Pigs and people share a common concern: the growing use of antibiotics. However you dress it up, that’s a problem, as the mounting resistance to these drugs makes it harder to combat disease. For producers, finding other means to fight pathogens is essential for preserving their business, protecting the herd and promoting animal welfare. For researchers, supporting that fight meant devising a new feeding approach for neonatal and weanling piglets by addressing a common problem for these animals: diarrhea caused by Salmonella.

Weaning is a critical time in a pig’s life. It is filled with stressors, particularly given the absence of a fully formed immune system puts piglets at risk. Adding to the challenge is a change in diet, moving from the sow’s milk to a regimen of solid food. The change is drastic and often jarring for piglets, as their intestines are not prepared for the upheaval. At this point, the animals are especially susceptible to diarrhea, and one culprit is Salmonella. Affected pigs often suffer from dehydration and anorexia, and some of them remain carriers and sources of infection for up to five months after recovery. This represents not only a risk for the health of other pigs, but also for public health, as Salmonella can also infect humans.

A Solid solution

To help prepare the animals for the transition from liquids to solids, producers will often introduce some solids to the diet when piglets are still with the sow. Scientists saw this as the perfect opportunity to insert feed additives in that diet to prevent or lessen diarrhea from Salmonella. In the process, they also wanted to identify the effects of Salmonella and explore the use of biomarkers as a less invasive means to study the animals. Biomarkers are changes to molecules or cells that aid in disease diagnosis and treatment, and help track the progression of disease. Employing these markers can enable researchers to preserve animals following a study and save money in the process.

One option explored by this project is a bacterium called Veillonella. Scientists observed that when Salmonella infection was present in the pig’s gut, Veillonella levels were reduced, and these levels rose in the absence of the infection. This could prompt future research on the potential value of this bacterium as a probiotic that would be added to feed and render pigs less susceptible to Salmonella.

Chain reaction

The study also found that by adding a medium chain fatty acid (a saturated or unsaturated fatty acid present at high concentrations in food such as coconut oil) and yeast extract to the diet, they were able to prevent diarrhea in some pigs and decrease its severity in others. Past research has shown that amino acid supplementation can reduce the severity of diarrhea in pigs, something that was confirmed in the present research, so this is another promising path to be explored.

Researchers are also intrigued by the potential of biomarkers. If all goes as planned, biomarkers could prompt a whole new area of study. Instead of trying to find solutions while working with a model in the lab, scientists could go directly to the barn. In doing so, they would observe the animals in their natural environment and note the action of the pathogen and how it affects the host. This change in methodology should produce more relevant results going forward.

Pitching In and Helping Out

To make the project and its findings possible, interaction was crucial. Université Laval performed the blood work and Agriculture and Agri-Food Canada (AAFC) ran the immune system analysis. The pigs were born at AAFC Sherbrooke, where they were fed under lactation before being transferred to Université de Montréal for infection. As well, a private company contributed its expertise towards the biomarker discovery.

Principal investigators – who are all based in Quebec - included Dr. Dominic Laprade-Poulin with AAFC Sherbrooke; Dr. Frédéric Guay, Université Laval; and Dr. Alexandre Thibodeau, Université de Montréal.

As a next step, researchers hope to explore more options for feed additives that promote pig health. This work will include a closer examination of Veillonella and the role it could play as a probiotic to assist pigs and producers. The team is also aiming to redo the experiment from this project on a larger scale to generate more data for analysis.

Finally, scientists would like to put medium chain fatty acids and yeast extract to the test on farms to assess performance in “real life” conditions.

Piglets may not have fashion sense, but if this study can help ease the stress of weaning, it could be the perfect fit.