USDA Certified Organic standards are defined by regulations of the National Organic Program. The standards are general and apply to all animals. They don't address many animal care issues such as weaning, physical alterations, minimum space requirements, handling, transport, or slaughter. The standards require some access to the outdoors for all animals, access to pasture for ruminants (cattle, sheep, goats), fresh air and sunlight, and freedom of movement. However, the USDA has allowed screened porches to qualify as outdoor access for birds. Physical alterations such as the removal of horns and docking of tails are allowed without pain relief. Compliance with the standards is verified by a USDA-accredited organic certifying agency, but an audit by the USDA Office of Inspector General revealed that consistency among certifiers is a problem. Consequently, the level of animal welfare varies widely among producers. The Cornucopia Institute offers a scorecard that rates organic dairy and egg producers.