You mention 'nuts'. Are these for ewes or for both sexes? Wethers are particularly susceptible to urinary stones which can block the urethra, so causing the bladder to burst. Watch him to see if he is passing urine and if he appears to have abdominal cramps. Any problem or concerns then take him down to the vet. He needs feed which is suitable for male sheep.
There is a saved thread which explains the problem somewhere on TAS, but I'm not sure where. [member=10673]SallyintNorth[/member] where did you save this to, please?
Do you mean a handful each of nuts, or a handful between the lot? They only need a tiny amount to keep them tame.
You are clearly watching your flock and recognising unusual behaviour - that's a sign of a good shepherd