A common cause of sour crop?

• A. Overfeeding weak birds
• B. Underfeeding
• C. Cold weather
• D. Lack of water

Answer: (A)

Sour crop happens when food in the crop ferments because the crop is overfilled and not emptied quickly enough. When a bird is fed too much at once or with feed that stays in the crop too long, bacteria and yeast multiply and produce a sour, foul-smelling content. The crop becomes distended and the bird may show signs like regurgitation or reluctance to eat. Preventing this comes down to giving appropriate portions and allowing the crop to empty between meals, rather than overloading it. The other factors—not eating enough, cold weather, or lack of water—don’t cause fermentation in the crop in the same way and would present with different issues (energy deficiency, general illness, or dehydration, respectively).