Genesis 47:17

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 31:1 Isaiah 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.