July 22, 2019

Interpretive Summary: The piglet mycobiome during the weaning transition: a pilot study

Interpretive Summary: The piglet mycobiome during the weaning transition: a pilot study

By: Dr. Caitlin Vonderohe

Weaning is a highly stressful period in the lives of young piglets, and is often associated with increased disease challenges, diarrhea, and reduced growth performance. The microbiome and mycobiome of the swine gastrointestinal tract are a diverse collection of bacteria and fungi that closely interact with the immune system and digestive physiology, having potentially significant effects on animal health and productivity. Specifically, fungi inhabiting the gastrointestinal tract may have profound positive and negative effects on pig health, but little work has focused on the mycobiome compared to the microbiome. “The piglet mycobiome during the weaning transition: a pilot study” by Summers et al., recently published in the Journal of Animal Science, examined the myco- and microbiome of pigs from birth until two weeks post weaning to examine how fungi and bacteria in the gastrointestinal tract may be affecting piglet health and performance during weaning.

Nine litters of Large White/Landrace piglets were monitored from birth to 35 days of age, and were weaned at 21 days of age. Piglet weight and fecal samples were taken daily. Feces were processed and cultured for fungal growth. DNA was extracted from fecal samples and sequenced using specialized primers and software to detect fungal and bacterial species present.  

Fungal cultures from fecal samples taken from pigs in the first week of life were low and variable. After the first week of life, cultured fungi persisted at undetectable levels until weaning at day 21, where fungal load increased significantly. Investigators cultured potential environmental sources of fungi (sow milk, creep feed, water etc…) and only found fungi in creep feed that was left in the crate for at least one day and in sow feces. The fecal micro- and mycobiomes changed significantly in diversity, composition and structure as the piglet aged. Diversity of bacterial species in the fecal microbiome increased with age, but the fecal mycobiome did not show this trend. For example, bacterial families Enterobacteriaceae, Enterococcaceae, Staphylococcaceae, and Pasteurellaceae were present in higher levels in day 1 piglets, but decreased over time. In the mycobiome, the fungal families present in days 1-21 were highly variable, but the family Sarrharomycetaceae became much more abundant in the post-weaning period.

Previous work has shown that diet, environment, gender and maternal effect can affect the micro- and mycobiome, and many of these environmental factors profoundly change at the time of weaning. This study showed significant changes in the composition of the microbiome and the mycobiome as the piglet aged from d1 to d35. Overall, the precise consequences of these changes need to be further explored with future research. The mycobiome particularly requires additional exploration to understand the significance of these changes for pig health and productivity.

To view the full article, visit the Journal of Animal Science.