John Gill Commentary Genesis 47:17

"And they brought their cattle unto Joseph; and Joseph gave them bread in exchange for the horses, and for the flocks, and for the herds, and for the asses: and he fed them with bread in exchange for all their cattle for that year." — Genesis 47:17 (ASV)

And they brought their cattle unto Joseph
Which they might the more readily do, since there was scarce any grass to feed them with; and though some of them were creatures used for food, yet might be so lean and poor for want of grass, as not to be fit to eat; and besides, they could do better without flesh than without bread:

and Joseph gave them bread [in exchange] for horses ;
with which Egypt abounded, to which many places of Scripture have respect, (Deuteronomy 17:16) (1 Kings 10:28) (Song of Solomon 1:9) (Isaiah 31:1Isaiah 31:3) ;

and for the flocks, and for the cattle of the herds ;
the sheep and the oxen; which shows that these creatures were bred and fed by them, and were, no doubt, slain, and used for food:

and for the asses ;
which were used for carrying burdens:

and he fed them with bread for all their cattle, for that year ;
which seems to be the sixth year of the famine:

one would wonder what Joseph should do with all their cattle, where put them, and feed them, in such a time of drought; though it is probable the number was not exceeding large, since they only fetched one year's provision of bread.