Clearly, the only thing better than a win-win for the pork sector is a win-win-win. 

As feed costs consume a growing portion of producer budgets, the challenge for industry is to maintain pig performance while ensuring the profitability and sustainability of pork production. Doing so can be especially hard in the post weaning period, a critical stage for pig development. In talking with industry, researchers pinpointed a number of stressors that impact post weaning pigs, such as the removal of antibiotics and the possible withdrawal of animal based proteins from the diet. In response, science set out to develop effective feeding strategies for weaned pigs that would maximize profits, reduce reliance on in-feed antibiotics and improve robustness.

Let’s get growing

A prime focus for achieving these goals was amino acids and their potential for boosting health and growth in post weaning pigs without breaking the bank on feed. In turn, this could reduce the industry’s reliance on antibiotics by offering an alternative means to treat disease and promote growth through diet alone. For both the pork sector and the general public, reducing the need for antibiotics is a top priority, which makes it top of mind for science as well.

As well, researchers sought chemical and biological tools to detoxify vomitoxin, a mycotoxin that is most common in grains like wheat, barley, oats, rye and corn. Not only could this boost pig growth and producer profits, but it may lead to greater food safety.

In the course of their study, the team also aimed to maximize the level of pulse grains in diets in order to reduce feed expense and improve gut health.

Pigs, plants and profit

Traditional post weaning diets usually feature animal-based protein sources such as whey and fish meal, as they are seen to be the best option for reducing the stress of weaning. These regimens are highly complex and easy to digest, but that comes at great cost to producers. Some studies, however, have suggested that such diets, when compared to plant-based options, do not enhance growth performance overall from the nursery to market weight hogs.

At the same time, there is evidence that plant-based diets may render pigs more vulnerable to disease compared to the animal-based route. This sort of “good news, bad news” scenario underscores the need for continued research on the pros and cons of various feed regimes.

Just add amino acids

For this study, researchers addressed the downside of plant-based meals by including a mixture of functional amino acids at 120 per cent of NRC recommendations (Nutrient Requirements of Swine). Functional amino acids govern vital metabolic pathways to enhance development and health and are key components of many immune system proteins. Previous studies have shown that this approach boosts growth and immunity of pigs facing a disease challenge such as Salmonella.

Pick your path

Based on this project, producers now have options. In some operations, the animal-based diet may be preferable for its ability to improve pig health. In other cases, switching to plant-based meals could help to offset rising feed prices and keep more dollars in producer pockets. For those choosing the latter approach, supplementing diets with the functional amino acids methionine, threonine and tryptophan in amounts that exceed current industry levels can help guard against the negative impact of plant-based strategies on disease resistance. Those amino acids become even more effective in safeguarding pig health the further out they are used from a disease challenge.

All told, the study covered a lot of ground, thanks to strong support from industry, government and academia. Swine Innovation Porc (SIP), the Government of Saskatchewan and the Government of Canada under the Canadian Agricultural Partnership participated as funding partners. The research itself was driven by co-leaders Dr. Daniel Columbus, research scientist and adjunct professor at the Prairie Swine Centre, University of Saskatchewan, and Dr. Martin Nyachoti, professor, Department of Animal Science at the University of Manitoba.

Just as many victories in life stem from making the right moves at the right time, scientists feel the same can be said for success in pork production. While the wrong decisions with post-weaning pigs may harm their performance down the road, choosing wisely will lower costs and antibiotic use, raise performance levels and improve the public image of the entire pork sector.

“Performing pigs” might sound like entertainment, but maximizing pig performance is serious business for producers. 

Just as a healthy diet keeps people going strong, the right amount of vitamins and minerals in pig feed can be the difference between profit and loss in the pork sector. Towards that end, researchers went to work on micronutrient strategies to maximize robustness and performance for pre- and post-weaning piglets.

Science has known for years that piglets are prone to iron deficiency. Although they are born with reasonable iron levels, they can begin to run low on this mineral by day 3, and will become anemic by weaning if they aren’t given iron supplements. So what happens with other trace minerals and vitamins?

Curious copper

Copper is an essential mineral for pigs, as it improves growth performance and feed conversion rate, especially in young pigs. While the National Research Council Canada recommends 6-10 ppm (parts per million) in the diet of postweaning pigs, the industry standard in Canada is 130 ppm on average. Through blood sampling in a previous study, researchers determined that copper levels decreased in the post-weaning period to very low values usually found at birth, even in animals given large amounts of copper. In spite of providing pigs with up to 20 times the suggested amount, they still emerged as copper deficient three weeks after weaning.

The results with copper prompted a highly scientific question: “What the heck happened?”

Let’s think about zinc

In search of an answer, scientists then added zinc to the mix, which is still used in high doses to prevent diarrhea in pigs in Canada. Experimenting with different levels of copper sulfate and zinc oxide supplementation, they found that large amounts of zinc (3000 ppm) stimulated an enzyme that trapped copper in the intestinal tissue. By not allowing copper to reach its intended destination of the liver and serum (the fluid component of blood), this enzyme caused pigs to become copper deficient.

Ironing out some issues

Another crucial mineral for pigs is iron, as it is essential for optimal health and growth. In spite of iron supplementation in the first week of life, recent research shows that piglets may be iron-deficient at weaning. Although post-weaning diets are rich in iron, again, high levels of zinc oxide proved problematic, impairing the building up of iron reserves in the liver.

From hazard to helpful

By exploring the effects of various mineral levels on piglets, researchers have begun homing in on the ideal supplement regimen to promote growth and performance. This quest is vital in light of developments in the industry. In 2021, the Canadian Food Inspection Agency (CFIA) consulted with the pork sector to better understand the effects of zinc and copper and propose new levels of supplementation with these minerals. Of particular concern to the CFIA is that high levels of zinc can be harmful to the environment when it is excreted in manure and spread on farmers’ fields. This may lead to a high concentration of zinc in the soil will remain for up to 50 years before fully dispersing, preventing crops from growing properly in that field. Zinc can also be a public health concern, as it stimulates the expression of some genes in bacteria that make them more resistant to antibiotics.

In 2022, the European Union banned the use of high zinc levels for pigs, and Canada appears headed in the same direction. The latest recommendation from the CFIA is to lower zinc limits from 3000 ppm to 300 pm. Once this change becomes mandatory, producers will have lost two of their greatest weapons for preserving pig health: antibiotics and zinc oxide. As farmers try and adapt to new regulations, studies like this are crucial to properly supplementing with minerals such as zinc and copper. From a scientific standpoint, if you don’t know what happens to pigs when given both high and low levels of minerals, how can you properly adjust feed to meet the new standards without compromising piglet health and growth?

Maintaining your balance

Because of the negative interactions between zinc and copper, a low dietary zinc-to-copper ratio may improve the absorption and utilization of both minerals. However, this study also showed that low levels of both copper (6 ppm) and zinc (100 ppm) appear not to fulfil the piglets’ requirements for these minerals during the first weeks post-weaning. That shortfall points to the need for a better understanding of zinc and copper nutrition for post-weaning piglets.

Ultimately, a balanced, holistic approach, considering pig health, nutrition, performance and the environment, will enable the animals to express their full potential while safeguarding humans and the planet.

Backed by funding from Swine Innovation Porc, this study drew on expertise from several organizations. These included DSM Animal Nutrition & Health, Lallemand Animal Nutrition, Agri-Marché, and the Deschambault Animal Science Research Centre (DASRC) of Agriculture & Agri-Food Canada (AAFC).

As always, a number of scientists brought their knowledge to the project: Drs. Jérôme Lapointe, Guylaine Talbot, Danyel Bueno Dalto, Jacques Matte (research scientist – retired) and Martin Lessard (research scientist – retired), all with AAFC in Sherbrooke, Quebec; Dr. Frédéric Guay, professor, Faculty of Agricultural and Food Sciences - Department of Animal Sciences at Université Laval; and Ms. Yan Martel-Kennes with (DASRC).

Looking ahead, the researchers will further study the interaction between zinc and copper sources, both organic and inorganic, and examine the effects of mixing, such as inorganic zinc and organic copper, and vice versa. They will also experiment with different supplementation timings, as well as various delivery methods, such as through drinking water, to see if that increases absorption and reduces the negative interactions between minerals.

It may seem beyond our grasp, but making pigs more resistant to disease, while reducing the use of antibiotics, is well within reach. 

Swine diseases associated with gut bacteria are regarded as the top risk factors for disrupting normal pork production, and this is especially true for weanling pigs. Weanlings often experience gut disruption brought on by enteric diseases (infections occurring in the gastrointestinal system), poor digestion of nutrients or a shortage of alkaline phosphatase (AP), an enzyme in the gut that helps maintain the gut micro-environment.

Gut Reaction

In response to these pig health issues, a research team led by Dr. Ming Fan, University of Guelph, worked on enhancing AP efficiency. That may sound complex, but the end goal was simple: a healthier gut, leading to healthier pigs that would grow faster without the burden of infectious disease. This would also limit the demand for antibiotics, reducing the threat that antimicrobial resistance in the pork sector poses to public health.

In recent years, scientists have discovered the critical role of APs in maintaining gut health, thereby protecting both pigs and people from the toxins that are produced by pathogenic microbes in the gut. These toxins frequently trigger disease, and while swine are akin to humans physiologically, there is a key difference in the effectiveness of APs between the two. In the human body, APs perform like a finely tuned sports car, doing their job smoothly as they coat our cells and guard them from invaders. By contrast, in weanling pigs, their own APs are more like clunkers, often breaking down and failing to thwart these intruders.

Fine Tuning Feeds for Health

In the interests of giving pig APs a “tune up”, researchers sought to develop feed additives. These would take the form of external AP enzymes that are not naturally produced by the body but could be added to pig diets to fortify their gut response. After much study, scientists created an enzyme that shows great potential in advancing the pig gut micro-environment and helping the animal to resist disease. 

Of course, as with most great discoveries, there is still one large mountain to climb before it leads to black ink for industry: red tape. Because the enzyme is a microbial product, it is highly regulated. Prior to making it available for use by producers, much data is needed to ensure the product is safe, effective and environmentally friendly. As part of the registration process, the federal government must also confirm that its biological working mechanisms are clearly revealed as a novel microbial product, since nobody else has developed and commercialized a similar product in the past.

From Health to Wealth

Once the team secures government approval, the newly developed enzyme could become a valuable new tool for industry. The product could support faster and more efficient growth for pigs, while precluding the need for antibiotics to promote health. Though primarily targeting weanling pigs, as swine is more vulnerable when younger, this enzyme may also aid feeder pigs and sows in a similar manner.

Though antibiotics have been a powerful weapon for decades in the fight against human and animal diseases, the landscape has clearly shifted. Today, the use of such drugs is under increasing scrutiny in the eyes of the public and faces growing concerns about antimicrobial resistance. These circumstances enhance the appeal of feed additives, like AP enzymes that strengthen natural immune defenses while developing treatments that balance the health of people, animals and the environment.

Building a Path from Lab to Barn

Against that backdrop, a new weapon was required to aid pigs and producers, and finding it was the ultimate team effort. Scientists relied on financial support from industry partners like Ontario Pork, as well as cluster funding from research bodies including Swine Innovation Porc (SIP) and Agriculture and Agri-Food Canada (AAFC). Apart from the dollars, this “made in Canada” solution relied heavily on lab technology at the University of Guelph and the brain power of researchers, associates and students.  

In the journey from lab to barn, however, several steps remain. Now that the essential research and efficacy testing is complete, the team must work on technology transfer to universities, businesses and governments. This process helps ensure that the scientific and technological developments from the project are available to a wider range of users, who can then help develop them further. From there, it is on to intellectual property protection, government approval and, ideally, commercialization of the product.

As a course of further study, scientists hope to explore the effects on soil fertility of applying manure from pigs who consume this enzyme. They also want to look more closely at the possible benefits of the enzyme in sow diets.

If herding cats is the ultimate challenge, managing sows is a close second. This is especially true with the advent of group housing and its unique dynamics. 

In such systems, proper management is key to minimizing stress for sows, thereby boosting sow reproductive performance and piglet development. Given the stakes for producers, scientists are working hard to find the best approach.

In exploring the pros and cons of different group management systems, Canadian researchers focused on dynamic versus static grouping and compared early and late mixing of sows. With the dynamic mixing approach, multiple breeding groups are housed together in each pen. As small groups of sows are moved out to be farrowed, new groups of recently mated sows join the pen.

In static groups, each pen houses only one breeding group of sows. The animals are only mixed at the start of gestation, and no sows can be brought in for replacement if a sow is removed. The choice to implement dynamic or static housing can have big impacts for barn design.

Mix and mingle

Dynamic mixing is a popular choice for producers, allowing use of new technology and providing individual feeding for sows. But researchers are concerned that there is potential for more conflict, aggression and stress as groups of sows move in and out of the pen. When it comes to sows, there is “mixing aggression” and “ongoing aggression”. Researchers were concerned that ongoing aggression in dynamic groups would be a problem. What they found was that mixing aggression, which happens only once at the beginning of gestation, was reduced in dynamic groups because there were fewer new group members. At the same time, they found that ongoing aggression resulted in more lesions in dynamic groups throughout gestation, but it was not enough to impact their production. This suggests that mixing aggression is more important than ongoing aggression in terms of the impact on reproduction.

Late mixing (after 28 days of gestation) is also largely favoured over early mixing, but this may not be sustainable given the concern shown by consumers. As pressure grows from the public to abolish month-long stays in gestation stalls, researchers are examining early mixing more closely as a viable option.

Interestingly, this study found less aggression in dynamic systems over static ones (both mixed early). In the former, aggression levels were low when each small group was added, compared to one large mixing event for the static housed sows, which occurred in early pregnancy.  The production results were also surprising: Dynamic sows had the highest farrowing rate over static sows, and even over a control group of late mixed sows.  There is not a clear winner between static and dynamic; both systems are popular and will continue to be so. They require very different approaches, so industry must be more aware of those differences to fine tune management strategies.

Social status is important, because if a system is not running well, it is always the subordinate sows who get the short end of the stick, and it is usually the younger/smaller animals that are subordinate.

With genetics, the swine industry needs to shift the genetic focus away from producing more piglets and onto finding less aggressive sows that are well built and robust to function well in group housing.

Climbing the Social Ladder

Another important factor influencing a sow’s reproductive performance was social status within the pen. Researchers determined each sow’s rank within the group as dominant, intermediate or subordinate based on a feed competition test. A sow’s rank played a large role in setting their stress level, which in turn affected piglet behavior and physiology. The exact connection is not yet clear, but scientists hope to learn more as they review the data.

As part of the project, researchers also examined sow mortality in the wake of growing death losses on farm. Using a survey and follow up visits that covered 104 herds, they found higher mortality in large herds (3,000 or more) versus small, and in group gestation versus stalls. Scientists were especially concerned that the majority of death losses in group gestation involved younger sows. Apart from the animal welfare implications, early culling is an economic blow for the business. Most producers can attest that sows who manage fewer than three parities don’t even cover their replacement cost.

Finding genes that fit

These mortality findings are critical for industry going forward. The increase in lameness should spawn a greater focus on all aspects of gilt development, and genetics companies could prioritize conformation (functional legs and feet) and a calmer temperament that is less prone to aggression. Greater robustness traits would be beneficial as well, making sows more durable in group systems as they navigate concrete floors and interact with their pen mates.

Addressing the mortality issue will take a combined effort from researchers and producers. It is vital that worker training and compliance on farm be more consistent, and that staff use the same definitions between farms and within the same operation. What constitutes “culled”, “euthanized” and “died on farm”? For their part, the project team plans to have recommendations for workers soon on what to record.   

Aiding in this study was Dr. Yolande Seddon, assistant professor, Department of Large Animal Clinical Sciences at the Western College of Veterinary Medicine. At the same time, Dr. Nicolas Devillers, research scientist in pig behaviour and welfare at Agriculture and Agri-Food Canada (AAFC), advised the team on dynamic mixing. Also of note, Dr. Brian Sullivan, CEO at the Canadian Centre for Swine Improvement (CCSI), worked closely with the group on sow mortality.

For the pork sector, the only constant is change, and the move to group sow housing is a prime example. The more producers can learn today about managing group gestation and limiting sow mortality, the better equipped they’ll be to face the future.