Electronic Sow Feeders, National Sow Housing Conversion Project

Posted in: Pork Insight Articles, Welfare by admin on January 8, 2014 | No Comments

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.

ESF

• 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 Options
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.

Training Sows or Gilts for ESF
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 will take 7 to 14 days to complete. A training pen can also be set up using gates similar to the ESF, but with-out the ESF unit, in order to facilitate training without the added cost.

Stockpersons with excellent animal handling skills and patience should be responsible for ESF training. 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.

Efficiency of the system
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.

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 recognise 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.

This project is a collaboration between Prairie Swine Centre, Manitoba University and Manitoba Pork. Funding for this project has been provided by Agriculture and Agri-Food Canada through the Canadian Agricultural Adaptation Program (CAAP). In Saskatchewan, this program is delivered by the Agriculture Council of Saskatchewan.

Free Access Stalls, National Sow Housing Conversion Project

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Free-access stalls are a non-competitive feeding system designed for group-housed sows and gilts. Sows enter the stalls via a back gate and a mechanism closes the gate behind them. To exit the stall, sows back into the gate which opens with the applied pressure, allowing the sow to exit. The free access system greatly reduces aggression at feeding because every sow has access to an individual stall, and can feed undisturbed. The area available to the sows outside the stalls is referred to as the loafing area. Loafing areas provide exercise and rest opportunities. Studies have shown that the design and shape of the loafing area affects how much time the sows choose to use it.

FREE ACCESS STALLS

• Balances the benefits of group housing with the protection of stalls
• Preferable to manage as static groups, possible to manage larger groups with continuous Introductions
• A significant reduction in herd capacity OR Significant increase to barn space is required when converting from stalls
• Higher capital costs required during conversion compare to ESF or competitive feed systems.
• Individual feed curves are not possible
• Little sow training is required
• Loafing area design is important for sow use
• Low levels of aggression when managed correctly

The free-access stalls balance the freedom of group housing with the protection of stalls. The quantity of feed dispensed into the troughs will be the same within each pen group, but there is opportunity for stock people to add additional feed by hand if necessary. There must be one stall available per sow in the group. During barn conversions there may be an opportunity to use gestation stall material to create the free access stalls, which can reduce costs.

Grouping sows by parity and weight can encourage more sows to spend time in the loafing area as there are less submissive sows in an uniform group. Spending time outside the stalls is important for the animals to obtain the benefits of improved fitness and muscle strength.

Training the sows

The majority of sows quickly learn to use the stalls to access feed and lie undisturbed. Some sows may need training when converting to a free-access stall feeding system depending on the stall design. Observing the sows at feeding time will highlight which sows are having difficulty entering the stalls. These sows can be quickly trained by providing small amounts of feed at the entrance to the stall or using low-stress animal handling techniques to put them into the stalls.

Some sows and gilts have trouble exiting the stalls because of the pressure needed to release the rear gate. This is likely to be more common with smaller and younger sows. Options for training sows to exit the feeding stalls include:

1. The stockperson may lift the gate up part way and allow the sow to finish the job which will encourage the animal by showing them that the desired result is attainable.
2. The stockperson may use a paddle by the sows head, while exercising patience, to put pressure on the sow to encourage her to reverse. Pressure from the paddle should be released immediately when the sow starts to reverse.
3. Placing a board flat on top of the metal work of the stall causes a shadow over the sow’s head which can be an effective method of encouraging the sow to reverse. This is a good ‘hands free’ low effort method to get the sow to reverse.

It is important to ensure that all sows learn how to exit the stall so the benefits of group housing can be achieved.

Additional Management Options

Free Access Stalls can be locked individually or by row to allow management practices such as vaccination or putting groups togeth-er for farrowing. Rear gate ‘open and close’ mechanisms vary between manufacturers, and different gate designs are available. Some gate designs provide stockperson entry for ease of access to the sow for pregnancy scanning and Artificial Insemination. Different flooring types can be used with free access stalls, including options for rubber matting and bedding. For ease of feeding sows and gilts should be grouped by parity, weight and body condition score and any animals deviating greatly from the average of the group should be identified and individual feeding carried out.

Design

Free-access stalls can be set out in I, T or L- shaped pen designs. The letter indicates the shape of the loafing area e.g the I design has one long loafing area with free-access stalls on either side, while T and L designs pro-vide extra loafing space. The more functional the loafing area the more the sows will use it. This functionality can be achieved by adding wood shavings, rubber matting and drinkers to the loafing area.

This project is a collaboration between Prairie Swine Centre, Manitoba University and Manitoba Pork. Funding for this project has been provided by Agriculture and Agri-Food Canada through the Canadian Agricultural Adaptation Program (CAAP). In Saskatche-wan, this program is delivered by the Agriculture Council of Saskatchewan.

Effectiveness of Sprinkling During Transport

Posted in: Meat Quality, Pork Insight Articles, Welfare by admin on October 28, 2013 | No Comments

Sprinkling pigs with water during hot weather is thought to reduce pig mortality and reduce stress, but there is no standard for when it is implemented. Recommendations for when to sprinkle pigs vary from 14.1-24.8ºC, and not all transport trucks are equip with sprinklers.  Transport can be stressful for pigs, and increased stress  leads to fatigue, and changes in lactate levels and pH, which in turn decreases meat quality. By measuring lactate and pH levels after slaughter, it was found sprinkling before loading and after unloading reduced stress, and increased meat quality when transporting at temperatures over 20ºC.

Behaviour, social interactions and lesion scores of group-housed sows in relation to floor space allowance

Posted in: Pork Insight Articles, Welfare by admin on September 25, 2013 | No Comments

The space allowance appropriate for sows in group housing remains scientifically undefined, since the social space requirement of a group of animals and the factors which affect this are unknown. Eight established groups of six pregnant, multiparous sows were used in a replicated Latin Square design of experiment, with 7 day periods, to compare four pen sizes providing 2.0, 2.4, 3.6 or 4.8 m2rsow. For the last 48 h of each 7 day period, a continuous video recording was made to determine general behaviour and all social interactions. Time spent rooting increased progressively with increasing space allowance, whereas time spent sitting and standing inactive were both progressively reduced. The total frequency of social interactions and aggressive
behaviour both increased with decreasing space allowance. The Attack:Retreat ratio was significantly higher, and the Avoidance Index significantly lower, in the smallest pen. All body regions had the highest count of lesions after sows had been in the smallest pen, with damage levels being reduced as pen area increased. Analysis of body lesion scores, combining incidence and severity, gave the same treatment effects. In conclusion, the results indicated that a minimum space of between 2.4 and 3.6 was necessary in the conditions of this experiment to promote good welfare. This result cannot be generalised to situations of different group size, group stability or feeding method.

Sandra Edwards

Appropriateness of nutrient budgets for environmental risk assessment: a case study of outdoor pig production

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Outdoor pig production has expanded rapidly in recent years due to economic and market pressures. Recent research has shown that a high degree of heterogeneity in soil nutrient distribution can occur as a result of this agricultural system. This study examined the consequences of dietary manipulation on total excretion and spatial distribution of N and P in soils under outdoor sow production. Small areas of land chosen for excretion received excessive amounts of both N and P. Values equivalent to up to 2861 kg ha
1 of soluble N were observed in preferred areas, up to 90% of this was in organic forms. Within 15 months, applied nutrients were sufficient to saturate the soil profile in preferred areas with respect to P and produce areas that represented a significant environmental risk. Lowering the amount of N and P in the diet has potential to reduce environmental impact but cannot eliminate spatial variability. The use of simple input output nutrient budgeting approaches may underestimate losses of N and P as they cannot account for mineralisation rates of organic nutrients excreted or for P saturation in areas preferentially used for excretion.

Animal welfare and economic optimisation of farrowing systems

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In many countries, including the UK, the majority of domestic sows are housed in farrowing crates during the farrowing and lactation periods. Such systems raise welfare problems due to the close confinement of the sow. Despite the fact that many alternative housing systems have been developed, no commercially viable/feasible option has emerged for large scale units. Current scientific and practical knowledge of farrowing systems were reviewed in this study to identify alternative systems, their welfare and production potential.

Sandra Edwards

Development of a spreadsheet based financial model for pig producers considering high welfare farrowing systems

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The model was developed to address the recognized deficiency in financial information on free-farrowing systems, and assist pig producers in estimating the cost of producing pigs in such systems.  The model is available on line at  http://www.ncl.ac.uk/afrd/research/project/4378.   Users can select from eight  different types of farrowing accommodation and four gestation housing systems, with additional variations on floor type and feeding system.  Input data on herd size and productivity are entered into one active sheet and, using built-in data on housing and other input costs, the model computes the cost of producing a weaner pig 8kg at 4 weeks of age) in each gestation/farrowing system combination selected.  Sensitivities to input or output changes can also be evaluated by altering herd performance.  The use of this model provides pig producers, policy makers and other stakeholders with a means to estimate  the likely cost of pig production prior to any investment in a new housing system.

Sandra Edwards

The welfare implications of large litter size in the domestic pig I: biological factors

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Increasing litter size has long been a goal of pig breeders and producers, and may have implications for pig welfare. This paper reviews the scientific evidence on biological factors affecting sow and piglet welfare in relation to large litter size.  It is concluded that, in a number of ways, large litter size is a risk factor for decreased animal welfare in pig production. Increased litter size is associated with increased piglet mortality, which is likely to be associated with significant negative animal welfare impacts.  In surviving piglets, many of the causes of mortality can also occur in non-lethal forms that cause suffering. Intense teat competition may increase the likelihood that some piglets do not gain adequate access to milk, causing starvation in the short term and possibly long-term detriments to health. Also, increased litter size leads to more piglets with low birth weight which is associated with a variety of negative long-term effects. Finally, increased production pressure placed on sows bearing large litters may produce health and welfare concerns for the sow. However, possible biological approaches to mitigating health and welfare issues associated with large litters are being implemented. An important mitigation strategy is genetic selection encompassing traits that promote piglet survival, vitality and growth. Sow nutrition and the minimisation of stress during gestation could also contribute to improving outcomes in terms of piglet welfare. Awareness of the possible negative welfare consequences of large litter size in pigs should lead to further active measures being taken to mitigate the mentioned effects.

Sandra Edwards

Effect of dietary fibre on the behaviour and health of the restricted fed sow

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The usual restricted feeding level during gestation, whilst adequate to maximise economic performance, might not fulfil behavioural needs of the sow. Hunger and frustration of feeding motivation have been linked to the occurrence of stereotypic activity, and accentuate aggression and feeding competition in group-housing systems. Incorporation of fbre in diets to increase bulk, without changing the daily dietary energy supply, has been shown to result in at least a doubling of eating time, a 20% reduction in feeding rate, a 30% reduction in operant response in feed motivation tests, a reduction of 7-50% in stereotypic behaviour, and a decrease in general restlessness and aggression. Results suggest a reduced feeding motivation, but only if nutrient intake with fibrous diets meets the nutrient requirements of the animals. Investigations of circulating glucose, insulin and volatile fatty acid levels in sows fed fibrous diets indicate a more constant nutrient absorption and greater microbial fermentation in the gut, which should increase satiety. There is inadequate information on effects of dietary fibre on physiological stress and health. In addition to welfare considerations, a range of technical requirements and economic factors must be considered when making decisions on the use of dietary fibre during gestation.

Sandra Edwards

Effects of Feed Station Design on the Behaviour of Group-Housed Sows Using an Electronic Individual Feeding System

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With electronic feeding system, sows carry an electronic identification device on a collar or ear tag and feed sequentially at a computer-controlled feed-dispensing station. The design of this station is important in maximising the number of sows which can share it, whilst minimising aggression. Earlier studies carried out with a “double-entry” feed station design, which allowed two separately housed groups of sows to share the same feed dispensing system, indicated a capacity of up to 50 sows (Edwards et al., 1984a). However, studies of this and other rear exit designs showed that, early in the feed cycle, a number of sows congregated behind the feed station and hindered the sow backing out (Edwards et al., 1984b; Smith et al., 1986). Although this did not cause major problems with aggression, it appeared that a forward exit system might improve station use. The following studies were, therefore, undertaken to investigate the effects of different feed station designs on the behaviour of sows using the station.

Sandra Edwards