Diet supplementation with marine algae (MA) in sheep alters rumen fatty acid (FA) metabolism via changes in the bacterial community, which may occur over an extended period. Examining these time-dependent variations, together with the FA profile, may allow to relate microbial groups to FA biohydrogenation. With this aim, 36 lactating ewes were divided in 6 lots (3 lots/treatment) and offered a diet containing alfalfa hay (40%) and a concentrate (60%) with 25 g of sunflower oil/kg dry matter (DM), and supplemented with either 0 (Control) or 8 g of MA/kg DM. On days 0, 26 and 52, samples of rumen fluid were collected through a stomach tube and composited per lot for microbial analysis, using quantitative PCR (qPCR) and terminal restriction fragment length polymorphism (T-RFLP), and FA determination. The genera Prevotella and Ruminococcus, quantified by qPCR, showed no changes due to the treatment or its interaction with time (P>0.05). Conversely, several fragments detected by T-RFLP were modified by MA over the long time similarly to certain FA, suggesting a potential role of the compatible bacteria in rumen FA metabolism. Some of these fragments may correspond to species of Ruminococcaceae and Prevotella that had not been previously related to FA biohydrogenation.

Este trabajo ha sido financiado por el MINECO (proy. AGL2011-23700). T. Castro-Carrera ha disfrutado de una beca predoctoral del CSIC (Programa JAE) cofinanciada por el Fondo Social Europeo.

3 páginas, 2 tablas.--Trabajo presentado a las XVI Jornadas sobre Producción Animal AIDA (Zaragoza, 19 al 20 de mayo, 2015).

Peer reviewed