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.

Effects of α- and β-adrenergic receptor stimulation and oxytocin receptor blockade on milking characteristics in dairy cows before and after removal of the teat sphincter

2003 ◽  
Vol 70 (3) ◽  
pp. 289-292 ◽  
Author(s):  
Tyra Inderwies ◽  
Johannes Riedl ◽  
Evangelos Kiossis ◽  
Rupert M. Bruckmaier
Keyword(s):  
Milk Yield ◽  
Adrenergic Receptor ◽  
Peak Flow ◽  
Muscle Tone ◽  
Blocking Agent ◽  
Receptor Blockade ◽  
Adrenergic Stimulation ◽  
Receptor Stimulation ◽  
Milk Flow ◽  
Before And After

Alpha (α)- and beta (β)-adrenergic receptors in the bovine mammary gland are mainly present in the teat muscles and in the region where large milk ducts reach the cisternal cavities. The aim of the study was to test the hypothesis that the region of the large mammary ducts is the most important location of α- and β-adrenergic receptor stimulation affecting milk ejection and milk removal. Effects of α- and β-adrenergic receptor stimulation and of oxytocin (OT) receptor blockade on milking characteristics were tested in six cows. Milk flow was measured before and after the distal part of one teat, including the teat canal and teat sphincter, had been partly amputated. Before the operation, milk yield and peak flow rate decreased during α-adrenergic receptor stimulation and during the OT receptor blockade, and increased during β-adrenergic stimulation. After removal of the teat tip, relations of milk yield and peak flow rates after administration of α- and β-agonists and after application of an OT receptor blocking agent were similar to those before operation. Only total milk yield had decreased in the teat-amputated quarter owing to unhindered flow of cisternal milk before cluster attachment. Since responses to α- and β-adrenergic receptor stimulation as well as to OT receptor blockade do not differ with or without the teat sphincter, it is concluded that milk flow is mainly influenced by the muscle tone of the large mammary ducts.

scholarly journals Reduced claw vacuum and b-phase during low milk flow does not impact oxytocin release and milking performance

2017 ◽  
Vol 85 (1) ◽  
pp. 70-77
Author(s):  
Anna-Lena Neuheuser ◽  
Ann-Catherine Schwinn ◽  
Olga Wellnitz ◽  
Lorenzo E. Hernández-Castellano ◽  
Rupert M. Bruckmaier
Keyword(s):  
Wall Thickness ◽  
Cross Sections ◽  
Peak Flow ◽  
Milk Ejection ◽  
Flow Curves ◽  
Flow Rates ◽  
Milk Flow ◽  
Oxytocin Release

Oxytocin release, milking characteristics, and teat condition were investigated with reduced claw vacuum and pulsation settings compared to milking at regular settings with or without pre-stimulation. The reduced vacuum and pulsation settings during low milk flow are expected to protect the teat tissue before the occurrence of milk ejection at the start of milking, and at the end of milking during a potential overmilking period, i.e. at a milk flow <200 g/min. Seven cows were machine-milked either after a 60 s manual pre-stimulation, or without pre-stimulation and reduced vacuum and pulsation settings, or at full vacuum and normal pulsation during the start of milking. Plasma oxytocin (OT) concentration increased similarly in response to manual pre-stimulation and to both milking with reduced, or with full vacuum and pulsation settings, however delayed by 1 min if the cluster was attached without pre-stimulation. In all treatments OT concentrations remained elevated throughout milking. Milk flow curves were mostly non-bimodal at milkings after manual pre-stimulation and bimodal at milkings without pre-stimulation. The main milking time was shorter and average milk flow was higher during milking after pre-stimulation, but did not differ between treatments without pre-stimulation. Milk yields and peak flow rates were not affected by treatments. Either reduced or full vacuum settings were again applied during an intended overmilking from 200 to 100 g/min of milk flow towards the end of milk harvest. Pre-milking teat ultrasound cross sections were recorded one day before the experiment started. Post-milking ultrasound cross sections were performed at 15 min after each experimental milking. Teat wall thickness was increased after milking as compared to pre-milking but did not differ among treatments. In conclusion, OT release and milking performance are similar if milking is performed with pre-stimulation, or without pre-stimulation but reduced claw vacuum and b-phase during low milk flow.

Influence of milk flow rate and streak canal length on new intramammary infection in dairy cows

1991 ◽  
Vol 58 (4) ◽  
pp. 383-388 ◽  
Author(s):  
Robert J. Grindal ◽  
Andrew W. Walton ◽  
J. Eric Hillerton
Keyword(s):  
Flow Rate ◽  
Peak Flow ◽  
Peak Flow Rate ◽  
Secondary Importance ◽  
Flow Rates ◽  
Intramammary Infection ◽  
Susceptibility To Infection ◽  
Milk Flow ◽  
Wide Range ◽  
Mastitis Control

SummaryEighteen cows with a wide range of quarter peak flow rates (0·35–2·22 kg/min) were inoculated with Streptococcus agalactiae and Str. dysgalactiae 4 mm into each streak canal every 3 d for 12 d. Thirty of the 72 quarters developed intramammary infection. Mean peak flow rate and length of streak canal of those quarters that became infected were 1·26 ± 0·08 kg/min (mean ± SEM) and 11·47 ± 0·41 mm respectively, compared with 1·01 ± 0·05 kg/min and 12·05 ± 0·35 mm for those that remained uninfected. Logistic regression analysis showed that the probability of infection increased significantly with the increase in peak flow rate (P = O·O1). The influence of streak canal length on new infection, after allowing for the effect of peak flow rate, was not significant at the 5% level (P = 0·07), suggesting that there may be an inverse relationship between teat duct length and infection, but that it is of secondary importance to peak flow rate. If increased mass of milk distends the teat duct by raising intramammary pressure, then quarter susceptibility to infection is further compromised. These results strongly suggest that the benefits of reduced infection from mastitis control, achieved despite dramatic increases in milk flow rate and milk yield, are significantly underestimated.

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.

scholarly journals Pre-milking mechanical teat stimulation and milking performance of dairy buffaloes in early lactation

2017 ◽  
Vol 48 (1) ◽  
pp. 53-55
Author(s):  
Francesco Maria Tangorra ◽  
Stefania Leonardi ◽  
Valerio Bronzo ◽  
Nicola Rota ◽  
Paolo Moroni
Keyword(s):  
Milk Yield ◽  
Flow Rate ◽  
Peak Flow ◽  
Early Lactation ◽  
Peak Flow Rate ◽  
Flow Rates ◽  
Enhancing Effect ◽  
Milk Flow ◽  
Total Milk ◽  
Automatic Removal

The objective of the present study was to investigate the effect of pre-milking mechanical teat stimulation on milk yield and milking performance of dairy buffaloes in early lactation. For this purpose, twenty-two healthy Italian Mediterranean buffaloes in their first to third lactation and in early lactation (<120 days in milk) were subjected to two treatments of teat stimulation: i) washing of the teats with water for about 5 s and attaching of the milking unit within 60 s, without any pre-milking massage (farm milking routine); ii) fast pulsation (FP), achieved by increasing pulsation rate to 120 pulsations per min during the first 60 s after application of teat cups. Each treatment lasted for 10 days and the following parameters were measured: milk yield (kg/milking), milk yield at 2 min after unit attachment (kg), time between milking unit attachment and its automatic removal (min), peak milk flow rate (kg/min), and milking time to reach peak flow rate (min). The average milk flow rate (kg/min) was calculated by dividing milk yield by the actual milking time. Milk yield was not affected by mechanical pre-stimulation and during the first 2 min of milking 20.2% and 19.6% of total milk yield were milked respectively when treatments 1 and 2 were applied. The time elapsed from attachment of the milking cluster until its automatic removal was less than 8 min both for buffaloes subjected to FP, and for buffaloes subjected just to washing of the teats before attaching the milking unit. FP stimulation did not show an enhancing effect on peak and average milk flow rates and on milking time to reach peak flow rate.

scholarly journals Machine milking of dairy goats during lactation: udder anatomy, milking characteristics, and blood concentrations of oxytocin and prolactin

1994 ◽  
Vol 61 (4) ◽  
pp. 457-466 ◽  
Author(s):  
Rupert M. Bruckmaier ◽  
Chantal Ritter ◽  
Dieter Schams ◽  
Jürg W. Blum
Keyword(s):  
Milk Yield ◽  
Cross Sections ◽  
Dairy Goats ◽  
Milk Ejection ◽  
Blood Concentrations ◽  
Flow Rates ◽  
Machine Milking ◽  
The Third ◽  
Milk Flow

SummaryForty-four goats were milked and milk flow recorded without or with 1 min manual prestimulation in early, mid and late lactation. Ultrasound measurements of cross sections of the whole mammary gland were performed in a water bath. In additional experiments with 15 goats, milk flow was recorded and frequent blood samples were taken for the determination of oxytocin and prolactin concentrations. Milk yield increased from the first to the third lactation and decreased markedly during the course of lactation. Average and peak milk flow rates were closely related to the actual milk yield. The ultrasound cisternal area was 27·4±1·5% of the entire udder half cross section. Milking characteristics were scarcely different without or with prestimulation, although oxytocin was released within 30 s after the start of prestimulation, whereas oxytocin concentrations without prestimulation increased only after the start of milking. Concentrations of prolactin were higher during July and August than in April, and increased similarly with or without prestimulation during milking. In contrast to dairy cows, prestimulation and an opportune release of oxytocin during milking does not significantly influence the course of milk flow in goats, and this is probably because large amounts of cisternal milk allow milk ejection to be induced only after the start of milking without causing bimodal or otherwise reduced 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.

Effects of α- and β-adrenergic agonists on intramammary pressure and milk flow in dairy cows

1991 ◽  
Vol 58 (4) ◽  
pp. 411-419 ◽  
Author(s):  
Rupert Bruckmaier ◽  
Harald Mayer ◽  
Dieter Schams
Keyword(s):  
Dairy Cows ◽  
Favourable Effect ◽  
Adrenergic Agonists ◽  
Adrenergic Agonist ◽  
Milk Ejection ◽  
Reflex Mechanism ◽  
Flow Rates ◽  
Inhibitory Mechanisms ◽  
Milk Flow ◽  
Milk Ejection Reflex

Summaryα-Adrenergic mimetics inhibit milk removal whereas β-adrenergic mimetics have a favourable effect upon milk removal in dairy cows. This work aimed to relate these effects to the milk ejection reflex mechanism and/or milk flow from the cisternal cavities only. The α-adrenergic agonist phenylephrine and the β-adrenergic agonist isoproterenol were injected prior to and after milk ejection. Applied after milk ejection, the phenylephrine treatment reduced intramammary pressure (IMP) and milk yield markedly. Phenylephrine application before milk ejection prevented IMP from rising during teat stimulation or after oxytocin injection. Milking produced small amounts of milk at minimal milk flow rates. The very different responses to phenylephrine application prior to and after milk ejection indicate separate adrenergic inhibitory mechanisms for milk ejection and milk flow. The application of the β-adrenergic agonist isoproterenol did not alter the IMP. Nevertheless, this compound improved milk removal by increasing milk flow. The observation of bimodal milk flow at milkings without preceding teat stimulation indicates a delayed milk ejection. Isoproterenol injection without teat stimulation enhanced milk flow rates, but the bimodality remained unchanged. We conclude that isoproterenol enhances milk flow without affectiiig milk ejection.

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