Gilt integration on outdoor units

As an outdoor producer, environmental factors, such as bad weather, can impact performance. 

Back to: Gilt management

Many gilts arriving on outdoor units will have come from indoor systems. This change in environment can create problems during the acclimatisation period.

Training paddocks and acclimatisation areas often double up in outdoor scenarios. Incoming gilts should be isolated for at least four weeks (depending on health status) to avoid a health breakdown.

Key to success

  • Gilt management should be consistent
  • Record gilt performance and pay attention to detail, if there is a drop in performance, evaluate and assess the factors that could have contributed to it
  • Good staff communication
  • Stay positive and don’t compromise good management

Group size

  • Optimise group size to encourage good feed and water intake
  • Lying space is critical for young gilts, so check the type of hut used suits the group size


Check with the gilt supplier what feed type was fed and how. It can take a few days for gilts to adjust to new feed and feeders; wait by the paddock and ensure all gilts find the feed.

Manage feed faces for gilt paddocks so food is presented well. Outdoor gilts need roughly 25% more food than indoor gilts. Check your feed levels with your feed supplier and make sure all staff are aware of the gilt requirements.

Target a body condition score (BCS) of 3–3.5 at first service, monitor gilt condition from delivery to service and adjust feed levels to achieve this target.


  • Gilts often become sunburnt after their first exposure to sun. Providing sun protection, such as shades, pre-made wallows and straw day beds, is critical, especially in the first days on the unit; make sure these are in place before gilts arrive
  • Sunburn and heat stress can quickly cause skin problems, decreased feed intake, discomfort and even death
  • During winter, ensure your gilts have provisions for extra warmth; ensure huts have no holes or damaged vents
  • Straw and well-sited huts will help drainage and protect gilts from winter winds


Worming for outdoor gilts is very important and you should discuss a programme with your vet. The timing of wormer administration is critical to success. Whether you are bringing in in-pig, maiden or weaner gilts, acclimatisation is the most essential part of any integration strategy. Some units will use natural service, while others will use AI, or a combination of both, depending on individual preference. Gilts are then artificially inseminated on the second parity.

Maiden gilts

  • Aim to provide an environment that:
    • Supports and maintains healthy gilts
    • Does not expose gilts to mycotoxins
    • Does not compromise growth
  • Record any natural services that you observe in the paddocks to enable you to plan farrowing dates
  • If batch farrowing, plan when the boars are moved in with the gilts so as many as possible farrow earlier in the batch to give them a longer lactation period
  • Keep the boar-to-gilt ratio at 1:2
  • Rotate boars twice a week, unless activity levels look high; if this is the case, consider more regular rotation

Farrowing paddocks

Doubling up is common among gilts, so many producers opt for individual farrowing paddocks which can reduce the liklihood of this happening. If a natural service system is in place for gilts, farrowing times can be varied, so individual farrowing paddocks allow each gilt to be fed individually.

The condition at weaning is critical to avoid second litter drop. If gilts were all together and there was a range of farrowing times, getting the correct feed curve for each gilt would be impossible. 

Mixing the farrowed gilts in with the main herd after weaning is the final stage of integration. There should be at least two huts in any dry sow paddock to allow submissive gilts to lie away from the main group. Also, ensure the feed face is wide enough for sows and gilts to feed easily.

Table 1. Example hut sizes and stocking densities 

Hut Length (m) Width (m) Total space (m2) Stocking density (gilts/hut)
2.3 m dry sow hut 2.3 2.3 5.29 3.5
3.0 m dry sow hut 3.0 2.3 6.90 4.6
3.8 m dry sow hut 3.8 2.3 8.74 5.8

Table 2. Gilt replacement strategies 

Strategy Pros Cons Comments
In-pig gilts Simplistic, avoids service Acclimatisation is critical to maintain pregnancy Lack of control on the service
Maiden 100 kg gilts Acclimatisation occurs prior to puberty stimulation Lack of control over farrowing date if using natural service Puberty stimulation should not occur before 180 days of age
Weaner gilts Long acclimatisation process. Full control of gilt pool, further selection possible Higher feed costs, extra huts and more space needed on the unit Specific transportation needed

Example system based on a 730-sow outdoor breeder, weaning all progeny off site, three-week batch farrowing

  • On arrival, gilts weigh around 105 kg. They are grouped in training paddocks of 25 and fed a gilt-rearer diet ad lib
  • After nine weeks, gilts are treated with in-feed Regumate® and fed 3 kg/day for 18 days
  • In the AI tent, gilts receive nose-to-nose boar contact; this is the first time gilts see the boar
  • If a gilt does not show standing heat when back pressure is applied, she is put into the boar pen to check if she will stand for the boar
  • Gilts showing standing heat on Sunday are served on Monday. Gilts standing on Monday onwards are served when detected. They receive two AI services 24 hours apart
  • After service, the gilts remain in stable groups
  • Gilts are grouped with a chaser boar one week post-service and scanned at four weeks, after which the chaser boar is removed
  • Initially, gilts are kept in pairs, with every other paddock left empty; this reduces stress and stops gilts jumping the fences to group up
  • After four days, the pairs are split up so that they farrow in single paddocks