Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-16T15:03:49.377Z Has data issue: false hasContentIssue false
  • English
  • Français

651. The lactose-chloride contributions to the freezing-point depression of milk: II. Examination of partial contributions over the full lactation period of two cows

Published online by Cambridge University Press:  01 June 2009

E. R. Cole ,
J. B. Douglas  and
M. Mead
E. R. Cole
Affiliation:
N.S.W. University of Technology, Broadway, Sydney, Australia
J. B. Douglas
Affiliation:
N.S.W. University of Technology, Broadway, Sydney, Australia
M. Mead
Affiliation:
N.S.W. University of Technology, Broadway, Sydney, Australia
Get access Rights & Permissions [Opens in a new window]

Extract

1. In testing the technique of using conversion factors (from determined concentration) for the calculation of the partial freezing-point depressions of lactose and chloride, regular weekly chemical analyses and freezing-point determinations have been made on the milk of one Jersey and one Friesian cow over a period of 7 months.

2. Relative constancy of freezing-point has again been noted, but slight though consistent differences were present between the milks of the two cows. No seasonal variations were observed, but changes in the freezing-point depression for the milk of one were generally associated with corresponding changes for the milk of the other.

3. Linear relationships were found and their adequacy tested between the partial depressions due to lactose and chloride for each animal. The relationships, though not statistically significantly different, differed considerably for each animal. It is suggested that formulae for the calculation of one of the constituents, lactose or chloride, from the determined amount of the other, need to be treated with caution in view of the results obtained for the two animals in this work.

For the Jersey milk it was found that 80% of the total freezing-point depression was due to the lactose and chloride content (on a fat and protein-free basis). For the Friesian milk, indications were that the lactose-chloride contribution was of the order of 75% of the total depression, but the result of statistical analysis was less satisfactory for this milk.

The co-operation of Mr J. McGibbon of the Hawkesbury Agricultural College is gratefully acknowledged. Thanks are due also to Mr J. V. Pascoe and the Dairy Farmers Co-operative Milk Co. Ltd. for their continued interest in the work.

Type
Original Articles
Information
Journal of Dairy Research , Volume 24 , Issue 1 , February 1957 , pp. 33 - 42
Copyright
Copyright © Proprietors of Journal of Dairy Research 1957

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

(1)Monier-Williams, G. W. (1933). Analyst, 58, 254.CrossRefGoogle Scholar
(2)Stubbs, J. R. & Elsdon, G. D. (1934). Analyst, 59, 146.CrossRefGoogle Scholar
(3)Denis-Lester, L. (1936). Bull. Dep. Agric. & Forestry S. Afr. no. 143.Google Scholar
(4)Denis-Lester, L. (1936). Bull. Dep. Agric. & Forestry S. Afr. no. 156.Google Scholar
(5)Denis-Lester, L. (1936). Bull. Dep. Agric. & Forestry S. Afr. no. 157.Google Scholar
(6)Richmond, H. D., Elsdon, G. D. & Walker, G. H. (1942). Dairy Chemistry, 4th ed. p. 103. london: Griffin.Google Scholar
(7)Golding, J., Mackintosh, J. & Mattick, E. C. V. (1935). J. Dairy Res. 6, 6.CrossRefGoogle Scholar
(8)Aschaffenburg, R. & Temple, P. L. (1941) J. Dairy Res. 12, 315.CrossRefGoogle Scholar
(9)Aschaffenburg, R. & Veinoglou, B. C. (1944). J. Dairy Res. 13, 267.CrossRefGoogle Scholar
(10)Scott-Dodd, A. & Cowan, R. (1943). Analyst, 68, 146.CrossRefGoogle Scholar
(11)Rowland, S. J., Aschaffenburg, R. & Veinoglou, B. C. (1943). Analyst, 68, 302.CrossRefGoogle Scholar
(12)Davies, W. L. (1939). The Chemistry of Milk, pp. 18, 44, 2nd ed. London: Chapman and Hall.Google Scholar
(13)Tocher, J. F. (1930). Variations in the Composition of Milk. London: H.M.S.O.Google Scholar
(14)Caulfield, W. J. & Riddell, W. H. (1935). Cornell Vet. 25, 333. (J. Dairy Res. 9, 102.)Google Scholar
(15)Davies, W. L. (1935). J. Dairy Res. 6, 363.CrossRefGoogle Scholar
(16)Davies, W. L. (1938). J. Dairy Res. 9, 327.CrossRefGoogle Scholar
(17)Blood, J. W. & Rowland, A. (1936). J. Dairy Res. 7, 47.CrossRefGoogle Scholar
(18)Mead, M. (1952). Aust. J. Dairy Tech. 7, 77.Google Scholar
(19)Davies, W. L. (1933). J. Dairy Res. 4, 275.Google Scholar
(20)Peskett, G. L. & Folley, S. J. (1933). J. Dairy Res. 4, 279.CrossRefGoogle Scholar
(21)Davies, W. L. (1939). The Chemistry of Milk, 2nd ed. p. 49. London: Chapman and Hall.Google Scholar
(22)Barry, J. M. & Rowland, S. J. (1953). Biochem. J. 54, 575.CrossRefGoogle Scholar
(23)Cole, E. R. & Mead, M. (1955). J. Dairy Res. 22, 340.CrossRefGoogle Scholar