Mycoplasma mastitis in dairy cattle

The most important characteristics of Mycoplasma mastitis on dairy farms are described, based on two case studies. Clinical symptoms, diagnostics, epidemiology, and a plan of action are presented. In the herds investigated, Mycoplasma mastitis was characterized by multiple affected quarters unresponsive to treatment with antibiotic and/or anti-inflammatory agents. Most striking were a sandy sediment, brown colouring, and rice-like structure of the milk of affected animals. Clinical symptoms differed in the two affected herds. Diagnosis was based on bacteriological investigation of samples of milk and synovial fluid taken from infected cows. Affected animals were culled immediately, and the herds were monitored by repeated testing of bulk milk samples. It was concluded that a consequence of the increasing size of cattle herds in the Netherlands is that subclinical/clinical Mycoplasma mastitis may be diagnosed more frequently than in the past. In the case of Mycoplasma mastitis, farmers and veterinary practitioners are advised to draw up a plan of action together, incorporating aspects such as diagnostics at cow level, direct culling of affected animals, hygiene during milking, including post-milking teat disinfection, and routine monitoring of bulk milk. Unpasteurized milk should not be given to calves.     

Studies of Mycoplasma mastitis in cattle. 7. Mycoplasma mastitis in 3 dairy cattle herds

Reported in this paper is the occurrence of enzootic mastitis in three dairy cattle stocks. The outbreaks had been caused by Mycoplasma bovis, Acholeplasma laidlawii, Acholeplasma axanthum as well as by one unidentified strain of the family of mycoplasmataceae. All animals with positive response to mycoplasma tests were identified an selected by repetitive testing of cultures in milk samples which had been taken from all lactating and dry cows and heifers as well as by evaluation of organ samples obtained from slaughtered cows. Regular cleaning and disinfection of stands in cowsheds, cattle tracks, and milk parlours as well as disinfection of udders and milking cups worked extremely well throughout the action in control of those cases of enzootic mycoplasma mastitis.     

如何有效预防奶牛乳腺炎

奶牛临床型乳腺炎占奶牛总发病率的21％～23％，高的可达45％～50％，乳腺炎已成为世界普遍流行而又危害严重的一种奶牛疾病。据科学研究与实践活动发现，乳腺炎是在环境、牛体和病菌三构成的连锁环中发生的。所以，要根除乳腺炎的发生难度较大，但是，减少传染源、降低乳腺损伤率、控制乳腺炎流行是可以努力做到的。因此，要想有效预防乳腺炎，应切实把好以下五个环节：     

Survey of mycotic mastitis in dairy cows from Heilongjiang Province, China

A survey of the prevalence rate, pathogenic subspecies, and risk factors of mycotic mastitis in dairy cows from Heilongjiang Province, China, was conducted. Milk samples from 412 cows with chronic mastitis were collected and cultured on 8 % sheep blood agar, MacConkey agar, and Sabouraud agar with chloramphenicol. Counting of the morphologically distinct colonies was performed, as well as the isolation and identification of organisms through phenotypical and physiological criteria. Four hundred seventy-eight aerobic microorganisms were isolated. Yeasts and yeast-like fungi 35.6 % (170/478) and bacteria 64.4 % (308/478) were isolated. The fungal isolates were identified as Candida (79.4 %), Trichosporon (5.9 %), Aspergillus (7.1 %), Cryptococcus (2.4 %), and Rhodotorula (4.1 %). More than ten species of yeast were isolated including Candida krusei 50/135 (37 %), Candida rugosa 16/135 (11.9 %), and Candida lusitaniae 15/135 (11.1 %). A higher positivity (18.5 and 56.3 %) (P ≤0.05) was observed in cows from environmental temperatures of 0–15 and 15–35 °C than those at <0 °C and in cows affected by the disease for >45 and 30–45 days compared with cows suffering 10–30 days. Meanwhile, a statistically significant difference (44.9 vs. 31.4 %) (P ≤0.05) was observed under extensive raising systems vs. intensive raising systems. It appears that Candida is a major pathogen of mycotic mastitis of dairy cows. Extensive raising system, high environmental temperature (15–35 °C), and the duration of the disease (>30 days) were important risk factors of the incidence of mycotic mastitis. Here, we provide a theoretical foundation for research into preventing and treating mycotic mastitis of dairy cows in China.     

Initial experience with the intravenous administration of colloidal carbon to cattle in relation to the incidence of mastitis

The influence was studied of intravenous application of colloid carbon to ten dairy cows of Bohemian Spotted breed in the seventh to eighth months of gravidity, as exerted on the health condition of mammary glands and on milk yield in the subsequent lactation. The cure consisted of three i. v. installations in 72-hour intervals; one dose contained 150 mg carbon in 20 ml of 20% glucose. No adverse by-effects were observed in the course of application and after it. During the subsequent lactation period (nine months) the test cows exhibited a better health condition of mammary glands if compared with the control group (ten dairy cows). In the test group no case was recorded of the clinical form of mastitis while in the control group one case of acute mastitis and two cases of chronic mastitis occurred. S. agalactiae was not isolated at all in the test group while in the control group it was isolated in two cows. S. aureus was also isolated more times (in 32 cases) in the control cows than in the test ones (in 27 cases). A higher average counts of cells in udder-quarter milk samples were found in the test group only at the onset of lactation (from the third month after calving), the average counts of cells over the whole period under study were however lower in the test group (1 380 000 per ml) than in the control group (1 234 000 per ml). The average daily milk yield per cow in the test group exceeded the average milk production in the control group in the period of study. An increase by 1.630 1 as compared with the untreated cow was observed in the average milk yield. It has been demonstrated by the results that by the intravenous instillation of colloid carbon nonspecific natural defensive mechanisms of dairy cows, mainly leucocytes, are stimulated, which enhanced the cell readiness to react to infectious process (mastitis) and overall injury of the organism (sepsis).     

Comparative bacteriological studies on summer mastitis in grazing cattle and pyogenes mastitis in stabled cattle in Denmark.

A total of 143 secretions from clinical cases of summer mastitis (SM) in grazing cattle and from 89 cases of pyogenes mastitis (PM) in stabled cattle were examined bacteriologically. The typical bacteriological finding was a mixed flora in which the predominant organisms were Actinomyces pyogenes (SM-70%, PM-85%), Peptostreptococcus indolicus (54%, 54%), a microaerophilic coccus (Stuart-Schwan coccus) (26%, 25%), Fusobacterium necrophorum biovar B (22%, 12%), Bacteroides melaninogenicus (20%, 9%) and Streptococcus dysgalactiae (21%, 5%). All except six cases occurred in non-lactating animals or within three weeks after parturition. The majority of animals (about 90%) had only one quarter affected and no differences in quarter distribution were observed between the two groups.     

Production effects related to mastitis and mastitis economics in dairy cattle herds

Mastitis is the most prevalent production disease in dairy herds world-wide and is responsible for several production effects. Milk yield and composition can be affected by a more or less severe short-term depression and, in case of no cure, by a long-acting effect, and, sometimes, an overlapping effect to the next lactation. Summary values in the literature for losses of milk production were proposed at 375 kg for a clinical case (5% at the lactation level) and at 0.5 kg per 2-fold increase of crude SCC of a cow. Due to the withdrawal period after treatment, composition changes in milk can almost be neglected in economic calculations. Lethality rate for clinical mastitis is very low on the average, while anticipated culling occurs more frequently after clinical and subclinical mastitis (relative risk between 1.5 and 5.0). The economics of mastitis needs to be addressed at the farm level and, per se, depends on local and regional epidemiological, managerial and economic conditions. To assess the direct economic impact of mastitis, costs (i.e. extra resource use) and losses (i.e. reduced revenues) have to be aggregated. To support decision making for udder health control, it is necessary to use a marginal approach, based on the comparison of the losses avoided and the additional costs of modified plans, compared to the existing ones.