Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-26T22:51:22.208Z Has data issue: false hasContentIssue false
  • English
  • Français

Bromocriptine treatment of periparturient goats: long-term suppression of prolactin and lack of effect on lactation

Published online by Cambridge University Press:  01 June 2009

Isabel A. Forsyth  and
Philip D. Lee
Isabel A. Forsyth
Affiliation:
Department of Cell Biology, AFRC Institute of Animal Physiology and Genetics Research, Cambridge Research Station, Babraham, Cambridge CB2 4AT, UK
Philip D. Lee
Affiliation:
Department of Cell Biology, AFRC Institute of Animal Physiology and Genetics Research, Cambridge Research Station, Babraham, Cambridge CB2 4AT, UK
Get access Rights & Permissions [Opens in a new window]

Summary

British Saanen dairy goats (n = 10) were treated with bromocriptine or vehicle from day 147 of pregnancy to day 4 post partum, a treatment duration of 8·8±1·7 d (mean ± SEM). The periparturient prolactin surge was abolished by this treatment, but there were no significant effects on plasma growth hormone or insulin concentrations. Lactogenesis was delayed in the bromocriptine-treated goats, milk yields being significantly depressed (P < 0·01) for the first week of lactation. Yields had recovered to control values by day 10 when prolactin concentrations were still significantly depressed. Mammary gland biopsies were taken on day 4 post partum from five animals in each group. Using this tissue, no significant differences could be shown in mammary morphology or DNA synthesis, but the RNA:DNA ratio was significantly reduced (P < 0·05). After week 1, there were no significant differences between bromocriptine-treated and control goats in milk yield, milk composition, udder volume, time of peak yield or persistence. The goats given short-term bromocriptine treatment at parturition showed prolonged effects on prolactin secretion, their seasonal prolactin rise being severely blunted (P < 0·001). A normal lactation is therefore not prevented in goats by a delay in lactogenesis, suppression of prolactin at parturition or the resulting prolonged depression of circulating prolactin. Goats in established lactation given bromocriptine for 8 d showed, by contrast, a rapid recovery of plasma prolactin concentrations within 5 d post treatment. Milk yield declined significantly (P < 0·03) compared with pretreatment values during and for 1 week after bromocriptine but then began to recover, with no significant change in vehicle-treated goats.

Type
Original Articles
Information
Journal of Dairy Research , Volume 60 , Issue 3 , August 1993 , pp. 307 - 317
Copyright
Copyright © Proprietors of Journal of Dairy Research 1993

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

Akers, R. M. 1985 Lactogenic hormones: binding sites, mammary growth, secretory cell differentiation, and milk biosynthesis in ruminants. Journal of Dairy Science 68 501–519CrossRefGoogle ScholarPubMed
Akers, R. M., Bauman, D. E., Capuco, A. V., Goodman, G. T. & Tucker, H. A. 1981 a Prolactin regulation of milk secretion and biochemical differentiation of mammary epithelial cells in periparturient cows. Endocrinology 109 23–30CrossRefGoogle ScholarPubMed
Akers, R. M., Bauman, D. E., Goodman, G. T., Capuco, A. V. & Tucker, H. A. 1981 b Prolactin regulation of cytological differentiation of mammary epithelial cells in periparturient cows. Endocrinology 109 31–40CrossRefGoogle ScholarPubMed
Bauman, D. E., Eppard, P. J., DeGeeter, M. J. & Lanza, G. M. 1985 Responses of high-producing dairy cows to long-term treatment with pituitary somatotropin and recombinant somatotropin. Journal of Dairy Science 68 1352–1362CrossRefGoogle ScholarPubMed
Beck, N. F. G., Tucker, H. A. & Oxender, W. D. 1979 Mammary arterial and venous concentrations of prolactin in lactating cows after milking or administration of thyrotropin-releasing hormone or ergocryptine. Endocrinology 104 111–117CrossRefGoogle ScholarPubMed
Choi, Y. J., Keller, W. L., Berg, I. E., Park, C. S. & Mackinlay, A. G. 1988 Casein gene expression in bovine mammary gland. Journal of Dairy Science 71 2898–2903CrossRefGoogle ScholarPubMed
Currie, W. B., Card, C. E., Michel, F. J. & Ignotz, G. 1990 Purification, partial characterization, and development of a specific radioimmunoassay for goat placental lactogen. Journal of Reproduction and Fertility 90 25–36CrossRefGoogle ScholarPubMed
Davis, A. J., Maule, Walker F. M. & Saunders, J. C. 1983 The role of prolactin in the control of the onset of copious milk secretion in the goat. Journal of Physiology 341 83PGoogle Scholar
Dils, R. R. & Forsyth, I. A. 1981 Preparation and culture of mammary gland expiants. Methods in Enzymology 72 724–742CrossRefGoogle Scholar
Fleet, I. R., Goode, J. A., Hamon, M. H., Laurie, M. S., Linzell, J. L. & Peaker, M. 1975 Secretory activity of goat mammary glands during pregnancy and the onset of lactation. Journal of Physiology 251 763–773CrossRefGoogle ScholarPubMed
Flint, A. P. F., Kingston, E. J., Robinson, J. S. & Thorburn, G. D. 1978 Initiation of parturition in the goat: evidence for control by foetal glucocorticoids through activation of placental Cy21-steroid 17α- hydroxylase. Journal of Endocrinology 78 367–378CrossRefGoogle ScholarPubMed
Forsyth, I. A., Byatt, J. C. & Iley, S. 1985 Hormone concentrations, mammary development and milk yield in goats given long-term bromoeriptine treatment in pregnancy. Journal of Endocrinology 104 77–85CrossRefGoogle ScholarPubMed
Forsyth, I. A. & Turvey, A. 1983 Fatty acid synthesis by expiant cultures from the mammary glands of goats on days 60 and 120 of pregnancy. Journal of Endocrinology 100 87–92CrossRefGoogle Scholar
Gow, C. B., McDowell, G. H. & Jenkin, G. 1983 The importance of prolactin for initiation of lactation in the pregnant ewe. Australian Journal of Biological Sciences 36 357–367CrossRefGoogle ScholarPubMed
Hart, I. C. 1973 Effect of 2-bromo-α-ergocryptine on milk yield and the level of prolactin and growth hormone in the blood of the goat at milking. Journal of Endocrinology 57 179–180CrossRefGoogle Scholar
Hart, I. C. 1974 The relationship between lactation and the release of prolactin and growth hormone in the goat. Journal of Reproduction and Fertility 39 485–499CrossRefGoogle ScholarPubMed
Hart, I. C. 1988 Altering the efficiency of milk production in dairy cows with somatotrophin. In Nutrition and Lactation in the Dairy Cow, pp. 232–247 (Ed. Garnsworthy, P. C.). London: Butterworths (Nottingham University Easter School in Agricultural Sciences 46)CrossRefGoogle Scholar
Hooley, R. D., Campbell, J. J. & Findlay, J. K. 1978 The importance of prolactin for lactation in the ewe. Journal of Endocrinology 79 301–310CrossRefGoogle ScholarPubMed
Johke, T. 1986 Prolactin secretion and lactogenesis in dairy cows and goats. Vlaams Diergeneeskundig Tijdschrift 55 251–257Google Scholar
Johke, T. & Hodate, K. 1978 Effects of CB154 on serum hormone levels and lactogenesis in dairy cows. Endocrinologia Japanica 25 67–74CrossRefGoogle ScholarPubMed
Karg, H., Schams, D. & Reinhardt, V. 1972 Effects of 2-Br-α-ergoeryptine on plasma prolactin level and milk yield in cows. Experientia 28 574–576CrossRefGoogle ScholarPubMed
Lamberts, S. W. J. & Macleod, R. M. 1990 Regulation of prolactin secretion at the level of the lactotroph. Physiological Reviews 70 279–318CrossRefGoogle ScholarPubMed
Linzell, J. 1966 Measurement of udder volume in live goats as an index of mammary growth and function. Journal of Dairy Science 49 307–311CrossRefGoogle Scholar
Lloyd, H. M., Mears, J. D. & Jacobi, J. 1975 Effects of oestrogen and bromocriptine on in vivo secretion and mitosis in prolactin cells. Nature 255 497–498CrossRefGoogle ScholarPubMed
Malven, P. V. 1983 Transfer of prolactin from plasma into milk and associated physiological benefits to mammary cells. Endocrinologica Experimentalis 17 283–299Google ScholarPubMed
Maule, Walker F. M. 1983 Lactation and fertility in goats after the induction of parturition with an analogue of prostaglandin F2α, cloprostenol. Research in Veterinary Science 34 280–286CrossRefGoogle Scholar
Munro, H. N. & Fleck, A. 1966 Recent developments in the measurement of nucleic acids in biological materials. Analyst 91 78–88CrossRefGoogle ScholarPubMed
Prysor-Jones, R. A. & Jenkins, J. S. 1981 Effect of bromocriptine on DNA synthesis, growth and hormone secretion of spontaneous pituitary tumours in the rat. Journal of Endocrinology 88 463–469CrossRefGoogle ScholarPubMed
Schams, D., Reinhardt, V. & Karg, H. 1972 Effects of 2-Br-α-ergocriptine on plasma prolactin level during parturition and onset of lactation in cows. Experientia 28 697–699CrossRefGoogle Scholar
Smith, V. G., Beck, T. W., Convey, E. M. & Tucker, H. A. 1974 Bovine serum prolactin, growth hormone, cortisol and milk yield after ergocriptine. Neuroendocrinology 15 172–181CrossRefGoogle Scholar
Tindal, J. S., Blake, L. A., Simmonds, A. D., Hart, I. C. & Mizuno, H. 1982 Control of growth hormone release in goats: effects of vagai cooling, feeding and artificial distension of the rumen. Hormone and Metabolic Research 14 425–429CrossRefGoogle Scholar
Tindal, J. S., Knaggs, G. S., Hart, I. C. & Blake, L. A. 1978 Release of growth hormone in lactating and non-lactating goats in relation to behaviour, stages of sleep, electroencephalograms, environmental stimuli and levels of prolactin, insulin, glucose and free fatty acids in the circulation. Journal of Endocrinology 76 333–346CrossRefGoogle ScholarPubMed
Wilde, C. H., Calvert, D. T., Daly, A. & Peaker, M. 1987 The effect of goat milk fractions on synthesis of milk constituents by rabbit mammary expiants and on milk yield in vivo. Evidence for autocrine control of milk secretion. Biochemical Journal 242 285–288CrossRefGoogle Scholar
Winder, S. J., Turvey, A. & Forsyth, I. A. 1989 Stimulation of DNA synthesis in cultures of ovine mammary epithelial cells by insulin and insulin-like growth factors. Journal of Endocrinology 123 319–326CrossRefGoogle ScholarPubMed