The goats and the sheep are able to breed at 4 months of age.
When I had goats, babies were weaned at 8-12 weeks. Once they are getting enough energy and nutrition from hay, kid starter etc, they can be weaned. Typically that's when they are about 2.5 times their birth weight and are consuming at least 30 grams of solid feeds, daily.
Last year I waited until the lambs were 5 months thinking that was fine, well 2 weeks ago i got a big surprise on a 10.5 month old ewe--she had a baby, which means she got bred when she was like 5 months old. Thankfully the ram lamb was completely unrelated, but still.
Onset of puberty is 3- 7 months.
Cathy