Boyd’s Bible Dictionary:

Straw used for cattle fodder and litter

Concise Bible Dictionary:

This is spoken of as being eaten by the cattle, and it is foretold that it will be the food even of the lion in a future day. This agrees with the practice in the East where the straw is cut up or crushed, and used as food for cattle (1 Kings 4:2828Barley also and straw for the horses and dromedaries brought they unto the place where the officers were, every man according to his charge. (1 Kings 4:28); Isa. 11:77And the cow and the bear shall feed; their young ones shall lie down together: and the lion shall eat straw like the ox. (Isaiah 11:7)). It was used in Egypt for mixing with the clay in making bricks: in some of the ancient Egyptian bricks the straw can be seen.