Whether due to lameness or unproductivity, culling sows is a frequent event on most hog farms. Because it is not a daily task, it is not given the emphasis and training needed to effectively manage this neglected profit center, says Terry Whiting, DVM, manager of Animal Health and Welfare, Manitoba Agriculture and Rural Initiatives.
When cull sows are not properly assembled and transported to the slaughter plant, injuries may culminate in mortalities during transit or within the plant.
When properly cared for, these sows can be converted to healthy ground pork that provides food for consumers and a humane end for the sow, Whiting says in an address at the Feet First Sow Lameness Symposium III in Minneapolis, MN, in September.
Planning for Retirement
Cull sow rates approach 50% on most farms. Each cull sow represents the added investment in an acclimated gilt to take her place. That’s a big challenge to producers, Whiting says.
Don’t forget about these sows near the end of their reproductive lives, because they can represent a profit center and therefore deserve our respect and care, he notes.
Realize that cull sows are a fairly fragile commodity. For most of their lives, they have been housed individually, never having to compete with others for feed or water.
Assemble them in a separate pen area with access to water, especially if they will be held for 24-36 hours prior to loading. When possible, provide straw for distraction from penmates.
Show patience in moving sows into pens and onto trucks. Sows walk at a much slower pace than market hogs. Their lower activity level can lead to more joint issues and lameness. Realize that, even if you push them, they will only go so fast.
“They have a different body proportion than market hogs, carrying a bigger proportion of their body mass on the front legs (big heads, tiny hearts), so lameness in front legs is more common in sows than in market hogs,” Whiting explains.
To account for limited mobility, it’s important to develop some standard operating procedures for working with sows:
• Sows may appear defiant or lazy, but they are not accustomed to having to move fast, so don’t let aggressive employees work with sows. “An individual who is calm, patient and truly identifies with livestock is the correct match for loading and handling cull sows,” Whiting says.
• Try to maximize body condition of sows. “Identify cull sows early in lactation and keep body condition scores up so they will be easier to transport,” he says.
• Don’t load a sick sow. “If she is not looking good, take her temperature. If it is over 101°F, don’t put her on the truck,” he urges. Identify sows that should be held back or euthanized on the farm. Even if a sick sow survives the rigors of transport, if she has a fever, she will be condemned at the plant, Whiting warns.
• Non-slip floors are essential for loading ramps and alleyway floors. “Moving too large of a group and pressuring sows to move faster than they are comfortable with results in increased slipping,” he says.
• Loading ramp slope should be no more than 20%. Cleats on ramps must be spaced to fit the normal walking stride of the animal. “If you can design your barns so that sows can come up a ramp to a platform that they can stand on before walking onto the truck (no internal truck ramps), then I think it will help in loading sows,” he says. Load weaker sows last.
Critical control issues in cull sow marketing include downer sows, shoulder ulcers and crowding on the truck.
Sow hoof health and the prevention of lameness can reduce downers. Proper animal density can cure problems of overcrowding.
Keeping lame sows in the herd too long results in higher death loss. When these sows are culled close to farrowing and shipped, dead on arrivals increase, Whiting says.
“Proper sow management starts with gilt selection and continues through the whole production process. Manage sows for optimum welfare and value. Treat cull sows like they are still part of the herd and still part of the profit center for your operation,” he concludes.