Interpretive Summary: Effects of dietary supplementation with essential oils and organic acids on the growth performance, immune system, fecal volatile fatty acids, and microflora community in weaned piglets.
By: Anne Wallace
During the post-weaning period, piglets may suffer from aliments such as diarrhea, which negatively impacts growth performance. Although antibiotics can mitigate these issues and enhance growth performance, alternatives to antibiotics are needed. Previous studies on essential oils and organic acids have demonstrated potential for these substances to benefit livestock.
In this study published in the January 2019 Journal of Animal Science, a mixture of plant-derived essential oils and organic acids were fed to post-weaning piglets. The goal was to evaluate the effects of this mix on piglet growth performance, immune function, and fecal microbiome, including microbial volatile fatty acid (VFAs) production.
A total of three hundred 21-day old piglets were given one of 3 different dietary treatments for 28 days. The treatment diets were comprised as follows: control basal diet (C), basal diet with essential oils and organic acids (T1), and basal diet with the tetracycline antibiotic terramycin (T2). The T1 mix contained the essential oils cinnamaldehyde and thymol, and also the organic acids citric, sorbic, malic and fumaric acid.
Results indicated that T1 piglets had significantly improved body weight and average daily gain compared to C and T2 pigs. Immune system blood markers for complement 4 were also increased in T1 pigs. Sequencing of the fecal microbiome at day 28 found that T1 pigs had more beta diversity than C and T2 pigs. Lactobacillus mucosae, a probiotic, was also increased in the feces of T1 pigs. The VFA isovaleric acid was also increased in T1 pig feces, when compared to C and T2 pigs. Additionally, in vitro, cinnamaldehyde and citric acid were found to damage the cell structures of Escherichia coli and Staphylococcus aureus, both potential pathogens.
Overall, this study reinforces the potential of plant-derived substances to benefit post-weaning piglets. More in-depth studies looking at the mechanisms behind how the cinnamaldehyde thymol, citric, sorbic, malic and fumaric acid mix modified the piglet microbiota is also an area of potential future study. Dr. Guangtian Cao says this research “aimed to find new substitutes [for] antibiotics in [livestock] production. We will continue to [look for] more useful materials or natural plant substances, which are good for… animal health.” Interestingly, the finding that citric acid and cinnamaleehyde damage the cell structures of E. coli and S. aureus in vitro suggest there may be potential for these substances or a mix of these substances to act as substitute for antibiotics, warranting in vivo studies.
To view the full article, visit the Journal of Animal Science.