Most goats are slaughtered when they're between 3 to 5 months of age.
When the goats are between 3 to 5 months of age they weight between 25 to 50 pounds which is usually optimal weight for the slaughtering of the goats.
Sometimes farmers who just farm goats for personal use may allow the goats to grow a bit larger before they slaughter them for meat.
Some goats are not marketed until they are around 1 year old or older and are heavier in weight.