Frank Owlsey Auburn University

Publish Date: July 2, 2012

All-In–All-Out (AIAO) swine production is a system that keeps animals together in groups. Animals from different groups are not mixed during their stay on the farm. The groups are closely matched by age, weight, production stage and condition. The group is moved into a phase of production together, such as into an empty nursery, and is moved out of that phase as a group according to a production schedule. When a group moves forward, the facility is completely emptied. AIAO is the norm for most system production systems today. AIAO in an ideal world is by site, which is rarely practical. AIAO can also be by barn, room, “air space” or pen. In an AIAO system, sows are bred as groups to farrow during a 5- to 10-day period. By comparison, sows in a continuous flow system are bred continuously and farrow continuously. In a continuous flow system, pigs move as individuals, not as closely matched age groups, and a facility is never totally emptied because pigs or sows are always moving through it.

Publish Date: March 25, 2010

Animal production involves the feeding and care of animals to obtain usable end products, such as meat or milk. Since the efficiency with which animals use nutrients is less than 100%, a portion of the nutrients supplied to the animal is excreted as feces. The end/byproducts of metabolism are excreted in urine. Traditionally, these excreta were used as fertilizers for crops and thus were an integral part of the nutrient cycle. Over the last decade, animal production has expanded significantly in areas without adequate local feed production. To sustain expanding animal agriculture, feed ingredients were shipped in from major crop producing regions, initiating the import of nutrients, including nitrogen and phosphorus into animal producing regions. Due to the bulk of animal manure relative to its weight, shipping it to the feed producing regions for use as a fertilizer was not economically viable. Alternative methods to deal with manure were thus sought. Some are focused on different processing and storage techniques after manure production, while others deal with reducing the excretion of nutrients in manure. This factsheet outlines some of the underlying principles for modifying pig diets with the objective of reducing nutrient excretion and ammonia and odor emissions.