Bio-economic impact of energy and protein level in feed for laying hens raised in organic system

The economic results of organic egg production are largely dependent on the cost of the feed and productive performance. The paper aims to establish the productive performance of laying hens raised under specific conditions specific for the ecological system, and also performing a feeding costs estimation based on mathematical models starting from experimental data required. The hens in the experiment were fed a mixture of concentrated (MC) with 2728 kcal metabolizable energy (ME), 15.85% crude protein (CP), 0.67% lysine, 0.52% methionine + cystine, containing in its structure only fodder types organically certified. Throughout the entire experimental period, chickens have recorded a total MC consumption of 13.240 kg with an average daily consumption between 0.110 and 0.130 kg, when they produced a daily average of 31.55 g mass-egg. The amount of mass-egg produced (y) under this experiment can be predicted based on metabolizable energy intake (x1) and crude protein (x2) using the following mathematical model y=a+b*x1+c*x12+d*x13+e*x14+f*x15+g*x2 (R2=0.99%). Between the values obtained after the experiment and the predicted values obtained using the mathematical relationship, the differences are very small 2.17% at the end of experimental period. The costs incurred by feeding the laying hens (y) organically raised can be predicted using the following mathematical model y=exp(a*x1+b*x2+c*x3+d) (R2=0,96), with a rate of error of less than 2.2%, depending on the amount of mass-egg produced (x1), metabolizable energy intake (x1) and crude protein intake (x2).