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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Genetics and Animal Breeding » Research » Publications at this Location » Publication #418670
Research Project: Multi-Dimension Phenotyping to Enhance Prediction of Performance in Swine

Location: Genetics and Animal Breeding

Title: Insights into microbial compositions of the respiratory tract of neonatal dairy calves in a longitudinal probiotic trial through 16S rRNA sequencing

Author
item TAN, JIA - Orise Fellow
item Eicher, Susan
item KRITCHEVSKY, JANICE - Purdue University
item BRYAN, KEITH - Chr Hansen Inc
item Dickey, Aaron
item Chitko-Mckown, Carol
item McDaneld, Tara

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/24/2024
Publication Date: 1/8/2025
Citation: Tan, J.W., Eicher, S.D., Kritchevsky, J.E., Bryan, K.A., Dickey, A.M., Chitko-McKown, C.G., McDaneld, T.G. 2025. Insights into microbial compositions of the respiratory tract of neonatal dairy calves in a longitudinal probiotic trial through 16S rRNA sequencing. Frontiers in Microbiology. 15. Article 1499531. https://doi.org/10.3389/fmicb.2024.1499531.
DOI: https://doi.org/10.3389/fmicb.2024.1499531

Interpretive Summary: Probiotics have a strong potential to impact animal health and the bacterial populations of the gut. This study examines the effect of probiotics on bacterial populations from multiple sites along the respiratory tract (nostril, tonsil, and lung) of calves fed probiotics for 52 days. Calves fed probiotic were compared to a control group fed only milk replacer. Variation in bacterial population diversity within the nostril, tonsil, and lung lavage samples was observed, indicating distinct bacterial compositions among sampling sites. Differentially abundant bacteria in the probiotic treated calves were identified and unique to their sampling site. Results from this study help to characterize the diversity of bacteria along the respiratory tract. Bacterial groups that are unique to the probiotic treatment will provide targets for future studies to determine whether probiotics can prevent respiratory disease pathogens.

Technical Abstract: Introduction: Probiotics are a promising intervention for modulating the microbiome and the immune system, promoting health benefits in cattle. While studies have characterized the calf lung bacterial profile with and without oral probiotics, simultaneous probiotic effects on the bacterial populations of multiple sites along the respiratory tract have not been characterized. Methods: This study utilized the same pre-weaning diary calf group from our previous studies to characterize the bacterial populations present in the nostril and tonsil across control and treatment groups and nine sampling time points. DNA was exacted from the nostril and tonsil swabs and lung lavage fluids, and 16S ribosomal RNA gene hypervariable regions 1-3 were subsequently sequenced. Results: Temporal variation in alpha bacterial diversity within the nostril, tonsil, and lung samples was observed, indicating distinct bacterial compositions among sampling time points. Oral probiotic treatment did not change alpha diversity in any respiratory tissue, however, spatial variability in bacterial taxa composition was observed among the three respiratory tract regions. While the majority of differentially abundant taxa in probiotic treated calves were unique to their anatomical location, a few were common to two anatomical locations and one Finegoldia amplicon sequence variant was differentially abundant in all three anatomical locations. Discussion: In conclusion, these findings contribute to the understanding of the dynamic nature of bacterial diversity and the potential effects of probiotics within the bovine respiratory tract and provides insight for future studies of probiotics on animal health, disease prevention, and management.