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Criteria outlined for sow group housing

Criteria outlined for sow group housing

THE National Pork Board recently began a sow housing webinar series to provide guidance on advantages and disadvantages of the housing system options currently available to pork producers.

The series is intended to help producers make sound decisions on which housing system will be best for their animals, their facilities and their business.

The first webinar in the series focused on the choice and design of group housing systems and featured Dr. Don Levis of Levis Worldwide Swine Consultancy.

Group housing has become a hot topic in the pork industry. As more retailers commit to buying pork sourced only from sows raised in group housing systems, producers have had to reassess their operations.

In addressing the group housing options, Levis said many components need to be considered when housing sows in groups, such as: the number of sows per group, floor space per sow, the size and shape of pens, the type of flooring used, the use of bedding, the type of feeding system, group management (dynamic versus static), the ventilation, heating and cooling system, an area for urination and defecation, the sleeping area and an area for eating -- and that's just a portion of the aspects to consider.

In a report coinciding with the webinar, Levis said group housing systems give sows the freedom to move around, to perform normal social interactions and to choose areas for urination/defecation and for sleeping.

However, he warned that poorly designed group housing systems can create great potential for poor sow welfare if the sows have to fight for access to feed, have difficulty avoiding aggressive encounters or do not have an appropriate place to rest.

The main criteria for choosing a certain group housing system will most likely involve investment costs, the ability to maintain a high level of health and welfare for the sows, ease of management, labor requirements, the feeding system and the overall simplicity of the system.

Group housing systems are primarily focused on the feeding method and whether sows are kept in static or dynamic groups.

Static groups mean that no new sows enter the group and no sow leaves the group until the group is moved to a farrowing system.

In static housing, sows establish a hierarchy in the beginning that remains the same once it has been formed.

Levis pointed out that, depending on the production schedule and facility design, static groups of gestating sows are formed during the first five days after insemination, or during days 28-35 of gestation after being removed from individual breeding stalls.

He said static groups should not be formed during the initial pregnancy or the period when embryos attach to the uterus.

Dynamic groups, on the other hand, consist of serviced sows that enter the group every one, two or three weeks, Levis explained. Additionally, sows that are due to farrow are constantly exiting.

Large dynamic groups result in a continual cycle of sows establishing hierarchies. With large groups of sows, Levis recommended providing adequate space for subordinate sows to avoid the aggressive encounters that arise from the frequent introduction of new sows.

He added that it may be easier to handle sows that are returning to estrus in dynamic groups compared to static groups.

Aggressive interactions between sows is one of the main reasons for the continued use of gestation stalls, but the movement toward increasing use of group housing means that the industry must find ways to minimize situations that may result in sow aggression within group housing systems.

"Aggressive interaction is always going to be present in these group housing systems," Levis said.

The interactions are more prevalent during mixing and feeding times, so design plays a key role in reducing incidences.

When group housing systems result in crowding, that can negatively affect sow welfare because of inadequate space for sows during times of mixing, eating, resting and estrous activities or to escape aggressive encounters.

Levis also said producers need to pay attention to the location and design of the eating, drinking, dunging and lying areas to reduce aggressive interactions among sows. He noted that it is important to consider patterns of sow movement so the sows do not run into each other as they navigate the pens.

Establishing sick pens within group housing systems also requires planning. In the webinar, Levis suggested placing sick pens where the animals can be viewed frequently. He said the pens need to be free of drafts, and, if necessary, warmth needs to be provided through something like supplemental heat, bedding, a mat or a hover.

Additionally, an easily accessible method of recordkeeping will help track the treatment of sows.

In a group housing system, Levis noted that managing the heat-check boars is important. He said two to three boars will be used in each pen and added that it is important to ensure the safety of the workers who handle and move the boars. Levis also said the boars should be housed away from the sows so they maintain sensitivity to the boars.

As far as the actual structure, Levis pointed out that when existing stall gestation facilities are remodeled to group house sows, it most likely will result in a reduction in the number of sows housed in the facility, which means the ventilation, heating and cooling system will have to be evaluated to determine whether it is sufficient or if modifications are required.

Levis said although it is necessary to have a well-designed system, there is another very important aspect to keep in mind.

"The critical factor for optimized resource performance and animal welfare is people," he emphasized. "They are going to make the system go."

Levis said the staff needs to be highly motivated and willing to learn since group systems are different from gestation stall systems. Additionally, workers must have excellent observational skills. Last, he pointed out that they need to have a good temperament.

For more in-depth information regarding the variety of feeding systems available for group housing systems or for more information on group housing in general, visit www.pork.org/sowhousing. Additional webinars will also be presented on other sow housing topics.


Virus controls flies

U.S. Department of Agriculture scientists have found an effective method to stop house flies from reproducing by infecting them with a virus.

House flies can transmit hundreds of animal and human pathogens like salmonella, Escherichia coli and shigella bacteria that can cause foodborne illnesses. Insecticides are used to help control flies, but the pests can develop resistance to chemicals.

Entomologist Christopher J. Geden, with the Agricultural Research Service (ARS) Center for Medical, Agricultural & Veterinary Entomology in Gainesville, Fla., examined salivary gland hypertrophy virus (SGHV), a member of a newly discovered family of viruses called Hytrosaviridae.

The virus reproduces in the salivary gland of the infected insects, which prevents the females from laying eggs and the males from mating.

Collaborating with scientists at the University of Florida and Aarhus University in Denmark, Geden looked at the distribution and host range of SGHV and the effectiveness of different application methods for controlling house flies.

ARS said the scientists examined different approaches to increase the virus infection rate in flies. The best method was a crude mixture of water and flies infected with a Danish SGHV strain.

A strain of healthy flies that had been dipped directly into the mixture or that walked on treated surfaces had an infection rate of 56%. A Florida strain had a 50% infection rate.

Liquid baits containing SGHV produced an infection rate in flies of 22% for the Danish virus and 26% for the Florida virus. When flies were sprayed directly with SGHV, the Danish virus infected 18% and the Florida virus infected 22%.

In other laboratory tests, Florida house flies were highly susceptible when injected with SGHV. Black dump flies were severely affected, and stable flies died quickly or failed to develop ovaries after injection.

While the virus shows great potential in controlling house flies and other filth flies, it is not a quick fix, according to Geden.

However, ARS noted that SGHV could become part of an integrated management program that involves treating natural fly populations early during peak season to reduce reproduction.

*Krissa Welshans holds a bachelor's degree in animal science from Michigan State University and a master's degree in public policy from New England College. Welshans has long been involved in agriculture and has worked with numerous agricultural groups, including the Animal Agriculture Alliance.

Volume:85 Issue:16

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