The most successful outdoor AI service systems are generally radial-based and have the following commonalities:

1. They operate using an efficient, low stress and above all simple system.

2. Their service centres are clean, tidy and light, and provide a comfortable working environment all year round.

3. They operate using a system based on the five "S" key principles.

• Segregation - Sows are kept away from boar presence and smell for around 12 hours pre-service.
  
• Stimulation - Sows are introduced to the boar at point of service.
  
• Serve - Sows are served individually, one inseminator to one sow in one service pen.
  
• Stimulation - Sows continue to be stimulated for 5-20 minutes post service, by allowing them nose-to-nose contact with other boars on the radial.
  
• Sleep - Sows return to their paddocks and rest.

4. They employ "team breeding" to allow services to be carried out in a shorter period of time. This is especially beneficial in batch systems, during periods of hot weather or when day length is short. A shorter service period also reduces the effect of "inseminator boredom."

5. They only inseminate sows during their period of true "standing heat."

Dry sows on an outdoor unit in Suffolk.

February 2007