A cross-sectional study was conducted between January and July 2014 in Unguja island of Zanzibar to establish prevalence of subclinical mastitis (SCM) in smallholder dairy cows and patterns of antibacterial susceptibility of major mastitis pathogens isolated. A total of 416 dairy cows from 201 farmers were randomly selected from three districts of Unguja Island to participate in the study. Questionnaire interview, field observation, individual cow examination, California Mastitis Test (CMT) and bacteriological examination were carried out. Kirby-Bauer disc diffusion technique was used to test drug sensitivity for common bacteria isolated. Based on CMT results, the overall prevalence of SCM was 28.6, 48.8 and 64.7% at quarter, cow and farm level, respectively. Prevalence of bacterial infection was recorded at 42.9, 70.9 and 78.6% at quarter, cow and farm examined, respectively. The common bacteria isolated included Staphylococcus aureus (36.8%), Pseudomonas aeruginosa (17.8%), Staphylococcus epidermidis (16.1%), Klebsiella spp. (9.5%), Micrococcus spp. (6.3%) and Escherichia coli (4.9%). In conclusion, findings of this study demonstrated high level of subclinical mastitis at farms, cows and quarters levels with both contagious and environmental bacterial pathogen involved. Therefore, efforts should be directed to the decreased subclinical mastitis by improving sanitary measures and proper milking practice.

Prevalence of bovine subclinical mastitis and antibiotic susceptibility patterns of major mastitis pathogens isolated in Unguja island of Zanzibar, Tanzania.

Huge livestock population of India is under threat by a large number of endemic infectious (bacterial, viral, and parasitic) diseases. These diseases are associated with high rates of morbidity and mortality, particularly in exotic and crossbred cattle. Beside morbidity and mortality, economic losses by these diseases occur through reduced fertility, production losses, etc. Some of the major infectious diseases which have great economic impact on Indian dairy industries are tuberculosis (TB), Johne's disease (JD), mastitis, tick and tick-borne diseases (TTBDs), foot and mouth disease, etc. The development of effective strategies for the assessment and control of infectious diseases requires a better understanding of pathogen biology, host immune response, and diseases pathogenesis as well as the identification of the associated biomarkers. Indigenous cattle (Bos indicus) are reported to be comparatively less affected than exotic and crossbred cattle. However, genetic basis of resistance in indigenous cattle is not well documented. The association studies of few of the genes associated with various diseases, namely, solute carrier family 11 member 1, Toll-like receptors 1, with TB; Caspase associated recruitment domain 15, SP110 with JD; CACNA2D1, CD14 with mastitis and interferon gamma, BoLA--DRB3.2 alleles with TTBDs, etc., are presented. Breeding for genetic resistance is one of the promising ways to control the infectious diseases. High host resistance is the most important method for controlling such diseases, but till today no breed is total immune. Therefore, work may be undertaken under the hypothesis that the different susceptibility to these diseases are exhibited by indigenous and crossbred cattle is due to breed-specific differences in the dealing of infected cells with other immune cells, which ultimately influence the immune response responded against infections. Achieving maximum resistance to these diseases is the ultimate goal, is technically possible to achieve, and is permanent. Progress could be enhanced through introgression of resistance genes to breeds with low resistance. The quest for knowledge of the genetic basis for infectious diseases in indigenous livestock is strongly warranted.

/pdf/molecular-markers-for-resistance-against-infectious-diseases-hbm7f6o1ff.pdf

Molecular markers for resistance against infectious diseases of economic importance

Intramammary infections change the composition of milk and increase
 electrical conductivity of milk and decrease milk electrical resistance.
 Electrical conductivity has been used to detect mastitis during last four
 decades. The aim of this research was to examine the reliability of the milk
 electrical conductivity measuring in detection of subclinical mastitis. The
 experiment was conducted on a dairy farm of Holstein-Friesian breed. A total
 of 113 quarter milk samples were examined, 55 samples from cows in first
 stage of lactation and 58 from cows in third stage of lactation. Electrical
 conductivity (EC) of milk samples was detected by Hand-held EC meter
 (Draminski mastitis detector). Quarter milk samples for bacteriological
 analysis were taken aseptically during the morning milking in sterile test
 tubes. Bacteria growth was not detected in 60 quarter milk samples (53.1%),
 while in the other 53 samples bacteria was found (46.9%). The most common
 isolated bacteria in first and third stage of lactation was Corynebacterium
 spp. (38.9%) and coagulase - negative staphylococci (3.54%). High quality and
 healthy milk with Draminski mastitis detector was observed in 59.29% of the
 samples (67/113). Cows with mastitis may not always show an increased EC of
 milk from the infected quarter. Electrical conductivity of milk can give
 useful informations about udder health status, but hand-held EC meters, such
 as Draminski mastitis detector, cannot be used alone in diagnosis of
 subclinical mastitis. [Projekat Ministarstva nauke Republike Srbije, br. TR
 31034]

/pdf/electrical-conductivity-of-milk-and-bacteriological-findings-yx215gbuei.pdf

Electrical conductivity of milk and bacteriological findings in cows with subclinical mastitis

The objective of this research was to evaluate the Zagreb mastitis test (ZMT) as screening test for mastitis diagnosis in dairy cows. The study was carried out within the framework of subclinical mastitis monitoring in the Varaždin region. Research included 1549 quarter milk samples from 389 Simmental dairy cows. Milk samples for bacteriological examination, mastitis testing and SCC were taken in a sterile plastic tube during milking. Bacteriology examination of milk samples obtained 760 (49.06%) positive samples. The most common isolated pathogens, Staphylococcus aureus, Streptococcus spp. Lancefield group D, Pseudomonas aeruginosa, were found in 388 (51.05%), 84 (11.05%), 62 (8.16%) positive quarter samples, respectively. Using a cut-off of ZMT by scores ≥ 1 as positive, 63.20% (CI 95%, 60.80% - 65.60%) quarter milk samples were estimated as being positive for subclinical mastitis. This cut-off had quite high sensitivity (96.84%, CI 95%, 95.60% - 98.06%) and negative predictive value (95.79%, CI 95%, 94.14% - 97.44%), however specificity (69.20%, CI 95%, 65.98% - 72.74%) and positive predictive value (75.17%, CI 95%, 72.47% - 77.86%) were low. Using a ZMT cut-off ≥4×105 cell/mL as positive, 49.56% of the quarters were positive. Sensitivity (88.37%, CI 95%, 86.06% - 90.68%) and specificity (86.98%, CI 95%, 84.57% - 89.38%), as well as predictive values, were similar. On the basis of the results of this study, comparing SCC and ZMT in mastitis diagnosis, ZMT is a reliable diagnostic method for use in field conditions.

/pdf/assessment-of-the-zagreb-mastitis-test-in-diagnosis-of-46dzcadeej.pdf

Assessment of the Zagreb mastitis test in diagnosis of subclinical mastitis in dairy cattle.

Lactating cows (n=100) were examined for subclinical mastitis (SCM) by California Mastitis Test (CMT) and cultural examination during the period from December, 2018 to December, 2019. On the basis of CMT; the prevalence of SCM was 42% and 24.50% on animal and quarter basis and on the basis of cultural examination; the prevalence was 51% and 29.75% on animal and quarter basis, respectively. Highest prevalence of SCM was observed in right hind quarter (45%) followed by left hind quarter (30%), right fore quarter (23%) and left fore quarter (21%). Maximum numbers of cows (72.22%) were affected with SCM in Vth parity, followed by 64.00, 63.63, 58.33, 31.57 and 13.33% in IVth, VIth, IIIrd, IInd and Ist parity, respectively.

https://www.entomoljournal.com/archives/2020/vol8issue1/PartS/8-1-56-785.pdf

Prevalence of subclinical mastitis in cattle in and around Bikaner district of Rajasthan

We have performed diagnostics of sub clinical mastitis in three different cow breeds with comparison of California mastitis test results, somatic cells count at quarter level and with bacteriological findings confirmation in order to justify their appliance in mastitis diagnostics. In total, 90 cows or 360 quarters of mammary gland have been examined. In 63.3 % of the examined cows, with different racial origin, positive reaction to California mastitis test have been established. Usually, positive reaction have been found in milk of one and two quarters, with reaction intensity of one and two plus. SSC higher than 200.000 in 1 ml is established in 60 % of cases and the most often causes of mastitis were staphylococcae, streptococcae and mixed infections. With continuous use of this methods it is possible to timely detect presence of sub clinical mastitis and so to obtain satisfactory results in prevention and therapy of mastitis, as well as improvement in amount and quality of milk.

/pdf/use-of-california-mastitis-test-somatic-cells-count-and-2nxg0yagek.pdf

K. Podzo

Papers

Use of California mastitis test, somatic cells count and bacteriological findings in diagnostics of subclinical mastitis