Abstract

The effect of high potassium concentration on rumen fermentation and fatty acid biohydrogenation (BH) were investigated in a 6 hour in vitroincubation. A pasture grass sample with 26.3 g/kg dry matter (DM) of potassium was used as control. Supplemental levels of 10, 20 and 30 g/kg DM of potassium were added as potassium chloride. Results showed that high potassium concentration had no significant effects (P >0.05) on pH, molar concentrations of total or individual volatile fatty acids (VFA), concentrations of C18:0, C18:1 trans 11, C18:1 cis 9, C18:2n-6, or BH of C18:2n-6after incubation. However, concentration and BH of C18:3 n-3were significantly (P <0.01) affected by potassium supplementation. Both the 20 and 30 g/kg DM supplementation significantly (P <0.05 and P <0.01, respectively) decreased the concentration but increased BH of C18:3n-3. This preliminary study indicates that high concentrations ofpotassium alter rumen fatty acid metabolism. Further studies are needed to confirm this and investigate the possible causal mechanisms.

XQ, Sun, and SJ Dewhurst RJ.Gibbs

Proceedings of the New Zealand Society of Animal Production, Volume 69, Christchurch, 238-241, 2009