You might to want to also give them some Multi-Min and some vitamins.
I bought a couple old cow pairs in mid March. They were from the same herd that was being sold because of a death. They were so poor looking I didn't even want to waste an eartag on them. One was SS and $625 the other was broke mouth and $720. Both had heifer calves about 10 days old. The wife looks at them and ask why would you buy those skinny &%@$ for? They look like they are ready to die in your pasture. Well I gave them the works. Injection wormer, Multi Min, a 7 way, and Vitamin E-AD. Today you wouldn't recognize them. Their hide has slicked off and is shiny. Their body score has gone up at least two notches and their udders have filled out. They are as calm as a lap dog.
I am not sure what they were deficient from but something evidentially worked.