Mean Somatic Cell Count Research Articles

Extensive Countrywide Field Investigation of Somatic Cell Counts and Total Bacterial Counts in Bulk-Tank Raw Milk in Sheep Flocks in Greece.

Objectives were to investigate somatic cell counts (SCC) and total bacterial counts (TBC) in the raw bulk-tank milk of sheep flocks in Greece, to study factors potentially influencing increased SCC and TBC in the bulk-tank milk of sheep and to evaluate possible associations of SCC and TBC with milk content. Throughout Greece, 325 dairy sheep flocks were visited for collection of milk sampling for somatic cell counting, microbiological examination and composition measurement. Geometric mean SCC were 0.488 × 106 cells mL−1; geometric mean TBC were 398 × 103 cfu mL−1; 228 staphylococcal isolates were recovered form 206 flocks (63.4%). Multivariable analyses revealed annual incidence risk of clinical mastitis, age of the farmer and month into lactation period (among 53 variables) to be significant for SCC > 1.0 × 106 cells mL−1 and month into lactation period at sampling and availability of mechanical ventilators (among 58 variables) to be significant for TBC > 1500 × 103 cfu mL−1. Negative correlation of SCC with fat, total protein and lactose and positive correlation of SCC with added water were found. With SCC > 1.0 × 106 cells mL−1, significant reduction of protein content (2%) was observed, whilst in flocks with SCC > 1.5 × 106 cells mL−1, significantly lower annual milk production per ewe (42.9%) was recorded.

Genes conferring anti­microbial resistance in cattle with subclinical mastitis

This study was carried out to evaluate the antimicrobial resistance (AMR) as a risk factor associated with some microorganisms isolated from subclinical mastitis (SCM) milk samples from Holstein Friesian dairy animals in Fayoum area, Egypt. The percentage of the SCM in the farm was found to be 41.18% and 63.88% at quarter and cows level respectively, with mean somatic cell count (SCC) of 8.8×105 ± 9.2×103 cells/mL and electrical conductivity (EC) 6.27 ± 0.066 mS/cm for SCM quarter milk samples. Out of the total 444 SCM cow milk samples, the most often isolated microorganisms were Staphylococcus aureus: 296 (66.6%), Enterococcus spp.: 230 (51.80%), Escherichia coli: 210 (47.29%) and Streptococcus agalactiae: 106 (23.87%). AMR was determined by disc diffusion test and the corresponding resistance genes were detected by PCR. Results of the in vitro susceptibility tests performed and the phenotypes indicated that the highest resistance to antibiotics for isolated microorganisms was against penicillin followed by amoxicillin + clavulanic acid, oxacillin and tetracycline, whereas moderate resistance was exhibited to oxytetracycline, ampicillin, sulfamethazole/trimethoprim, cefotaxime and erythromycin. However the most effective antibiotics against most isolates were nitrofurantoin and gentamicin followed by enrofloxacin, norfloxacin and cefoxitin. It was shown that the resistance to tetracyclines was due to the tetK or tetA(A) genes, the resistance to β-lactams (penicillins) – to blaZ and blaTEM genes, to macrolides (erythromycin): to ermB and ermC genes. Methicillin resistance genes were mecA, mec1 and mecC, glycopeptides (vancomycin) resistance gene was vanA, and norfloxacin resistance was attributed to norA gene.

Seasonal variations in some quality parameters of milk produced in Khorasan Razavi Province, Iran

In this trial, 60 samples of raw cow’s milk collected during summer and winter in five collective centers from Khorasan Razavi Province of Iran were analyzed for penicillin residues, somatic cell counts (SCC), mesophilic counts (TMC) and adulteration materials. The mean penicillin level (0.57 ± 0.20 μg/L) was much lower than the maximum permitted level (MPL) recommended by the Codex Alimentarius Commission (4 μg/L). However, the mean SCC and TMC (Log 5.71 ± 0.08 cells/mL and Log 6.18 ± 0.11 colony forming units (CFU)/mL, respectively) exceeded their respective MPLs adopted in Iran for grade C milk (Log 5.69 cells/mL and Log 6.0 CFU/mL, respectively), with higher counts (P < 0.05) in the summer. High frequencies of samples containing salt (53-60%), detergents (16-20%) and formalin (7-10%) were observed in milk samples, stressing the need for stringent control measures to improve the quality of milk delivered in the evaluated collection centers.

Animal welfare assessment based on Welfare Quality® criteria in a dairy farm in Turkey

This study served as a pilot to examine the practical implementation of the Welfare Quality® assessment protocol for cattle in dairy farms in Turkey. The study was carried out in the large-scale dairy farm of Ataturk University, in a free-stall-housed herd composed of Holstein, Brown Swiss and Simmental cattle. Whether the standards of the farm management programme and some of the welfare criteria chosen from the protocol were met was determined with the scoring method described in the Welfare Quality® publications. The somatic cell count (SCC) of the milk samples, and the avoidance distance and body condition score (BCS) of the animals were also determined and recorded. The body condition scores (BCS) of the Holstein, Simmental and Brown Swiss cattle were determined as 2.56, 3.16 and 3.88, respectively. Only 7% of the 53 cows had lameness, and none of the animals were evaluated as ‘resting a foot, standing on the edge of a step, displaying stepping (weight shifting) or showing reluctance to bear weight’. The animals were also evaluated based on some health indicators. The percentages of animals displaying nasal and ocular discharge were 16% and 9%, respectively. No clinical signs were recorded for hampered respiration, diarrhea or vulvar discharge. The mean SCC of the milk samples was (log 10) 4.43 cells/ml and below the European Union’s raw milk SCC threshold. In conclusion, according to the assessment based on Welfare Quality® criteria, the animal welfare level at the dairy farm of Ataturk University was scored as %70.92 and was considered to meet the relevant EU standards.

Status of Subclinical Mastitis in Crossbred Cattle of Peri-urban Unorganized Herd of Middle Indo-gangetic Plains

Background: Mastitis is the most common and economically important disease of dairy cattle. Subclinical mastitis is a more important form in India than clinical mastitis. Subclinical mastitis (SCM) detection done by periodic examination of the udder health by evaluation of milk at the herd level or the individual cow level by milk somatic cell count (SCC), followed by culture of random milk samples. The presented study was undertaken by survey and sampling of milk from lactating crossbred cattle of unorganized dairy farms and farmer’s dairy of the peri-urban region of middle Indo-Gangetic Plains. The objective of the study was to monitor the status of SCM in crossbred cattle and associated changes in milk constitutes and oxidative stress in milk. Methods: A total of 147 lactating crossbred cattle were screened for SCM using the modified California Mastitis Test (CMT) using detergent based CMT reagent and compared with conventional CMT reagent, followed by SCC, milk constituents, bacterial isolation and antibiotic sensitivity testing (ABST). General information was collected in pre-tested questionnaire. The data obtained were statistically treated to evaluate significance of the study.Conclusion: The overall prevalence of subclinical mastitis in peri-urban cross-bred cattle was 36.74% which varied with parity and stage of milking. Prevalence of subclinical mastitis was highest (55.77%) in cross-bred cattle in mid-lactation and Parity 3-5. The mean SCC was significantly higher (7.21±0.27) in subclinical mastitis compared to CMT negative (3.66±0.06) milk sample. Somatic cell count was positively and significantly correlated with CMT reactions using conventional CMT reagent (rs= 0.86) as well as modified CMT reagent (rs=0.815) attempted using Spearman rank-order correlation coefficient. The mean values of milk pH, fat and lactic acid acidity increased significantly (P£0.01) in SCM compared to the milk of healthy cattle, except lactose which decreased significantly in SCM milk. The common contagious bacteria responsible for SCM isolate were coagulase-positive Staphylococcus spp. (64.82%) isolates from these SCM milk followed by Streptococcus spp. ABST test conducted on random CMT positive milk sample indicated that gentamicin as most sensitive, followed by enrofloxacin. The present finding indicates the suitability of enrofloxacin as the most useful antibiotic for the treatment of subclinical mastitis in cross-bred cattle of the peri-urban area of middle Indo-Gangetic plains.

Translocation of intrauterine-infused bacterial lipopolysaccharides to the mammary gland in dexamethasone-treated goats.

Our previous study showed that intrauterine-infused lipopolysaccharide (LPS) can be translocated to the mammary gland to induce weak inflammation. This study aimed to determine whether dexamethasone treatment facilitated the translocation of LPS from the uterus to the mammary gland to induce a heavy inflammatory response. Sixteen goats were divided into control and LPS groups, subjected to daily dexamethasone administration before saline or LPS infusion. Milk and blood samples were collected before and after LPS infusion to determine the milk yield and somatic cell count (SCC) and blood leucocyte count (BLC), cytokines, antimicrobial peptides and serum amyloid A (SAA) concentrations. Mammary gland tissues were collected from two goats before and 24hr after LPS infusion for immunohistochemical analysis of LPS. The mean SCC in the LPS group was significantly higher, whereas the milk yield was significantly lower than that in the control group after LPS infusion. The mean BLC in the LPS group was significantly lower than in the control group after LPS infusion. Furthermore, milk concentrations of IL-1β, S100A8 and lactoferrin were higher in the LPS group than in the control group after infusion. LPS was detected in the connective tissues and inner alveolar spaces of the mammary glands 24hr after LPS infusion. We concluded that dexamethasone administration facilitated the translocation of intrauterine-infused LPS to the mammary gland, where it induced an inflammatory response. Therefore, LPS translocated from other organs, such as the uterus, can induce heavy inflammation in the mammary gland under immunosuppressive conditions.

The occurrence and distribution of livestock-associated methicillin-resistant Staphylococcus aureus ST398 on German dairy farms

The objective of this study was to investigate the occurrence and distribution of methicillin-resistant Staphylococcus aureus (MRSA) on 20 German dairy farms. Farms were selected based on previous MRSA reports from phenotypic susceptibility testing of mastitis pathogens. Samples were collected from predefined groups of cows, young stock, farm personnel, and the environment. A high MRSA-positive test rate was detected in swab samples from milk-fed calves (22.7%; 46/203). In postweaning calves, the MRSA-positive test rate was 9.1% (17/187). From prefresh heifers, both nasal swabs and udder cleft swabs were collected if possible. Including both sample types, the MRSA-positive test rate in prefresh heifers was 13.0% (26/200). The positive test rate was 8.9% (17/191) in nasal swabs and 6.5% (11/170) in udder cleft swabs. In quarter milk samples (QMS), the MRSA-positive test rate was 2.9% (67/2347), and on cow level, 7.9% (47/597) of the dairy cows were affected. Among all cows included in this study, the geometric mean of somatic cell counts was higher in QMS that carried MRSA (345,000 cells/mL) in comparison to all QMS (114,000 cells/mL). No differences in parity or the affected mammary quarter position on the udder were observed among the 47 infected cows. Methicillin-resistant S. aureus was also detected in boot swab samples (dust), teat liners, and in suckers from automatic calf feeders. All isolates belonged to livestock-associated sequence type 398 and most common staphylococcal protein A (spa)-types were t011 and t034. Most isolates harbored the staphylococcal cassette chromosome mec (SCCmec)-type V, with the exception of some isolates with SCCmec-type IVa on 1 farm. Similar MRSA genotypes in samples from humans and dairy cows underline the possible zoonotic and reverse-zoonotic transmission of livestock-associated MRSA strains from dairy farms. Similar MRSA genotypes in pig and cattle barns were detected on only 1 of 5 farms that kept both cattle and pigs. Similar MRSA spa-types were detected in samples from different sources (dairy cows, young stock, environment, and humans), suggesting a possible contagious transmission on some of the farms. Sporadically, up to 3 different MRSA spa-types were detected in QMS from the respective farms. On MRSA-affected farms, improper milking hygiene procedures and elevated bulk-tank milk somatic cell counts (>250,000 cells/mL) were observed. The occurrence of livestock-associated MRSA ST398 in different samples from dairy farms, and especially in young calves, should be considered for future MRSA-monitoring programs and biosecurity guidelines.

Relationship Among NAGase Enzyme Activity, CMT Score and Somatic Cell Count in Milk of Crossbred Dairy Cows with Sub-Clinical Mastitis in North-Western Province of Sri Lanka

The assay procedure for N-acetyl-β-D-glucosaminidase (NAGase) was considered to be the most reliable, simple, and rapid enzymatic method for estimating the severity of mammary tissue damage. This study was carried out to assess the relationship of NAGase enzyme activity, California mastitis test score (CMTS) and somatic cell counts (SCC) in milk and the influence of breed, parity and age of the cow on NAGase activity. The results showed that prevalence of sub-clinical mastitis (SCM) was 74.5% (41/55) in the population of cows tested. The isolated pathogens were Staphylococcus spp. (34%, 14/41), Escherichia coli (34%, 14/41) and Streptococcus spp. (32%, 13/41). The SCC showed a significant (p<0.05) positive correlation with the activity of NAGase (R2= 0.796) and CMTS (R2= 0.709). A significant correlation was observed between the NAGase activity and SCC in SCM positive milk, where the correlation was stronger (R2= 0.748) in the former than in the latter. The parity (R2= 0.843) and age (R2= 0.758) of the cow also showed a significant (p<0.05) positive correlation with enzyme activity. The mean SCC and enzyme activity of different crossbreds of the study population did not show a significant correlation, but mean values of SCC and enzyme activity were higher when an animal was phenotypically more related to European breeds (779– 1848 x103 SCC/ml;0.64 -0.89 μmole/min/ml) than tropical breeds (427–534x103 SCC/ml; 0.26-0.43 μmole/min/ml). It could be concluded that, the prevalence of SCM in crossbred cows in North-Western Province of Sri Lanka is considerably high. The determination of NAGase enzyme activity in milk could be used as a method for early detection of SCM more accurately than CMTS and SCC.

Efficacy of ketoprofen for treatment of spontaneous, culture-negative, mild cases of clinical mastitis: A randomized, controlled superiority trial

The objective of this randomized, controlled superiority trial was to assess the efficacy of ketoprofen for the treatment of spontaneous, culture-negative clinical mastitis cases that were not treated with antimicrobials. Holstein cows from 3 herds were eligible for inclusion if they had mild or moderate culture-negative clinical mastitis cases in 1 quarter or more. Upon detection of clinical mastitis, farm personnel performed on-farm culture (OFC) using commercially available bi-plates. Samples used for OFC were also cultured in a research laboratory. Cows with culture-negative clinical mastitis that met the inclusion criteria were randomly allocated to 1 of 2 experimental groups: in the ketoprofen (KET) group, cows received an intramuscular injection of 3 mg/kg of ketoprofen upon confirmation of a negative OFC result; and in the control (CON) group, cows received no treatment or placebo. Milk samples were collected 14 and 21 d after detection of clinical mastitis for microbiological examination and somatic cell counting. Study outcomes were clinical cure (within 7 d after inclusion in the study), relapse (within 14 d after inclusion) and recurrence of clinical mastitis (15 to 90 d after inclusion), risk of new intramammary infection, and quarter milk somatic cell count at 14 and 21 d. We used Cox proportional hazards, logistic regression, and repeated-measures models to compare each outcome between groups. After exclusion of moderate cases (n = 6), a total of 123 clinical mastitis cases (CON = 58 and KET = 65) were used for analyses. Risks of clinical cure [83.08% (54/65) and 91.23% (52/57); hazard ratio = 1.20, 95% confidence interval (CI) = 0.82-1.76], relapse [19.23% (10/52) and 18.00% (9/50); hazard ratio = 1.09, 95% CI = 0.45-2.62], and recurrence of clinical mastitis [17.31% (9/52) and 18.00% (9/50); hazard ratio = 1.26, 95% CI = 0.49-3.38] were not different between the KET and CON groups, respectively. The odds of a new intramammary infection at 14 d [20.75% (11/53) and 29.79% (14/47); odds ratio = 1.76, 95% CI = 0.66-4.73] or 21 d [28.57% (12/42) and 15.22% (7/46); odds ratio = 0.45, 95% CI = 0.16-1.30] were not different between the KET and CON groups, respectively. Mean somatic cell count was not different between the groups at 14 or 21 d. The results of this study suggest that a single intramuscular injection of ketoprofen as sole treatment for OFC-negative, mild clinical mastitis did not reduce time to clinical cure, relapse or recurrence of clinical mastitis, risk of subsequent intramammary infection, or milk somatic cell count compared with untreated controls.

Dynamics of somatic cell count and intramammary infection in lactating dairy cows.

Objective:The influence of intramammary infection (IMI) and types of bacteria was assessed on somatic cell count (SCC) in dairy cows’ milk with respect to breed, age, parity, stage of lactation, milk production, and mammary quarter location.Materials and methods:After recording data in a structured questionnaire, 360 samples of quarter milk were collected. The samples were subjected to SCC and isolation and identification of bacteria. The data were analyzed to find out the significant influence of independent factors on SCC and IMI.Results:The infected quarters had a significantly higher mean SCC (210.52 × 103 cells/ml) compared to uninfected ones (32.72 × 103 cells/ml). The mean SCC was the highest for IMI with Enterobacter spp. (338.00 × 103 cells/ml) followed by Bacillus spp. (319.20 × 103 cells/ml), coagulase-negative Staphylococci (CNS) (268.17 × 103 cells/ml), Staphylococcus aureus (218.31 × 103 cells/ml), and Escherichia coli (200.75 × 103 cells/ml) and the lowest for Pseudomonas aeruginosa (66.33 × 103 cells/ml). Milk of rear quarters had a significantly higher SCC than the front quarters. SCC increased with increasing age, parity, and lactation stage regardless of whether cows are infected or not. The IMI was more prevalent in rear quarters (42.2%) and cows at early (≤7 days) lactation (100.0%). Cows having a parity of ≥5 and crossbred and high yielding (>5 l) cows had also a higher rate of IMI of 38.2%, 36.7%, and 38.2%, respectively.Conclusion:The IMI and type of bacteria were the principal factors for SCC variation. Besides, mammary quarter location, age, and parity should be taken into consideration during the interpretation of SCC.

Association between teat-end hyperkeratosis and mastitis in dairy cows: A systematic review

A systematic review was conducted to elucidate the role of teat-end hyperkeratosis (THK) as a risk factor for clinical mastitis (CM) or subclinical mastitis (SCM). Scientific papers on the subject were identified by means of a database search. All types of peer-reviewed analytical studies, observational or experimental and published in English, could be included in the review, regardless of publication year. Of 152 identified records, 18 articles were selected, of which 8 were prospective cohort studies, 9 were cross-sectional, and 1 was a hybrid case-control study. Internal validity of studies was assessed using a score system ranging from 0 to 6, based on design, risk of bias, and statistical methods. The most frequent study limitation was improper use of statistical methods to avoid confounding of associations between THK and CM or SCM. The 3 studies that used CM as outcome (all with high validity scores) showed positive associations with THK (especially severe), although the magnitude and statistical significance of the estimates differed among them. Most studies that used SCM as the primary outcome (based on microbiological examination of milk) reported that only severe THK was associated with SCM. Two studies with high validity scores reported moderate to strong associations between severe THK and incidence or prevalence of Staphylococcus aureus intramammary infection. Two studies with high validity scores reported that only severe THK was associated with the risk of somatic cell count (SCC) ≥200,000 cells/mL and increased mean SCC, respectively. Although 4 cross-sectional studies reported positive associations between THK and SCC, these associations were possibly spurious because confounding factors, such as parity, were not considered in the analyses. Results of the reviewed studies suggest that severe THK is a risk factor for both CM and SCM, as defined by microbiological examination of milk, SCC thresholds, or mean SCC. The effect of severe THK on both contagious (especially Staphylococcus aureus) and environmental CM or SCM emphasizes the importance of teat health for mastitis control. Four studies demonstrated that quarters with mild THK had lower prevalence of intramammary infection or lower mean SCC than quarters with no THK, suggesting that development of mild THK, as a physiological response to milking, can have a protective effect. Dairy consultants should focus on monitoring and minimizing occurrence of severe THK to prevent CM and SCM.

Effect of automatic cluster remover settings on milkability, milk quality and milking irregularities of crossbred cows.

Automatic cluster remover (ACR) settings regulate the end of milking by detaching the clusters based on milk flow dropping below a preset level, which needs to be standardised for different breeds of dairy animals based on their production. A study was conducted to find out the best ACR setting for milking Indian crossbred cows based on milkability, milking irregularities and milk quality. Fifty six crossbred dairy cows in lactations 1 to 4 were categorised into three groups based on the level of production; low (N = 16; 18 kg/d). The ACR settings tested were 0.1, 0.2, 0.3 and 0.4 kg/min, keeping the vacuum level and pulsation settings constant. The ACR settings significantly (P &lt; 0.01) affected the milk yield at all levels of production with a significant effect (P &lt; 0.01) on machine-on time at 0.4 kg/min. The yield during the first 2 min of milking, average flow and peak flow rates were not affected at any level of production. The average electrical conductivity in milk was significantly (P &lt; 0.01) lower for the low and medium yield cows without affecting the mean somatic cell count. At 0.4 kg/min, more cluster reattachments were needed because of significant amount of milk remaining in the udders post-cluster removal.

Aetiology and prevalence of subclinical mastitis in dairy herds in peri-urban areas of Kigali in Rwanda

The aim of this cross-sectional study was to evaluate the prevalence of subclinical mastitis (SCM) and associated risk factors in dairy cows in peri-urban areas of Kigali, Rwanda, and identify causative udder pathogens. A sample of 256 cows from 25 herds was screened with the California Mastitis Test (CMT), and udder quarters with CMT score ≥ 3 (scale 1–5) were milk sampled for culture and final bacteriological identification with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). All resultant staphylococci species were tested for beta-lactamase production with the clover leaf method. In parallel, herd bulk milk somatic cell count (SCC) of each herd was analysed using a portable device, the DeLaval cell counter. The prevalence of SCM was 43.1% at quarter level and 76.2% at cow level based on CMT test. Multiparous, Holstein cows were 2.50 (C.I = 1.32–4.71) and 10.08 (C.I = 1.54–66.13) times more likely to contract SCM infection than primiparous animals or cows of other breeds, respectively. The median and mean SCC of all herds were 1108 × 103 cells/mL and 1179 × 103 cells/mL, respectively. The most prevalent pathogens were non-aureus staphylococci (NAS; 40.2%) followed by Staphylococcus aureus (22%) and less prevalent pathogens (6%). Samples with no growth or contamination constituted 30.4% and 1.4% of the diagnoses, respectively. The most prevalent species within NAS were S. epidermidis (38.2%) followed by S. sciuri (19.5%), S. chromogenes (9.8%), and nine less prevalent NAS species (32.5%). Out of 209 staphylococci isolates, 77% exhibited beta-lactamase production. The study shows that there is high prevalence of SCM and high herd bulk milk SCC in herds in Kigali, indicating udder health problems in dairy cows. Additionally, beta-lactamase production among staphylococci species was common. Improved milking hygiene and application of biosecurity measures, or a complete mastitis control plan, is required to lower the prevalence of SCM and minimize the spread of pathogens among dairy cows.

Evaluation of test-day milk somatic cell count information to predict intramammary infection with major pathogens in dairy cattle at drying off

The objectives of this study were (1) to determine the test characteristics and predictive values of cow-level milk somatic cell count (SCC) information from (multiple) test-day recordings before drying off to identify major-pathogen-infected cows at drying off; and (2) to explore to what extent (an estimate of) the herd prevalence of subclinical mastitis, milk yield level, and parity of the cows affects the estimates. In total, 550 cows from 15 commercial dairy herds with overall good udder health management were dried-off during a study period of 6 mo. Test-day SCC were available through milk recording and within 5 d before drying off cows were sampled for quarter-level bacteriological culturing serving as the gold standard. Sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) were calculated at different threshold values of SCC, ranging between 50,000 and 500,000 cells/mL, to detect major-pathogen-infected cows. At a commonly used threshold of 200,000 cells/mL, the Se and Sp of (a combination of) test-day SCC before drying off ranged between 37.6 and 57.6% and between 66.7 and 79.3%, respectively. Still, estimates were modified by the herd level prevalence of subclinical mastitis and the cow's milk yield and parity. For instance, at the 200,000 cells/mL threshold using the geometric mean SCC of the 3 last test-days, the overall Se, Sp, PPV, and NPV were 37.6, 79.3, 30.8, and 83.9%, respectively, whereas these were 27.8, 87.5, 21.7, and 90.6%, respectively, for heifers and 40.3, 73.5, 33.3, and 78.9%, respectively, for multiparous cows. In conclusion, test-day SCC records obtained via milk recording are reliable to detect dairy cows at drying off that are not infected with major pathogens as determined by bacteriological culture and could eventually facilitate implementation of selective dry cow therapy in commercial dairy herds. Because estimates of the herd-level prevalence of subclinical mastitis, milk yield level, and parity of the cows affect the estimates of the test characteristics and predictive values to some extent, one should consider taking these parameters into account when differentiating infected from uninfected cows based on SCC data.

Evaluation of combination of antibiotic with multienzyme preparation on bovine mastitis

The study evaluated the efficacy of multienzyme therapy as an adjunct or alternative to antibiotic therapy in mastitic cows. Twenty one cows affected with clinical mastitis were selected and divided into three treatment groups: Group 1 (n=7) animals were treated with enrofloxacin @ 10 mg/kg b.w, I/M for 5 days. Group 2 (n=7) cows received an intramammary infusion consisting of a mixture of three enzymes viz. chymotrypsin (8 mg), trypsin (8 mg) and papain (4 mg) dissolved in 5 ml NS, at 24 hr. interval for 7 days. Group 3 (n=7) cows received a combination of both parental antibiotic (Enrocin) and intramammary infusion of multienzymes for 7 days at 24 hours interval. Milk samples were collected prior to the treatment (day 1) and on days 4, 7 and 14 post treatment and blood samples on day 1, 7 and 14. There was significant (P<0.05) decrease in the mean serum total protein (TP) and globulin levels in all the treatment groups post treatment as compared to the pretreatment levels while as the mean serum albumin levels and the A: G ratio showed significant (P<0.05) increase post treatment. There was a significant (P<0.05) decrease in the mean total sialic acid (TSA) levels on days 7 and 14 after treatment as compared to the pre-treatment levels in all the three groups. Mean somatic cell count (SCC), standard plate count (SPC) and electrical conductivity (EC) values decreased significantly on days 4, 7 and 14 as compared to that of the day 1. It was concluded that therapeutic intervention with parenteral enrofloxacin and intramammary infusion of proteolytic enzymes improved the udder health of dairy cows affected with clinicalmastitis.

The Use of Fuzzy Logic Approach in Evaluation of Subclinic Mastitis

This study was carried out with the aim of investigating the possibility of detection of subclinical mastitis in the number of Somatic Cell Count and Electrical Conductivity by using fuzzy logic method in Holstein cows raised in a private operation in the Karapinar district of Konya. As a result of the analysis, mean of somatic cell count was 348153 ± 52340 and average of electrical conductivity was 4.23 ± 0.18. Linear regression of electrical conductivity and milk oil to somatic cell count were found to be very important (P &lt;0.01), while the parity was insignificant to the somatic cells count. For the electric conductivity, the effect of the parity, animal group and the protein group was very important (P &lt;0.001) and the effect of the milk fat group was significant (P&lt;0.05). In the analysis according to the fuzzy logic method, the accuracy ratio between the number of somatic cells count and the electrical conductivity was determined as 92.45%. As a result, 92% of subclinical mastitis can be correctly detected using the number of somatic cells and electrical conductivity values.

Associations of teat morphometric parameters and subclinical mastitis in riverine buffaloes.

The possible association between teat morphometric traits and subclinical mastitis (SCM) in dairy buffaloes was studied. Teat morphometric parameters, i.e. teat shape (bottle, conical, cylindrical, and others), teat-end shape (flat, round, and pointed), teat length (TL), teat diameter (TD), and teat-end to floor distance were measured before milking, but after proper milk let-down, in clinically healthy buffaloes (47 Murrah and 34 Nili-Ravi breeds). Subclinical mastitis was defined on the basis of bacteriology and somatic cell count (SCC) of quarter foremilk samples. A high proportion of cylindrical teats (40%) and pointed teat-ends (64·4%) was observed. Hind teats were longer and thicker than fore teats (P < 0·05). A significant breed effect was found with respect to teat shape, length and diameter (P < 0·05). Teats were mostly cylindrical (43·3 vs. 35·4%) and conical (34·2 vs. 30·8%) shaped, smaller (mean 8·2 vs. 9·5 cm) and thinner (mean 3·3 vs. 3·6 cm) in the Murrah breed compared with the Nili-Ravi breed. Teats that had 'other' shapes and were longer, wider, and placed closer to the floor were more associated with SCM (P < 0·05). Mean SCC was significantly higher (P < 0·05) in Nili-Ravi buffaloes, teat shapes classified as 'others', and quarters with SCM. Teat morphometric traits seem to be associated with indicators of udder health in buffaloes, thus, their inclusion in breeding programmes for selection against undesirable dairy type traits may be of value in reducing susceptibility to intramammary infections in Indian buffaloes.

The Prevalence and Etiology of Subclinical Mastitis in Sheep and Goats

From September 2016 to August 2017, four hundred and twenty four milk samples were collected from mammary halves of 212 apparently healthy lactating animals (108 ewes and 104 does) from small private flocks in different localities at Sharkia Governorate. All samples were investigated by California mastitis test (CMT) and bacteriological examination to determine prevalence and etiology of subclinical mastitis (SCM) in sheep and goats and to estimate the mean somatic cell count (SCC) of infected milk samples with different pathogens. The prevalence rates of SCM using CMT were 44 (40.7%) in ewes [59 milk samples, (27.3%)] and 50 (48.1%) in does [62 milk samples, (29.8%)]. Furthermore, out of ewes’ and does’ milk samples examined by bacteriological culture 54 (25.0%) and 56 (26.9%) samples were bacteriologically positive, respectively. The isolated bacterial causing SCM in ewes’ milk samples were E. coli (44.4%), S. aureus (38.9%), Streptococcus spp. (27.8%), coagulase negative Staphylococci (26.0%), Citrobacter spp. (3.7%) and Enterobacter spp. (1.9%). The identified isolates from does’ milk samples were S. aureus (46.4%), E. coli (26.8%), Streptococcus spp. (25.0%), coagulase negative Staphylococci (19.6%), Citrobacter spp. (5.4%) and Enterobacter spp. (3.6%). The geometric mean of SCC of milk samples harbored major pathogens was significantly (P < 0.05) higher than those harbored minor pathogens. Polymerase Chain Reaction (PCR) was applied on a total of 26 isolates from the most recovered species associated with mastitic milk samples of ewes and does. Suspected S. aureus, E. coli, Strep. agalactiae, Strep. dysagalactiae, and Strep. uberis isolates showed characteristic bands at 270 bp, 366 bp, 487 bp, 279 bp, and 723 bp which were specific for the used genes, respectively. In conclusion: a great attention should be directed to the early diagnosis of SCM in ewes and does.

Pathogenesis and inflammatory response in experimental caprine mastitis due to Staphylococcus chromogenes

Coagulase-negative staphylococci (CNS) are the most frequently isolated bacteria in cases of subclinical mastitis in dairy cows. CNS species may differ in their pathogenicity, but very little is known about their virulence factors or their immune response in intramammary infections. To our knowledge, no experimental studies into the mastitis pathogenesis caused by CNS have been described in lactating goats. The aim of this study was to induce an experimentally Staphylococcus chromogenes mastitis in lactating goats aimed at verifying if the model can be used to evaluate the inflammatory response, the dynamics of infection and the pathological findings within the first hours of intramammary inoculation. Six Saanen goats in mid-lactation were inoculated with 1 × 107 colony forming units of S. chromogenes. Bacterial growth peaked in milk from the challenged right halves of the mammary glands (RMG) at 4 h post inoculation (PI). Shedding of viable bacteria showed a marked decrease at 12 h PI. An increase in mean somatic cell counts was observed in the milk samples from 8 h PI onwards. Mild clinical signs were evoked by intramammary inoculation. Staphylococcus chromogenes could be isolated in tissue from all RMG. Histological examination of specimens of the RMG and lymph nodes of the goats showed an increased inflammatory response throughout the experiment with respect to control halves. In conclusion, the experimental inoculation of S. chromogenes in lactating goats is capable of eliciting an inflammatory response and capable of causing pathological changes. This research represents a preliminary study for a better knowledge of the mastitis pathogenesis caused by S. chromogenes.

Canadian National Dairy Study: Herd-level milk quality

The objective of this study was to estimate Canadian national milk quality parameters and estimate the bulk tank milk (BTM) prevalence of 4 mastitis pathogens, Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma bovis, and Prototheca spp., on Canadian dairy farms. A questionnaire was sent to all Canadian dairy producers. Of the 1,062 producers who completed the questionnaire, 374 producers from across the country were visited and milking hygiene was assessed. Farm-level milk quality data for all Canadian dairy producers was collected from the provincial marketing boards and combined with the questionnaire and farm visit data. In addition, a BTM sample was collected either during the farm visit or by the marketing board in November of 2015 and was tested for 4 major mastitis pathogens using the PathoProof Mastitis Major 4 PCR Assay (Thermo Fisher Scientific Inc., Waltham, MA). Apparent herd-level prevalence was 46% for S. aureus, 6% for Prototheca spp., 0% for M. bovis, and 0% for Strep. agalactiae. Due to the low prevalence of M. bovis and Strep. agalactiae and a lack of significant factors associated with farms testing positive for Prototheca spp., an association analysis could only be carried out for Staph. aureus-positive farms. Factors associated with Staph. aureus-positive farms were not fore-stripping cows before milking (odds ratio = 1.87), milking with a pipeline system (odds ratio = 2.21), and stall bases made of a rubberized surface (mats and mattresses), whereas protective factors were using blanket dry cow therapy (odds ratio = 0.49) and applying a tag or visible mark on cows known to have chronic mastitis infections (odds ratio = 0.45). The Canadian national production-weighted geometric mean somatic cell count was determined to be 208,000 cells/mL. This is the first national dairy study conducted in Canada. Participating farms had higher milk yield; were more likely to have a loose housing system, parlor, or automated milking system; and had lower weighted mean BTM somatic cell count than the national level. Sampling larger farms with better milk quality means the apparent prevalence of the 4 mastitis pathogens likely underestimates the true levels.