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The article focuses on study of materno-placental microbiome of gravid beef cows under feed intake restriction. Topics discussed include existence of reproductive microbiome as evidence in cattle, matured bovine rumen influenced by feed intake restriction, and counts of phyla presented in abundance in mature rumen being impacted.

Maternal gestational nutrition is known to impact gut physiology and the gut microbiome of offspring early in life; however, it remains unknown if these changes persist later in life. We hypothesized that the impacts of maternal feed restriction in late gestating beef cows on early colonization of the calf gut would impact the rumen microbiome post-weaning. Our objective was to compare the post-weaning rumen microbiome of calves born with feed restricted dams and those born to dams with adequate nutrition. Starting roughly 60 d before expected calving, dams were stratified to either receive 100% of NRC requirements (CON) or 70% intake of NRC requirements (FR) through 28 d post-parturition. Pairs were then moved on to native grass until weaning. Rumen fluid was collected from the calves at the time of weaning (PRE) and after a 70 d backgrounding feed efficiency study (POST). Microbial DNA was isolated and the V4 region of the 16S rRNA was sequenced on the MiSeq platform. Data were analyzed within each time point using QIIME2. Maternal treatment had no impact on alpha diversity (Faith's phylogeny, Shannon's diversity, and Evenness) in the PRE group, but CON calves had greater (q = 0.05) evenness than FR calves in the POST samples. There were differences in composition between CON and FR in the PRE samples (unweighted unifrac q = 0.04; bray-curtis q = 0.03). No differences (q = 0.14) in composition were found in the POST samples. These data indicate that at the time of weaning (PRE) differences in composition existed in CON vs. FR calves, specifically in the rare taxa, but the microbial composition converged by the end of the feeding trial. Interestingly, previous findings in our lab reported differences in alpha and beta diversity 28 d after birth in these calves. Together, these data indicate the potential for long-term impacts of maternal nutrition on the gut microbiome. This coupled with the previously published work where feed efficiency tended to differ between CON and FR, suggests that early perturbations during gestation may have had lasting impacts on gut physiology and subsequent performance in the presence of rumen microbial shifts. [ABSTRACT FROM AUTHOR]

The American beef bulls have been neglected in terms of animal science research. Metabolomics is a respected for of science that will aid in developing hypothesis for future research in beef bulls. The objective of this study was to identify metabolites within a 65-day breeding season that were affect by breeding season duration and workload. Over a two-year period, 8 purebred Angus bulls owned and housed by the Cal Poly beef unit were surveyed using serum (collected via the coccygeal vein) and seminal fluid (collected via electroejaculation) at the beginning and end of a 65-day post-AI breeding season. Samples underwent HPLC-MS to observe metabolites within the fluids. Data were stratified for sample day and workload and compared using t-test for day and ANOVA for workload. Within serum, 8 metabolites of interest were observed. Effects included differences between workload groups in the abundance of guanosine (P = 0.01) a metabolite associated with purine metabolism. Within seminal fluid, 13 metabolites of interest were observed including Inosine, a metabolite also involved in purine metabolism and fluctuating based on workload (P = 0.05). Purine metabolism will be of interest to future research of beef bulls. [ABSTRACT FROM AUTHOR]