Prevention of mastitis is a major concern in dairy cattle breeding, and is among the most costly diseases of dairy companies. The purpose of this study was to compare two types of milking practices; one using manual milk-ing and the other using mechanical milking to determine milking type consequences on the occurrence and spread of subclinical mastitis. One hundred dairy cows were brought to the slaughterhouse following a fall in milk production due to subclinical mastitis, of which 64 cows were mechanically milked and 36 cows were manually milked. After anti-mortem and post-mortem examinations, we found that 58% of cows in mechanical milking mode had mastitis. Amongst them 9% of cows had mastitis spread on the four teats. However, the rate was higher (68%) in cows where milking was done manually, of which 49% mastitis spread on the four teats. The bacterio-logical analyses was carried out regarding coliforms, Staphylococci and Streptococci on the raw milks of cows suspected of mastitis, irrespective of the mode of milking.. We chose E. coli and found that its resistance against antibiotics tested was important, except Gentamicin where the sensitivity was average with an inhibition zone of 1.6 cm. We then evaluated the effect of pure honey on the strain to see its antiseptic effect. We noticed the inhibition zone diameters of 2.2 cm. We also tested the effect of diluted honey, the results of which were not satisfactory because of the decreased antisep-tic activity possibly owing to decreased acidity of the honey.

The aim of this study is to test two different methods for evaluating the in vitro antibacterial effect of Thymus fontanesii Boiss. et Reut. essential oil against standard and clinical bacterial strains responsible for bovine mastitis: the disc diffusion method or the aromatogram which allows the demonstration of the antibacterial power of essential oils on the bacterial strains tested, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and two strains isolated from bovine mastitis milk S. aureus and E. coli. The inhibition activity of the essential oil of T. fontanesii on bacterial strains by the two methods shows that the antimicrobial power of this oil is very important and is characterized by bactericidal and bacteriostatic action against gram negative and gram positive bacteria. The antimicrobial evaluation by the aromatogram showed good antibacterial activity against all the strains tested, the zones of inhibition of the bacteria were between 23,33±1,527mm and 37,5±3,535 mm. The search for minimum inhibitory concentrations MIC and bactericides CMB made it possible to quantitatively assess the antimicrobial power of this essential oil. In this work, the MIC was 0,625 µl/ml for all strains tested, and the lowest CMB was that of T. fontanesii against E. coli ATCC 25922 was 0,625 µl/ml.

The aims of this work was to study the sensitivity of Staphylococcus aureus strains isolated from bovine mastitis antibiotics. A total of 22 pure strains of S. aureus were collected from 58 quarter milk samples from 29 (69,04%) dairy cows detected with subclinical mastitis by California mastitis test (CMT). The isolates were subjected to an antibiogram. The tests showed that one strain among the isolates tested is MRSA (Methicillin resistant Staphylococcus aureus). This MRSA exhibited cross-resistance to all betalactamines which extends to other families of antibiotics. SASM strains also showed strong resistance. vis-à-vis penicillin (95,23%) and tetracycline's (90,47%) Resistance was also recorded vis-à-vis; the combination amoxicillin + clavulanic acid (47,61%), erythromycin (19,04%), the combination trimethoprim + sulfamethoxazole (4,76%) and bacitracin (9.52%). neomycin, gentamicin, ciprofloxacin and clindamycin were active on MRSA's. The high prevalence of subclinical mastitis and multi-resistant S. aureus strains testifies to the need for an effective control strategy based essentially on the early detection of subclinical mastitis, the identification of the causative agent and the study of its sensitivity to common antibiotics.

The aim of this work was to estimate the sero-prevalence and associated with Culicoides trapping in study area in cattle. BTV sero-positive from seven provinces in north western Algeria, seven provinces were selected. A total 272 animals included three phases of blood collection in season of autumn were randomly collected for detection of BTV group specific antibodies through competitive ELISA (c-ELISA) for assessment of situation epidemiological by prevalence and presence of Culicoides trapping in sites was revealed seropositive. The significant (p<0,05) highest prevalence of BTV was recorded in province Oran followed by Mostaganem, Relizane, Mascara, Tiaret, Chlef, whereas, the lowest sero-prevalence for BTV was recorded in cattle in province