Frequency of Cryptosporidium infection in broiler breeding flock of Ghaemshahr

Cryptosporidium is a protozoan that lives in the epithelial cells of the respiratory, gastrointestinal and urinary systems of vertebrates. In the present study 300 samples were collected from 30 broiler flocks, 25-50 days old, and then classified into 5 groups. Sample obtained from tracheal fork and bursa of fabricius (BF) at necropsy. Meanwhile two smears were prepared, one from BF cut surface by touch imprint (pressure smear) and another one from tracheal linning membrane by light scraping. Smears, after being fixed in methanol (70%), were stained by modified Ziehl- Neelsen (MZN) technique. Microscopic examination of the stained smears revealed that 7 flocks (23.33%) out of 30 flocks were infected and out of the 300 samples, 39 samples (13%) were positive for Cryptosporidium parasite. The highest incidence of the infection belonged to the group 25-30 days old which have indicated 28.58% of infection in this age.