Topics:
Animal Nutrition, Animal Refresher
Polyether Ionophore Antibiotics
Which of the following is a polyether Ionophore antibiotic?
- Monensin
- Lasalocid
- Both a & b — Correct Answer
- Amprolium
Explanation:
Correct Answer: Both Monensin & Lasalocid
Both Monensin and Lasalocid are classic polyether ionophore antibiotics. They act by facilitating transport of ions (Na⁺, K⁺, Ca²⁺) across bacterial cell membranes, disrupting the ion gradient and selectively killing Gram-positive bacteria in the rumen while sparing Gram-negative bacteria.
Ionophore Antibiotics — Comparison
| Feature | Monensin | Lasalocid |
|---|---|---|
| Trade name | Rumensin | Bovatec (Bovitec) |
| Produced by | Streptomyces cinnamonensis | Streptomyces lasaliensis |
| Potency | Standard | More potent (binds divalent cations better) |
| Ion selectivity | Monovalent (Na⁺, K⁺) | Mono + Divalent (Ca²⁺, Mg²⁺) |
| Use | Rumen modifier; anticoccidial | Rumen modifier; anticoccidial |
Note
- Amprolium is an anticoccidial but is a thiamine analogue, NOT an ionophore
📚 About this Topic — Animal Nutrition
This multiple choice question is from Animal Nutrition, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Nutrition to strengthen your preparation.
