Does he sweat at all when not working, now that we're into the summer and the heat has been taxing just standing around? If so, then he needs to have his daily salt intake increased to 2oz (4 tbsp) just to keep up with normal, non-working needs. Does he have a salt block/loose salt available? Does he use it?
The salt drive is basic but will get shut down when an animal becomes salt-deprived and dehydrated to some degree. Turning it back on can take some time. It took almost 3 years of making sure one of my boys was consuming adequate amounts of salt and remaining properly hydrated before he finally started to use a salt block on his own and stopped resenting it in his food.
Sherry already addressed the working needs part of your question.
Lavinia, George Too, Calvin (PPID) and Dinky (PPID/IR)
Nappi, George and Dante Over the Bridge
Jan 05, RI