Period prevalence and etiology of subclinical mastitis in Awassi sheep in southern Jordan

To investigate the period prevalence, etiology and some epidemiological features of subclinical mastitis in Awassi ewes from the southern part of Jordan, milk samples from 318 lactating ewes were aseptically collected for bacterial and somatic cell counts (SCC) tests. Milk samples were collected at monthly intervals. The period prevalence of subclinical mastitis was 18.3% and the prevalence within each flock remained relatively constant throughout the study period. A significant association (P < 0.001) was observed between the occurrence of subclinical mastitis and the age of ewe. Presence of teat lesions has no impact on the prevalence of subclinical mastitis. The prevalent bacterial species isolated from mammary glands with subclinical mastitis were Staphylococcus aureus (39%), Streptococci (25%), Escherichia coli (19.6%) and coagulase-negative Staphylococci (17.9%). Coagulase-negative Staphylococci were the most prevailing isolates from samples that showed negative SCC results. (C) 2002 Elsevier Science B.V. All rights reserved.