Seleno-Cystine Affects the Fatty Acid Profile in In Vitro Incubated Ovine Ruminal Fluid Containing α-Linolenic Acid

Abstract

The influence of seleno-cystine (CySe2) added to ovine ruminal fluids containing -linolenic acid (LNA) on the profile of fatty acids (FA) was investigated. Fluids were incubated in vitro at 39°C under CO2 either alone (RF) or with LNA (1.67 mg/ml) or with a combination of LNA with either a low (1.34 μg/ml) or high (3.33 μg/ml) level of Se as CySe2. Fluids were removed after 0, 6, 12, 18, 24 hrs of incubation and then analyzed to determine FA levels. LNA added to the fluids without/with CySe2 decreased the C180 concentration for incubation at all times from 6 hrs compared with the RF or the fluid containing CySe2. LNA added to the fluids without/with CySe2 decreased the biohydrogenation yield to C18:0. CySe2 added to the fluids decreased the C18:0 concentration and the index of the biohydrogenation to C18:0 compared with the RF. The higher concentration of CySe2 in the fluids with LNA reduced the accumulation of trans11C18:1 for incubation at all times from 18 hrs compared with the fluids with LNA, irrespective of the presence of the lower concentration of CySe2. The lowest concentration of trans11C18:1 in the fluids with LNA and the higher concentration of CySe2 correlated with the lowest yield of the isomerization of LNA into cis9trans11cis15C18:3 and the lowest yield of the initial biohydrogenation of cis9trans11cis15C18:3 to trans11cis15C18:2 in the fluids containing LNA and the higher concentration of CySe2. CySe2 added to the fluids with LNA decreased the ratio of polyunsaturated FA to saturated FA for incubation at all times from 12 hrs compared with the fluids containing LNA. CySe2 in the fluids without/with LNA reduced the FA sum in the fluids.