Gilt isolation, acclimatisation and integration

Achieving successful isolation, acclimatisation and integration of incoming gilts is the first stage of any good gilt replacement plan.

Maintaining the health status of your herd is critical to sustaining productivity, therefore it is important to know the disease profile of both the incoming stock and the receiving herd.

Breeding companies can declare the health status of their gilts. This information can be shared between vets. If you are purchasing breeding stock, you should ask your veterinary advisor to talk with that of the supplier. A unit breeding its own replacements should consult their vet if any health changes occur on farm.

Managing incoming gilts through proper isolation and acclimatisation will minimise any potential health challenges that could affect the main herd. Good management in terms of housing, feeding, lighting, temperature, boar contact and heat detection will enable a smooth integration and optimise the productivity and longevity of the breeding herd.

Isolation facilities

Isolation is a method of quarantining stock. New gilts entering a unit from a different site (purchased or home-bred off-site) should be isolated for at least four weeks to avoid a breakdown of the herd health status.

  • Facilities should be at least 50 m from the main herd accommodation
  • Buildings and equipment must be fit for purpose
  • Ideally, staff and equipment on the isolation unit should be different to those on the main unit
  • If staff are shared between facilities:
    • Enforce a shower-in shower-out policy and/or ensure clothing and footwear are changed
    • Staff should start their work at the site with the known health status (usually the main herd) and end at the site with unknown health status (usually the isolation unit). This is important when restocking and upgrading the farm health status
    • Work with the isolated gilts last so that staff can shower and be pig-free overnight before entering the main herd again
  • Ensure visitors are at least 24 hours pig-free after visiting the isolation unit before entering the main herd
  • Provide separate vet and med facilities for the isolation area
  • Monitor the gilts’ health status daily and seek veterinary advice if any concerns arise
  • Overall biosecurity should be reviewed regularly
  • On arrival, sort gilts by age, weight and genetic line
  • Ensure the paperwork (including ID and gilt date of birth) is correct
  • Ensure the stocking densities are correct

The facilities at the supplying site will most likely be different from those at the isolation unit. Making the gilt comfortable as quickly as possible is an important part of isolation. Key areas to focus on are:

  • Feed and water: Check the system and feed type the gilts received on the source unit and ensure they all drink and eat after delivery
  • Floor type: If pigs come from a straw-based system, use straw or solid flooring before introducing them to slatted systems
  • Medication: The gilts may require additional vaccines or medication in line with the farm VHP and discussions with your vet

If your acclimatisation facility is separate from the isolation unit, ask your vet to check with the supplier’s veterinary advisor that no new health problems have occurred in the source herd since the gilts left.


Acclimatisation ensures that the gilts are exposed to, recovered from and fully immune to the recipient herd’s diseases before entering the main herd. Although some units start their acclimatisation programme during the isolation period, veterinary advice would normally be to start the programme after isolation but within a semi-isolated area of the unit. This can help identify any breakdowns that occur, that came in with the gilts or were acquired after arrival.

  • Acclimatisation can be achieved by introducing cull sows or grower/finisher stock to the new arrivals
  • With very high-health gilts, it may be necessary to introduce adult pigs for the first 14 days and then replace with growers, which shed more disease
  • Depending on how your gilts respond during the acclimatisation period, they may need medicating – discuss this further with your vet
  • Work with gilts last
  • Acclimatisation will take up to four weeks, with exposure ending at least two weeks before the gilts are moved into the main service area
  • Timely vaccinations should be carried out in line with your herd health plan

All replacement boars should go through the same process as replacement gilts


  • Home-bred gilts build up natural immunity and have less chance of developing health problems
  • Where gilts are split into separate accommodation from 60 kg onwards, or taken off-site before returning as maiden gilts, you may need to have an acclimatisation programme – discuss with your vet
  • Before integrating with the main herd, ask your vet to check with the supplier’s veterinary advisor that no new health problems have occurred in the source herd since the gilts left

Example system based on a 520-sow farrow-to-finish unit

  • Gilts bought as a split group of four age groups (12, 16, 20 and 22 weeks)
  • They are delivered to an off-site isolation building
  • Gilts are vaccinated according to the unit herd health plan and after eight weeks, and clearance from a ‘vet-to-vet’ with the breeding company, they are moved to the main unit in their original groups
  • A V-boar is introduced immediately on arrival and on a daily basis from then on; after the initial observation of heats, he is left in the pen for at least one hour
  • The boar is then removed and housed away from the gilts until being reintroduced the next day


  • All heats are recorded and colour-coded by week, providing a visual record of when gilts are cycling
  • The aim is to serve on the second or third observed heat, at about 150 kg liveweight and body condition score 3–3.5
  • Gilts are moved to the service area five days before their planned service week and given fence-line boar contact during the day
  • They are fed a lactator diet ad lib until the end of the service week, when they are fed 2.25 kg of dry sow ration
  • Gilts are served with 100% DIY AI as soon as they show a standing reflex
  • They are inseminated either am-pm-am or pm-am-pm and post-AI they are given another 30 minutes of fence-line boar contact before returning to their pens; they remain in these groups for four weeks
  • Gilts are scanned and if positive they are mixed in with the rest of the service week to make groups of 24


  • First parity performance is equal with the herd average
  • High retention rate and so reduced replacement rate
  • Controlled parity profile with high number of voluntary culls
  • It is a way of managing gilts without Regumate®, saving time and money

Keys to success

  • Having a well-run, off-site isolation unit away from the main herd
  • Carrying out a vet-to-vet check to make sure there has not been a breakdown in health at the breeding unit
  • Recording all heats with a colour-coding system
  • Ensuring gilts are in the target body condition for breeding
  • Keeping stress to a minimum by keeping gilts in stable groups until confirmed in-pig