No. Grass only is "turned into" hay when it is cut and collected for the sole purpose of feeding animals i.e., livestock. Grass will be grass no matter if it's alive and green, or brown and dead.
Besides, FYI, grass hay is cut when grass is green, not when it has reached full maturity and gone into dormancy (i.e., turned brown and "died"). If grass is cut at this stage it contains very little nutritional value for livestock, and is otherwise considered the same value as straw.
When you cut grass in the meadow, this is called mowing the grass and if the grass is to be used for hay it is called mowing the hay or a 'hay mow'.
hay or grass(Y)
pasture grass and hay
all dried grass is called hay. it is where you dry fresh cut grass make it into hay.
Timothy is a grass hay
There is grass in that bundle of hay because that's what was cut and gathered up as hay. A little extra grass in a bale or bundle of hay isn't going to hurt anyone or anything. Pretty sure the cows will enjoy it just as much as there was no grass in the hay you're feeding them.
Hay
Hay is made from forage grasses and legumes.
Orchard hay is a type of grass hay grown from orchard grass. This type of hay is excellent horse feed, but can be fed to most any grazing animal.
If they were given a choice, they'd choose grass over hay any day. But during the winter months when there is no grass to eat, hay is their primary choice.
Yes, hay is dead grass.
Hay = grass + scythe