Cud population to live and function. Consumption by ruminants of an insufficiently fibrous diet leads to little cud formation and therefore lowered amounts of saliva production. This in turn is associated with rumen acidosis, where the rumen pH can fall to 5 or lower. Rumen acidosis is associated with a lowered appetite which leads to still lower rates of saliva secretion. Eventually, a collapse of the microbial ecosystem in the rumen will occur because of the low pH. Acute rumen acidosis can lead to death of the animal, and will occur if the animal is allowed to eat a diet with
Retroperistalsis of humans are weak compared with those of most other mammals. In cud-chewing animals, such as cows, reverse peristalsis can occur so that the food is brought back from the stomach to the mouth for rechewing. When the stomach is filled, peristaltic waves are diminished. The presence of fat in a meal can completely stop these movements for a short period until it is diluted with gastric juices or removed from the stomach. Peristaltic waves start as weak contractions at the beginning of the stomach and progressively become stronger as they near the distal stomach regions. The waves help to