Ruminants, such as cows, have a unique way of digesting their food. They consume plants, chew them roughly, swallow the half-chewed mash, regurgitate it repeatedly, and continue chewing. A research team, including the University of Göttingen, has shown that this process has clear advantages. The regurgitated food contains much less hard grit, sand, and dust than the food they first ingested. This protects their teeth from being ground down during the chewing process, which may explain why the crowns of their teeth are less pronounced than those of other herbivores. The findings have been published in the journal Proceedings of the National Academy of Science (PNAS).
The researchers fed four cows grass feed mixed with sand for several days and took samples of the regurgitated food pulp and feces. They then measured the silicate content of each sample. The compounds from sand and grass are particularly abrasive to teeth because of their hardness. The feces contained about the same amount of silicates as the grass feed mixed with sand, whereas the regurgitated food contained significantly less.
The only explanation is that the silicates must have stayed in the stomach, or more precisely in the “rumen.” The rumen is the largest stomach compartment in ruminants and the place where food is fermented and broken down by microorganisms.
Because this laborious chewing is partly carried out on food pulp that has been “washed” in the rumen, the teeth of ruminants are less worn than those of horses, for example. The latter chew their food completely after ingestion, including the abrasive bits.
2023-05-14 01:30:03
Post from phys.org
