Effects of milking, over-milking and vacuum levels on front and rear quarter teats in dairy cows

Mechanical forces to the teat and vacuum during milking negatively affect teat condition and may result in increased mastitis risk. We compared vacuum levels during milking and over-milking as well as teat condition before and after milking between front and rear teats. We expected that the lower milk yield of the front quarters would result in a longer over-milking and higher vacuum levels in front teats, resulting in morphological differences. The study comprised 540 dairy cows in 41 Austrian dairy farms with conventional milking systems. Before and after milking teats were visually assessed (colour, swelling, rings, hyperkeratosis) and teat dimensions (length, diameter, wall thickness, teat canal length) were measured manually and ultrasonographically. Vacuum measurements were taken using a vacuum measurement device attached to the cluster (short milk tube, pulsation tube and mouth-piece chamber). These various measurements of front and rear teats were compared and a multivariable analysis with backward stepwise procedure was used for inclusion or exclusion from the model. Front teats showed a poorer teat condition and were over-milked for longer in comparison to the rear teats. However, during milking and over-milking the vacuum levels in the mouthpiece chamber were significantly higher at the rear teats. The changes in front teat morphology were only partially caused by milking, over-milking and vacuum levels, with approximately 70% of the variation due to other, undetermined variables. Milking, over-milking and vacuum levels had no or very limited impact on the morphological changes of the rear teats.

EFFICIENCY OF WHIRLPOOL ELECTROSTATIC PHYSIOTHERAPY IN COMPLEX TREATMENT OF HARD-MILKING IN COWS

It was found that diseases of the mammary gland in cows included various types of mastitis –.35%, wounds – 15%, abscess – 15%, phlegmon – 5%, stenosis of the teat canal (hard-milking) – 30%. It was discovered that in the conditions of the city of Dnipro, stenosis of the teat canal (hard-milking) is registered in 30 % of cows as a complication of the purulent catarrhal mastitis in the absence of treatment or its ineffectiveness. Application of whirlpool electrostatic implosion physiotherapy using the apparatus “Vikhr-9T” and the Mishin's coils in a complex treatment of hard-milking in cows, leads to a complete recovery 2-4 days faster and without a disease recurrence.

Cellular Response of Neutrophils to Bismuth Subnitrate and Micronized Keratin Products In Vitro

The aim of this study was to assess the effect of bismuth subnitrate and micronized keratin on bovine neutrophils in vitro. We hypothesized that recruitment and activation of neutrophils into the teat canal and sinus are the mechanisms of action of bismuth subnitrate and keratin-based teat sealant formulations. To test this, a chemotaxis assay (Experiment 1) and a myeloperoxidase (MPO) assay (Experiment 2) were conducted in vitro. Blood was sampled from 12 mid-lactation dairy cows of variable ages. Neutrophils were extracted and diluted to obtain cell suspensions of approximately 106 cells/mL. In Experiment 1, test substances were placed in a 96-well plate, separated from the cell suspension by a 3 µm pore membrane and incubated for 3 h to allow neutrophils to migrate through the membrane. In Experiment 2, neutrophils were exposed to the test products and the amount of MPO released was measured by optical density. Results showed that neutrophils were not activated by bismuth or keratin products (p < 0.05) in all of the tests performed. These results suggest that the mechanisms of action of bismuth subnitrate and keratin-based teat sealants do not rely on neutrophil recruitment and activation in the teat canal and sinus after treatment.

Effect of Bismuth Subnitrate Teat Canal Sealant with Ampicillin-Cloxacillin Combination in Control of Bovine Mastitis in Selected Farms in Kenya

This study presents the results of effect of a combination of bismuth subnitrate teat canal sealant (Boviseal® -Bimeda® Animal Health, Ireland) and the antibiotic Ampicillin & Cloxacillin (Bovaclox® DC-Norbrook Laboratories Ltd-UK) when used during the dry period on occurrence of mastitis 100 days post-calving. The objectives of this study were: to determine the effect of Boviseal® teat canal sealant in combination with Bovaclox® DC in control of dairy cow mastitis 100 days after calving; to determine bacterial pathogens causing mastitis in the selected farms and to determine risk factors for occurrence of dairy mastitis in the selected farms. This controlled field trial was carried out in two Kenyan dairy farms: Chemusian Farm in Nakuru County and Gicheha Farm in Kiambu County. 156 dairy cows were used in the study. Healthy cows with no history of mastitis in their current lactation were recruited. They were randomly placed into either of the two study groups: the control and the test group. The Control group received Bovaclox® DC while the Test group received the Bovaclox® DC followed by Boviseal®. The cows were followed during the entire dry period and 100 days post-calving monitoring for mastitis occurrence. Cows in the control group were more susceptible to mastitis 100 days post-calving compared to cows in the treatment group (P<0.001, RR=4.4, OR=17.7). Of the bacterial pathogens, coagulase negative Staphylococci (CNS) were the most common pathogens isolated from mastitic milk at 34.6 % followed by Micrococcus spp. (9.0%). Other bacteria isolated were Streptococcus agalactiae (3.8%), Staphylococcus aureus (1.9%); Escherichia coli (0.6%) and various bacterial mixtures. Results of logistic regressions at P≤0.05 showed that farm, position of the quarter, type of barn floor and type of treatment were significantly associated with occurrence of mastitis. Cows in Gicheha farm whose barn floor was earthen, those cows in the control group and hindquarters were risk factors for mastitis (RR=1.5, 4.4 and 1.18 respectively). The results of this study showed that Bovaclox® DC + Boviseal® teat canal sealant combination applied during the dry period is more effective in controlling bovine mastitis 100 days post-calving compared to the use of Bovaclox® DC alone. The study thus recommends the use of Bovaclox® DC + Boviseal® dry cow combination for control of bovine mastitis.

Timing of entry of Streptococcus uberis into the mammary gland of the dairy cow

Streptococcus uberis do not colonise the teat canal and appear to invade the mammary gland of the dairy cow by direct entry though the canal. When they enter the mammary gland, and the early resulting processes, are unclear. Experimental infusions of the lactating mammary gland have been made to determine outcomes of infection, mastitis and disease. Infusion of 500 cfu bacteria was made immediately after milking (8 and 16 h intermilking interval) and 1, 4 or 12 h prior to milking. A mastitis resulted from all infusions, probably in response to the skim milk carrier. Infusions post milking resulted in clinical mastitis in more than half of the quarters, whereas infusion 1 h premilking created no clinical mastitis. Infusion 4 or 12 h pre milking resulted in the most severe reactions, with all quarters developing moderate to severe clinical mastitis. This was more rapid with the 4 h pre milking group. The results demonstrate that the initial inflammatory response caused by an invasion of the mammary gland is not necessarily protective against establishment of a pathogen, and that especially the response to invasion in the intermilking interval is often insufficient to prevent infection and/or disease.