we feed a combination of hay - oat, alfalfa, bermuda. straight alfalfa can cause urinary calculi in male goats and it's pretty rich and can contribute to bloat when it's all you feed. we do feed more alfafla for does in milk or pregnant, but we always feed several hay types. alfalfa + whichever other hay we can get. just transition from one to another so you don't make an abrupt change - some goats can have some digestive upset if you change the feed all at once.
we feed 25-50% alfalfa and the rest in oat, bermuda, or forage hay or a combination of those. 25% for bucks and 50% for in millk and mid- to late-pregnancy does.
we dont feed a goat ration pellet except for our weaned kids, but its worth looking at because it provides a very consistant feed program.
we supliment late pregnancy and in-milk does with a 3-way rolled grain to suplement their extra calorie needs.