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Continuously elevated concentrations of oxytocin during milking are necessary for complete milk removal in dairy cows

Published online by Cambridge University Press:  01 June 2009

Rupert M. Bruckmaier
Affiliation:
Institut für Tierzucht der Universität Bern, CH-3012 Bern, Schweiz
Dieter Schams
Affiliation:
Institut für Physiologie der Technischen Universität München, D-85354 Freising-Weihenstephan, Deutschland
Jürg W. Blum
Affiliation:
Institut für Tierzucht der Universität Bern, CH-3012 Bern, Schweiz

Summary

The importance of elevated concentrations of oxytocin (OT) during the entire milking period was investigated in seven primiparous dairy cows with inherent disturbed milk ejection and in sixteen healthy cows with disturbed milk ejection induced by placing them in an operating theatre. Disturbance of milk removal in both groups has previously been demonstrated to be exclusively due to central blockage of the expected OT release in response to teat stimulation and milking. However, milk ejection can be induced by exogenous OT. OT (0·2 i.u.) was injected i.v. before milking and 49 ± 6% of the total milk was removed. When plasma OT decreased, milk flow stopped. In response to a second and third injection of 0·2 i.u. OT, 30 ± 4 and 7 ± 2% of the milk were removed respectively. The remaining milk was removed with 10 i.u. OT. The lag time from injection of OT to the start of milk flow was inversely correlated with the amount of milk actually removed in response to the OT injection. If 0·2 i.u. OT was injected during intramammary pressure (IMP) recording, IMP immediately increased to its maximum value. After 2·5 ± 0·3 min, IMP decreased to an intermediate IMP (between preinjection and maximum IMP). After two additional injections of 0·2 i.u. OT and after injection of 0·5 i.u. OT, IMP increased to a similar maximum. However, after injection of 0·5 i.u. OT, maximum IMP lasted longer (2·9 ± 0·3 min; P < 0·05) than after injections of 0·2 i.u. If OT was continuously infused (0·15 i.u./min) during milking, milk flow lasted until the udder was completely emptied. IMP increased during OT infusion to a maximum which remained stable until infusion was stopped after 10 min. The same IMP maximum was reached after the first individual OT injection (0·2 i.u.), but when plasma OT decreased towards basal concentrations, milk flow ceased and IMP decreased to an intermediate level. Thus continuously elevated OT concentrations such as those during infusion or during normal milking are necessary for complete milk removal.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1994

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References

REFERENCES

Andreae, U. & Pfleiderer, U.-E. 1972 [Residual milk as a criterion of udder emptying in cows kept in tie-up type and cubicle-type cowsheds.] Milchwissenschaft 27 629634Google Scholar
Bruckmaier, R. M. 1988 [Oxytocin Release, Intramammary Pressure and Milk Production in the Cow in Relation to Stage, of Lactation and Effect of the Adrenergic System.] Thesis, Technische Universität München, Weihenstephan, GermanyGoogle Scholar
Bruckmaier, R. M. & Blum, J. W. 1992 B-mode ultrasonography of mammary glands in cows, goats and sheep during α- and β-adrenergic agonist and oxytoein administration. Journal of Dairy Research 59 151159CrossRefGoogle ScholarPubMed
Bruckmaier, R. M., Mayer, H. & Schams, D. 1991 Effects of α- and β-adrenergic agonists on intramammary pressure and milk flow in dairy cows. Journal of Dairy Research 58 411419CrossRefGoogle ScholarPubMed
Bruckmaier, R. M., Rothenanger, E. & Blum, J. W. 1994 Measurement of mammary gland cistern size and determination of the cisternal milk fraction in dairy cows. Milchwissenschaft In pressGoogle Scholar
Bruckmaier, R. M., Schams, D. & Blum, J. W. 1992 Aetiology of disturbed milk ejection in parturient primiparous cows. Journal of Dairy Research 59 479489CrossRefGoogle ScholarPubMed
Bruckmaier, R. M., Schams, D. & Blum, J. W. 1993 Milk removal in familiar and unfamiliar surroundings: concentrations of oxytocin, prolactin, cortisol and β-endorphin. Journal of Dairy Research 60 449456CrossRefGoogle ScholarPubMed
Gorewit, R. C. & Gassman, K. B. 1985 Effects of duration of udder stimulation on milking dynamics and oxytocin release. Journal of Dairy Science 68 18131818CrossRefGoogle ScholarPubMed
Gorewit, R. C., Svennersten, K., Butler, W. R. & Uvnäs-Moberg, K. 1992 Endocrine responses in cows milked by hand and machine. Journal of Dairy Science 75 443448CrossRefGoogle ScholarPubMed
Lefcourt, A. M. & Akers, R. M. 1991 Teat stimulation-induced oxytocin and catecholamine release in pregnant and lactating Holstein heifers. Domestic Animal Endocrinology 8 235243CrossRefGoogle ScholarPubMed
Mayer, H., Bruckmaier, R. M. & Schams, D. 1991 Lactational changes in oxytocin release, intramammary pressure and milking characteristics in dairy cows. Journal of Dairy Research 58 159169CrossRefGoogle ScholarPubMed
Mayer, H., Schams, D., Prokopp, A. & Worstorff, H. 1984 a Effects of manual stimulation and delayed milking on secretion of oxytocin and milking characteristics in dairy cows. Milchwissenschaft 39 666670Google Scholar
Mayer, H., Schams, D., Worstorff, H. & Prokopp, A. 1984 b Secretion of oxytocin and milk removal as affected by milking cows with and without manual stimulation. Journal of Endocrinology 103 355361CrossRefGoogle ScholarPubMed
Mayer, H., Worstorff, H., Schams, D. & Klein, M. 1985 Secretion of oxytocin and milking characteristics in cows as affected by several modes of tactile teat stimulation. Milchwissenschaft 40 15Google Scholar
Mielke, H. 1963 [Fractionated oxytocin release and milk ejection in the lactating cow.] Archiv für Experimentelle Veterinärmedizin 17 7390Google Scholar
Rajamannan, A. H. J., Linnerud, A. C. & Graham, E. F. 1966 Lactation studies. IX. Relationship of milk flow rate and complementary milk to milk yields in a herd of Holstein cattle. Journal of Dairy Science 49 3235CrossRefGoogle Scholar
Rasmussen, M. D., Frimer, E. S., Galton, D. M. & Petersson, L. G. 1992 The influence of premilking teat preparation and attachment delay on milk yield and milking performance. Journal of Dairy Science 75 21312141CrossRefGoogle Scholar
Sagi, R., Gorewit, R. C., Merrill, W. G. & Wilson, D. B. 1980 Premilking stimulation effects on milking performance and oxytocin and prolactin release in cows. Journal of Dairy Science 63 800806CrossRefGoogle ScholarPubMed
SAS 1990 SAS Users' Guide: Statistics. Cary, NC: SAS InstituteGoogle Scholar
Schams, D. 1983 Oxytocin determination by radioimmunoassay. III. Improvement to subpicogram sensitivity and application to blood levels in cyclic cattle. Acta Endocrinologica 103 180183Google ScholarPubMed
Schams, D., Mayer, H., Prokopp, A. & Worstorff, H. 1984 Oxytocin secretion during milking in dairy cows with regard to the variation and importance of a threshold level for milk removal. Journal of Endocrinology 102 337343CrossRefGoogle Scholar
Wachs, E. A., Gorewit, R. C. & Currie, W. B. 1984 Half-life, clearance and production rate for oxytocin in cattle during lactation and mammary involution. I. Domestic Animal Endocrinology 1 121140CrossRefGoogle Scholar
Wehowsky, C., Moritz, P., Tröger, F. & Lohr, H. 1986 [Deliberate initiation of incomplete alveolar milk ejections for determining the effect of stimuli.] Wissenschaftliche Zeitschrift der Karl-Marx-Univesität Leipzig, Mathemalisch-Naturwissenschaftliche Reihe 35 273282Google Scholar