He may have cocci and/or worms. Scours do not have to be present.
How are his inner lower eyelids, pale pink, white or dark pink?
What is his temp? 101.5 to 103.5 is normal range. Being it is cold there, it should be on the lower end of normal, but not sub temp.
Being hunched like that is not good. Pain, too cold or not feeling well.
Does he have a goat friend at all. If not, he needs a goat buddy. They can cuddle. This is crucial for him to want to eat ect.
Putting a sweater on him or better yet, a heat lamp will help until he gets stronger. During the day or at night, unless he is alone then putting him in the house is best.
What kind of milk? Replacer or cows whole milk?
Pan feeding I feel isn't good, but some do feel it is OK.