Ruminants have a specialised stomach to cope with their diet of indigestible vegetation, such as grass. By having a four chambered stomach, these animals can extract enough nutrients from the relative un-nutritious grass to survive. Ruminants include animals such as cows and sheep. Cows even perform a behaviour called " chewing the cud" to increase their digestion efficiency; they regurgitate partially digested food and re-chew it to maximise the nutrition they gain from the grass.
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