عنوان مقاله [English]
Microbial and chemical changes in milk cause it’s processing disorder and so, decrease shelf life of dairy products which can lead to hazardous effects on consumers and society health. In present study, 6 traditional dairy farms were selected in order to evaluation milk changes in production sites. Samples of raw milk were harvested monthly for a year, in morning milking from cow teats, milking machine, buckets in collection centers, cooling tank of collection centers and transporting tanker in factory. Samples were examined for total microbial count and PH. Geometrical means of total microbial count of raw milk in above mentioned sites were 1.6×105, 8.2×105, 3.2×106, 9.3×106 and 7.2×106 cfu/ml. Total microbial count in milking machine, buckets and cooling tank of collection centers increased significantly in comparison to earlier sites (p<0.01). Total microbial count and PH in summer were significantly higher than winter (p<0.05). According to the results, more attention of milk producers to healthy principles was recommended especially in summer.