As with other mammal ruminants, they are even-toed ungulates. Bunostomum is a genus of nematodes of the small intestine of ruminants and camelids. The rumen is the major site of methane production in ruminants. However this generalization does not extend to wild ruminants or camelids. Maize silage is one of the most valuable forages for ruminants. The rumen of the water buffalo has important differences from that of other ruminants. It can be fed to cattle, sheep and other such ruminants (cud-chewing animals). Herbivores have evolved cecums (or an abomasum in the case of ruminants). Wild ruminants and other mammals, including humans, can act as definitive hosts as well. Baobab leaves are sometimes used as forage for ruminants in dry season. It is valued as a good roughage source for ruminants such as cattle. Oxytocin is synthesized by corpora lutea of several species, including ruminants and primates. The seeds are also used to feed fish, domestic rabbits and ruminants. It is commonly grazed by domestic and wild ruminants. Llamas are not ruminants, pseudo-ruminants, or modified ruminants.