Concentrate finishing systems for store lambs often involves a dramatic change in the basal diet as lambs are moved from being managed on, e.g. grass and / or roots to concentrates. If this is done too quickly there is a risk of digestive disturbances leading to acidosis and secondary infections. However, the desire of the lamb finisher is to transfer the lambs onto the concentrate diets as quickly as possible and reduce rumen friendly materials such as straw to maximise performance. Yeast products have been shown repeatedly to reduce the production of lactic acid and stimulate the utilisation of lactic acid by certain rumen microflora, e.g. M. elsdenii leading to a more optimal rumen environment for the rumen microflora that in turn enhances nutrient supply and animal performance.

The aim of this trial was to determine whether there would be any response to the inclusion of two yeast products, a live yeast, Yeasacc 1026 and a yeast culture, Diamond V XP, in intensively finished Swaledale wether store lambs.