Electronic Sow Feeders

The ESF provides a non-competitive environment for the sow at feeding and allows individual feeding curves to be programmed for each sow during gestation.

The Electronic Sow Feeder (ESF) is a feeding system for group housed sows and gilts. Sows enter the ESF feeding stall through a gate which closes behind them, preventing access by any other sow. The feeding system is regulated by a computer which scans the sow’s ear tag and delivers the appropriate feed ration for each sow. The ESF provides a non-competitive environment for the sow at feeding and allows individual feeding curves to be programmed for each sow during gestation. Aggression may still occur at the entrance to the ESF as sows compete for entry to the feeding stall. One standard, walk-through ESF station can readily accommodate 50 to 65 sows. Multiple ESF stations per pen can be used for larger groups of animals. Particular attention must be paid to the design of the feeding station and the pen layout

Electronic sow feeder management

Provides individual feed curves for each sow
Balances the benefits of undisturbed feeding and group housing
Some computer knowledge is important for the operator
Training of sows is required
Low levels of aggression when managed correctly
Able to manage groups with continuous introductions (dynamic) or with stable groups (static)
Moderate capital cost at conversion due to reduced space and minimal penning requirement
Minimal reduction in herd capacity OR Minimal increase in barn space requirements

The sows and gilts can enter the ESF at any time of day to consume their daily ration of feed, which minimizes stress and competition. Sows may enter numerous times to finish their daily allowance, or it can be consumed in one visit. This is possible due to the feed being delivered in small amounts as the sow eats, when she leaves the feeder the ration delivery will stop and the computer will calculate the remaining ration left to consume in that 24 hour period. Daily feed volumes can be easily regulated for each individual sow and adjusted based on body condition score. When the sows are not feeding they are in a group situation, which is important for achieving the benefits of improved fitness and muscle strength. Space requirements are lower than in other systems as only one feeder space is needed for up to 60 sows

Additional management tools are available in many ESF systems. These may include automated sorting for management processes such as vaccinations, pregnancy checking, formation of groups to be moved to farrowing etc. Colour marking and mineral supplements can also be allocated to individual sows by programming their ear tag numbers into the computer program. Liquid and dry feeding versions of ESF are available. Most dry feed systems also provide water with the feed, as this allows sows to consume their feed more quickly, helping to improve the efficiency and throughput of the system.

The computer system provides real time updates on which sows have fed, and more importantly, on those that have not. A sow not visiting the feeder can indicate ill health or injury, or that the sow has lost her ear tag. Stockpersons should be trained on the use of the computer system in order to get the most from this housing option.

It is important that the overall design of the pen does not allow sows that have finished feeding to recycle and return back to the feeders, thinking they will obtain extra feed. This problem can be overcome by including walkways to increase the distance between the feeder exit and entrance. This design will discourage sows from returning to the feeding station after consuming their allotted ration.

Training

Some training of sows and gilts is required with the ESF system. When transitioning to ESF all animals must be trained, however, once the initial training is complete, only new gilts entering the system will require training. Some sows and gilts may be cautious and reluctant to enter the feeding station if they have not come in contact with it before. A separate training pen should be used to train the sows and gilts on how to access the feeder system .This system of gated areas allows staff to adjust the size of the entrance and exit pens as the day progresses. Some sows or gilts will need encouragement to enter the feeder. This can be done by placing a small amount of feed on the floor at the feeder entrance to encourage the sow or gilt in. Use of low stress animal handling techniques is also an option to get the sow or gilt into the feeder.

Training pens should consist of groups of 30 – 40 sows or gilts, and training should ideally occur before breeding when any missed feeds will not affect production. Early in the training period, the gate to the ESF can be tied open, and feeders should be well illuminated with overhead lighting to encourage exploratory behaviour of the sows.
Some feeders have a manual training button that, when pressed, will dispense feed when the sow enters, providing an immediate reward for entering the feeder. As sows become accustomed to the ESF, less interference by staff will be necessary and the gate to the feeder can be gradually closed.
The training period generally takes 7 to 14 days to complete. A training pen can also be set up using gates similar to the ESF, but without the ESF unit, in order to facilitate training without the added cost.
It is vital that sows or gilts do not have a negative experience when learning to use the feeder as they can become reluctant to enter.
After the whole barn has been trained, the training area will be used only for gilt training. This should also take place prior to breeding. If carried out correctly, gilts will become used to the feeder and to handling as the training progresses.
Training of gilts and other new animals to the ESF stations is critical to the success of the system. Stockpersons that are conducting the training need to follow a carefully structured program and be patient with the animals to avoid creating any negative association with the feeders.
Stockpersons with excellent animal handling skills and patience should be responsible for ESF training.

Design Considerations

Feeding stations should be designed and placed to prevent sows from easily circling back to the entrance of the feeder from the exit.
Placement of the feeder in a pen should ensure sows cannot get caught in blind corners. The in-gates should be freely accessible from both sides, full 180° access.
Feeder capacity should be strictly adhered to the range of 50 to 65 per ESF, depending on whether they are gilts or sows and number of feeders per pen.
Over-stocking feeders will increase pressure on the system, reduce the time allowed for each animal to obtain its daily ration, resulting in increased aggression around the feeder. Considerable variation can exist in feeding time between animals; gilts tend to take longer to eat than sows.
A feeding cycle that starts in the late afternoon or evening means that most of the animals should feed before mid-morning of the next day. Any animals not eating can be identified and checked promptly during the work-day. Evening cycles may also reduce sow aggression.
A separation area can be utilized for removing animals from the group (repeats, sick, pre-farrow) and should provide 1.8 m2 (19 ft2) per animal.
Assurance of computer and equipment reliability and accessible technical support is essential.
ESF design and pen layout are particularly important to avoid problems with aggression, allow easy access to the feeder, and provide defined resting and dunging.

Social Management

Once per day, the feeder program is reset to initiate a new round of feeding. This can result in aggression at the ESF entrance gate, as sows will recognize this daily ‘event’ and dominant individuals will compete to access the feeder. Timing of the reset has been shown to influence aggression, with less aggression occurring at the feeder entrance with a 10pm reset than at 4am. Subordinate sows will be displaced and will access the feeder later in the daily cycle. Because of this, sorting of sows with respect to weight, parity, and body condition score may be desirable. A maximum group size of 60 sows is recommended per ESF unit as this is the maximum number that can be reliably fed per day. Larger groups can be accommodated (e.g. with dynamic grouping systems) by providing additional pen space and multiple feeders.

Dynamic Grouping Guidelines

It is possible to manage dynamic groups of sows in ESF. New groups of sows are added periodically, and sows ready for farrowing are taken out. When designing the barn always remember to calculate for the maximum number of feeders and floor space required. Some practical measures must be taken to manage the system well and limit the aggression from the change in hierarchy that occurs when adding to the group. When adding sows into the group they should be between 21—38 days pregnant and have been preg checked. The group being added should equate to 20% of the total group. On the day of mixing make sure all sows are fed their full daily ration before adding them to the dynamic group and try to mix in the evening

BENEFITS

ESF systems allow sows to be protected during feeding.
Individualized feed intake and diet control including phase feeding.
Sows have the freedom to move around and choose their location in the pen, in addition have control of their social partners.
There is moderate to low feeding-associated aggression, as it can only occur outside the actual feeder.
The system can accommodate a single group of 50 to 65 animals or larger group sizes of 200 or more sows per pen with multiple ESF stations.
The system works with both static and dynamic groups depending on herd size and breeding groups.
ESF stations can be used on a partially-slatted, solid-floor, and bedded systems.
Sows that have not eaten during the feeding cycle are identified on the computer and personnel can readily determine if sows are sick, injured or have simply lost an ear tag.
People are not associated with feeding time. Sows are often more docile and easier to handle, and workers often report a more satisfactory work environment.
Automatic marking and separating functions can be incorporated as part of the feeding station. This makes segregating and/or identifying sows for heat checking, pregnancy checking, vaccination, other treatments, or transfer to the farrowing unit relatively easy.
Ear tag loss is usually very low if it is correctly implanted in the ear and equipment is maintained to prevent snagging.
Reproductive performance and longevity can be as good as, or better than, with conventional gestation stalls.
Successful conversions to this system in existing barns can sometimes be accommodated, but is often more difficult when compared to other systems.

CONSTRAINTS

Aggression, including vulva biting, at the feeding station entrance can be a problem, particularly when there is no foraging material or other enrichment distractions. Exceeding the feeder’s sow capacity will only increase these problems.
In pens with a single ESF, sows cannot eat at the same time.
The success of the system hinges on good gilt training. An inadequate training area or rushed training will lead to more animals not adapting to the feeding system. A small percentage of gilts may not be readily trainable to the ESF station. For barn conversions, training sows that were previously housed in stalls to use an ESF may be more difficult.
A separate breeding area is most commonly used so that only bred animals are introduced into the group pen.
Highly committed stockpersons and management are required for Personnel must check the computer daily, monitor sows, and adjust feed allowance or take corrective actions as needed.
High level of competency with computer software and/ or ready access to technical support is A separate training area with ESF is needed for animals being introduced into the system.
If an automated separating function is not part of the feeding system, a lot of time can be taken for personnel to sort out animals in a large group system. If available, separation areas with slatted floors should provide a minimum of 1.8 m2 (19 ft2) of space per sow.
A back-up plan for feeding due to power outage or equipment failure is essential, but can be very challenging with fully-slatted floor systems which will not allow for floor feeding. The risk of having to use a back- up feeding plan due to equipment failure is reduced in systems that have multiple ESF stations in each pen.