Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-10T02:53:37.576Z Has data issue: false hasContentIssue false
  • English
  • Français

Milk yield in rats in relation to activity and size of the mammary secretory cell population

Published online by Cambridge University Press:  01 June 2009

Christopher H. Knight ,
Ann H. Docherty  and
Malcolm Peaker
Christopher H. Knight
Affiliation:
Hannah Research Institute, Ayr, Scotland, KA6 5HL
Ann H. Docherty
Affiliation:
Hannah Research Institute, Ayr, Scotland, KA6 5HL
Malcolm Peaker
Affiliation:
Hannah Research Institute, Ayr, Scotland, KA6 5HL
Get access Rights & Permissions [Opens in a new window]

Summary

An attempt was made to partition changes in milk yield during lactation in the rat between changes in the size of the secretory cell population and changes in cellular activity. Groups of rats were studied on d 2, 7, 14, 21 and 28 of lactation. Milk yield increased between d 2 and 7, less markedly between d 7 and 14 and decreased between d 14 and 21. Milk secretion had apparently ceased on d 28. Total mammary DNA (DNAt) and RNA (RNAt) increased from d 2 to 14. It is concluded that of the increase in milk yield between d 2 and 14, an increase in cell population accounted for 75% and an increase in cellular activity for 25%. A decrease in activity appeared to be entirely responsible for the decrease in yield between d 14 and 21.

Type
Original Articles
Information
Journal of Dairy Research , Volume 51 , Issue 1 , February 1984 , pp. 29 - 35
Copyright
Copyright © Proprietors of Journal of Dairy Research 1984

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

Baldwin, R. L. & Yang, Y. T. 1974 Enzymatic and metabolic changes in the development of lactation. In Lactation: a comprehensive, treatise vol. 1, pp. 349–411 (Eds Larson, B. L. and Smith, V. R.). New York: Academic PressGoogle Scholar
Baverstock, P. R., Spencer, L. & Pollard, C. 1976 Water balance of small lactating rodents. II. Concentration and composition of milk of females on ad libitum and restricted water intakes. Comparative Biochemistry and Physiology 53A 47–52CrossRefGoogle Scholar
Campbell, R. C. 1967 Statistics for biologists. Cambridge: Cambridge University PressGoogle Scholar
Cowie, A. T., Forsyth, I. A. & Hart, I. C. 1980 Hormonal Control of Lactation. Berlin: Springer-Verlag.CrossRefGoogle ScholarPubMed
Griffith, D. R. & Turner, C. W. 1961 Normal growth of rat mammary glands during pregnancy and early lactation. Proceedings of the Society for Experimental Biology and Medicine 106 448–450CrossRefGoogle ScholarPubMed
Hanwell, A. & Linzell, J. L. 1972 A simple technique for measuring the rate of milk secretion in the rat. Comparative Biochemistry and Physiology 43A 259–270CrossRefGoogle Scholar
Hanwell, A. & Linzell, J. L. 1973 The effects of engorgement with milk and of suckling on mammary blood flow in the rat. Journal of Physiology 233 111–125CrossRefGoogle ScholarPubMed
Knight, C. H., Maltz, E. & Peaker, M. 1983 A simple technique for estimating milk yield in rats and mice. Journal of Physiology 336 73–74P.Google Scholar
Knight, C. H. & Peaker, M. 1982 a Development of the mammary gland. Journal of Reproduction and Fertility 65 521–536CrossRefGoogle ScholarPubMed
Knight, C. H. & Peaker, M. 1982 b Mammary cell proliferation in mice during pregnancy and lactation in relation to milk yield. Quarterly Journal of Experimental Physiology 67 165–177CrossRefGoogle ScholarPubMed
Knight, C. H. & Peaker, M. 1982 c Mammary development in mice: effects of hemihysterectomy in pregnancy and of litter size post partum. Journal of Physiology 327 17–27CrossRefGoogle ScholarPubMed
Tucker, H. A. 1966 Regulation of mammary nucleic acid content by various suckling intensities. American Journal of Physiology 210 1209–1214CrossRefGoogle ScholarPubMed