Swapping the only diet they’ve known for a different one, and learning a new eating system, puts a great deal of stress on piglets making the transition from sow’s milk to solid food and water. Producers can lean on a few solid strategies to make newly weaned pigs comfortable enough to thrive in the nursery.
Those working with nursery pigs observe firsthand the learning curve that comes with getting used to their new diet, flavors and textures, as well as pans, feeders, waterers and other equipment they have to learn to navigate. It’s important to help them start wanting to use these new tools to eat within the first 48 hours weaning off milk, as it gives them a desire for mealtime throughout their lives.
The Science of Stress
The stress response of pigs, like other livestock, is influenced by activation of the hypothalamic-pituitary-adrenal (HPA) axis — glands that trigger adrenaline and cortisol when the animal is in a stressful situation. This is great in danger, such as escaping a predator, as the hormones can help the body override physical limitations or injury to get away. The problem is that the stress felt in less deadly situations also trips the HPA, and sustained stress keeps cortisol levels elevated.
In a wean pig, sustained cortisol release suppresses its immune system, which can lead to damaged gut microbiome integrity and leakiness. Successful stress management in the nursery goes back to trying to prevent too much cortisol-spiking.
One good way to gauge the pig’s stress level is if it is eating and drinking adequately. Monitor your pigs’ interest level as well as consumption. Are they interested in the waterers? Are they going to the feeders on their own and interacting with the equipment well? Group huddling and zero interest in getting up to eat at feeding time should be of concern.
I am in favor of using electrolytes or other additives in water for freshly weaned pigs — this helps them want to hydrate frequently, and some additives also stabilize their gut microbiome and may help immunocompromised piglets get started. Producers shouldn’t use these for long, since too much could lead to diarrhea — but for those critical first few days in the nursery, it can be an effective tool to help establish good habits.
Multiple Sources of Stress
Going from the farrowing space to nursery is one of the more stressful events in a pig’s life, not just because of a new diet. Everything is changing — separation from sow and littermates, living in a new pen or barn, increased socialization, a new schedule and things to learn. Even if you’re a veteran producer, reviewing practices from time to time isn’t a bad idea.
Before your influx of new pigs, make sure the barn is set up correctly. This includes preheating the space, making sure brooders work correctly and comfort mats are placed correctly.. This helps lessen the shock of temperature change from the farrowing space and being close to the sow. Check the ventilation — do the fans work? Are the controls set appropriately for the season and environment? Manage humidity to make sure the pigs get plenty of fresh air.
Use proper handling techniques when picking up and moving young pigs. You can learn more about the correct manner of handling through Pork Quality Assurance (PQA) Plus guidelines from the Pork Checkoff. Rough handling increases cortisol levels and the chance of injury, as well as contributing to the pig’s fear of people; proper handling ensures that pigs remain fear free of humans.
Stocking density is also important in managing young pigs’ stress levels. Ensure they have adequate square footage per pig according to their age and proper feeder spaced and water station access per head. Also, make sure the space is sturdy — you don’t want them breaking through pens as they get bigger, since some aggression is normal as they socialize.
Good preparation of the living space and supplies goes a long way toward reducing stress and promoting pig health and welfare. Genetics companies can often provide specific recommendations about ideal stocking density, feeder space and other metrics for animals from their lines. If you have access to such a source, I encourage you to review their guidelines.
Don’t Forget Transport Stress
One other source of potential stress for new nursery pigs is in transport. Be sure your hauler maintains clean, dry trucks that are disinfected thoroughly between runs — producers are encouraged to run empty trailers through a “bake” to reduce the possibility of infection between groups.
Drivers should use the safest routes possible, to minimize animals’ time on the road, especially in extreme temperatures. In hot weather, pigs rely on evaporative cooling since they can’t sweat, so spraying with water when appropriate is critical to survival and welfare.
Of course, also make certain you have plenty of feed and water ready for incoming wean pigs, including medications or other additives — discuss these with your veterinarian. If you don’t already, I highly recommend having both a veterinarian and nutritionist to help develop a plan with maximum benefit for your nursery pigs. This should address gradual diet changes as they age, use of any functional additives and probiotics, a vaccination program tailored to health status and geared for the prevention of disease and more to aid in proactive stress management.
Claire Mtezankuni, DVM, MVS is an associate swine veterinarian with Carthage Veterinary Service, Ltd.
