Effect of the prolactin-release inhibitor quinagolide on lactating dairy cows

Lacasse, P.; Lollivier, V.; Bruckmaier, R.M.; Boisclair, Y.R.; Wagner, G.F.; Boutinaud, M. (2011). Effect of the prolactin-release inhibitor quinagolide on lactating dairy cows. Journal of dairy science, 94(3), pp. 1302-9. Savoy, Ill.: American Dairy Science Association 10.3168/jds.2010-3649

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In most mammals, prolactin (PRL) is essential for maintaining lactation, and yet the short-term suppression of PRL during established lactation by bromocriptine has produced inconsistent effects on milk yield in cows and goats. To assess the effect of the long-term inhibition of PRL release in lactating dairy cows, 5 Holstein cows in early lactation received daily intramuscular injections of 1mg of the PRL-release inhibitor quinagolide for 9 wk. Four control cows received the vehicle (water) only. During the last week of the treatments, one udder half was milked once a day (1x) and the other twice a day (2x). Blood samples were harvested at milking in wk -1, 1, 4, and 8. The daily injections of quinagolide reduced milking-induced PRL release but not the basal PRL concentration. Quinagolide induced a faster decline in milk production, which was about 5.3 kg/d lower in the quinagolide-treated cows during the last 4 wk of treatment. During wk 9, the inhibition of milk production by quinagolide was maintained in the udder half that was milked 2x but not in the half milked 1x. Milk production was significantly correlated with the quantity of PRL released at milking. Quinagolide did not affect the release of oxytocin at milking. Serum concentration of insulin-like growth factor-1 was not affected by treatment or correlated with milk production. Serum concentrations of leptin and the calciotropic hormone stanniocalcin were not affected by the treatment. In conclusion, the chronic administration of the PRL-release inhibitor quinagolide decreases milk production in dairy cows. The effect is likely the result of the reduced release of milking-induced PRL and is modulated at the level of the gland by milking frequency.

Item Type:	Journal Article (Original Article)
Division/Institute:	05 Veterinary Medicine > Department of Clinical Research and Veterinary Public Health (DCR-VPH) > Veterinary Physiology
UniBE Contributor:	Bruckmaier, Rupert
ISSN:	0022-0302
Publisher:	American Dairy Science Association
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:32
Last Modified:	05 Dec 2022 14:10
Publisher DOI:	10.3168/jds.2010-3649
Web of Science ID:	000287473500023
URI:	https://boris.unibe.ch/id/eprint/12246 (FactScience: 218558)