Sq. Lafi et al., INCIDENCE OF CLINICAL MASTITIS AND PREVALENCE OF SUBCLINICAL UDDER INFECTIONS IN JORDANIAN DAIRY-CATTLE, Preventive veterinary medicine, 18(2), 1994, pp. 89-98
Nineteen Jordanian dairy farms selected by stratified random sample we
re monitored between July 1991 and August 1992 in order to: (a) determ
ine the incidence of clinical mastitis; (b) assess the influence of se
ason and herd size on the incidence of clinical mastitis; (c) estimate
and identify major udder pathogens and their prevalence. Sixty-five p
ercent of clinical mastitis cases occurred between December and April.
The incidence of clinical mastitis was 6.8, 5.0 and 3.3 cases per 100
cow-months at risk for herds with 10-29 cows, 30-59 cows, and more th
an 59 cows, respectively. The most common organisms isolated from clin
ical cases were coagulase-negative staphylococci (16%) and Staphylococ
cus aureus (14%). The most prevalent bacterial pathogens in subclinica
l udder infections were coagulase-negative staphylococci (9.4-11.8%),
Staphylococcus aureus (9.2-12.1%) and Corynehacterium bovls (5.8-7.5%)
. The prevalence rates of Escherichia coli and Enterobacter spp. incre
ased during the winter season for the three herd-size strata.