Roos will avoid the feed with extra calcium if they have any other source of feed (incl. free ranging) > all you have to do is set a separate feeder out with a non-layer in it and thye will eat from that (if your roos have never eaten anything but layer it may take some time but in general free...
regarding the "Rooster Booster" recipe :
...¼ teaspoon calcium powder (if you cant get the yoghurt)..
Do NOT add this for a rooster (roosters should NOT have a layer feed nor extra calcium >only laying birds/hens need this)
he is fighting you because injury in the beak area can be excruciatingly painful (even dry feed can cause pain so all feed should be moist) .... in addition to the suggestions already made:
offer a live culture yogurt free choice > a dollop on top of his feed will moisten it...
If you have a...