Teat thickness changes may provide biological test for effective pulsation

1996 ◽  
Vol 63 (2) ◽  
pp. 179-189 ◽  
Author(s):  
Jörn Hamann ◽  
Graeme A. Mein
Keyword(s):  
Dynamic Test ◽  
International Standards ◽  
Biological Test ◽  
Short Term ◽  
Flow Rates ◽  
Vacuum Level ◽  
Pulsation Rate ◽  
Milk Flow ◽  
Induced Changes ◽  
Pulsation Cycle

SummaryPulsation rates of 40, 60 and 80 cycles/min were combined with pulsator ratios of 50, 60, 70 or 80% in two experiments with different liners. Machine-induced, short-term changes in teat thickness of 14 cows were compared with milk flow rate characteristics and machine strip yields to evaluate the effectiveness of pulsation in relation to liner type. Post-milking teat thickness increased progressively as the b phase of the pulsation cycle was lengthened, and as the d phase was shortened, at all pulsator rates and with either liner. Teat thickness values increased significantly (P < 0·05) when the d phase was <15%. For ratios of 50 and 60%, teat thickness decreased progressively as pulsation rate was increased. At the higher ratios, thickness values were lowest at 60 cycles/min. Pulsation settings that tended to increase teat thickness values also increased both peak milk flow rates and machine strip yields. The influence of liner type on teat thickness changes appeared to be at least as important as the influence of pulsator ratios and greater than the effect of pulsation rate. If so, then international standards for acceptable pulsation characteristics cannot be defined solely in terms of pulsator settings. A limit of ±5% for machine-induced changes in thickness of the teat apex would be an additional guideline for effectiveness of pulsation in relation to both liner type and vacuum level. This could provide a basis for a dynamic test applied to milking cows under field conditions.

Increased milking vacuum in teatcups fitted with non-return valves

1988 ◽  
Vol 55 (4) ◽  
pp. 495-503 ◽  
Author(s):  
R. Jeffrey Andrews ◽  
Graeme A. Mein ◽  
David M. Williams
Keyword(s):  
Strain Energy ◽  
Air Leakage ◽  
Bench Tests ◽  
Vacuum Level ◽  
Milk Flow ◽  
The Mean ◽  
Pulsation Cycle ◽  
Return Valve ◽  
Maximum Pulsation ◽  
Collapse Phase

SummaryAn experimental non-return valve was fitted in the short milk tube so that flow was permitted only in one direction, away from the teat. Liner movement was minimal because no air admission to the liner above the valve was provided. The extent of liner opening therefore depended on the amount of milk extracted within a pulsation cycle and on any air leakage past the liner mouthpiece. Milking experiments using four cows showed that the mean vacuum level in nominally open liners of valved teatcups during peak milk flow was 8·6 kPa higher than in conventional teatcups. Bench tests showed that the increase in liner vacuum (LV) depended on the nominal plant vacuum level, the pressure difference between initial LV and maximum pulsation chamber vacuum, the liner elasticity and mounting tension. The main source of energy available to raise LV above the nominal plant vacuum is the release of strain energy, stored within the liner during the collapse phase of each pulsation cycle.

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

2019 ◽  
Vol 86 (2) ◽  
pp. 196-200
Author(s):  
Ahmad Fahim ◽  
Madan Lal Kamboj ◽  
Ajayvir Singh Sirohi ◽  
Mukesh Bhakat ◽  
Tushar Kumar Mohanty
Keyword(s):  
Dairy Cows ◽  
Somatic Cell Count ◽  
Peak Flow ◽  
Milk Quality ◽  
Flow Rates ◽  
Vacuum Level ◽  
Crossbred Cows ◽  
Milk Flow ◽  
Dairy Animals ◽  
The Mean

AbstractAutomatic 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; <12 kg/d), medium (N = 32; 12–18 kg/d) and high (N = 08; >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 < 0.01) affected the milk yield at all levels of production with a significant effect (P < 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 < 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.

Effects of vacuum level and pulsation rate on milk ejection and milk flow traits in Tunisian dairy camels (Camelus dromedarius)

2014 ◽  
Vol 47 (1) ◽  
pp. 201-206 ◽  
Author(s):  
Moufida Atigui ◽  
Pierre-Guy Marnet ◽  
Ahmed Barmat ◽  
Touhami Khorchani ◽  
Mohamed Hammadi
Keyword(s):  
Camelus Dromedarius ◽  
Milk Ejection ◽  
Vacuum Level ◽  
Pulsation Rate ◽  
Milk Flow

Factors affecting vacuum within the teatcup liner during milking

1968 ◽  
Vol 35 (2) ◽  
pp. 303-316 ◽  
Author(s):  
C. C. Thiel ◽  
P. A. Clough ◽  
D. R. Westgarth ◽  
D. N. Akam
Keyword(s):  
Peak Flow ◽  
Vacuum Fluctuation ◽  
Flow Rates ◽  
Factors Affecting ◽  
Practical Consequence ◽  
Factors Associated ◽  
Milk Flow ◽  
The Mean ◽  
Pulsation Cycle

SummaryFactors associated with the milking cluster and the long milk tube which cause a diminished or a fluctuating vacuum within the liner of the teatcup assembly during simulated milking with an artificial udder fell into 3 groups. 1. Lower milk flow rates and admission of air at the clawpiece greatly decreased vacuum fluctuation within a pulsation cycle and increased the mean level of vacuum in the liner during that part of the cycle in which milk was flowing from the teat. 2. Larger bore of the short milk tube connecting the liner to the clawpiece, pulsation of the teatcup liners in pairs instead of all 4 together, and larger volume of the clawpiece bowl in the main decreased fluctuation in vacuum within the liner. 3. Larger bore and shorter length of the long milk tube connected to the clawpiece and decreased height above the outlet of the clawpiece to which the milk was raised mainly increased the mean vacuum in the liner during that part of the cycle in which milk was flowing from the teat.In a milking experiment with 75 cows mean overall fluctuations in milking vacuum within the liner in a pulsation cycle at peak flow were 11·5 and 4·8 inHg and corresponding mean levels of vacuum during that part of the cycle when milk was flowing from the teat were 11·75 and 13·0 inHg. There were no differences in milking performance of practical consequence.

Influence of milk flow rate on new intramammary infection in dairy cows

1991 ◽  
Vol 58 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Robert J. Grindal ◽  
J. Eric Hillerton
Keyword(s):  
Flow Rate ◽  
Peak Flow ◽  
Fold Increase ◽  
Infection Rates ◽  
Short Term ◽  
Flow Rates ◽  
Intramammary Infection ◽  
Milk Flow ◽  
Milking Machine ◽  
Mastitis Control

SummaryIn a series of short-term experiments cows were subjected to exaggerated bacterial challenge and accentuated milking machine conditions known to predispose to new mammary infection. The incidence of new intramammary infection was significantly greater in quarters with peak flow rates > 1·6 kg/min whether they were exposed to impacts (P < 0·05) or milking without pulsation (P <0·001). The infection rates were much lower (P < 0·001) in quarters milked with ‘pulsation and shields’ to protect against these two machine factors. Despite this, quarters with peak flow > 1·6 kg/min still showed a 12-fold increase in mastitis incidence compared with quarters with peak flow < 0·8 kg/min. Rates of milk flow have increased dramatically in the last 40 years through selection and breeding: whole udder peak flow rates in heifers have doubled from 1·9 to 3·8 kg/min. Increased emphasis, therefore, should be placed on hygiene, husbandry and milking techniques to minimize bacterial numbers at teat ends to control mastitis as the drive for higher flow rate and yield make cows increasingly more susceptible to infection. These results suggest that the benefits of reduced infection rate from mastitis control are significantly underestimated since animals are now considerably more susceptible than 40 years ago.

Improved milking characteristics of teatcups fitted with non-return valves

1988 ◽  
Vol 55 (4) ◽  
pp. 505-511 ◽  
Author(s):  
R. Jeffrey Andrews ◽  
Graeme A. Mein ◽  
Murray R. Brown
Keyword(s):  
Peak Flow ◽  
Reverse Flow ◽  
Flow Rates ◽  
Vacuum Level ◽  
Milk Flow

SummaryThe milking characteristics of conventional clusters were compared with individual teatcups or clusters fitted with valves in the short milk tubes without external air admission to the liners. Individual teatcups fitted with non-return valves had peak milk flow rates 13% higher than conventional teatcups. A daily cross-over experiment involving 36 cows compared clusters fitted with non-return valves to conventional clusters. Valved clusters milked 18% faster, showed significantly better teatcup stability and 3% higher machine milk yields, but 48% higher strip yields were recorded. Clusters with non-return valves were difficult to remove after milking because the valve closed when the vacuum supply was shut off, thereby maintaining the vacuum level under the teats. When the nominal plant vacuum level for teatcups with non-return valves was reduced by 10 kPa to compensate for the higher effective milking vacuum level, the valved teatcups had peak flow rates 20% lower than the conventional teatcups. Clusters fitted with a modified valve, which allowed some reverse flow when closed (a ‘leaky’ valve), milked significantly faster than conventional clusters, had 33% lower strip yields and were easy to remove after milking.

scholarly journals Increased take-off level in automatic milking systems – effects on milk flow, milk yield and milking efficiency at the quarter level

2018 ◽  
Vol 86 (1) ◽  
pp. 85-87 ◽  
Author(s):  
Sabine Ferneborg ◽  
Måns Thulin ◽  
Sigrid Agenäs ◽  
Kerstin Svennersten-Sjaunja ◽  
Peter Krawczel ◽  
...  
Keyword(s):  
Flow Rate ◽  
The Other ◽  
Mean Flow ◽  
Flow Rates ◽  
Decline Phase ◽  
Flow Profiles ◽  
Milk Flow ◽  
Automatic Milking ◽  
Automatic Milking Systems ◽  
Time Required

AbstractThis research communication describes how different detachment levels (0.48, 0.3 and 0.06 kg milk/min) at the quarter-level affect milk flow profiles and overall milking efficiency in automatic milking systems. We hypothesized a higher detachment level would result in greater mean flow rates without affecting the volume of harvested milk per cow during 24 h compared to lower detachment levels. The data suggest milk flow decreased to a rate below the overmilking limit within the 6-s delay time required for termination in all treatments, but the duration of overmilking was shorter for the greatest detachment level compared to the other treatments. We conclude that setting a detachment level at a greater milk flow rate reduces the duration of overmilking without affecting the amount of milk harvested when applied to cows in mid-lactation during quarter-level milking. We also suggest that the steepness of the decline phase of the milk flow curve might have a larger effect than the actual detachment level on the duration of overmilking.

scholarly journals Effect of milking vacuum level and overmilking on cows’ teat characteristics

2011 ◽  
Vol 59 (5) ◽  
pp. 193-202 ◽  
Author(s):  
M. Pařilová ◽  
L. Stádník ◽  
A. Ježková ◽  
L. Štolc
Keyword(s):  
Wall Thickness ◽  
Treatment Effects ◽  
Vacuum Level ◽  
Milk Flow ◽  
Before And After ◽  
Teat Canal ◽  
Test Treatment

The influence of milking vacuum and milk flow level (resp. detachment level) on cows’ teat characteristics were studied in four experiments. The MIXED procedure was used to test treatment effects on the level of teat length, teat thickness at the base and half-way between the teat end and the base of udder, teat canal length, teat end width, teat wall thickness, teat cistern width after milking and on differences between these teat characteristics measured before and after milking. A total of 51 cows were included in all experiments. All the cows had clinically healthy udders. Some cows were involved in two or more experiments. Finally, 330 teat measurements of 165 cows were taken and statistically processed. Vacuum and milking with or without overmilking significantly (P < 0.05-0.001) influence monitored parameters. Milking vacuum has an influence on two of three measured external teat parameters: teat diameter measured at the base of the teat and half-way between the udder base and the teat tip. Change in teat length measured before and immediately after milking was higher when higher vacuum of 45 kPa was used. Detachment level also has an influence on teat proportions. Overmilked teats were longer and narrower compared to non-overmilked teats. Interaction between milking vacuum and detachment level influences external teat parameters as well.

scholarly journals Evaluation of short-term changes of hydrological response in mountainous basins of the Vitim Plateau (Russia) after forest fires based on data analysis and hydrological modelling

2015 ◽  
Vol 371 ◽  
pp. 157-162 ◽  
Author(s):  
O. M. Semenova ◽  
L. S. Lebedeva ◽  
N. V. Nesterova ◽  
T. A. Vinogradova
Keyword(s):  
Forest Fires ◽  
Model Performance ◽  
Burned Area ◽  
Model Parameters ◽  
Hydrological Response ◽  
Short Term ◽  
Burnt Area ◽  
Area Product ◽  
Induced Changes ◽  
Fire Impact

Abstract. Twelve mountainous basins of the Vitim Plateau (Eastern Siberia, Russia) with areas ranging from 967 to 18 200 km2 affected by extensive fires in 2003 (from 13 to 78% of burnt area) were delineated based on MODIS Burned Area Product. The studied area is characterized by scarcity of hydrometeorological observations and complex hydrological processes. Combined analysis of monthly series of flow and precipitation was conducted to detect short-term fire impact on hydrological response of the basins. The idea of basin-analogues which have significant correlation of flow with "burnt" watersheds in stationary (pre-fire) period with the assumption that fire impact produced an outlier of established dependence was applied. Available data allowed for qualitative detection of fire-induced changes at two basins from twelve studied. Summer flow at the Amalat and Vitimkan Rivers (22 and 78% proportion of burnt area in 2003, respectively) increased by 40–50% following the fire.The impact of fire on flow from the other basins was not detectable.The hydrological model Hydrograph was applied to simulate runoff formation processes for stationary pre-fire and non-stationary post-fire conditions. It was assumed that landscape properties changed after the fire suggest a flow increase. These changes were used to assess the model parameters which allowed for better model performance in the post-fire period.

Inhibition of milk ejection in cows by oxytocin receptor blockade, α-adrenergic receptor stimulation and in unfamiliar surroundings

1997 ◽  
Vol 64 (3) ◽  
pp. 315-325 ◽  
Author(s):  
RUPERT M. BRUCKMAIER ◽  
OLGA WELLNITZ ◽  
JÜRG W. BLUM
Keyword(s):  
Adrenergic Receptor ◽  
Peak Flow ◽  
Oxytocin Receptor ◽  
Receptor Blockade ◽  
Milk Ejection ◽  
Receptor Stimulation ◽  
Flow Rates ◽  
Milk Flow ◽  
Drug Treatments ◽  
Similar Peak

Inhibition of milk ejection in cows by oxytocin receptor blockade (Atosiban) and α-adrenergic receptor stimulation (phenylephrine) prior to prestimulation was compared with inhibition of milk ejection in unfamiliar surroundings. In addition, Atosiban and phenylephrine were administered after a 1 min prestimulation or 1 min after the start of milking. Oxytocin concentrations increased during milking in all treatments. The spontaneously removed milk fraction (before oxytocin was injected) was similar for Atosiban and phenylephrine treatments and in unfamiliar surroundings, but lower than in controls. Peak flow rates were similar in all treatments, but reduced as compared with controls when phenylephrine and Atosiban were administered before prestimulation. Peripheral (Atosiban, phenylephrine) and central (unfamiliar surroundings) inhibition of milk ejection reduced the amount of available milk similarly. Drug treatments resulted in similar peak flow rates; however, teats were contracted after phenylephrine administration but not after Atosiban. The inhibition induced by Atosiban could be abolished by oxytocin injection, but not that induced by phenylephrine, which was antagonized by α-adrenergic receptor blockade. These results indicate that inhibition of milk ejection through activation of α-adrenergic receptors is based on blockade of milk flow into the cistern, but not through the teats.

Sign in / Sign up

Export Citation Format

Share Document