With the anticipated population growth by 2050, the demand for high-quality protein for human consumption is set to rise. To enhance the sustainability of U.S. cattle production, producers and researchers have traditionally concentrated on improving the feed efficiency of steers through advancements in genetics, nutrition, and microbiome tools, resulting in a more marketable beef product. However, without successful pregnancies, there would be no marketable animals to feed. Despite extensive research on hormonal impacts on cattle physiology, including nutrition and reproduction, there is limited knowledge about how the rumen microbial environment is impacted by pregnancy and feed efficiency in female beef cattle. Understanding the rumen microbiome’s role in feed efficiency and its response to hormonal changes during pregnancy is crucial for advancing sustainable beef cattle production. Therefore, this review highlights the importance of understanding the microbial dynamics in the rumen of pregnant beef females. Although progress has been made, gaps remain in understanding how varying nutritional requirements throughout pregnancy affect the rumen microbiome, highlighting the need for continued research. Addressing these areas will lead to more efficient and sustainable cattle production practices, benefiting beef production and contributing to global food security.

Tall fescue toxicosis negatively impacts blood flow, elevates body temperature, and reduces beef cattle’s average daily gain (ADG). In previous studies, isoflavones have diminished the symptoms of tall fescue toxicosis in ruminants. Therefore, this dataset determined the impact of low concentrations of isoflavone doses on animal vasculature, body temperature, ADG, and rumen microbial communities in beef cattle. A 21-day experiment with Angus cattle consisted of four isoflavone doses: 0 g, 2 g, 4 g, and 6 g, along with a control group. Isoflavones were mixed with 0.5 kg of dried distiller’s grains (DDGs). Daily individual rectal temperatures were recorded. Weekly blood serum was collected via coccygeal venipuncture, blood vasculature data were measured via color Doppler ultrasound, and body weight (BW) was recorded. Approximately 100 mL of rumen content was collected at the end of the trial. The pulsatility index (PI) decreased in the control group compared to the 2 g and 4 g groups (p = 0.01). Animals in the isoflavone treatment groups recorded a higher rectal temperature (p < 0.05). ADG was reduced in animals undergoing isoflavone treatments (p < 0.001). Finally, there was no impact on the rumen microbial communities (p > 0.05). Isoflavone supplementation may mitigate tall fescue toxicosis and improve animal performance at greater doses.