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Effect of legume–grass silages and a-tocopherol supplementation on fatty acid composition and a-tocopherol, b-carotene and retinol concentrations in organically produced bovine milk

Höjer, Annika; Adler, Steffen; Martinsson, Kjell; Jensen, Søren K.; Steinshamn, Håvard; Thuen, Erling and Gustavsson, A.-M. (2012) Effect of legume–grass silages and a-tocopherol supplementation on fatty acid composition and a-tocopherol, b-carotene and retinol concentrations in organically produced bovine milk. Livestock Science, 148 (3), pp. 268-281.

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Summary

Two feeding experiments were performed to study the effects of silage botanical composition, regrowth interval and α-tocopherol supplementation on the fatty acid (FA) composition and α-tocopherol, β-carotene and retinol concentrations of milk. In experiment 1, 24 Swedish Red dairy cows were fed two- or three-cut red clover-grass silages (R2 and R3, respectively), or two-cut birdsfoot trefoil-grass silage (B2). In experiment 2, 16 Norwegian Red dairy cows were fed short-term ley silage with red clover (S3) or long-term ley silage with white clover (L3) in combination with supplementation of RRR-α-tocopheryl acetate (1,600 mg/day). The FA proportions in the milk and the recoveries of C18:2n-6 and C18:3n-3 were higher on the red clover diets R2 and S3 than on B2 and L3, respectively, and the n-6/n-3 FA ratio was also higher on the red clover diets. Shorter regrowth interval increased both the concentrations of FA in silage and the proportions of unsaturated FA in milk. Intakes of α-tocopherol, β-carotene and lutein were higher on B2 than on R2 due to higher silage intake on B2. However, highest intake was seen on diet R3 due to higher concentrations in the silage mixture. In experiment 2, intakes of α-tocopherol, β-carotene and lutein were higher on L3. However, not all of these differences affected the milk, since the only significant differences related to silage diet in the two experiments were a higher milk α-tocopherol concentration on L3 than on S3 and a slightly lower β-carotene concentration on B2 than on R2. Supplementation with α-tocopherol increased milk α-tocopherol concentrations from 0.77 to 1.05 and from 1.07 to 1.24 mg/kg milk for S3 and L3, respectively, but did not affect milk FA composition.
A higher concentration of antioxidants in the feed could be beneficial as a larger proportion of the animal’s vitamin requirements would be met by the forage and the need for supplementation might decrease.


EPrint Type:Journal paper
Subjects: Animal husbandry > Production systems > Dairy cattle
"Organics" in general
Crop husbandry > Production systems > Pasture and forage crops
Research affiliation: European Union > CORE Organic > PHYTOMILK
Denmark > AU - Aarhus University > AU, DJF - Faculty of Agricultural Sciences
Norway > UMB - Norwegian University of Life Sciences
Norway > Bioforsk - Norwegian Institute for Agriculture and Environmental Research > Bioforsk Organic Food and Farming Division
Sweden > University SLU > Agricultural Research for Northern Sweden
ISSN:1971-1413
Deposited By: Höjer, Miss Annika
ID Code:21679
Deposited On:29 Oct 2012 13:33
Last Modified:29 Oct 2012 13:33
Document Language:English
Status:Published
Refereed:Peer-reviewed and accepted

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