economic evaluation of laying hen breeding in tehran province

this study carried out for economic investigation on laying hen farms in tehran province. the data was collected through completion of questionnaire by direct interview from 41 layer farms, which were selected by stratified random sampling method in 2013. among all types of production functions, the cobb-douglas production function was selected and its coefficients was estimated and average product, marginal product and the ratio of value of marginal product to input prices and inputs’ production elsaticity was estimated. the results showed that more than 87 percent of cost of egg production belongs to the feed and pullet costs. the production elasticity of all studied inputs including feed intake, pullet and labor were positive and less than one, which shows that the producers were utilized these inputs economically. the average production of feed and pullet inputs was 0.49 and 18.5, respectively and on this basis, on an average, 0.49 kilograms eggs were produced for one kilogram of feed and 18.5 kilograms of eggs for one pullet in studied laying hen farms. according to the results, feed intake and pullet were most important effective factors on egg production in tehran province. meanwhile, considering the price of purchased inputs and sold egg, producers utilize these inputs economically and efficiently based on the ratio of value of marginal product to input price index.