Electronic sow feeding

• System Componenets
• The feeding System
• Building Design
• Gilt Management
• Use of Electronic Sow Feeding (ESF)
• Timing of Mixing
• Stockmanship
• Positive and Negetive Features

• A transponder/responder carried on an ear tag to identify each individual sow.
• A receiving aerial to identify the transponder number.
• A computer to store details of daily feed allowance and the amount of feed dispensed daily to each sow, with a data printout facility.
• A dispensing mechanisim to deposit the correct number of equal sized feed drops to the sow whilst in the feed station.
• A feed station to isolate the sow from the rest of the group while feeding.

• The eartag carries a unique ID number which identifies that sow.
• The ear tag transponder’s number is picked up by the aerial in the feed station when the tag in the sow’s ear enters the ID field in the feed trough.
• All new systems involve transponders carried in eartags.
• Ear tag loss is very low when tags are correctly placed inside the ear. Tagging well before mixing may reduce tag loss during bouts of aggression.

• Computer operated systems consist of computer control of exit gates and/or opening the rear gate to admit a sow to the feed station.
• Gate closing speed can be adjusted so that the gates can close slowly for training sows and gilts and more quickly for trained animals.
• A timer dictates the release of the sow from the feed station after she has received her last drop of feed. She can leave the station at any time by pushing the exit gate open. The system needs careful adjustment to ensure that all sows have sufficient time to consume their ration before the rear gate opens. Gilts take longer to feed than sows. Training sows and gilts need to be allocated a longer feeding time.
• A typical time allocation for feeding for a 2.25 kg feed allocation would be 12-15 minutes, with a delay of 2 minutes before the gate opens following last feed delivery.
• As a guide a computer operated feed station will feed 70 sows.

• A passageway or race should be used to bring the sow back into the dunging area at least 2 m (6’6") away from the feed station. This means that sows in the dunging passage do not have direct access to the feed station exit and they cannot interfere with sows leaving the station. The exit race must incorporate sow-proof non-return gates.

• Breaker switches should be used to identify hoppers that are running out of feed. All hoppers should store enough feed to last overnight.
• Any water system incorporated in the feeder must be protected against freezing and should only provide enough water to assist eating – not a full allocation.
• Pelleted feed or meal can be fed. Meal can bridge in the feed hopper. Meal is consumed more slowly than pellets. Water should be provided in the feed trough if meal is fed to maintain an acceptable eating speed.
• The system can be adapted for liquid feed.

• Close monitoring of the feeding activity of the sows from the computer records and the operation of the equipment is essential.
  • Experience has indicated that starting the feed cycle in the evening for overnight feeding may reduce activity behind the feeder with benefits of lower aggression levels. This feeding strategy means that the bulk of sows feed overnight and sows which have not been through the feed station can then be dealt with during the working day. It also means that the feed stations are not so busy in the day facilitating training of sows and gilts.
  • When new batches of sows are introduced it may be useful to add them to the group at the start of the working day to allow adequate time for feeding/training before the next feed cycle starts.

• Daily feed allowance is allocated by the stockman on an individual basis to every sow.
• Overall feed allocation can be programmed to fit feeding curves as specified on an individual or herd basis.

• Most systems incorporate a shedding or capture facility. This will divert sows which have been selected by the stockman, for example sows required for transfer to the farrowing house, into a separate pen. This is mainly applicable for larger groups.
  Great attention needs to be given to the design and management of capture facilities to ensure that large numbers of sows are not inadvertently diverted into small pens designed for a few sows.
• Automatic spray marking of sows in the feeder to indicate sows requiring management attention (for example removal to farrowing or vaccination) is a useful aid in identifying individual sows.

• Action lists are produced by the computer on demand to indicate which sows have not consumed any or all of their feed.
• Action lists do not give warning of an empty feed hopper.
• Regular calibration of feeders is required to ensure that computer records of feed consumption are accurate.

• Stockpersons must be particularly diligent in observing sows when the system is installed.
• A back-up system of visual sow identification is required.
• Tags must be checked regularly.
• Large, bright, easily read ear tags can be an advantage.
• Staff need to be trained to use the computer, calibrate the feeders and maintain the equipment.
• Action lists must be monitored at least daily and remedial measures should be implemented promptly so that no sow goes without feed for more than 24 hours.
• Daily checks are required on the operation and state of repair of the station.
• A first class repair and technical back-up service will be essential including same day service for breakdowns.
• Some sows may prove to be untrainable.
• The full daily feed allowance should be available to the sow at a single visit even though she may not elect to consume it at one visit.

• Buildings can often be converted but of all group housing systems adopting the correct design principles is essential for a successful system. Any conversion should not compromise the design principles. Minimum house width required is typically 12.2 m (40’).
• The system is usually installed in a general purpose type building rather than an insulated, controlled environment house though this is not exclusive.
• Typically natural ventilation but thermal comfort in the lying area and correct pen usage must be assured.

• A straw based system is recommended.
• Deep straw bedding may use more straw than scrape through systems but levels of straw use will be influenced by pen layout, stocking density, drainage etc.
• If slatted systems are used slats must be of the highest quality, well laid and level. The type and quality of slats for breeding animals need to be very specific to provide adequate support for the foot, good grip to prevent slipping and no sharp edges to cause foot or leg damage.

• Thermal comfort is normally achieved by liberal use of straw bedding.
• The use of plastic curtains along the front of kennels can prevent draughts on the sows.
• Where liberal amounts of straw are not used a kennelled lying area is recommended.
• Dunging/feeding areas must be well ventilated to create a cooler environment.

• It is essential to train sows to use the system. Specific arrangements are required for training facilities. The use of a time shared feeder for different groups can be useful for training purposes. Alternatively a separate training pen must be provided.
• Initial training sows/gilts can be time consuming and some sows may prove untrainable.
• Sows coming back into the system after weaning/service may require a few days of less intensive retraining before they are re-introduced into the main group.

• Lying areas for large groups need to incorporate maneuvering space for sow movement. Space requirements for feeding, dunging, drinking and exercise will depend on overall space arrangement.
• Minimum total space required for lying and dunging/exercise/feeder access is likely to be 2.33-3.0 m² (25-32 sq. ft) per sow.
• Minimum lying area is normally 1.5 m² (16 sq. ft) per sow.

• Typically 60-70 sows per feed station.
• Typically several feed stations are used to service one large group with commercial application in groups up to 200+ sows.
• Larger groups can minimise levels of aggression but sow observation and locating individual sows is more difficult.

• Adopting the correct design principles is essential for a successful system.
• Aim for a one-way flow of sows from the dunging area, though the feed station, back out into the dunging area, to the water and back to the lying area.
• Do not install feed stations in a restricted space.
• Access to the feed station ideally should be unimpeded through 180O. Where a station is shared between two pens 90O access is normal but this should be taken as the minimum standard.
• Allow a minimum of 3 m (10’) of unobstructed space behind each feeder.
• Feed stations should be situated with adequate space between them to prevent sows guarding 2 entrances, minimum 1.2 m (4’).
• The use of exit races which take the sows away from the feed stations is recommended.
• Exit races must have non-return, sow proof gates.
• The number of sows per feed station should be kept well within the capacity of the station and management system. The use of a pre-access gate to the area behind the feed stations may marginally increase feeder capacity and reduce competition behind the feed stations.
• The feed stations will lie empty for a large proportion of the day. This is an essential feature of the system to allow sows to feed at any time. Producers should not be tempted to add more sows to the system.

• An example of a system which is operating on a commercial unit
  

• This involves the use of an electronically operated gate which identifies the sow’s transponder and prevents sows which have already fed entering the feeding area. This option may increase the throughput of the feeder and may reduce levels of aggression associated with dominant sows revisiting the feed station but will increase the capital cost, although wear and tear on the feed station will be reduced. Some producers consider the pre-access gate to be an essential feature.

• Sows pass from yard 1 to yard 2 via the feed station with no return facility. This has the advantage that when a sow has fed she has no further access to the feed station. More dominant sows pass through the feed station leaving the timid ones easier access later on.
• At the start of the feed cycle sows are moved into yard 1. During the day they pass through the feeder to yard 2.
• The system will require slightly more overall space than conventional systems and may disrupt lying patterns due to constantly changing space allocations.
• The stockperson can more easily identify non-feeders or timid sows.
• Sows which do not take their full feed allocation have no opportunity for a re-visit but the computer will highlight the fact.
• Eliminating return visits by sows may give an opportunity to increase the number of sows per feeder.

• Separate training facilities are required for gilts. They should not be trained with sows.
• Gilts can find it difficult to compete at the feed station and they should be housed in a separate group from the sows’ yard until their second pregnancy. This may require a separate feed station or sharing a feed station.
• Gilts generally take longer to eat their feed than sows.

• It is unlikely to be cost effective to operate an ESF with individual service groups, except perhaps for large herds serving, for example, 30 sows per week, or in systems operating split groups sharing the same feeder.
• Sows can be weaned directly into the main dry sow group as long as there are boars present and there are good facilities for heat detection and service.
• Electronic ID systems can be used to register visits to boar pens as a guide to sows in oestrus.

• As in all dynamic groups, sows should not be mixed during the implantation phase of gestation.
• The main option is mixing immediately post service.
• Sows would come out of the service house into a re-training pen for perhaps 2-3 days prior to integration into the main group.
• Once in the group these sows will normally lie together throughout gestation.
• Other options include mixing sows immediately after weaning. This means mixing a group of weaned sows into the main yard and serving from the group. Boars and service facilities have to be close at hand and stockmen have to work hard at their heat detection routines. Management of this type of system is difficult.
• Alternatively, sows can be housed separately until beyond the implementation phase when they are established well in pig. This requires an alternative housing/feeding system for the first 4-5 weeks of pregnancy.

• Managing an ESF demands a high level of stockmanship involving detailed stock observation and equipment monitoring.
• Staff must be trained to use the computer, calibrate the feeders and maintain the equipment.
• Staff responsible for day to day care of the sows should be involved in choosing the feeders and designing the layout before the system is installed.
• In large groups where sows may be inactive for much of the working day it is particularly important that checking each sow should be incorporated into the daily routine so that injury or health problems can be quickly detected.