Editor’s note: Dr. Dominiek Maes, professor of Veterinary Medicine at Ghent University in Belgium, recently spoke at the global event, LifeStart: Nourishing Animal & Business Potential. The event was hosted online by Trouw Nutrition, and more than 1,100 people from 66 counties participated. Dr. Maes spoke to attendees about reducing stress during the weaning phase.

In nature, the weaning process takes place between two to three months of age, and it's a gradual process. However, European legislation allows producers to wean piglets at greater than four weeks of age or at three weeks of age if there are special facilities for the weaned piglets. The nursery facilities on most farms are considered special facilities, so very often the legislation interpretation is that weaning is allowed from three weeks of age. It's only by exception that piglets can be weaned younger than three weeks of age, usually related to health reasons for the sows or the piglets.

Outside the EU, piglets can be weaned at a younger age. This begs the question of whether weaning younger is preferred? Dr. Maes says it offers some advantages and disadvantages.

Advantages:

• Lower risk for pathogen transmission from sow to offspring
• Creates a shorter reproduction cycle for the sows, thus more efficient use of farrowing units, which are the most expensive units on a farm

Disadvantages:

• Weaning age is lower, so extra care for the piglets is needed
• More intense use of sows which may decrease sow longevity
• Sow fertility post-weaning may be decreased

If piglets are weaned at three weeks of age and no major health or disease problems are seen, it can still have a significant stress effect on the piglet.

“Early weaning is translated in the decreased integrity of the intestinal epithelium. The height of the villi and microvilli is decreased, and there are more crypts,” he said. “Looking at the feed intake of the piglets shortly after weaning, on average it’s only 100 to 200 grams per day. This creates insufficient energy for maintenance in many piglets in the first days of the weaning. It is imperative to provide a sufficient feed intake after weaning to minimize the atrophy and these morphological changes in the intestinal epithelial cells.”

Feed composition matters

“In terms of feed composition, good digestible proteins, carbohydrates and essential amino acids are important,” he said. “Recently, wean piglets have had more problems lowering the pH in the stomach, which is needed because the stomach is a buffer against pathogens. If the pH remains too high for too long, it increases the risk for disease. Try to minimize nutrients that have a buffering capacity, such as proteins or minerals.”

Avoid damaging substances like lectins and soybeans. Plan to provide sufficient vitamins, like A, E and C, and selenium as they have antioxidant activity, which helps growth in that stage of production.

At weaning the piglets lose lactation immunity, so infections can easily occur. Very often E. coli infections will be seen, but other infections may occur as well.

“Infections produce free radicals; these are toxic substances for tissue damage. So, it's vital to have sufficient antioxidant activity,” said Dr. Maes. “Also pay attention to essential fatty acids, because they are a good source for molecules involved in immune response. Omega 3 fatty acids and weaning diets have been shown to be associated with fewer E. coli infections and more feed intake.”

Spray dried plasma is a very good digestible protein, and immunoglobulins are important during this phase. Organic acids are often used in feed or also in drinking water and have been shown to be beneficial against E. coli and infections. Also, prebiotics and probiotics have beneficial effects on the microbiome, the immune response, and the body response of the animal.

Zinc oxide has been banned in the EU starting in 2022, but many EU countries have already stopped providing Zinc oxide because of resistance issues and due to its impact on the environment. Because it’s a heavy metal, it can influence the soil and surrounding environment.

Types of feed

• Pellets - provide a soft pellet for better intake
• Wet feeding - pellets are provided in a feeding draft including one of several drinking nipples so the piglet can make its own mixture which may lead to a better intake
• Liquid feed - pumped into pipes and offers several advantages. The dry matter level of liquid feed is compatible with the dry matter level of sow’s milk, and the composition is in line with requirements for nutrients and water. Plus, the piglet doesn’t need to discriminate between hunger and thirst, which is very advantageous at that stage of production.

A sufficient number of feeding places and drinking nipples and good accessibility to both are needed. Quality drinking water is important.

• Number – 1 per 10-15 pigs
• Flow – 0.5-1 liter per min

“I know from experience that on many pig farms the quality of the drinking water is sometimes not optimal,” he noted. “There may be deviations in chemical composition, and there may also be microbial contamination. The flow of the drinking nipples is critical and should also be checked regularly.”

Management practices can alleviate post-weaning challenges

By slightly increasing the weaning age - moving from 23 days to 26 days of age – it may decrease the risk of E. coli and help prevent infections. When piglets are older, they have more mature enzyme activity, which can help minimize E. coli problems post-weaning.

Intermittent suckling has been researched in multiple studies, but an interesting study that's still valid is by Wikke Kuller in 2010. She showed that intermittent suckling stimulates feed intake of the entire litter during lactation during the first two weeks post-weaning. It also improves average daily gain shortly after weaning. However, the study concluded there were no long-lasting effects on feed intake and growth. The study also indicated that intermittent suckling stimulates mainly the feed intake of the pigs that already had good feed intake during lactation.

Limiting mixing of different litters is recommended to reduce stress and from a biosecurity point of view.

Providing more light during the first 24- 48 hours after weaning may be beneficial to increase feed intake. However, with more light, it’s possible to see problems with aggression or biting, resulting in skin injuries.

Stocking density is not a problem immediately after weaning, but it becomes a problem on many farms in the last week to 10 days at the nursery when the pigs become bigger and heavier. Producers should consider pen size. Most wean pigs are housed in pens of 15 to 30 pigs, but sometimes larger groups are used.

Larger groups have a disadvantage in that it’s more difficult to identify problems in pens with many animals. For example, if a few pigs have diarrhea and you have 100 pigs in a pen, it's not so easy to find the pigs who have diarrhea. However, in terms of performance, there are no major differences in the range from 10 to 60 pigs per pen. In one study (O’Connell 2001) that showed that if you compare a pen size of 20 compared to 100 pigs per pen, the average daily gain was lower in the larger pen, and it had more weight variation.

Should producers move pigs immediately at weaning or wait a few days? Some farms choose to keep the piglets in the farrowing house at weaning and move them after a couple of days. So the amount of different stress factors is spread over a longer period, and the piglets don’t have to experience them all at once. Splitting the group after several weeks is also practiced on a few farms, but it can cause an extra stress after a few days.

“In the all-in /all-out management system, hygiene is especially important because the pigs are very vulnerable at this stage, so take care that the facilities are properly cleaned and disinfected. Ideally, there is a waiting period before moving a new batch of piglets into nursery facilities.”

Ambient temperature and air speed are important because when combined they determine the microclimate. The climate should be in accordance with the comfort zone of the piglets.

“Often, producers only focus on temperature, but they must also consider air speed and in some cases relative humidity,” he said. “For example, with an air temperature of 25°C (77°F) at the level of the piglets and an air velocity of 0.15 meters per second, the heat loss of the piglets under these conditions is the same as if it is only 20°C (68°F) and almost no air velocity.”

Risk of infection

Before weaning and after weaning, piglets are at high risk to contract an infection. Many of these infections will interfere with optimal production and can cause significant losses. E. coli infections causing diarrhea or edema in the immediate post-weaning phase are critical to monitor. Streptococci infections usually occur slightly later in the second, third or fourth week after weaning.

“Remember, it's not only about E. coli and streptococci,” he said. “There are many other infections that may also raise an alarm, it's up to the farmer together with the herd veterinarian to find out which pathogens play a key role in causing problems in a farm.”

To watch Dr. Maes’ full presentation, go here

Or to read more from Dr. Maes presentation, click here to learn about the critical factors affecting preweaning piglet health.