Free Access ESF

Free-access ESF system provides individual sow feeding similar to an ESF system, but at a reduced sow-to-feeder ratio.

Free-Access ESF feeders are a relatively recent feeding system that was developed by producers in Quebec. Since their development they have become a popular alternative for feeding sows. As the name suggests, the feeder combines the features of both free-access stalls and ESF systems.

Free Access ESF management

Free-access electronic sow feeder (free-access ESF) systems combine attributes of the free-access stalls with those of standard ESF systems. The feeder provides individual feeding to sows, using an RFID ear tag and offers programmable feed curves, similar to ESF systems, but at a reduced sow-to-feeder ratio compared to ESF. The recommended sow to feeder ratio is 20:1, with typical group sizes of 40 to 60 sows. For larger group sizes, pens are equipped with multiple feeders.. This results in less competition at the feeder entrance and more social facilitation of feeding behaviour as multiple sows can feed side-by-side in the feeder stations. Like free-access stalls, sows are fed in a self-closing stall which protects them during feeding, and they must back out of the stall to exit. Because of the lower sow numbers fed, there is little aggression observed at the feeder entrance- sows enter the feed stations and feed calmly, with minimal displacements or aggressive interactions at the feeder entrance.

Compared to free-access stalls, the free-access ESF feeder has the advantage of providing individual feeding, while requiring less pen space and penning because each feed stall is shared. Based on these characteristics, the system combines the advantages of existing non-competitive feeding systems, and at a reasonable cost.

Training

The stall is also very easy for sows to use, with a simple gating system that requires minimal supervision or training. Most sows learning the system with no manual training. Gilts should be introduced to the system a week before mature sows, or can be trained in a separate pen with additional space and reduced sow numbers. Gilts and sows require some training to learn how to use the feeding stalls. Training areas can be used prior to breeding and should provide 1 feeder per 7 to 10 animals. Sows will tend to learn the system faster than gilts; slower learners will learn by observing faster.

Stockpersons that are conducting the training need to follow a carefully structured program and be patient with the gilts to avoid creating any negative association with the feeders. Special attention should be paid to ensuring the gilts learn how to trigger the mechanisms that allow them to feed and to exit the stall.

Design Considerations

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, a full 180° access.
Feeder capacity should be strictly adhered Generally, this is in the range of 15 to 20 animals per feeder; pens with only one feeder and gilt pens should have at least 1 feeder per 15 animals. Over-stocking feeders will increase pressure on the system, reduce the time allowed for each animal to obtain its daily ration, and can result in increased aggression around the feeder.
Only dry feed should be presented in the feeders with water available outside the feeders; this encourages sows to exit the An “anti-lay” bar centred on the floor of the feeding stall discourages sows from lying down while in the stall.
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,
When groups are initially mixed, closing the back gates of the feeding stalls for the first 3 to 4 hours prevents submissive sows from hiding in the feeding stalls, which, if allowed, could become habitual, and allows the social hierarchy to be formed more readily.

BENEFITS

Individualized feed intake and ration control is possible, and phase feeding is readily achievable.
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.
Free-access ESF systems allow sows to be protected during feeding.
There is moderate to low feeding-associated aggression, as it can only occur outside the actual feeder.
Sows have the freedom to move around and choose their location in the pen. They also have some control over choice of social partners.
A less-rigorous training regime to the feeding system is required than with a standard ESF system. Sows previously housed in gestation stalls tend to adapt well to this system. Gilts may require more time to learn how to use them, including how to access feed and exit the stalls.
This system can accommodate a wide range of group sizes, from small static groups to larger dynamic groups. A single free-access ESF is intended for a relatively small group of 15 animals. Larger group sizes, with up to 20 animals per feeder, can be accommodated by incorporating multiple free-access ESF stalls in a pen.
Free-access ESF stalls can be used on a partially-slatted floor system without foraging material as well as in solid- floor, bedded systems; however, they are considered to work best in combination with foraging material, which may decrease aggression around the feeder.
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.
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.
Successful conversions to this system in existing barns can be accommodated a a lower cost when compared to traditional ESF systems.

CONSTRAINTS

A separate breeding area is most commonly used so that only bred animals are introduced into the group pen.
In pens with a single free-access ESF, sows cannot eat at the same time.
The pen layout is particularly important to avoid problems with aggression, allow easy access to the feeder, and provide defined resting and dunging
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.
Younger, smaller or more timid animals may remain in the stalls for longer periods to avoid aggressive encounters with more dominant animals.
A small percentage of gilts may not be readily trainable to the free-access ESF system. The back gate mechanism of the feeder can sometimes deter gilts from exiting the stall.
Highly committed stockpersons and management are required for success. 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 required.
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 feeders in each pen.