Preventing goose diahrrea...any ideas??

[LakeGooseBerry]

I have two Toulouse goslings (about 4 weeks). Mostly their poos are nice and firm, but several times a day they have black tar-like poos that smell awful. They have been wandering the yard, grazing this and that, with poultry food to supplement their diet when they want it.
Does anyone know which plants and foods are associated with goose diarrhea? I would like to help them avoid these?

 

[AmandaVirus]

Sound like cecal poops, which are normal and unavoidable, unfortunately.

 

[The goose girl]

Sound like cecal poops, which are normal and unavoidable, unfortunately.

X2.

 

[LakeGooseBerry]

Thanks you. I will have to look up what "cecal" means