How can a cow wrap their tongue around grass stalks and pull them out to eat and not destroy a pasture?

Answer 1

It's all about the roots: 60 to 80% of the biomass (i.e., the roots) of a grass-plant is underground. Healthy root systems of grasses grows out and down in such a way that it firmly anchors it to the ground. Grass roots are fibrous, not tapered, so that it makes it much more difficult for the grazing animal to pull the grass out by its roots. Grasses have evolved over billions of years so that they are highly resistant to being pulled out by the roots when being eaten by grazers like bison, cattle, elk, sheep and goats. The root system of grasses grow as the pasture is being grazed properly, simply by letting cattle graze a certain pasture or paddock for a certain amount of time before being moved on to another paddock or pasture to allow the grasses to rejuvenate growth both above and below ground before being grazed again.

What will kill grass is when it's being grazed too close to the earth, or an animal comes back and takes a bite from the grass that has just started putting new leaves out all the time. When this occurs, the root system dies, becomes more shallower and less robust because more energy is being put into growing new leaves than growing new roots. This is called overgrazing.

However it's not all about overgrazing that will destroy a pasture. When a pasture is reseeded or re-sprigged and needs to establish itself enough to take on grazing pressures from livestock, it cannot have any animals grazing it during that time of establishment, nor should it be mowed or hayed. If an owner or grazing manager grazes their cattle when the grass has just started growing or just been recently sprigged, then the cattle WILL destroy the pasture. This is all because the root systems have not been given time enough to establish themselves enough to resist any sort of grazing pressure. If the owner prevents any livestock from being on the pasture nor does any haying or mowing while the new grasses are growing and establishing their new root systems for at least a year, then the possibilities of having a pasture destroyed by the grazing actions of the livestock will not be a problem.

Thus it's all down to the responsibility of the owner to make sure they graze their cattle at the right time to ensure healthy, vibrant and vigorous grasses.