditions. These data suggest that the C-E:P model is the best method of formulation to maximize performance or profitability; however, for some corn price variation the DBP model can be more profitable though the carcass quality can be negatively affected.
