It really depends on the donkey. Generally speaking, jennies are more likely to get along with smaller stock than geldings or jacks. Even so, a male donkey who has been introduced to small stock when he is young, and then gelded early, will probably continue to get along with small stock. An older, settled jack is very likely to kill goats, chickens and ducks (dogs and cats, too!) especially if he thinks that protecting larger stock is his job. Great care and supervision must be in place when introducing a jack to smaller stock, and be aware that instant separation may be necessary.