I had i think 3 trader caravan arrival events this being on a fresh colony and they showed up with animals along them, one of which being a muffalo.
Every event the muffalo didn't appear in the trader's sell list. i would expect the muffalo to appear as well on the list right? i tried doing it on dev mode as well and i got a trader event spawn on a brand new colony where the traders came with 2 wargs and a muffalo along, the wargs showed up but the muffalo didn't.
I am quite certain this should be a bug.
Here a screenshot with the muffalo and the traders
(http://i.imgur.com/iFQ8yac.jpg)
Here the list of the trader's items to sell and buy
(http://i.imgur.com/hejBa9z.jpg)
Not all muffalo are for sale. Some are beasts of burden that carry goods. Check the muffalo's inventory to confirm.
okay yeah i checked and indeed the muffalo is used to carry stuff. i thought all animals that come with the traders are for sale. then this topic can get closed or removed :)