It's hard to be precise. But I think the point here is to paint a picture of a man who has embarked on a substantial enterprise (owning beautiful white horses)

It's hard to be precise. But I think the point here is to paint a picture of a man who has embarked on a substantial enterprise (owning beautiful white horses) with an unrealistic dream of how it would turn out (they would recognise him as their father), has failed completely (the horses are extremely ill and do not recognise him as their father), and now wants to abandon the whole thing (by selling them) while refusing to contemplate his own role in that failure (they are the Burden of his life). It's an impressionist portrait of naivité, narcissism, incompetence, and irresponsibility. Just a rather weird one.