Grain overload (Rumen Overload; Rumen Acidosis) is an acute disease of ruminants characterized by indigestion, rumen stasis, dehydration, acidosis, toxemia, incoordination, collapse, and frequently death. It is most common in cattle that accidentally gain access to large quantities of readily digestible carbohydrates, particularly grain.
Body temperature is usually below normal (36.5-38.5°C) , it may be increased to 41oC if animals are exposed to the sun in hot weather. Respirations tend to be shallow and rapid, up to 60-90/min and heart rate may be as high as 120-140/min. In severe cases, rumen motility is completely absent, the contents of the rumen may feel firm and doughy.
The diagnosis is from the history if available, a low ruminal pH (5.5-6) and examining the microflora of the rumen where the number of protozoa per field will be reduced from its usual value of 6-7. A pH of <5 indicates severe acidosis.
- Remove the rumen contents & replace with ingesta taken from healthy animals e.g. animals slaughtered in the abattoir
- Antiacids like Magnesium carbonate or magnesium hydroxide 1g/kg, PO mixed in 8 to 12 liters of warm water, repeated every 6 to 12 h
- Activated charcoal 2g/kg to inactivate endotoxemia
- Fluid therapy
- Avoid sudden ration changes
- Restrict animals from accessing grain and the feed should contain at least 10% of roughage