There have been a number of threads from newbies about using grit so I'm adding my 2-cents worth to help. Feel free to add or challenge. For those who don't know, since chickens do not have teeth to chew, they rely on gravel, stones, etc. in their gizzards to grind up their food. If they don't have this then they can have problems with impacted crops or nutrition since the food will go right through them. Under most situations there is plenty of material around that the birds can use for grit but when they are kept away from this kind of thing it has to be supplied--usually in the form of ground up granite. In my case, since my birds range over a lot of good old fashioned glacial till, they usually don't have a problem. The only time I supply it is for chicks before I allow them anything but starter or to adults during the winter when they can't get at the bare ground. In the winter, I wouldn't feed either BOSS or scratch unless they had access to grit. Fortunately they don't need a lot--a little goes a long way(I have a 50lb bag that I've had for close to 25 yrs). The best way to feed it is either scatter it on the coop floor, in the run or allow them free choice out of a separate container. There is no need to mix it in with their food, they know when they need it. Also, if the bird are on a diet of strictly processed food--starter,grower or layer--grit isn't necessary, the food is broken down enough so further grinding isn't necessary. It is when they are getting "treats" or free ranging that they need the grit.