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Impact force as a possible cause of mechanical transfer of bacteria to the interior of the cow's teat

Published online by Cambridge University Press:  01 June 2009

C. C. Thiel
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading
Carol L. Thomas
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading
D. R. Westgarth
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading
B. Reiter
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading

Summary

Using bacterial endotoxin as a tracer material, it has been shown that a jet of liquid impinging on the end of the teat for 1 min after milk flow had ceased during machine milking could force material past the barrier of the streak canal. Positive results were obtained when the maximum pressure at the centre of the impact area was about 0·25 bar, with a considerably higher frequency of positives at 0·3–0·5 bar. It seems possible that such impact pressures might occur during milking and cause transfer of infective material to the teat sinus. Impact force could arise when milk returned to the teatcup liner as the result of local or general conditions of instability in the milking machine vacuum.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1969

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References

REFERENCES

Andreae, U. (1954). Quoted in Johansson, I. (1962). Genetic Aspects of Dairy Cattle Breeding, p. 124. Edinburgh and London: Oliver and Boyd.Google Scholar
Andreae, U. (1958). Z. Tierzücht. ZüchtBiol. 71, 289.CrossRefGoogle Scholar
Babcock, S. U. (1889). Rep. Wis. agric. Exp. Stn no. 6, p. 42.Google Scholar
Caroll, E. J., Schalm, O. W. & Lasmanis, J. (1964). Am. J. med. Res. 25, 720.Google Scholar
Cowhig, M. J. & Nyhan, J. F. (1965). Anim. Prod. Div. Res. Report An Foras Talúntais, p. 36.Google Scholar
Cowhig, M. J. & Nyhan, J. F. (1966). Anim. Prod. Div. Res. Report An Foras Talúntais, p. 49.Google Scholar
Cowhig, M. J. & Nyhan, J. F. (1967). Anim. Prod. Div. Res. Report An Foras Talúntais, p. 60.Google Scholar
Dodd, F. H. & Neave, F. K. (1951). J. Dairy Res. 18, 240.CrossRefGoogle Scholar
Glover, F. A. & Thomas, C. L. (1968). Rep. natn. Inst. Res. Dairy.Google Scholar
Johansson, I. (1957). Z. Tierzücht. ZüchtBiol. 70, 233.Google Scholar
Johansson, I. & Korkman, N. (1952). Hereditas 38, 131.CrossRefGoogle Scholar
McDonald, J. S. (1968). Am. J. vet. Res. 29, 1315.Google Scholar
McDonald, J. S. (1969). Proc. Symp. Machine Milking 1968, p. 83. Reading: Nat. Inst. Res. Dairying.Google Scholar
McEwen, A. D. & Samuel, J. McA. (1946). Vet. Rec. 58, 485.Google Scholar
Murphy, J. M. (1944). Cornell Vet. 34, 64.Google Scholar
Nyhan, J. F. (1969). Proc. Symp. Machine Milking 1968, p. 71. Reading: Nat. Inst. Res. Dairying.Google Scholar
Phipps, L. W. (1968). J. Dairy Res. 35, 295.CrossRefGoogle Scholar
Reiter, B. & Oram, J. D. (1967). Nature, Lond. 216, 328.CrossRefGoogle Scholar
Ribi, E., Haskins, W. G., Landy, M. & Milner, K. C. (1961). J. exp. Med. 114, 647.CrossRefGoogle Scholar
Thiel, C. C. (1969). Proc. Symp. Machine Milking 1968, p. 99. Reading: Nat. Inst. Res. Dairying.Google Scholar
Tolle, A., Zeidler, H. & Heeschen, W. (1966). Milchwissenschaft 21, 93.Google Scholar