Shifts in uterine bacterial communities associated with endogenousprogesterone and 17β-estradiol concentrations in beef cattle
Sep 01, 2022
Rebecca K. Poole, Autumn T. Pickett, Ramiro V. Oliveira Filho, Gabriela Dalmaso de Melo, Vignesh Palanisamy, Sapna Chitlapilly Dass, Reinaldo F. Cooke, Ky G. Pohler
Department of Animal Science, Texas A&M University, College Station, TX 77843
Corresponding Author: Rebecca K. Poole, Ph.D, Department of Animal Science, Texas
A&M University, College Station, TX 77843-2471
Email: Rebecca.Poole@ag.tamu.edu
Phone: 979.458.8464
Abstract
The relation between circulating concentrations of progesterone and 17β-estradiol prior to insemination play a key role in optimizing fertility in cattle. This study aimed to determine the impact of endogenous progesterone (P4) and estradiol (E2) concentrations on uterine bacterial community abundance and diversity in beef cattle. Angus-influenced heifers were subjected to an industry standard estrous synchronization protocol. Uterine flushes were collected on day -2 (endogenous P4) and day 0 (endogenous E2) and used for targeting the V4 hypervariable region of 16S rRNA bacterial gene. Plasma was collected on days -2 and 0 for quantification of P4 and E2 concentrations by radioimmunoassay, respectively. Heifers were allotted to one of the following groups: High P4 + High E2 (H-H; n = 11), High P4 + Low E2 (H-L; n = 9), Low P4 + High E2 (L-H; n = 9), Low P4 + Low E2 (L-L; n = 11). Results indicated that Shannon’s diversity index tended to be greater for H-L heifers compared to L H heifers on day 0 (P = 0.10). For H-L heifers from day -2 to day 0, the relative abundance of Actinobacteria decreased and Tenericutes increased (P < 0.01). Within phylum Actinobacteria, the relative abundance of Corynebacterium decreased from day -2 to day 0 in treatment groups H-H, H-L, and L-L (P < 0.05); however, did not differ by day for L-H heifers. Within phylum Tenericutes, the relative abundance of Ureaplasma increased from day -2 to day 0 for H-L heifers (P = 0.01). Additionally for H-L heifers, the relative abundance of Bacteroidetes tended to increase from day -2 to on day 0 (P = 0.07). For H-L heifers, uterine pH increased from day -2 to day 0 (P = 0.05). These results suggest that differing endogenous concentrations of P4 and E2 may be associated with shifts in uterine microbiota and pH, and this could ultimately impact fertility outcomes in beef cattle.
