Hypertonic NaCl infusions affect milk composition in goats

Olsson, Kerstin; Mengistu, Urge; Stein, Jennie; Bekele, Tafesse; Bruckmaier, Rupert M (2006). Hypertonic NaCl infusions affect milk composition in goats. Journal of dairy research, 73(3), pp. 306-11. London: Cambridge University Press 10.1017/S0022029906001828

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The capability of goats to maintain milk production during water deprivation is remarkable and not yet fully understood. The aim of the present study was to investigate whether intravenous infusions of hypertonic NaCl cause release of both vasopressin and oxytocin and whether the peptides, in combination with the hyperosmolality, affect milk flow and milk composition. Six Swedish domestic landrace goats in their first to third lactation were milked every 30 min during experiments. Hypertonic NaCl (HNaCl) or isotonic NaCl (IsoNaCl) were infused for 90 min. Goats were not allowed to drink during infusions. Plasma vasopressin concentration increased during HNaCl infusions, and did not change in response to IsoNaCl infusions. Plasma oxytocin concentration did not change during either infusion. Milk flow was maintained during the infusions. Milk fat concentration decreased in the three samples taken before onset of the infusions, but then increased gradually during HNaCl infusions, while it continued to fall during the IsoNaCl infusions. Milk osmolality followed the rise in plasma osmolality during the HNaCl infusions and did not change in IsoNaCl experiments. Milk lactose concentration increased throughout both series of experiments, the concentration being higher during HNaCl infusions. Milk protein concentration did not change during HNaCl infusions, but fell in the IsoNaCl experiments. It is concluded that the hyperosmolality in combination with elevated plasma vasopressin levels did not disturb the secretory activity of the mammary cells, but rather facilitated emptying of the alveolar milk. Such a mechanism may help to explain the sustained milk production in water deprived goats.

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:

0022-0299

Publisher:

Cambridge University Press

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:45

Last Modified:

04 May 2014 23:13

Publisher DOI:

10.1017/S0022029906001828

PubMed ID:

16569280

Web of Science ID:

000239939600008

URI:

https://boris.unibe.ch/id/eprint/18750 (FactScience: 988)

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