What is the main cause of bloat on pasture vs feedlot?

• A. Pasture bloat is gaseous from rapid concentrate adaptation and dehydration.
• B. Pasture bloat is frothy from legume forages; feedlot bloat is often gaseous from rapid concentrate adaptation and dehydration.
• C. Both are always frothy.
• D. Bloat is unrelated to feeding type.

Answer: (D)

Bloat is driven by how the animal’s diet interacts with rumen fermentation and gas handling. There are two common forms: frothy bloat and free-gas bloat, and the feeding type largely predicts which form you’ll see. When cattle graze legume-rich pastures (like alfalfa or clover), foam forms in the rumen and traps gas, so eructation can’t relieve the distension—this is frothy bloat. On the other hand, rapid introduction to high-concentrate feeds in feedlots tends to produce more free gas in the rumen as fermentation kicks in rapidly and saliva buffering and rumination are overwhelmed; dehydration or abrupt diet changes can worsen gas buildup. So bloat is not unrelated to feeding type; pasture bloat is typically frothy due to legume forage, while feedlot bloat is often gaseous from rapid concentrate fermentation.