Metabolism of grazed vs. zero‐grazed dairy cows throughout the vegetation period: hepatic and blood plasma parameters
Grass may have a differential impact on the metabolism of the dairy cow, depending on the grazing system applied. In this study, the hypothesis was tested that metabolism of grazed vs. zero‐grazed dairy cows is differently regulated throughout the vegetation period. The study included three experime...
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Published in | Journal of animal physiology and animal nutrition Vol. 96; no. 2; pp. 228 - 236 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Publishing Ltd
01.04.2012
Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Grass may have a differential impact on the metabolism of the dairy cow, depending on the grazing system applied. In this study, the hypothesis was tested that metabolism of grazed vs. zero‐grazed dairy cows is differently regulated throughout the vegetation period. The study included three experimental periods (p1, p2 and p3) of 14 days each, and two treatments [grazing from pasture, PASTURE, n = 9; or zero‐grazing in a free‐stall barn (BARN, n = 9)]. Blood and liver samples were collected at the end of each period when the cows were on average 64, 120 and 197 DIM. Concentrations of metabolites and hormones, and activities of various enzymes were determined in plasma. Liver samples were measured for mRNA abundance of genes encoding enzymes and nuclear receptors involved in metabolic pathways. PASTURE cows had higher plasma concentrations of T3, BHB, and total protein than BARN cows across periods (p < 0.05). BARN cows had higher concentrations of NEFA (in p1) and urea (in p1 and p2) in relation PASTURE cows (p < 0.05), and had higher mRNA abundance of liver‐X‐receptor‐α and glycerol‐3‐phosphate‐acyltransferase across periods (p < 0.05). The results confirm the hypothesis that metabolism is different between BARN and PASTURE cows throughout the vegetation period, and show that the observed differences are mainly reflected in parameters of lipid metabolism. |
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Bibliography: | http://dx.doi.org/10.1111/j.1439-0396.2011.01142.x istex:BBA08E2507AFA075F91BA847286039C8BB66F9A5 ark:/67375/WNG-H7FL3KJ9-C ArticleID:JPN1142 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0931-2439 1439-0396 |
DOI: | 10.1111/j.1439-0396.2011.01142.x |