Pig and piglet.

MN Impact: Pig microbiome discoveries show promise for swine industry

March 30, 2021

The Issue

The trillions of microbes that inhabit the gastrointestinal tract of mammals, the gut microbiome, play indispensable roles in energy harvest, nutrient synthesis and gut health. Although these issues have been well-known in the animal science field, microbiome work in swine production systems is still in its infancy. 

Key Activities

The microbiome in the gut or respiratory tract provides a protective layer against infectious diseases in swine. Thus, with microbiome research, researchers can determine how novel feed additives and management interventions work, by either enhancing the abundance of microbes that promote health and/or displacing those that cause disease. Even though microbiome research in swine production systems has shown an altered microbiome in poor performing or sick pigs, we need more studies that better characterize the systematic changes in microbiome diversity over time (from birth to after weaning) to predict health and performance outcomes. 

A team of UMN researchers hypothesized that increased sanitation level in maternal environments affects development of piglet fecal and nasal microbiomes, and physiological performance. The team conducted their study at the West Central Research and Outreach Center, where six sows were allocated to two treatment groups: farrowing stalls cleaned with or without disinfectant. Swabs were collected from stall floors, drinkers and feeders, and from sows’ vaginal, rectal, oral and udder surfaces at day 109 of gestation and the day before farrowing. They also collected fecal and nasal swabs from piglets at days: 0 (within 24 hours of birth), 7, 14, and 21 postpartum. Nine piglets were then selected from each sow (n = 27/treatment) for microbiome analyses.

Results

Although environmental microbiomes were different between disinfected and not disinfected stalls after cleaning, they detected no compositional differences among any disinfected or not disinfected sow samples. However, at day 0, not disinfected piglets compared with disinfected piglets exhibited higher gut and nasal bacterial diversity. Not disinfected piglets also displayed greater nasal bacterial diversity at 0 but also at day 21 (weaning), and different gut and nasal microbiome compositions across all time-points, including higher abundance of potentially probiotic gut bacteria (Lactobacillus). However, disinfected piglets exhibited higher average birth and weaning weights compared to not disinfected piglets. These results show that sanitation level during farrowing persistently alters swine microbiomes and growth performance.

Because of the multiple environmental, nutritional and health factors influencing the pig’s microbiome, determining which factors are most important in shaping this microbiome early in life is key to devising microbiome-based interventions. Ultimately, discoveries like this will allow producers to manipulate the pig’s microbiome through nutritional and environmental interventions and ultimately will improve performance and health.  

Public Value

Minnesota is home to over 3,000 pig farms and ranks second in the nation for both the number of pigs raised and pig value. In 2013, Minnesota pig farmers marketed 14 million pigs and the Minnesota pork industry generated $7.28 billion in economic activity. Knowledge of the diversity of the swine microbiome can provide a novel, alternative perspective on the biological process that affects some of the most important issues in swine production systems. Regular “microbiome snapshots” along the most critical stages of pig growth (e.g., pre- and post-weaning), can predict health and potential pathogen threats for disease by early identification of bacteria in slow-growing pigs or those that are at most risk of infection. This would allow producers to make early decisions on therapeutic or dietary interventions to enhance performance and health.