An ass mounting a horse produces a hinney. A jenny is a female donkey, the opposite number to jack-ass. For muckey going, give me a calm sure-footed mule. They were good enough for Festus (Remember " Gunsmoke ?" Mules and hinneys are not always sterile, but often enough that it doesn't make much difference
Fair winds (up wind of the mules and hinnys)
SKP,Glad to help clarify another important question