Because the plants that they eat do not contain sufficient amounts of sodium and chloride. Also, a lot of salt is lost as perspiration during warm weather or if they are being worked. Salt needs also increase during lactation and during periods of rapid growth. As such, cattle need to have access to salt at all times. The best type of salt you can supplement your animals with is either a trace-mineral block, a loose-mineral mix, or a cobalt-iodine-salt block. Loose minerals are much more recommended among many cattlemen than salt that comes in block form.
No, they are not.
yes they do.
No
table salt and salt licks for cattle food
no, since there is no metalic element in salt, its not magnetic.
A trace-mineral sheep salt lick lacks copper. A trace-mineral lick for cattle (and horses) includes copper.
This question has already been answered in two separate questions. See them in the Related Questions section below.
table salt and salt licks for cattle food
Salt is sodium chloride, and because salt is this chemical compound, this is the main reason why it is used so frequently as a source of sodium AND chloride for livestock like horses and cattle.
Salt does not repel bugs. In fact, some bugs like ants are attracted to salt.
There is no difference, really. The salt licks that are given to cattle are the same ones that are given to horses. Horses may get a smaller salt block, but other than that, the mineral content is all the same.
Cattle usually will lick themselves to scratch an itch or remove flies off of their bodies. Another term for lick could be the salt lick, this is a block of salt or minerals that the cattle will lick, it just gives them extra nutrients.