The effects of a blend of coriander oil, eugenol, geranyl acetate, and geraniol on bull fattening and slaughter performance.

A blend of essential oils (eugenol, geranyl acetate, coriander oil) has been earlier shown to improve dairy cow productivity by means of reduced methanogenesis. Thus far, no data is available for beef cattle and a transfer of lessons learned from dairy cows to bulls is difficult. The present study tested the material according to manufacturer instruction in beef bulls under Swiss rearing conditions. No effect on zootechnical or slaughter performance could be confirmed, despite a multitude of earlier positive reports from dairy trials. This questions the suitability of the product under the simulated conditions. Further studies including dose-response studies and considering different roughage:concentrate ratios are urgently needed.