FRANCA, Luis Gustavo Figueiredo, M.Sc., Universidade Federal de Vicosa, February, 2014. Influence variables and propose of maximum ammonia emission index by the activity of laying hens for the Minas Gerais state. Adviser: Ilda de Fatima Ferreira Tinoco. Co-advisers: Cecilia Fatima Souza and Jairo Alexander Osorio Saraz. New production systems for laying hens, fully automated, bring great advantage as compared with conventional production systems eggs, greater efficiency in the housing birds/m. The sheds where there is this type of system can provide up to five rows of cages (alas), containing up to seven floors of overlapping cages allowing the lease of up to 120,000 birds in one aviary with approximate dimensions of 130m long by 14m wide. For these facilities, the fully mechanized system has become a trend in commercial poultry farms in Brazil posture. Minas Gerais is in leading position in the Brazilian scenario, production of chicken eggs, is the second largest egg producer in the country, yet, the state's biggest export. Effective flock of laying hens of the State in 2012 was 21.265.722 birds, about 10 % of Brazil's total herd. Due to the intensification of the production process of chicken eggs, there is a greater concentration of generation and waste coming from the birds. This fact causes major concerns with environmental issues, therefore, the rate of volatilization of ammonia formed in manure, is linked to factors such as: the pH, relative humidity and waste, ambient temperature, amount of crude protein present in ration and age of the birds. The total production of waste attributed to laying hens in Minas Gerais, is estimated at values of around 2126.6 to 2551.89 tons per day. Systems of agricultural production transform carbohydrates and vegetable proteins in milk, meat and eggs. Much of the vegetable protein ingested is excreted through urine and manure. From the compositional characteristics of the waste, combined with bacterial action and climatological variables, the mineralization of manure and nitrogen emissions in the form of ammonia to the atmosphere occurs. Two climatic factors directly affect the generation and emission of ammonia: the ambient air temperature and relative humidity. The Chapter I of this study was to characterize factors influencing ammonia emission by slurry from laying hens, as well as proposing the establishment of a maximum potential score for the emission of this gas due to laying hens, to the state of Minas Gerais. In Chapter II we sought to conduct a zoning egg producers municipalities in Minas Gerais, and construct maps with values of temperature and relative humidity of the average maximum air to the State. The results of a field study in a commercial laying farm, representative of the constructive pattern of fully mechanized vertical aviaries of Minas Gerais, where the