Publikationsdatenbank

Assessment of magnesium intake according to requirement in dairy cows (2019)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Martens, Holger (WE 2)

Stumpff, Friederike (WE 2)

Quelle

Journal of animal physiology and animal nutrition : official journal of the European Society of Veterinary and Comparative Nutrition and the American Academy of Veterinary Nutrition

Bandzählung: 103

Heftzählung: 4

Seiten: 1023 – 1029

ISSN: 0931-2439

Sprache

Englisch

Verweise

URL (Volltext): https://onlinelibrary.wiley.com/doi/full/10.1111/jpn.13106

DOI: 10.1111/jpn.13106

Pubmed: 31025783

Kontakt

Institut für Veterinär-Physiologie

Oertzenweg 19 b
14163 Berlin
+49 30 838 62600
physiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

To date, no specific hormonal regulation system has been identified for homoeostatic control of the essential mineral Mg. In cattle, the maintenance of physiological plasma Mg concentration depends on gastrointestinal absorption, primarily from the rumen, which serves as a pool for covering the requirement. Whereas a possible surplus (absorption greater than requirement) is rapidly excreted by the kidneys, a shortage (absorption lower than requirement) cannot be compensated for by mobilization from the large Mg pool in bones or soft tissue, so that the maintenance of the necessary physiological Mg concentration in plasma relies on continuous and sufficient absorption. Our knowledge concerning the site and mechanisms of Mg absorption has improved during the last few decades, and meta-analyses of the absorption of Mg in dairy cows have shown that the K content has a pronounced negative effect on Mg digestibility. The current recommendations of Mg intake propose a constant percentage of Mg and emphasize the depressive effect of high potassium (K) intake on Mg absorption. The current knowledge about the antagonism between K intake and Mg absorption allows a more flexible solution which includes the K content of the diet. An assessment of Mg intake is proposed that incorporates the improved knowledge of Mg absorption, metabolism and requirement. Within this framework, an equation is derived that allows a prediction of the amount of Mg required to compensate for dietary K content, the goal being to avoid both possible undernutrition or an unnecessary surplus of dietary Mg.