Prevalence and etiology of subclinical mastitis in dairy ewes in two seasons in Semnan province, Iran

Abstract

Twenty-one dairy ewe flocks selected by stratified random sampling were subjected to study the prevalence and etiology of subclinical intramammary infections and to assess the influence of parity on the prevalence of intramammary infections. Also, spontaneous cure rates were determined over study period. A total of 1192 milk samples were collected at 2 weeks after lambing until tenth-week postpartum. All flocks had hand milking; those which were classified by bacterial culture and California Mastitis Test (CMT) as positive were deemed to have glands with subclinical mastitis (SCM). Of 1192 halves examined, 791 samples were collected during spring and 401 samples were collected during summer. Prevalence rate of SCM in spring was 14.7 %; and spontaneous cure that occurred in this season was 88.8 %; coagulase-negative staphylococci (CNS) were the most common isolates (66.6 %). Samples collected in spring showed higher prevalence rate of SCM than summer samples. This rate was 8.9 % in summer. Spontaneous cure rate in this season was 69.4 %, and Staphylococcus aureus (72.2 %) was the most common isolates. SCM was seen at significantly lower rates in left half than in right one (p < 0.05). Multiparous ewes had significantly higher (p < 0.05) SCM prevalence rates than primiparous ewes. The incidence of clinical mastitis (defined as number of clinical cases per 100 ewe-months) was 0.21 and 0.74 in spring and summer, respectively. The isolates from clinical cases in spring were fungi and, from summer, were S. aureus. Also, S. aureus SCM cases were not significantly severe than other SCM cases. In conclusion, multiparous ewes were most at risk, and severity of infection was higher in summer.

Microbial agents in macroscopically healthy mammary gland tissues of small ruminants

“…Already Bergonier et al (2003b) reported a CNS prevalence in subclinical mastitis ranging from 25 to 93%. Similar results (42.9%) were recently observed also in Portugal in milk samples from clinically affected sheep udders ( Queiroga, 2017 ), in Iran in subclinical ovine mastitis ( Narenji Sani, Mahdavi & Moezifar, 2015 ), in Greece in dairy goats ( Gelasakis et al, 2016 ) and in Italy in both species ( Dore et al, 2016 ). The identification of Staphylococcus xylosus in sheep and Staphylococcus caprae in goats is also in agreement with the literature ( Bergonier et al, 2003b ; Contreras et al, 2007 ; Ergün et al, 2009 ), while Staphylococcus equorum was isolated only by Hariharan et al (2004) in sheep and by Contreras et al (2003) in goats.…”

Isolation, Biochemical and Molecular Identification, and In-Vitro Antimicrobial Resistance Patterns of Bacteria Isolated from Bubaline Subclinical Mastitis in South India

“…aureus [ 42 , 43 ], but similar to observations in dairy cattle in some countries such as Uganda [ 44 ], as well as in modern cattle dairy farms where contagious pathogens have been controlled [ 45 – 48 ]. Higher prevalence of CoNS has also been reported for ovine or caprine mastitis in China, Iran, Israel, Italy, the Netherlands, New Zealand, Spain, and Sweden [ 49 – 59 ]. Whereas all these studies, including ours, suggest a potential role for CoNS in causing SCM, there is as yet no concrete evidence for a cause and effect relationship between the two [ 47 , 48 ].…”

Effect of mastitis on some hematological and biochemical parameters of Red Sokoto goats

“…Mastitis is a common disease entity of Red Sokoto goat (RSG), accompanied by physical, chemical, pathological, and bacteriological changes in milk and glandular tissues [1,2]. The disease is usually classified as subclinical, acute, subacute, chronic, and gangrenous based on etiopathological findings and observations [3]. Predisposing factors such as poor management and hygiene, teat injuries, and faulty milking machines are known to hasten the entry of the infectious agents and the course of the disease [4].…”