Polyether ionophores--effect on rumen function in feedlot cattle

Area of Science:

• Animal Science
• Ruminant Nutrition
• Pharmacology

Background:

• Ionophores are commonly used feed additives in beef cattle diets.
• Monensin sodium and lasalocid sodium are the most studied ionophores.
• Understanding ionophore mechanisms is crucial for optimizing cattle performance.

Purpose of the Study:

• To review the known modes of action of ionophores in beef feedlot diets.
• To highlight differences in the mechanisms of monensin and lasalocid.
• To caution against assuming similar actions for newly approved ionophores.

Main Methods:

• Literature review of ionophore action in beef cattle.
• Analysis of studies focusing on monensin sodium and lasalocid sodium.
• Synthesis of existing data on ionophore efficacy and mechanisms.

Main Results:

• The predominant literature focuses on monensin and lasalocid sodium.
• There is evidence suggesting distinct modes of action between monensin and lasalocid.
• Current understanding may not apply to all ionophores.

Conclusions:

• The modes of action for ionophores in beef cattle diets are not uniform.
• It is essential to investigate the specific mechanisms of each ionophore.
• Assuming similar actions for new ionophores could lead to suboptimal outcomes.