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. 1979 Mar;288:33–44.

Changes in mammary function at the onset of lactation in the goat: correlation with hormonal changes*

A J Davis 1, I R Fleet 1, Jane A Goode 1, Maureen H Hamon 1, Felicity M Maule Walker 1, M Peaker 1,†
PMCID: PMC1281413  PMID: 469721

Abstract

1. Changes in mammary function and plasma hormone concentrations during late pregnancy and the onset of lactation have been studied in conscious goats.

2. Mammary blood flow, oxygen consumption and glucose uptake increased markedly and significantly between 2 days and 0·5-1 day pre-partum.

3. The increase in mammary glucose uptake was relatively greater than that of oxygen consumption or blood flow.

4. The concentration of citrate in mammary secretion increased; the first significant change was apparent 0·5-1 day pre-partum but the main rise occurred after this time.

5. It is concluded that the marked increase in mammary glucose uptake 0·5-1 day before parturition indicates the time of onset of copious milk secretion.

6. The first significant increase in the concentration of unconjugated oestrogens in arterial plasma occurred 3 days pre-partum, whereas the first significant decrease in progesterone and increase in 13,14-dihydro-15-oxoprostaglandin F2α occurred 0·5-1 day pre-partum, thus coinciding with the mammary changes; there was also a peak in prolactin concentrations at the latter time.

7. The hormonal changes are discussed in relation to current concepts of the initiation of parturition and the onset of copious milk secretion in this species. It is suggested that the fall in plasma progesterone concentrations triggers milk secretion at high rates.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Burd L. I., Lemons J. A., Makowski E. L., Battaglia F. C., Meschia G. Relationship of mammary blood flow to parturition in the ewe. Am J Physiol. 1975 Sep;229(3):797–800. doi: 10.1152/ajplegacy.1975.229.3.797. [DOI] [PubMed] [Google Scholar]
  2. Buttle H. L., Forsyth I. A., Knaggs G. S. Plasma prolactin measured by radioimmunoassay and bioassay in pregnant and lactating goats and the occurrence of a placental lactogen. J Endocrinol. 1972 Jun;53(3):483–491. doi: 10.1677/joe.0.0530483. [DOI] [PubMed] [Google Scholar]
  3. Challis J. R., Heap R. B., Illingworth D. V. Concentrations of oestrogen and progesterone in the plasma of non-pregnant, pregnant and lactating guinea-pigs. J Endocrinol. 1971 Oct;51(2):333–345. doi: 10.1677/joe.0.0510333. [DOI] [PubMed] [Google Scholar]
  4. Currie W. B., Kelly P. A., Friesen H. G., Thorburn G. D. Caprine placental lactogen: levels of prolactin-like and growth hormone-like activities in the circulation of pregnant goats determined by radioreceptor assays. J Endocrinol. 1977 May;73(2):215–226. doi: 10.1677/joe.0.0730215. [DOI] [PubMed] [Google Scholar]
  5. Fleet I. R., Goode J. A., Hamon M. H., Laurie M. S., Linzell J. L., Peaker M. Secretory activity of goat mammary glands during pregnancy and the onset of lactation. J Physiol. 1975 Oct;251(3):763–773. doi: 10.1113/jphysiol.1975.sp011120. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Fleet I. R., Linzell J. L., Peaker M. The use of an autoanalyzer for the rapid analysis of milk constituents affected by subclinical mastitis. Br Vet J. 1972 Jun;128(6):297–300. doi: 10.1016/s0007-1935(17)36934-8. [DOI] [PubMed] [Google Scholar]
  7. Fleet I. R., Peaker M. Mammary function and its control at the cessation of lactation in the goat. J Physiol. 1978 Jun;279:491–507. doi: 10.1113/jphysiol.1978.sp012358. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Flint A. P., Kingston E. J., Robinson J. S., Thorburn G. D. Initiation of parturition in the goat: evidence for control by foetal glucocorticoid through activation of placental C21-steroid 17alpha-hydroxylase. J Endocrinol. 1978 Sep;78(3):367–378. doi: 10.1677/joe.0.0780367. [DOI] [PubMed] [Google Scholar]
  9. Hardwick D. C., Linzell J. L., Mepham T. B. The metabolism of acetate and glucose by the isolated perfused udder. 2. The contribution of acetate and glucose to carbon dioxide and milk constituents. Biochem J. 1963 Aug;88(2):213–220. doi: 10.1042/bj0880213. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Hart I. C. A solid phase radioimmunoassay for ovine and caprine prolactin using sepharose 6B: its application to the measurement of circulating levels of prolactin before and during parturition in the goat. J Endocrinol. 1972 Oct;55(1):51–62. doi: 10.1677/joe.0.0550051. [DOI] [PubMed] [Google Scholar]
  11. Hart I. C. Basal levels of prolactin in goat blood measured throughout a 24-h period by a rapid double antibody-solid phase radioimmunoassay. J Dairy Res. 1973 Jun;40(2):235–245. doi: 10.1017/s0022029900014564. [DOI] [PubMed] [Google Scholar]
  12. Heap R. B., Galil A. K., Harrison F. A., Jenkin G., Perry J. S. Progesterone and oestrogen in pregnancy and parturition: comparative aspects and hierarchical control. Ciba Found Symp. 1977;(47):127–157. doi: 10.1002/9780470720295.ch7. [DOI] [PubMed] [Google Scholar]
  13. Kjaersgaard P. Mammary blood flow ante and post partum in cows. Acta Vet Scand. 1968;9(2):180–181. doi: 10.1186/BF03547884. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. LINZELL J. L. Mammary-gland blood flow and oxygen, glucose and volatile fatty acid uptake in the conscious goat. J Physiol. 1960 Oct;153:492–509. doi: 10.1113/jphysiol.1960.sp006550. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Lindsay D. B., Setchell B. P. The oxidation of glucose, ketone bodies and acetate by the brain of normal and ketonaemic sheep. J Physiol. 1976 Aug;259(3):801–823. doi: 10.1113/jphysiol.1976.sp011496. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Linzell J. L. Measurement of udder volume in live goats as an index of mammary growth and function. J Dairy Sci. 1966 Mar;49(3):307–311. doi: 10.3168/jds.S0022-0302(66)87853-0. [DOI] [PubMed] [Google Scholar]
  17. Linzell J. L. Measurement of venous flow by continuous thermodilution and its application to measurement of mammary blood flow in the goat. Circ Res. 1966 Jun;18(6):745–754. doi: 10.1161/01.res.18.6.745. [DOI] [PubMed] [Google Scholar]
  18. Linzell J. L., Peaker M. Changes in colostrum composition and in the permeability of the mammary epithelium at about the time of parturition in the goat. J Physiol. 1974 Nov;243(1):129–151. doi: 10.1113/jphysiol.1974.sp010746. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Linzell J. L., Peaker M. Mechanism of milk secretion. Physiol Rev. 1971 Jul;51(3):564–597. doi: 10.1152/physrev.1971.51.3.564. [DOI] [PubMed] [Google Scholar]
  20. Linzell J. L., Peaker M. The distribution and movements of carbon dioxide, carbonic acid and bicarbonate between blood and milk in the goat. J Physiol. 1975 Jan;244(3):771–782. doi: 10.1113/jphysiol.1975.sp010825. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Mitchell M. D., Flint A. P., Turnbull A. C. Plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F during pregnancy in sheep. Prostaglandins. 1976 Feb;11(2):319–329. doi: 10.1016/0090-6980(76)90154-4. [DOI] [PubMed] [Google Scholar]
  22. Peaker M. Gestation period and litter size in the goat. Br Vet J. 1978 Jul-Aug;134(4):379–383. doi: 10.1016/s0007-1935(17)33441-3. [DOI] [PubMed] [Google Scholar]
  23. Peaker M., Linzell J. L. Citrate in milk: a harbinger of lactogenesis. Nature. 1975 Feb 6;253(5491):464–464. doi: 10.1038/253464a0. [DOI] [PubMed] [Google Scholar]
  24. Wright P. J., Jenkin G., Heap R. B., Walters D. E. Pituitary responsiveness to LH-RH and TRH and the effects of progesterone or progesterone and oestradiol treatment in anoestrous sheep. J Reprod Fertil. 1978 Mar;52(2):343–348. doi: 10.1530/jrf.0.0520343. [DOI] [PubMed] [Google Scholar]

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