Which feedstuffs predispose to frothy bloat?

• A. Grass hay
• B. Legume forages such as alfalfa and clover
• C. Silage
• D. Concentrates

Answer: (B)

Frothy bloat happens when gas produced in the rumen is trapped in a stable, persistently foamy layer. Feedstuffs that create or promote that foam are the ones that predispose to frothy bloat. Legume forages such as alfalfa and clover are especially foamy because they are high in soluble proteins and other surface-active compounds and are often eaten as lush, young, high-moisture forage. This combination accelerates gas production and stabilizes the foam, trapping gas in the rumen and leading to frothy bloat. Grass hay tends to be lower in these foaming agents and higher in fiber, so it causes less foam formation. Silage and concentrates can cause other problems but are not as strongly associated with the persistent foam characteristic of frothy bloat as legume forages are.