Proper hoof care is essential for sheep and goats. The kids trim the hooves on the goats. They had been left too long before trimming so they were really needing trimming. Many people don't consider the need to trim goat and sheep hooves, but they need care just as any other animal. The hooves continue to grow just as a human fingernail continues to grow. If they don't have rocky ground to keep their hooves in shape - and sometimes even if they do - their hooves can overgrow to the point of causing disability and even death.
Watch the video for a basic introduction to goat hoof care.