The mouthpiece chamber vacuum pattern indicates the cessation of milk flow and suits as an indicator to reduce teat end vacuum at a quarter level.

We investigated the suitability of the quarter mouthpiece chamber vacuum (MPCV) as an indicator for cessation of quarter milk flow to potentially adjust the teat end vacuum at a quarter level. We tested the hypothesis that a MPCV increase is a clear indicator of quarter milk flow cessation. In addition, we tested if a quarter-individual vacuum reduction at MPCV increase reduces the mechanical effect on the teat. Ten dairy cows were milked twice daily with a quarter-specific vacuum supply with continuously high (51 kPa; TRT51) or low vacuum setting (41 kPa; TRT41), or high vacuum setting combined with a quarter-specific vacuum reduction by 10 kPa immediately after the quarter-specific MPCV increase (TRT51/41). Whole udder milk flow was continuously recorded. Each treatment was repeated at 4 subsequent milkings. The high vacuum settings (TRT51; TRT51/41) reached higher values in peak flow rate and average milk flow and consequently shorter machine-on time. The time from start of milking until the steep increase of the MPCV was shorter in front than rear quarters, and hence the time from start of MPCV increase until end of milking was longer in front than rear teats. Teat condition of the right front teats was measured for teat wall diameter by ultrasound and teat tissue thickness by cutimeter at 5 and 20 min after each experimental milking. The teat measurements were taken at the teat tip (distal barrel) and 2 cm above the teat tip (proximal barrel). The proximal teat wall diameter tended to be higher in TRT51 than in TRT41, both 5 and 20 min after milking. The distal teat wall diameter at 5 min was greater in TRT51 than in TRT41. In TRT51/41 the teat wall diameter at both locations was intermediate, not significantly different from either TRT51 or TRT41. The distal teat tissue thickness was greater in TRT51 than in TRT41, and tended to be greater in TRT51/41 than in TRT41 at 5 min. The proximal teat tissue thickness at 5 min was higher in TRT51 and TRT51/41 than in TRT41. The teat tissue thickness decreased from 5 to 20 min only in the proximal barrel. The quarter-individual MPCV increase appears to be a suitable indicator of the cessation of milk flow. The lack of a significant reduction of mechanical effect on the teat by a reduced vacuum of 41 kPa indicates that the vacuum level chosen may be still too high under conditions of a separate vacuum supply for each quarter, which prevents a vacuum drop caused by the whole udder milk flow.

The prevalence and risk factors of subclinical mastitis in water buffalo (Bubalis bubalis) in Bangladesh.

Subclinical mastitis (SCM) in water buffalo is responsible for reduced milk yield and quality. This cross-sectional study was carried out to a) estimate the prevalence of SCM, b) identify risk factors associated with SCM, and c) identify farm-level risk factors associated with bulk milk somatic cell count (BMSCC). The buffalo farms included in this study represented five rearing systems: free-range, semi-free-range, household, semi-intensive, and intensive, providing a total of 3491 functional quarters of 880 lactating buffalo on 248 farms. The California mastitis test score was used to identify SCM. Bulk milk samples (n = 242) were used for farm-level BMSCC. Quarter and buffalo-level risk factors for SCM were measured using questionnaires and observations. The overall SCM prevalence was high at 27.9% at the quarter-level (25th and 75th percentiles: 8.3% and 41.7%) and 51.5% at buffalo-level (25th and 75th percentiles: 33.3% and 66.7%). The geometric mean BMSCC was 217,000 cells/mL of milk (ranging from 36,000-1,213,000 cells/mL), which is low on average, but some farms could improve substantially. The buffalo rearing system, udder location (left versus right), teat shape, udder asymmetry, number of milkers, and having a quarantine facility were associated with buffalo udder health. Our findings suggest that mainly using free-range rearing systems may help decrease the prevalence of SCM primarily by employing buffalo breeding and better farm biosecurity, and udder health control strategies can be designed based on our findings.

Effect of polymyxin B on ex vivo tumor necrosis factor-alpha responsiveness of blood leukocytes in Danish Holstein Friesian cows.

Whole blood stimulation assay (WBA) with killed gram-positive and gram-negative udder pathogens were used to investigate the interference of the endotoxin-binding antibiotic polymyxin B (PMB) on the ex vivo TNF-α response. Blood samples were collected from first to third lactating dairy cows in their early lactation (<50 days in milk, n = 32) period. The WBA was stimulated with both inactivated bacteria (e.g., dead Escherichia coli, Staphylococcus aureus, Streptococcus dysgalactiae, Streptococcus uberis), at a concentration of 2.5 × 106/mL; and pathogen-associated molecular pattern molecules, namely E. coli LPS (10 µg/mL), and S. aureus peptidoglycan (PG, 10 µg/mL). The PMB was added at a concentration of 0, 12.5, 25, 50, 100, and 200 µg/mL to each stimulant, respectively. All bacteria stimulants resulted in an increased TNF-α response compared to the negative control. The PMB affected the TNF-α responses of gram-positive (except S. dysgalactaie), gram-negative bacteria; and bacterial cell wall components at a PMB concentration of 25-50 µg/mL. The LPS and E. coli had similar TNF-α response but PG had a lower TNF-α response than gram-positive bacteria. The doses of PMB (≥ 25 µg/mL) should be used with caution when using different types of pathogens or should be avoided in ex vivo TNF-α studies.

Ex vivo tumor necrosis factor-alpha response of blood leukocytes in Danish Holstein-Friesian cows stimulated by Gram-positive and Gram-negative bacteria isolated from mastitic milk.

A whole blood stimulation assay was used to investigate the effects of parity, number of weeks after calving and Gram-positive and Gram-negative bacteria on the ex vivo TNF-α responsiveness of Danish Holstein-Friesian cows of first to third lactation (n = 28). Blood samples were collected in weeks 2, 3, 5 and 8 after parturition and stimulated with Escherichia coli LPS (10 µg/mL), Staphylococcus aureus peptidoglycan (PGN, 10 µg/mL) and dead Escherichia coli, Streptococcus uberis, Staphylococcus aureus, and Streptococcus dysgalactiae at a concentration of 2.5 × 106/mL. The antibiotic polymyxin-B (100 µg/mL) was added to the Gram-positive bacteria to avoid the influence of environmental endotoxin by ELISA test. Overall, parity had no effect, whereas number of weeks after calving altered the TNF-α responsiveness of the majority of the stimulants. Ex vivo, Gram-positive bacteria always resulted in a higher TNF-α response than Gram-negative bacteria with large differences within the individual cows. High correlations were found within the Gram-negative stimulants panel (r = 0.83) and within the Gram-positive (r = 0.81 to 0.86) stimulants panel except PGN. The higher TNF-α responsiveness by Gram-positive bacteria is in agreement with in vitro studies in human but in contrast to the in vivo TNF-α responsiveness in bovine udder.

Risk factors and therapy for goat mastitis in a hospital-based case-control study in Bangladesh.

Bangladesh has a large population of goats, which contribute to the income, nutrition and welfare of the households of many families. Mastitis in goats has a low incidence, but is often very severe, making veterinary care necessary. The aim of this study was to identify seasonality and risk factors for goat mastitis in a hospital-based matched case-control study in a teaching veterinary hospital in Chittagong, Bangladesh and to describe the range of antimicrobial treatments applied in this situation. Cases of mastitis and controls were drawn from the hospital patient recording system, along with their risk factor status. Multiple imputation was applied to deal with the missing values in the data analysis. Mastitis occurred somewhat more in the rainy season, and comprised about 3% of all goats admitted to the hospital during January 2011-June 2014. Free-ranging farming system, poor body condition score and non-native goat breeds were significantly associated with case status. Treatment of clinical mastitis was variable and unsystematic, but the use of gentamicin was commonly recorded. The need for more prudent and evidence-based antimicrobial therapies is discussed.

In vitro maturation and fertilization of prepubertal and pubertal black Bengal goat oocytes.

Oocytes retrieval, in vitro maturation (IVM) and fertilization (IVF) efficiency are inevitable steps towards in vitro production of embryos. In the present study, these parameters were investigated in the ovaries of prepubertal (n = 31) and pubertal (n = 61) black Bengal goats obtained from a slaughterhouse. Nuclear maturation was evaluated upon aspiration and following IVM in TCM-199 (Earle's salt with L-glutamine and sodium bicarbonate) for 27 h at 39°C under 5% CO(2) in humidified air. The oocytes retrieval and efficiency (mean ± SD) per prepubertal and pubertal goats were 5.2 ± 0.6 and 6.8 ± 0.6, and 77.3 ± 0.1% and 80.5 ± 0.6%, respectively. Anaphase I - telophase I stages differed significantly (7.3 ± 0.8 vs. 2.6 ± 0.2, p < 0.05) between the two groups of goats. After IVM, the percentages of metaphase II were significantly higher (66.3 vs. 60.3, p < 0.05) in pubertal goats than in their prepubertal counterparts. The percentages of normal in vitro fertilization (IVF) in Fert-Tyrode's albumin lactate pyruvate of pubertal goat oocytes did not differ between Percoll and swim-up sperm separation methods (36.7 ± 0.9% vs. 32.7 ± 1.3%, p > 0.05). Furthermore, sperm capacitation by heparin alone or in combination with ionomycin did not lead to a significant increase in the normal fertilization rate (34.8 ± 1.7 vs. 32.2 ± 1.5%, respectively) in the oocytes of pubertal goats. In conclusion, the ovaries of pubertal black Bengal goats obtained from the slaughterhouse could be used for in vitro embryo production. However, further optimization of the IVM and IVF techniques are necessary for satisfactory in vitro embryo production.