Latent Mastitis Research Articles

Biochemical Indicators of Blood and Milk in the Cows Affected by Latent Mastitis

Latent mastitis harms the health of animals, their milk production, and the quality of milk. In cows affected by this disease sharp changes in hematological parameters, and biochemical parameters of blood and milk, which is the focus of our research. This work studies the morphological and biochemical parameters of blood and the biochemical parameters of milk in dairy cows affected by latent mastitis. The research was performed in several farms and farm households of Kotayk and Ararat regions, as well as in the ANAU Research Center of Veterinary Medicine and Veterinary Sanitary laboratories. The research outcomes prove that latent mastitis significantly impacts the composition of blood and milk components. Data obtained during the research enables a better understanding of the causes of mastitis as well as the necessity of using informative diagnostic methods in farm veterinarians’ practices.

НЕКОТОРЫЕ АСПЕКТЫ ТЕХНОЛОГИИ ПРОИЗВОДСТВА И ПОВЫШЕНИЯ КАЧЕСТВА МОЛОКА

A systematic analysis of the dairy market’s state and literature data reflecting the current milk production situation, as well as veterinary department’s statistics indicating low commercial quality of milk due to mastitis’ clinical and subclinical forms development had given. The Russian cows’ average age is 2,7 lactation. The decisive role in mastitis’ etiology depends on three interrelated factors - infectious agents, macroorganism’s protective properties and environmental influences. The mastitis’ incidence in dairy cows averages about 25%, but the latent mastitis’ form occurs in 50% of lactating cows. The legislative, regulatory and methodological framework for safety ensuring and milk and dairy products quality in our country is largely consistent with international requirements. At the same time some standards for Russian raw milk quality and safety assessing are significantly lower than European ones. The operating and logistics costs increasing, limited of foreign components availability and equipment have led to dairy producers’ costs increasing. High producing costs, the number of cows reducing, import prices rising and processing utilization capacities decreasing are important factors of raw milk prices’ dynamic changing. Measures of efficiency improving and competitive dairy cattle products’ producing volume and consumer’s market saturation increasing are proposed. The main directions of subindustry effective development creating, technical reequipment and dairy farms and complexes’ comprehensive modernization, that capable safe high quality milk producing are highlighted. The economical-and-biological, technical-and-technological, organizational-and-financial factors that dairy cattle breeding resourcesaving technologies development are determined. The reserves of milk production increasing and quality of milk improving, production costs in agricultural organizations’ conditions reducing are considered.

Effectiveness of a new means of etiotropic therapy of mastits in cows during the lactation period

The aim: is to study the therapeutic effectiveness of the new veterinary medicinal product Revozyn RTU 400 mg/ml (suspension for injections), manufactured by Eurovet Animal Health B.V. (Netherlands), in the treatment of acute (clinical) and hidden (subclinical) mastitis in cows during lactation.
 Materials and methods. The research was conducted on dairy cows of the Simmental breed with a milk productivity of 6000-6500 kg of milk per lactation (F "Pchany-Denkovich", Pchany village, Stryi district, Lviv region). To confirm the diagnosis of "acute mastitis" and to identify cows with hidden (subclinical) mastitis, as well as to establish the effectiveness of the researched drug after treatment, a sample was taken with the California Mastitis Test (CMT), manufactured by Bayer Animal Health GmbH, Germany. For bacteriological research, milk samples were taken from the affected quarters of the mammary gland (1 sample from each cow) in compliance with generally accepted sanitary rules. The sensitivity of bacterial isolates to the drug was determined by diffusion in agar using standard discs with benzylpenicillin.
 Results. A clinical examination of 127 Simmental dairy cows of different periods of lactation was carried out. During the clinical-diagnostic examination of animals, 8 cows with clinically pronounced, acute course of mastitis were found. According to the nature of the exudate in 3 cows, mastitis was serous, in 5 cows it was purulent-catarrhal. For serous mastitis, the CM test gave a positive result – thickening, the milk solution looks like a gel. In case of purulent catarrh, a sample with the CMT gave a strongly positive result – the mixture thickened, the gel took on a certain shape and became very viscous. The CMT revealed 12 cows with suspected latent mastitis. Representatives of opportunistic microflora – Streptococcus agalactiae, Staphylococcus aureus, and Escherichia coli bacteria were isolated and identified from mastitis milk. The summarized results of the clinical trial of the drugs Revozyn RTU 400 mg/ml and Procillin® 30 % on cows suffering from the clinical form of mastitis were as follows. On the 10th day of the experiment, a milk sample with the California mastitis test showed that all milk samples from cows of both groups (with the exception of one milk sample from a cow from the control group) gave a negative result (the solution remained liquid, blue or gray and homogeneous, without clots). Taking into account the results of the CMT and the number of somatic cells in the milk after the therapy, the therapeutic effectiveness of the veterinary medicinal product Revozyn RTU 400 mg/ml in the treatment of various forms of mastitis in lactating cows was 100 %, and the one of the comparative drug Procillin® 30 % was 83.3 % .
 Conclusions. A clinical study of the veterinary medicinal product Revozyn RTU 400 mg/ml, suspension for injections, manufactured by Eurovet Animal Health B.V. (Netherlands) established its effectiveness in the dosage, recommended by the manufacturer, in the treatment of clinical and subclinical mastitis in lactating cows, caused by microorganisms sensitive to benzylpenicillin. In terms of therapeutic effectiveness, the drug Revozyn RTU 400 mg/ml was not inferior to the comparative drug Procillin® 30 % in its dosage form and active substance when used in the treatment of various forms of mastitis in lactating cows

Bovine Udder Health: From Standard Diagnostic Methods to New Approaches-A Practical Investigation of Various Udder Health Parameters in Combination with 16S rRNA Sequencing.

Bovine udder health is an important factor for animal wellbeing and the dairy farm economy. Thus, researchers aim to understand factors causing mastitis. The gold standard for diagnosing mastitis in cows is the conventional culturing of milk samples. However, during the last few years, the use of molecular methods has increased. These methods, especially sequencing, provide a deeper insight into the diversity of the bacterial community. Yet, inconsistent results regarding the mammary microbiome have been published. This study aimed to evaluate the udder health of eight dairy cows at seven days postpartum with the standard methods in veterinary practice. Additionally, swabs from the teat canal and milk samples were analyzed using 16S rRNA gene amplicon sequencing. The sensitive low-biomass milk samples displayed only a few contaminations even though they were sampled in a field environment. In healthy udders, no bacterial communities were detected by the bacterial culture nor the 16S rRNA gene amplicons. The results from the standard examination of the cows, the cell count, and the bacteriological examination were comparable with the results from 16S rRNA gene amplicon sequencing when cows displayed subclinical or latent mastitis. Besides the pathogen detected in bacterial culturing, a second bacterial strain with low but significant abundance was detected by sequencing, which might aid in the understanding of mastitis incidence. In general, molecular biological approaches might lead to promising insights into pathological events in the udder and might help to understand the pathomechanism and infection source via epidemiological analyses.

Analysis of the efficiency of a rapid test for the early diagnosis of mastitis in cows

This article describes the results of a study of the content of somatic cells in milk using various methods. Milk samples were tested using a standardized apparatus method using a Somatos-V viscometer, from which 3 groups of 20 samples were selected. The formation of groups was based on the content of somatic cells in the samples (up to 200; 200-400 and over 400 thousand/cm3). Further research was aimed at studying the diagnostic properties of the new test, the action of which is based on the suppression of foaming by mastitis milk. All samples were tested using the foam test and the California mastitis test. The coincidence of the results of the study of the studied test systems with the reference method was revealed in relation to samples containing a small (up to 200 thousand/cm3) and an increased (over 400 thousand/cm3) number of somatic cells. In samples with a cell concentration from 200 to 400 thousand/cm3, there are different results in the study by express testing methods. The foam test showed 90% and the California test showed 75% agreement with the results of viscometry. Given the difficulty in diagnosing latent mastitis, the foam test studied in this work may have promising prospects for use on farms for the early detection of sick cows. This method allows more accurately, qualitatively, to determine the increase in the number of somatic cells in milk, which is important in the diagnosis of latent subclinical mastitis and their timely treatment.

Efficiency of probiotic culture consortium application for disinfection of dairy farm premises and prevention of mastitis in cows.

In this work, the effect of probiotics on the state of the microbial background of the livestock building, on the state of udder teats, and on the prevalence of latent mastitis was investigated. Long-term use of the consortium has bactericidal activity against all cultures studied, especially the causative agent of mastitis, Staphylococcus aureus, except Proteus mirabilis, Proteus vulgaris, and Escherichia coli. The washes from animal housings and milk samples were collected from the dairy farms "Astana-Onim" Joint Stock Company and "Rodina" Limited Liability Partnership (Kazakhstan). The cleaning solutions and probiotic agents were applied directly to the udder teats of cows before and after milking. Diagnosis of subclinical mastitis was performed using the Kenotest rapid mastitis test. Directly counting the number of somatic cells in the collected milk samples from each cow was performed on a somatic cell counter. Pathogenic microorganisms, including S. aureus bacteria (50% of samples) and bacteria of the E. coli group, Enterobacter aerogenes, and P. mirabilis (36% of samples), were detected on the udder skin and milk wipes. Using a consortium of probiotic microorganisms positively affects the mammary gland more quickly than using mastitis prevention agents alone. Probiotic use for a month resulted in a significant improvement in udder teat condition, with 60.7% of teats showing normal physiological reaction to milking, a decrease in complicated hyperkeratosis, and an increase in uncomplicated mastitis. The studies showed that in the experimental group, there was a 1.5-fold reduction in the number of cows with clinically pronounced mastitis. The experimental group showed no significant changes in the number of animals with high somatic cell levels before and after the study, while the control group without probiotics had a significant increase in diseased animals after 1 month. The use of a probiotic consortium has shown promising results in reducing the incidence of mastitis and improving milk quality in cows.

ԳԱՂՏՆԻ ՄԱՍՏԻՏԻ ԲՈՒԺՈՒՄԸ ԿԱՊՈՒՅՏ ՅՈԴԻ ԿԻՐԱՌՄԱՄԲ

The investigations have been conducted in four regions of Armenia to detect the cows diseased with latent mastitis in different livestock farms and to treat them through the new recommended method by using blue iodine. The latent mastitis has been diagnosed by means of Californian test. Out of 127 heads of researched animal latent mastitis was detected in 48 stocks (37.7 %). The animals of control group were treated with Eficur drug and those of experimental group – with blue iodine. Due to the active agents, blue iodine has provided high efficiency speeding up the treatment by 2-3 days

Biotechnology of the New Al-Test - an Indicator for the Diagnosis of Subclinical Mastitis and an Indication of the Effectiveness of the Bactericidal Drug Dioxinor for Serous Mastitis in Lactating Sheep

The article is devoted to the study of the effectiveness of the Al-test indicator for rapid diagnosis of mastitis in ewes. In laboratory studies using the Al-test diagnosticum, the main criterion for the presence of subclinical mastitis in animals was the formation of a well-formed purple jelly-like clot (moderate to dense) of in the milk samples, which was partially (+) or entirely (++) of thrown of out the from the hole in plate with stirring. On the plate, with a negative reaction (-), the mixture of milk and the indicator remained homogeneous, pale raspberry colored, with a dubious (+) - it contained traces of the formation of the color of raspberry jelly. To detect latent mastitis in sheep, we proposed the rapid test of the A1 test, which is an aqueous solution of sulfanol and cresol red. Unlike a 2% mastidine solution, it is more sensitive. We also recommend for the treatment of serous mastitis in lactating sheep, intramuscularly administer Dioxinor at a dose of 0.1 ml / kg body weight, in twice a day until complete recovery and oxytocin, at a dose of 5 units in once a day on of the first 2 days of treatment, and also of carry out arrogant novocaine blockade according to D.D. Logvinov, twice 0.25% novocaine of solution, at a dose of 0.5 ml / kg body weight. In the experimental group, where the complex antimicrobial preparation Dioxinor was used, the effectiveness of treating serous mastitis in sheep was 96,3%.

Исследование влияния «Промевита», витаминно-минеральной добавки, на производство молока и репродуктивные показатели молочных коров

At the present time vitamin-mineral and energy cows' feed additives made from natural components gain more and more popularity. The work considers the influence of the complex feeding additive "Promevit" on the indices of raw milk quality of cows and also milk productivity and indices of reproduction of animals. At adding the feed additive to the basic diet an increase in haemoglobin level of experimental cows by 21.4%, an increase in erythrocytes by 14.5%, a moderate increase in white blood cells, a slight increase (by 5.2%) in protein content in the blood of experimental cows and an increase by 6, 6% of albumin level, relatively initial indicators, increase of urea content by 23,1% within reference values, decrease of aspartataminotransferase, as well as glutamate dehydrogenase, that shows restoration of hepatobiliary system work. The milk yield of the experimental group cows was 285 kg higher than that of the control group and the percentage of milk fat was 1.3 times higher. On average the mass fraction of fat in milk of the cows from the experimental group was 3.32%, which was 4.2% higher than in the control group. There was a 10.9% increase in the amount of milk protein in raw milk compared to the initial data. The milk fat yield increased by 19.5 kg relative to the control group as well as the protein yield increased by 13.9 kg. With the use of the dietary supplement no complicated forms of hyperkeratosis were recorded in the experimental group cows, while in the control group cows' number increased by 20.7%. The number of teats with uncomplicated forms of hyperkeratosis also increased by 20% relative to baseline data. In the experimental group cows had a reduction of udder quarters with signs of clinical mastitis, the level of latent mastitis remained practically unchanged. A positive effect of the feed additive on the course of the parturition and postpartum period in cows was also noted.

The occurrence of mastitis and its effect on the milk malondialdehyde concentrations and blood enzymatic antioxidants in dairy cows

Early identification of mastitis is a serious challenge for dairy farmers and veterinarians in ensuring the health of an animal and the hygienic quality of the produced milk. The purpose of this study was to detect the occurrence and aetiology of mastitis in a dairy herd of 15 milked cows localised in a farm in west Slovakia. During the complex investigation, 606 quarter milk samples were examined (6 quarters were discarded) and classified based on the clinical status, the presence of abnormal udder secretions, the result of the California mastitis test (CMT), the somatic cell count (SCC) and the bacteriological identification of the pathogens causing the intramammary infection (IMI). The study was augmented by the detection of malondialdehyde (MDA) in the milk and the measurements of the blood enzymatic activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) as potential biomarkers for the udder health screening. A positive CMT score was recorded in 19.5% (118) of the examined quarters and 12.5% (76) of the quarters were infected with bacterial pathogens causing latent mastitis (LM; 1.3%), subclinical mastitis (SM; 8.3%), and clinical mastitis (CM; 2.9%). The most commonly isolated bacteria from the infected quarters were coagulase-negative staphylococci (55.2%), Staphylococcus aureus (11.8%) and streptococci (10.5%). The concentration of MDA and SCC were significantly higher from both the SM and CM cases than in the milk samples from the healthy cows, while the blood activities of SOD and GPx were lower in the cows with CM compared to the healthy cows. The higher MDA concentrations in the SM and CM milk observed in this study showed the presence of an oxidative stress in the infected milk, accompanied by a decrease in the antioxidative enzymatic activity in the blood of the cows. Therefore, the measurement of the milk MDA concentration and the activity of the blood SOD and GPx may prove insightful for the better screening of the udder health in the early diagnosis of mastitis.

Investigation of antimicrobial resistance of the bacteria isolated from cows with latent mastitis

The main problem of dairy farms is mastitis – inflammation of the mammary gland. Resistance of bacteria causing latent mastitis to antibiotics is increasing every year. Bacteria that have resistance genes to antibiotics are transmitted from one animal to another and through food chains or direct contacts from animals to humans. Latent mastitis is 15–40 times more frequent than clinical mastitis, which is more difficult to detect and is the major source of pathogens for the whole herd of cattle. The aim of this study was to isolate bacteria which cause mastitis from cow milk and determine their susceptibility to antimicrobials. Milk samples from two dairy farms (farm A and farm B) in Anykščiai District were taken in July 2018. Microbiological assays were performed at the Microbiology Laboratory of the Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University. In total, 36 cows were tested. Using common methods of cultivation and identification tests, strains of Streptococcus spp., coagulase negative Staphylococcus spp. and Staphylococcus aureus were identified. Susceptibility of all isolated strains to neomycin, tetracycline, erythromycin, kanamycin, clindamycin, penicillin, ampicillin, streptomycin, gentamicin, rifampin, cefoxitin and oxacillin was performed using the disc diffusion method according to the guidelines of the Clinical Labaratory Standards Institute. It was concluded that the most frequent agent of mastitis was Staphylococcus spp. Also, a high level of resistance to penicillin, ampicillin and tetracycline in S. aureus strains was determined. All isolated bacteria were susceptible to neomycin, erythromycin, kanamycin, clindamycin, gentamycin, rifampin, cefoxitin and oxacillin.

Status of subclinical mastitis and associated risk factors in Indian water buffalo in Doaba region of Punjab, India.

Abstract Sub clinical mastitis in buffalo is considered as multi-factorial disease, which leads to huge economic losses by reducing the quality and quantity of the milk. It does not lead to any change in phenotypic expression, so diagnosed through various tests as California mastitis test, Somatic cell count, Electrical conductivity test etc. Although bacteria are considered to be the main causative agent for mastitis, beside this farm management practices are found to be associated with the disease. In the present study, the pathogens related to the occurrence of the disease were examined via bacteriological culture of milk sample of the animal. Animal wise prevalence of sub clinical mastitis was found to be (20.4%), out of this 7.8%, 9.8%, 2.8% were found to be effected with latent mastitis, specific mastitis and nonspecific mastitis respectively .On the basis of individual quarter, the highest prevalence was in LH (33.9%), followed by RH (24%) and RF (22.4%) and the least prevalence in LF (14.5%). The microorganisms isolated from sub clinical mastitis constituted Staphylococci (39%), Streptococci (31%), Corynebacterium (25%) and E. coli .(5%).Farm management associated determinants (Type of feed, type of floor, education of the owner, feeding after milking, type of labor) were studied in association with sub clinical mastitis. Out of these education of the owner , type of labor and feeding after milking were found to be significantly associated with disease occurrence (p<0.05). While looking at the animal determinants in association with sub clinical mastitis in the present investigation buffaloes with higher parity showed more risk of developing sub clinical mastitis. So the present investigation helps to understand the various risk factors for the occurrence of sub clinical mastitis in water buffalo in Doaba region of Punjab.

Structural equation models to estimate risk of infection and tolerance to bovine mastitis

BackgroundOne method to improve durably animal welfare is to select, as reproducers, animals with the highest ability to resist or tolerate infection. To do so, it is necessary to distinguish direct and indirect mechanisms of resistance and tolerance because selection on these traits is believed to have different epidemiological and evolutionary consequences.MethodsWe propose structural equation models with latent variables (1) to quantify the latent risk of infection and to identify, among the many potential mediators of infection, the few ones that influence it significantly and (2) to estimate direct and indirect levels of tolerance of animals infected naturally with pathogens. We applied the method to two surveys of bovine mastitis in the Walloon region of Belgium, in which we recorded herd management practices, mastitis frequency, and results of bacteriological analyses of milk samples.Results and discussionStructural equation models suggested that, among more than 35 surveyed herd characteristics, only nine (age, addition of urea in the rations, treatment of subclinical mastitis, presence of dirty liner, cows with hyperkeratotic teats, machine stripping, pre- and post-milking teat disinfection, and housing of milking cows in cubicles) were directly and significantly related to a latent measure of bovine mastitis, and that treatment of subclinical mastitis was involved in the pathway between post-milking teat disinfection and latent mastitis. These models also allowed the separation of direct and indirect effects of bacterial infection on milk productivity. Results suggested that infected cows were tolerant but not resistant to mastitis pathogens.ConclusionsWe revealed the advantages of structural equation models, compared to classical models, for dissecting measurements of resistance and tolerance to infectious diseases, here bovine mastitis. Using our method, we identified nine major risk factors that were directly associated with an increased risk of mastitis and suggested that cows were tolerant but not resistant to mastitis. Selection should aim at improved resistance to infection by mastitis pathogens, although further investigations are needed due to the limitations of the data used in this study.

Microscopic differential cell counting to identify inflammatory reactions in dairy cow quarter milk samples

The diagnosis of intramammary infections is mostly based on somatic cell count (SCC) and bacteriological analysis. As an alternative, differential cell counting (DCC) could be a useful method, because it identifies changes in the relative cell populations before the increase in total cell number occurs. The aim of the study was to identify cytological parameters that could be used in the field to classify mammary quarters as healthy or diseased, comparing cyto-bacteriological results with DCC. Overall, 48 cows were randomly selected from 3 herds in Lombardy region of Italy. Herd A was characterized by the absence of contagious microorganisms; in herds B and C, the prevalence of Staphylococcus aureus was 20 and 50%, respectively. Foremilk samples were aseptically collected from 188 quarters and submitted to bacteriological analysis, SCC, and DCC. For statistical analysis, the samples were clustered into 4 health groups, and DCC results were compared in each group. Ninety-six samples were classified as normal secretions (N), 30 as mastitis (M), 15 as latent mastitis (LM), and 47 as unspecific mastitis (UM) based on SCC and bacteriological results. Single percentages of lymphocytes, polymorphonuclear neutrophilic leukocytes (PMNL), or macrophages were first evaluated to established variables capable of identifying healthy and inflamed quarters. Then, combinations of cell populations were tested to increase the discrimination power of DCC: phagocytes, logarithmic PMNL:lymphocyte ratio, and logarithmic phagocyte:lymphocyte ratio. The mean percentage of lymphocytes was significantly higher in group N than in groups LM, UM, and M. The mean percentage of PMNL was significantly lower in group N than in groups UM and M, but not LM. Mean percentages of macrophages were not significantly influenced by the 4 groups. The mean value of phagocytes was significantly lower in group N than in the other groups. Both the logarithmic PMNL:lymphocyte and the logarithmic phagocyte:lymphocyte ratios were significantly lower in group N than in groups LM, UM, and M. Fisher (F-)values were calculated, and the highest F-value was that of log PMNL:lymphocytes ratio (48.23). The explanation for this could be that log PMNL:Lym is the only variable that involved both cell populations statistically influenced by health groups but excluded macrophages. Microscopic DCC has potential as a tool to identify cows affected by any inflammatory process of the mammary gland, with the best results being achieved using log PMNL:lymphocyte as variable.

INCIDENCE OF LATENT MASTITIS IN BUFFALOES OF JABALPUR REGION OF MADHYA PRADESH

Latent mastitis in lactating animals is a condition characterized not only by the presence of pathogens in the udder but also by changes in the biochemical profile in the milk. It causes decrease in milk quality and its market value as well as it is responsible for up to 70% of losses in mastitis (Ahmed et al., 2008). Latent mastitis causes great economic losses than clinical mastitis (Joshi and Gokhale, 2006). The prevalence of latent mastitis has increased enormously in India in the recent years (Tiwari and Sisodia, 2000). The latent form of mastitis is more difficult to identify and can only be diagnosed by a variety of direct or indirect laboratory tests. The detection of latent mastitis happens to be first pre-requisite of a modern dairy establishment. If the owner wishes to avoid the economic losses in their herd early detection of latent mastitis has always been a matter of great curiosity since latent mastitis shows no gross signs of inflammation. Even though the treatment of mastitis was undertaken; some cases will end up in failure. This may be due to the late commencement of the treatment, improper antibiotic and resistance of the pathogen to the antibiotic.

Investigations on Prevalence and Oxidative Stress Aspects of Mastitis in Buffaloes

The 424 quarter milk samples collected from 106 apparently healthy lactating buffaloes were screened for mastitis using bacterial cultural examination and somatic cell count. The prevalence of sub-clinical mastitis (SCM), latent mastitis and non-specific mastitis were found to be 9.90% (42/424), 4.24% (18/424), and 15.80% ( 67/424), respectively. There was significant (P≤0.05) elevation of blood malondialdehyde (MDA) level in SCM and clinical mastitis cases. Besides, milk malondialdehyde levels were also found to be appreciably elevated in both SCM and clinical mastitis in buffaloes. The occurrence of lipid peroxidation as revealed by elevated blood and milk MDA levels, in present study, indicated the involvement of oxidative stress and the possible oxidative damage in SCM and clinical mastitis in buffaloes

Prevalence and etiology of subclinical mastitis in intensively managed flocks and related changes in the yield and quality of ewe milk

A total of 1140 milk samples from 380 randomly selected Comisana ewes, in parities 1–6, were collected aseptically during early-, mid- and late-lactation from five intensively managed flocks located in the Apulia region, southern Italy. All flocks were housed on straw litter in prefabricated buildings, were given hay and pelletted concentrates and were milked twice daily using pipeline milking machines. Individual milk samples were analyzed for composition, renneting parameters and somatic cell count (SCC), and cultured for mastitis related pathogens. No cases of clinical mastitis were detected. Mean incidence rates were 8.4, 5 and 4.1%, respectively, for infectious (bacteriologically positive milk samples with >10 6 somatic cells/ml), latent (bacteriologically positive milk samples with <3×10 5 somatic cells/ml) and non-specific subclinical mastitis (bacteriologically negative milk samples with >10 6 somatic cells/ml). Environmental pathogens, primarily E. coli, were largely predominant in the milk from infected ewes and markedly increased with the advancement of lactation. Reduction in ewe milk yield and deterioration of milk quality and renneting ability were more marked in infectious and non-specific than in latent mastitis cases, whereas various kinds of pathogens had a similar impact on milk yield and composition. The low incidence of contagious pathogens suggests that, in intensive production systems, ewe udder health may benefit from more efficient control of sanitation of milking practices and equipment. The high prevalence of environmental and opportunistic micro-organisms also indicates that poor ambient hygiene and exposure of ewes to environmental and management stressors must be regarded as the main risk factors for udder infections .

異常牛乳細胞分画の推移と乳房炎診断への応用

From 840 quarters of 210 cows showing no clinical mastitis, 7 cases of abnormal milk in somatic cell counts (AMSCC)(SCC<3×105/ml, no bacteria), 2 cases of latent mastitis milk, 5 cases of infected milk and 5 cases of normal milk were examined for temporal changes in the ratio of epithelial cell and neutrophil counts. While the pattern and change of somatic cell count (SCC) was comparable in all cases, 5 of the 7 cases of AMSCC had larger epithelial cell fractions than neutrophil ones. Subsequent bacterial examination revealed that the remaining 2 cases of AMSCC which were diagnosed as latent mastitis, had the number of bacteria in the milk and the neutrophil fractions were larger. Differential count of SCC at 30 to 60 minutes after milking should help the diagnosis of AMSCC.

THE INCIDENCE OF OVARIAN ADHESIONS IN COWS ON DAIRY FARMS IN THE FAR EAST

In this article the results of many years researches of 236900 dry cows in dairy farms of the South of the Far East are presented. From 1965 to 2018 were studied Simmental, Holstein-Friesian, Red Holstein cow breeds of different ages with productivity from 1,500 to 10,000 kg of milk per lactation at dairy farms in the Primorsky, Khabarovsk Territories, the Jewish Autonomous and Amur Regions. A rectal examination was carried out on a monthly basis for 2, 3, 4, 5, 7, 23, 39 years at the Sadovoye farm of the All-Russian Research Institute of Soybean, the Chernorechensky state farm, the Garovsky farm, the Primorsky instructional farm of agricultural artel, the Central experimental production farm of the Primorskiy research institute, and the Daurskoe experimental production farm of Jewish Autonomous Province and "Vostochnoe" experimental production farm, respectively. In 17 households it was once every three to four months, and in 38 households – from one to 13 times for all observation years. A total of 236 900 dry cows were examined. Once a month on dairy farms of the Khabarovsk Territory milk was examined for latent mastitis on cows by the electrophoresis using established method. The sodium selenite injections to down- calver cows and heifers were performed 20 days before the expected calving. 96808 cows from this quantity turned out to be pregnant, 75724 were with pathology of reproductive organs. Clinically marked ovarian adhesions were detected in 1098 individuals (1.45 % of all cows in this group), or 0.46 % of all researched cows. The occurrence of mastitis (36000 cows were counted) and pathologies of reproductive organs were researched in dairy farms of Khabarovsk region. Clinic forms of mastitis were detected in 8.6 %, subclinic - in 24.5 % of individuals. The presence of pathologies of reproductive organs was detected in 12629 individuals (35.1 %), including in 74.8 % - with subclinic mastitis and 42.0 % - in cows with healthy udder. According to many times over- walking cows ovarian adhesions with adjoining tissues were detected accordingly in 1.95 %, 1.03 % and 0.87 %of individuals of all quantity of animals with udder diseases.