Propionate supplementation did not increase whole body glucose turnover in growing lambs fed rye grass.

The objective of the present study was to investigate the effects of propionate supplementation on whole body glucose turnover in growing lambs fed frozen rye-grass at 1.5 x maintenance using [1-13C]-glucose. Intraruminal infusion of propionate (0.55 and 0.91 mol x d(-1)) increased the ruminal molar proportions of propionate from 25% with the control to 40% with the highest propionate treatment. It did not however modify glucose turnover (26 mmol x d(-1) x kg(-1)), nor the conversion of its carbon into L-lactate (21%) and alanine (21%), nor glucose recycling (9%). All of the results suggest that in the present conditions glucose turnover and metabolism were not influenced by the supply of propionate.