Intensive lamb fattening systems require high concentrate diets to assure high productivity and fast growth which causes ruminal
acidosis and affects the ruminal microbial population. referred such adversity as ‘high-concentrate syndrome’ and suggested to adopt strategies to modulate pH and fermentation pathways in the rumen with yeast, organic acids or essential oils (EO) to ameliorate the rumen environment. Essential oils are naturally occurring, secondary plant metabolites that can be steam-volatilized or extracted using organic solvents.
Limited literature exists that highlights the potential of EO to manipulate ruminal microbial fermentation and increase feed efficiency in ruminants.
By providing growth factors including organic acids, B vitamins and amino acids that stimulate microbial growth in the rumen, Saccharomyces cerevisiae may stabilize ruminal fermentation suggested that the yeast effects were due to the nutrients and/or soluble growth factors provided to the ruminal microbes.