BACKGROUND: Mastitis could be detected in various ways, including physical, on-farm, and laboratory tests. OBJECTIVES: The present research aimed to evaluate the accuracy of the diagnosis of mastitis using lactate dehydrogenase (LDH)-based dipsticks and to assess these dipsticks with regard to the effects of different lactation days, the amount of milk production, and parity. RESULTS: Considering bacteriologic culture as a gold standard method for the diagnosis of subclinical mastitis, the sensitivity and specificity of LDH test were 68.9 % and 54 %, respectively. The results revealed a high correlation between SCC and LDH. A statistically significant relationship was observed between the response of dipstick and CMT results; with the increase in the CMT score, the score of LDH dipstick increased. By investigating the effects of lactation days, the amount of milk production, and parity, it was determined that the chance of having subclinical mastitis in cows with positive dipstick result was 5.59 times greater than that in cows with negative dipstick result. There were no significant relationships among SCC, LDH, and CMT with lactation days and milk production; meanwhile, with the increase in parity, the three above-mentioned variables showed significant increase. CONCLUSIONS: The results of the present study indicated that the best methods for subclinical mastitis detection were SCC, CMT, and LDH based dipsticks, respectively.

Mastitis is the most costly disease of dairy cows. A pro-active approach includes insuring adequate levels of selective trace minerals. The aim of this study was to determine the effect of two different commercially available, injectable selenium products, (sodium) Na-selenite (inorganic) and (selenium) Se-methionine (organic), on milk composition and on serum and milk selenium concentrations in high-yielding Holstein cows on total mix ration. Sixty multiparous cows were randomly selected into three groups of 20, one control group and two groups supplemented with injectable trace minerals. Blood and milk samples were collected over a period of 60 days. No specific change was indicated in milk yield, lactose, milk urea nitrogen (MUN) and milk pH levels compared with baseline values. The Se-methionine supplemented group showed a numerical increase in total milk protein percentage. In the group injected with Se-methionine, a negative correlation was present for the initial 72 hours between serum selenium concentration and somatic cell count (SCC) and a highly significant (p 0.001) increase in milk selenium concentration for the initial 24 hours. Serum selenium concentration of Se-methionine-supplemented cows was however not significantly changed. Injection of Na-selenite led to a 60-day initial increase in serum selenium concentration above baseline levels and a significant milk selenium concentration on day 1 but to a negative correlation between serum selenium concentration and SCC. Differences in serum and milk selenium concentrations followed with the use of organic and inorganic selenium injectables. Injectable Na-selenite, as selenium, can be of important value for cattle farmers if supplemented on strategically physiological periods to improve production, reproduction and immunity.

The somatic cell count (SCC) is a screening test for the evaluation of intramammary infection; however, changes in mammary secretion during colostrogenesis can promote a physiological increase in the SCC, potentially reducing its reliability in the diagnosis of mastitis. Therefore, the aim of this study was to evaluate bovine colostrum SCC as an indicative parameter of breast infection in Holstein periparturient cows. A total of 80 samples were harvested from the first milking colostrum of 20 cows and were subjected to manual SCC and bacteriological examination. Bacterial growth was present in 36.62% of the crops; coagulase-negative Staphylococcus (CNS) was the predominant microorganism (76.92%). The median SCC in infected cows (1.8 × 106 cells/mL) was significantly higher than in uninfected cows (0.9 × 106 cells/mL) (p = 0.0451). The sensitivity (100–15%), specificity (100–2.2%), and false positive (100–2.2%) of the SCC decreased gradually when thresholds of 0.2–10.0 × 106 cells/mL were adopted. In contrast, the proportion of false negatives (0–84.6%) revealed an opposite trend. The threshold of greatest concordance between SCC and bacteriological examination was 10.0 × 106 cells/mL; however, the sensitivity rates (15.4%), specificity (2.2%), and false positive (2.2%) were very low. Based on these results, we conclude that SCCs increased prior to the infectious processes of the mammary gland, particularly in the CNS group. However, physiological changes caused by colostrogenesis resulted in poor concordance between the SCC and bacteriological examination of the colostrum.

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 quar¬ter 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 inter¬pretation of SCC. [J Adv Vet Anim Res 2020; 7(2.000): 314-319]

Objective-To investigate effects of intramammary administration of prednisolone on the immune response of mammary glands in cows. Animals- 5 lactating Red Holsteins. Procedures- Cows received a different intramammary infusion in each mammary gland (10 mg of prednisolone, 100 μg of lipopolysaccharide [LPS], 100 μg of LPS and 10 mg of prednisolone, or saline [0.9% NaCl] solution). Milk samples were collected before (time 0) and 3, 6, 9, 12, 24, and 36 hours after treatment. Somatic cell count (SCC), lactate dehydrogenase (LDH) activity, and concentrations of serum albumin (SA) and tumor necrosis factor (TNF)-α in milk and mRNA expression of TNF-α, interleukin (IL)-8, and IL-1β in milk somatic cells were analyzed. Results-Saline solution or prednisolone did not change SCC, LDH activity, and SA and TNF-α concentrations in milk and mRNA expression of TNF-α, IL-1β, and IL-8 in milk somatic cells. The SCC and TNF-α concentration in milk increased similarly in glands infused with LPS, independent of prednisolone administration. However, the increase of LDH activity and SA concentration in milk after LPS infusion was diminished by prednisolone administration. The mRNA expression of TNF-α, IL-8, and IL-1β in milk somatic cells increased after LPS infusion and was unaffected by prednisolone. Conclusions and Clinical Relevance- Intramammary administration of prednisolone did not induce an immune response and did not change mRNA expression of TNF-α, IL-8, and L-1β during the response to intramammary administration of LPS. However, prednisolone reduced disruption of the blood-milk barrier. This could influence the severity and cure rate of mastitis.

Mastitis is the most costly disease of dairy cows. A pro-active approach includes insuring adequate levels of selective trace minerals. The aim of this study was to determine the effect of two different commercially available, injectable selenium products, (sodium) Na-selenite (inorganic) and (selenium) Se-methionine (organic), on milk composition and on serum and milk selenium concentrations in high-yielding Holstein cows on total mix ration. Sixty multiparous cows were randomly selected into three groups of 20, one control group and two groups supplemented with injectable trace minerals. Blood and milk samples were collected over a period of 60 days. No specific change was indicated in milk yield, lactose, milk urea nitrogen (MUN) and milk pH levels compared with baseline values. The Se-methionine supplemented group showed a numerical increase in total milk protein percentage. In the group injected with Se-methionine, a negative correlation was present for the initial 72 hours between serum selenium concentration and somatic cell count (SCC) and a highly significant (p < 0.001) increase in milk selenium concentration for the initial 24 hours. Serum selenium concentration of Se-methionine-supplemented cows was however not significantly changed. Injection of Na-selenite led to a 60-day initial increase in serum selenium concentration above baseline levels and a significant milk selenium concentration on day 1 but to a negative correlation between serum selenium concentration and SCC. Differences in serum and milk selenium concentrations followed with the use of organic and inorganic selenium injectables. Injectable Na-selenite, as selenium, can be of important value for cattle farmers if supplemented on strategically physiological periods to improve production, reproduction and immunity.

Objective—To compare results for 3 commercially available microbiological media plates with those for standard bacteriologic testing of bovine milk. Sample—Milk samples from postpartum cows and cows with a high somatic cell count (SCC) or clinical mastitis (CM). Procedures—Sample-ready Staphylococcus culture medium (SRSC) plates were used to detect Staphylococcus aureus in milk samples obtained from postpartum cows and cows with a high SCC or CM. Rapid coliform count (RCC) plates were used to detect coliforms in milk samples obtained from cows with CM. Aerobic count (AC) plates were used to detect streptococci in CM samples. Fresh mastitic milk samples were frozen and then thawed to evaluate the effects of freezing for the SRSC and RCC plates. The effects of dilution (1:10) of samples were determined. Agreement of results between the commercially available plates and standard bacteriologic testing was evaluated. Results—The ability of SRSC plates to detect S aureus in milk samples was highest with diluted samples from postpartum cows and cows with a high SCC or CM. Sensitivity of the RCC plate for detection of coliforms was highest with diluted mastitic milk samples. The AC plates had a poor positive predictive value for detection of streptococci in mastitic milk samples. Freezing increased S aureus detection. Conclusions and Clinical Relevance—Overall, the SRSC and RCC plates were accurate, were easy to use, and yielded results comparable to those of standard bacteriologic testing for the detection of S aureus and coliforms in bovine milk.

Approximately 45 Holstein cows that were Mycobacterium paratuberculosis-positive on the basis of fecal culture results were maintained at any one time in a 210-cow dairy herd. Farm management participated in the New York State Paratuberculosis Eradication Program. Paratuberculosis-positive cows were grouped separately from paratuberculosis-negative cows, but they were otherwise managed identically. During a 1-year study, 180 paratuberculosis-negative cows and 113 clinically normal paratuberculosis-positive cows were identified. Quarter milk samples (n = 6,100) were aseptically collected for microbiologic culture of mastitis pathogens from paratuberculosis-negative cows, and 3,129 quarter samples were obtained from paratuberculosis-positive cows. Dairy Herd Improvement Association (DHIA) records were used to monitor milk somatic cell count linear scores, mature equivalent milk production, new mastitis infections, and chronic mastitis infections. For second-lactation cows greater than 100 days in milk production, and increasing with age beyond that point, paratuberculosis-positive cows had lower mature equivalent milk production than did negative herdmates. Rates of new and chronic mastitis infections, as measured by DHIA linear scores were significantly (P less than 0.05, P = 0.05, respectively) lower in cows with nonclinical paratuberculosis. Infected cows were cuffed from the herd at a faster rate than were paratuberculosis-negative herdmates. Therefore, paratuberculosis was associated with financial loss attributable to reduced milk production and increased culling of infected cows.

An intramammary device (IMD) was adapted for use in ewes; this device was made of abraded poly. ethylene material (1.7 mm in diameter, 47 mm long) and formed a 15-mm-diameter loop in the gland cistern. The IMD was inserted in 1 gland in each of 43 ewes. A significant (P < 0.0001) increase in milk somatic cell count (SCC) was observed in glands provided with an IMD. This increase was attributable to an increase in neutrophil numbers and was observed during the first 12 weeks after insertion. The IMD had a protective effect against experimentally induced staphylococcal mastitis (Staphylococcus aureus and S epidermidis), although different milk SCC were required for protection from each bacterial species in most ewes (10(6) and 2 X 10(5) cells/ml, respectively). Histologic studies revealed that the IMD induced local squamous metaplasia in the glandular part of the lactiferous sinus. Erythrocytes were found in milk from glands provided with an IMD throughout the studied period (35 days of the 45-day lactation) and, in some cases, blood clots were observed during the first 2 weeks of lactation. Glands with IMD also had lower milk production and quality at 30 and 32 days of lactation. Eight ewes with IMD were studied throughout a subsequent lactation. Milk from the IMD-containing glands had an increase in SCC, as in the previous lactation period; did not contain blood clots or erythrocytes; and had normal composition (similar to that in glands without the IMD).

Subclinical mastitis is a major problem threating the cows' industry in Egypt. This study aimed to investigate the impact of SCC on the milk composition and evaluate the effect of spirulina supplementation on SCC and milk quality. Total of 270 milk samples were examined using CMT, BacSomatic and MilkoscanTMFT1 system. For evaluation of spirulina effect, ten cows were supplemented with spirulina powder (20 g per head for one month).The prevalence of SCM according to CMT and SCC was 32.2% and 54.4%, respectively.  SCC negatively correlated with Fat, protein, lactose, and casein% which had Means of 2.94±0.75, 3.48±0.37, 4.82±0.23, and 2.58±0.39, respectively at SCC (<200 ×103cell/ml) while, at SCC above 400 ×103cell/ml were 2.43±0.95, 3.24 ±0.33, 4.61±0.22, and 2.4±0.38, respectively. There was a significant decrease in the average of SCC from 6638.9±4675.9×103 to 361.1±321.4×103cell/ml after 3 weeks of spirulina supplementation. The Mean of Fat, protein, lactose, and casein% were increased from 2.84±0.29, 3.02±0.4, 4.49±0.4 and 2.34±0.28, respectively to reach 3.62±0.16, 3.65±0.43, 4.86±0.41 and 2.59±0.3, respectively and Milk yield increased from average of 21.7±3.23 kg/day to 24.2±2.39kg after 21 days of spirulina treatment. Therefore, milk quality and quantity can be improved by using Spirulina supplementation which reduces SCC.