Abstract
The present study was conducted to determine impact of application of Virkon S disinfectant in milk parlour on microbial load from possible sources of contamination and on raw milk. Therefore, this study was carried out on ten dairy cows (equal in their milk production and free from clinical and subclinical mastitis) in a private dairy farm of Holstein cows in Kafr El-Zayat, El-Gharbia Governorate. two hundred samples including 70 swabs samples from (teat cup, milk jar, teat surface, rubber tube, milk pipeline, milk tank and worker’s hand), 10 water samples, 10 individual milk samples, and 10 bulk milk tank samples, were collected regular farm application and after application of virkon S disinfectant. the obtained results revealed that worker’s hand swabs and bulk tank milk samples were the most contaminated points in milk parlour. Virkon S gave reduction percent on all investigated indicators organisms with different percent. in addition, higher reduction percent reach to 100% on coliforms counts from teat cup swabs, wash water, cow milk samples. Our study revealed that milkers’ hand, milking equipment, udder of animal, water used for cleaning and washing of equipment were the most potential sources of raw milk contamination, so these points were counted as points needs attention for production of high-quality milk. virkon S is highly effective in reducing bacterial population for quality milk production.

Key words: Indicator organism, virkon S., Swabs ,water, cow’s milk, bulk milk.