Nutrient disruption is a bigger issue in swine units today than many producers imagine. Sometimes it’s due to mechanical or system failures. But sometimes it is because we don’t accommodate the pigs’ needs and behavior as we should.

So, what is nutrient disruption and why is it so important? Start with proper gut function, which depends on a regular flow of nutrients being ingested orally. If that flow is interrupted, the gut’s villous architecture deteriorates, often in a matter of days.

When this happens, the gut cannot absorb nutrients as effectively, and it can lead to undigested nutrients entering the lower gut, which makes it easier for negative micro-flora to develop. The gut will become permeable and more susceptible to pathogens and enteric challenges. Since the gut represents about 80 percent of a pig’s immune system, it’s important to give it every opportunity to stay healthy.

Disruption at weaning

There are four common times and events when nutrient disruption can occur: 

  • Weaning
  • Transition from nursery to finishers
  • Out-of-feed events
  • Disease challenges

Let’s look at the weaning event. In commercial systems, weaning is an abrupt process, with many things happening all at once. Even though commercial production has trended toward weaning a slightly older pig (21 to 24 days old), piglets are still quite immature.

Prior to weaning, the pig receives feeding cues from its mother, drinks all of its meals and eats as part of a group. When pigs are weaned into a nursery or wean-to-finish barn, they receive no feeding cues, are no longer with littermates and must adapt to drinking water and eating dry feed.

Because of this abrupt event, pigs struggle to appropriately regulate dry feed and water intake. Often, piglets will not consume dry feed during the first 12 to 24 hours after weaning. This nutrient disruption is far greater than any the pig has experienced so far. In looking at pig behavior after weaning, what’s most apparent is high water intake and low dry-feed intake, which can be expected since piglets are used to receiving liquid meals. The result is variable feed intake by individual pigs that lasts a full week after weaning.  

How does significant nutrient disruption at weaning ultimately affect pigs? Are they able to deal with it and go on or are there long-term ramifications? Adam Moeser, DVM, and his team at North Carolina State University, have focused on the impact of early life stress on intestinal-barrier health and permeability in early weaned piglets compared to their un-weaned littermates.

Moeser’s studies revealed that early weaning caused piglets’ intestines to become more permeable, indicating a compromised intestinal barrier. His studies showed that barrier disturbances in these pigs persisted up to nine weeks after weaning. This suggests that stress which occurs early in life results in permanent defects in the gastrointestinal barrier. He also observed that when early weaned pigs faced a mild social stress later in life, they were more sensitive to it as measured by high blood levels of stress mediators (corticotrophin-releasing factor and cortisol) and increases in intestinal permeability compared with the late-weaned, control pigs.

Nutrient disruption often happens at the same time pigs are experiencing “additive stressors.” Normally, pigs can cope with one stress event and maybe two when they have time to rest and recover between those stresses. However, some events, such as weaning, present four, five or more stresses.

Setting the right environment

Understanding what a pig goes through at weaning can help you minimize the adverse effects. But it starts before the pig is weaned.

The farrowing house gives the pig a fairly protected environment, and it’s a great time to prepare the pig for coming events. Creep feeding is a way to help pigs experience the future and start training them to eat. You may not see significant benefit in weaning weight, but there are subsequent benefits in nursery-feed intake when pigs become eaters.

Once pigs are weaned and placed in the nursery or wean-to-finish barn, everything should be predicated on pig comfort. Start with a warm and dry environment. Pigs sleep a considerable amount after weaning and you can tell when they are comfortable. If they are spread out evenly and are resting well, they’re more likely to explore their environment and find food when they’re awake.

Whether pigs are on a truck for a long period or have a short haul, they won’t eat much dry feed in the first 24 hours after weaning. Individual feed intake will actually be erratic for the first full week. Therefore, it’s important to keep nutrients flowing into the pigs even if it meets only a portion of their maintenance needs.

Enriching the water

The weaning event and sudden removal from sow’s milk results in transient starvation. Piglets literally don’t know what or how to eat. Enriching the water is a fairly new concept that’s been shown to reduce nutrient disruption. Pigs will drink immediately after weaning, so enriching the water can provide a base level of nutrients until normal dry-feed consumption occurs. Options to enrich the water include plasma-based products, glucose- or lactose-based energy products, or combinations of energy, dry-fed microbials and electrolytes.

From a behavior standpoint, it’s important to cue the pig to eat as much as possible. Placing temporary round feeders into pens can be helpful. Since pigs are used to eating as a group, accessible feeder space for the first few days is important. Fresh feed in small amounts in standard feeders, or starting them on mats, is much better than dumping large quantities of feed into the automated feeder. The more you can interact with pigs and teach them to eat, the easier the pigs will transition to dry feed.

Once pigs have been in the barn for a few days, start identifying the non-eaters. This is a bigger problem than often realized, and non-eaters can be large or small pigs. They generally show up three to four days into the nursery period and may continue to surface for as many as 14 days. Walk the pens and look at the pigs’ toplines; also look at the flank to see if any are gaunt or drawn in. Pick up any questionable pig and feel its stomach to tell if it’s been eating. Pigs that you identify as non-eaters should be separated and put in a pen where they can receive special care. Treat them as if they are just weaned and work to encourage nutrient intake.

Weaning pigs often has adverse effects on everything from growth to gut health to animal behavior. The more you do to recognize the stress of weaning and accommodate the pigs’ needs, the easier your pigs will adapt to their new environment. You will help reduce stress and nutritional disruption, and put pigs on track for a healthy and productive future.

(Editor’s note: For more information, contact Brent Ratliff, swine nutritionist, or Denny McKilligan, swine technical director, at (800) 422-3649 or info@techmixinc.com.)