MATHEMATICAL-MODELS FOR THE ESTIMATION OF EGG-PRODUCTION OF MOLTED AND NON-MOLTED LAYER FLOCKS

Mathematical models for the description of the hen-day egg production as well as for the egg grading curves (egg size, second grade eggs) we re developped. These models can be introduced in computer programmes e ither to fit egg production standards or to predict total egg producti on of layer farms with several flocks. Data from moulted an non-moulte d commercial layer flocks were used for determining the parameters of the presented models. Then the flock datas were compared with the pred icted curves. The model for the weekly hen-day egg production allows a good description of the non-linear increasing and decreasing parts of the curve. By dividing the egg production curve into two parts with d ifferent parameters and basing on recent data, also a standard egg pro duction curve for the first and second cycle of moulted Rocks could be found. The second model allows the estimation of the weekly percentag e of three egg sizes and of second grade eggs (broken, hairline-cracke d and dirty eggs). By using the corresponding parameters, the same fun ction can be used for each category.