Sheep and goats are not native to Africa, and are introduce into Africa at with the appearance of farming. Just a brief entry so I can find the info again. From Archaeology, language, and the African past, By R. Blench.
Sahara Air Massif Adrar Bous 5000 BC
Sahara Niger Arlit 4300 BC
East Africa Sudan Esh Shaheinab 3,200 BC
West Africa Mali Winde Koriji West 2,200 BC
West Africa Mali Kolima Sud 1,400 BC
West Africa Nigeria Gajiganna 1,520BC
Horn Africa Ethiopia Lake Besaka 1,500 BC
East Africa Kenya Ga Ji 4 2,000 BC
East Africa Kenya Ngamuriak 1000 BC
Southern Africa Namibia Falls rockshelter 190 BC
Southern Africa SA Ma38 200 AD
And another PDF with some info on it that includes dates for chickens, horses, etc, for reference.