What age to start hiking? packing?

[Sanhestar]

keep the weight off them until they are at least 2,5 years old and then start with 1 lbs in each pannier. Build up more weight over several weeks and pay close attention to your goats.

The more you load, the shorter distance you can travel per day. Rule of thumb is 20% of body weight which can be increased to up to 25% in goats in really good shape. Also, the more difficult the terrain, the less load a goat should carry. So, if you're planning to cross a glacier f.e. you should rather opt for 20% and shorter distances per day.