ALTERNATIVE SOW HOUSING UPDATE

Gestation stalls were developed for a reason says Dr. Laurie Connor, University of Manitoba:

• Economic – fewer herdspersons required, rapid identification by location. Note: initial investment for stalls is expensive;
• Welfare – better control over individual feed intake, decreased aggression between sows, particularly when mixing strange animals.

However, gestation stalls have been criticized for adverse effects on sow welfare:

• High incidence of stereotyped behaviors;
• Increased incidence of sow lameness, reduced bone strength, poor muscle tone;
• Increased farrowing duration;
• Higher levels of cystitis and reduced immune function.

In Canada, Dr. Connor feels, “the industry does tend to be interested, but there is no great move [to group sow housing] at present.” Dr. Harold Gonyou, Prairie Swine Centre, has seen an increased interest in group housing using Electronic Sow Feeders (ESF). “Less than a tenth of 1% of barns were using ESF two years ago. Now about 2% of the Canadian herd is using ESF.” Both researchers agree that the drive for more welfare-oriented sow housing systems will continue to grow.

John Maltman, Swine Specialist with Manitoba Agriculture & Food believes there are some key challenges for group housing:

• Banks – financing can be challenging when banks are not familiar with a new system;
• Labor requirements – group housing requires quality animal husbandry and depending upon the system, sometimes greater labor inputs;
• Aggression – key times such as when feeding or mixing animals can lead to aggression. Gilts, in particular are victimized.

“Individualized feeding is often considered the key to truly successful group housing,” says Dr. Connor. ESF systems, where sows are fitted with a transponder via a collar, ear-tag or implant, are particularly popular.

Harry Huysman, an Alberta producer who has run a continuous herd of 140 pigs using ESF for the last four years is very pleased with the system. “I get more life out of a sow, more parities than before. Before we got 6 to 7 litters from a sow. Now its 8 to 10.”

Osborne Industries promotes a system for management of sows within a group setting, including the use of ESF. Ron Thibault states, “our company’s research has shown no economic or productive disadvantages and several key advantages.” He also notes that their system is cheaper than conventional stall systems.

“Group systems require good stockmanship skills if they are going to be operated successfully,” says Dr. Connor. Edwards adds, “[group housing] demands a greater quality of input. Without this quality of input, group housing systems will fail to deliver to potential and can be economic and animal welfare disasters.” Dr. Gonyou’s research has found that overall welfare improves in group housing, but some individuals (particularly gilts) may suffer decreased well-being.

Thibault agrees that “poor management practices” can cause group-housing systems to fail. “It means relearning some simple animal management skills.”

Osborne Industries studies have found that aggression decreases in large groups (>40) with proper management. Dr. Gonyou’s research, with group sizes of 100 to 250 pigs, supports this finding.

Huysman has not found aggression to be a problem in his herd.“There is some fighting and gilts are tougher to deal with, but less than 1% of sows need to be pulled [due to aggression]. Sows stay extremely healthy and are way better on feed, four pounds a day, and never constipated.”

While aggression in group housing is a concern, gestation stalls are not without aggression issues. A 1995 study by Broom, Mendl & Zanella found that sows in gestation stalls show high levels of aggressive behavior (biting through bars). They speculated that aggression remains high, as it is not possible to resolve the issue due to confinement.

Huysman says “In time you’ll see more and more [group housing].” Maltman agrees, “Producers haven’t coalesced around one system yet. It’s not a uniform movement, but it will happen.”