Alterations of rumen and fecal microbiome in growing beef and dairy steers fed rumen protected Capsicum oleoresin

Authors: BIERLY, STEPHANIE - Pennsylvania State University; VAN SYOC, EMILY P - Pennsylvania State University; WESTPHALEN, MARIANA - Pennsylvania State University; Miles, Asha; GAETA, NATALIA - Universidad De Sao Paulo; FELIX, TARA - Pennsylvania State University; HRISTOV, ALEXANDER - Pennsylvania State University; GANDA, ERIKA - Pennsylvania State University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2024
Publication Date: 1/16/2024
Citation: Bierly, S.A., Van Syoc, E., Westphalen, M.F., Miles, A.M., Gaeta, N.C., Felix, T.L., Hristov, A.N., Ganda, E.K. 2024. Alterations of rumen and fecal microbiome in growing beef and dairy steers fed rumen protected Capsicum oleoresin. Journal of Animal Science. https://doi.org/10.1093/jas/skae014.
DOI: https://doi.org/10.1093/jas/skae014

Interpretive Summary: The microbiome has been linked to animal health and productivity, and thus modulating animal microbiomes is becoming of increasing interest. Capsaicin has antimicrobial properties and could be used to manipulate the rumen and fecal microbiome of cattle. Both the rumen and fecal microbiomes are essential to cattle health and production, and modulation of either microbiome can affect their health. To determine this impact, 4 Holstein and 4 Angus steers were fed various levels of rumen protected capsicum (0mg (Control), 5mg, 10mg, or 15mg). Cattle were fed in treatment groups in a 4x4 Latin Square design with a 21-day adaptation phase and a 7-day sample collection phase. Rumen samples were collected at 0, 2-, 6-, 12-, and 18-hours post feeding and fecal swabs were collected on the last day of sample collection. These results show that there is no modulation of the rumen microbiome of steers due to concentration of rumen-protected capsaicin; however, there is modulation of the fecal microbiome of Holstein steers fed varying concentrations of rumen-protected capsaicin. This study demonstrates that while capsaicin may be a beneficial growth promoter for production of steers, it has a potential effect on the fecal microbiome of Holstein steers.

Technical Abstract: The microbiome has been linked to animal health and productivity, and thus modulating animal microbiomes is becoming of increasing interest. Antimicrobial growth promoters (AGP) used to be one of the most common technologies used to modulate the microbiome, but regulation and consumer pressure has led to a decrease in AGP use in food animals. One alternative to antimicrobial growth promoters are phytotherapeutics, compounds derived from plants. Capsaicin is a compound from the Capsicum genus, which includes hot peppers. Capsaicin has antimicrobial properties and could be used to manipulate the rumen and fecal microbiome of cattle. Both the rumen and fecal microbiomes are essential to cattle health and production, and modulation of either microbiome can affect their health. Because of capsaicin’s antimicrobial effect, it is predicted that the addition of rumen-protected capsaicin to the diet of cattle will alter the composition of the fecal microbiome, but not the rumen microbiome. To determine this impact, 4 Holstein and 4 Angus steers were fed various levels of rumen protected capsicum (0mg (Control), 5mg, 10mg, or 15mg). Cattle were fed in treatment groups in a 4x4 Latin Square design with a 21-day adaptation phase and a 7-day sample collection phase. Rumen samples were collected at 0, 2-, 6-, 12-, and 18-hours post feeding and fecal swabs were collected on the last day of sample collection. Sequencing data of the 16s rRNA gene was analyzed using the dada2 pipeline and taxa were assigned using the SILVA database. No significant differences were observed in alpha diversity among fecal or rumen samples for either breed and no significant difference between groups was detected for either breed in rumen samples or for Angus steers in fecal samples. There was a significant difference between treatments in fecal samples of Holstein steers (P = 2.5e-4). A pairwise comparison on the treatment groups showed no significance between treatments after adjusting for multiple comparisons. These results show that there is no modulation of the rumen microbiome of steers due to concentration of rumen-protected capsaicin; however, there is modulation of the fecal microbiome of Holstein steers fed varying concentrations of rumen-protected capsaicin. This study demonstrates that while capsaicin may be a beneficial growth promoter for production of steers, it has a potential effect on the fecal microbiome of Holstein steers.