Technical note: Stearidonic acid metabolism by mixed ruminal microorganisms in vitro

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

Maia, MRG (Autor) ICBAS; Correia, CAS (Autor) Outra; Alves, SP (Autor) Outra; Antonio J M Fonseca (Autor) ICBAS; A. Cabrita (Autor) FCUP

Revista

Título: Journal of Animal Science

Vol. 90

Páginas: 900-904

ISSN: 0021-8812

Editora: American Society of Animal Science

Indexação

ISI Web of Knowledge - 9 Citações

Scopus - 9 Citações

Classificação Científica

CORDIS: Ciências Naturais > Ciências agrárias > Zootecnia

FOS: Ciências agrárias > Ciência animal e dos lacticínios

Outras Informações

ID Authenticus: P-002-CSY

DOI: 10.2527/jas.2011-4118

Abstract (EN): Dietary supplementation of stearidonic acid (SDA; 18:4n-3) has been considered a possible strategy to increase n-3 unsaturated fatty acid content in ruminant products; however, little is known about its metabolism in the rumen. In vitro batch incubations were carried out with bovine ruminal digesta to investigate the metabolism of SDA and its biohydrogenation products. Incubation mixtures (4.5 mL) that contained 0 (control), 0.25, 0.50, 0.75, 1.00, 1.25, or 1.50 mg of SDA supplemented to 33 mg (DM basis) of commercial total mixed ration based on corn silage, for dairy cows, were incubated for 72 h at 39 degrees C. The content of most fatty acids in whole freeze-dried cultures was affected by SDA supplementation. Branched-chain fatty acids decreased linearly (P < 0.01), and odd-chain fatty acids decreased quadratically (P < 0.01), particularly from 1.00 mg of SDA and above, whereas most C18 fatty acids increased linearly or quadratically (P <= 0.04). Stearidonic acid concentrations at 72 h of incubation were very small (< 0.6% of total fatty acids and <= 0.9% of added SDA) in all treatments. The apparent biohydrogenation of SDA was extensive, but it was not affected by SDA concentration (P > 0.05). Biohydrogenation followed a pattern similar to that of other C18 unsaturated fatty acids up to 1.00 mg of SDA. Stearic acid (18:0) and vaccenic acid (18:1 trans-11) were the major fatty acids formed, with the latter increasing 9-fold in the 1.00 mg of SDA treatment. At greater inclusion rates, 18:0 and 18:1 trans isomers decreased (P <= 0.03), accompanied by increases in unidentified 18:3 and 18:4 isomers (P = 0.02), suggesting that the biohydrogenation pathway was inhibited. The present results clearly indicate that SDA was metabolized extensively, with numerous 18:4 and 18:3 products formed en route to further conversion to 18:2, 18:1 isomers, and 18:0.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 5