If your alpacas are grazing short, dry-standing feed at the moment, there are not enough nutrients in the feed to maintain body condition score, let alone grow, gestate or lactate. You need to supplement them with palatable forage (e.g. leafy green hay/silage) up to maintenance requirements, then can add a source of protein (e.g. lupins/peas) and/or energy (e.g. oats) as necessary. Have a look at the CriaGenesis-adult nutrition for help.
Make sure you run your weaners separate to mature animals as they get bullied out of the way during feeding and miss out. They are your next crop of genetics so look after them!
Have a look here to learn how to body condition score your herd to monitor feeding practises. You need to body condition score your herd every time animals come into the yards (e.g. at shearing time, vaccination time, drenching time). If you have scales, use them! Particularly to monitor growth of animals less than 2 years of age.
