Ardacin is an antibacterial glycopeptide effective against gram positive bacteria. Research elsewhere has shown that in growing calves, it increased the efficiency of microbial protein synthesis and protein flow to the duodenum. In goats it reduced methane production but did not affect the site or extent of organic matter digestion. Results on its effects on feed intake are equivocal but it has been shown to increase liveweight gain in finishing cattle. The objective of the present study was to ascertain the effects of Ardacin on feed intake and growth rate of growing and finishing steers.

Two experiments were carried out simultaneously using the same feeds and Ardacin dose levels. In Experiment 1, 72 Friesian and Charolais x Friesian growing steers (8 months old and 240 kg initial weight) were blocked to 4 treatment groups, tied in individual stalls, and offered grass silage ad libitum plus 1 kg ground barley containing Ardacin per head daily.