The primary market for slaughter goats is a 15–36 kg (35-80 lb) kid; kids should reach marketable size at weaning age. The kid of a proven fast-growing sire might weigh 36 kg (80 lb) at 90 days, while the kid of a poor quality sire might weigh only 15 kg (35 lb) at 90 days. An average quality buck will initially be less expensive to purchase; however, they can significantly undermine an operation's long-term profitability. Other criteria for a breeding buck include:
* Jaw alignment – most meat goats are raised on pasture. A goat with poor jaw alignment will be at a significant disadvantage when feeding on pasture; poor jaw alignment is not acceptable in a commercial herd sire.
* Good feet and legs: needed to move about the pasture. Hoof rot is a common problem for goats that live in high rain areas if the hooves are not clipped regularly.
* Two well formed equal-size testes in a single scrotum: the main purpose of a buck is to breed does.
Bucks are normally separated from the does except for when breeding is specifically intended.
Successful bucks must be able to survive on pasture. Pen-raised bucks will stay near their pen, while the does they are supposed to breed are out in the pasture.