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Metabolism of phytoestrogens in dairy cows - effect of botanical composition of silages

Njastad, Kari Marie (2011) Metabolism of phytoestrogens in dairy cows - effect of botanical composition of silages. Masters thesis, Norwegian University of Life Sciences , Animal and Aqualcultural Sciences. . [Submitted]

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Metabolism of the isoflavones biochanin A, genistein, formononetin, daidzein, equol and prunetin, the lignans matairesinol, secoisolariciresinol, enterodiol and enterolactone and the coumestan coumestrol was investigated to study the metabolism of phytoestrogens in dairy cows, and the possibilities to influence the content in milk. Four Norwegian Red Cows where allocated in a 4x4 latin square with four different silages. Silages had different botanical composition; red clover, botanical diverse, perennial ryegrass and timothy. The concentration of phytoestrogens was measured in feeds, omasum phases, feces, urine and milk by using the liquid chromatography (LC)-mass spectrometry (MS)/MS technique. Metabolism in reticulorumen
and in digestive tract as well as apparent recovery in milk was calculated. Concentration of isoflavones was highest in red clover silage and lowest in timothy silage. For lignans it was the opposite. Phytoestrogens was extensively metabolized in reticulo-rumen. Biochanin A and genistein had the highest metabolism on the red clover diet and lowest on timothy. A number of unknown lignans was metabolized to the mammalian lignans enterodiol and enterolactone in the reticulo-rumen. When passing to omasum, isoflavones and coumestrol mainly followed large particles, while lignans was in greater extent evenly distributed between phases. Through the digestive system, differences in content of phytoestrogens between diets became smaller or disappeared. The concentration of isoflavones in milk was increasing with increasing intake. Red clover diet had the highest concentration of isoflavones in milk, with a dominance of equol. It appears that concentration of phytoestrogens in milk can be manipulated trough intake, but the effect is diminishing with increasing concentration in feeds.

EPrint Type:Thesis
Thesis Type:Masters
Keywords:isolvaones, lignans, milk, transfer rate, equol, enterolactone, PhytoMilk
Subjects: Animal husbandry > Production systems > Dairy cattle
Crop husbandry > Production systems > Pasture and forage crops
Food systems > Food security, food quality and human health
Animal husbandry > Feeding and growth
Research affiliation: European Union > CORE Organic > PHYTOMILK
Norway > NMBU - Norwegian University of Life Sciences
Norway > RCN - Research Council of Norway > Norsk mat fra sjø og land (MATPROGRAMMET)
Norway > Other organizations
Deposited By: Steinshamn, Dr Håvard
ID Code:18824
Deposited On:04 Jul 2011 14:41
Last Modified:04 Jul 2011 14:41
Document Language:English
Refereed:Submitted for peer-review but not yet accepted

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