hi, welcome!
now i don’t know a lot about training donkeys, but i know that with training cattle is simpler and more straightforward than training equines.
anyway, there’s lots of info on training calves for oxen. they are two separate species, and training your heifer would be best to follow the rules about oxen.
training a single ox or training a pair is essentially the same, if you commit yourself you will get an obedient ox.
if you want the most complete information, get a book “oxen; a teamster’s guide”, by dr. drew conroy.
also, google “oxen training”.
good luck!
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