Ruminal protozoal contribution to the duodenal flow of fatty acids following feeding of steers on forages differing in chloroplast content
Autor: | Mark Boileau Scott, Eun Joong Kim, Michael R. F. Lee, Alison H. Kingston-Smith, John K. S. Tweed, Nigel D. Scollan, Sharon Huws |
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Rok vydání: | 2012 |
Předmět: |
Male
Chloroplasts Rumen Duodenum Conjugated linoleic acid Medicine (miscellaneous) Vaccenic acid chemistry.chemical_compound Ruminant Animals Food science chemistry.chemical_classification Nutrition and Dietetics biology Fatty Acids Fatty acid food and beverages Straw DNA Protozoan biology.organism_classification Diet chemistry Biochemistry Protozoa Cattle Polyunsaturated fatty acid |
Zdroj: | The British journal of nutrition. 108(12) |
ISSN: | 1475-2662 |
Popis: | Ruminant products are criticised for their SFA content relative to PUFA, although n-6:n-3 PUFA is desirable for human health ( n-3 PUFA flow due to intracellular chloroplast content. A total of six Holstein × Friesian steers were fed, in a two-period changeover design, either straw:concentrate (S:C, 60:40; DM basis; S:C, low chloroplast) or fresh perennial ryegrass (PRG; high chloroplast). Following 12 d adaptation to diet, ruminal protozoal and whole duodenal samples were obtained. N and fatty acid content of whole duodenum and rumen protozoal samples were assessed and protozoal 18S rDNA quantitative PCR performed, enabling calculation of protozoal N flow. The ratio of individual fatty acids:N in rumen protozoal samples was calculated to obtain protozoal fatty acid flows. Based on total fatty acid flow, contribution (%) of protozoa to individual fatty acid flows was calculated. Protozoal fatty acid data and microscopical observations revealed that protozoa were enriched with 18 : 3n-3 following PRG feeding, compared with the S:C diet, due to increased intracellular chloroplast content. However, duodenal protozoal 18S rDNA concentration post PRG feeding was low, indicating rumen retention of the protozoa. Nutrition influences the 18 : 3n-3 content of protozoa; the challenge is to increase protozoal flow to the small intestine, while maintaining sustainable rumen densities. |
Databáze: | OpenAIRE |
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