Seasonal study of poultry feed contamination with molds in laying poultry farms around Tehran

Mold contamination of feeds is a common problem in poultry industry. The aim of this study was to investigate mold contamination of laying hen diets around Tehran (Shahriar and Malard). For this purpose, 5 laying poultry farms were subjected to random sampling so that a total of 60 samples were taken from each poultry farm during four consecutive seasons. For counting and separation of molds, surface cultivation in the culture medium was used. After the primary growth of molds, slide culture was prepared and the macroscopic and microscopic indices of molds were defined. Seven types of molds were separated by macroscopic and microscopic studies. In terms of the total number of molds in laying poultry farms in each season, no significant difference was observed, but between seasons a significant difference was observed (p<0.001), as such, the number of molds in autumn (3.11±0.10 Log CFU/g) and winter (3.35±0.10 Log CFU /g) showed the highest level of contamination in all laying poultry farms. Also, the lowest number of mold contamination was observed during the spring and summer in all laying poultry farms. Fusarium, Penicilium, Aspergillius flavus, Mucor, Aspergillus niger, Alternaria and Ulocladium were the most prevalent molds in all seasons. Overall, there was a seasonal trend in the amount of mold contamination with maximal contamination observed during autumn and winter seasons.