RESUMEN
Components of the immune system (e.g., cytokines and chemokines) can influence reproductive efficiency. Characterizing the influence nutrition has on shifts in circulating cytokine concentrations will allow for a better understanding of reproductive efficiency in beef cattle. This study aimed to determine the effect of diet composition on circulating cytokine concentrations of beef heifers. Using a 3â ×â 3 Latin square design, pubertal Bos taurus-influenced rumen-cannulated heifers (nâ =â 15) were fed a diet based on different concentrate percentages. The treatment period consisted of 28-d feeding periods with a washout interval of 21 d. Treatment groups were fed 100% grass hay (high forage; HF), 60% grass hay with 40% corn-based concentrate (intermediate; INT), and 25% grass hay with 75% corn-based concentrate (high grain; HG). Heifers were offered 2% of their body weight in feed daily. Blood was collected on days 0 and 28 of the treatment period for cytokine analysis. Plasma cytokine concentrations were quantified using RayBiotech Quantibody Bovine Cytokine Array Q1 kit according to manufacturer instructions. Concentrations of interferon gamma-induced protein 10 (IP10) linearly decreased with an increased concentrate diet (Pâ =â 0.037). Concentrations of IP10 differed for heifers consuming HF diet vs. HG diet (3,069.52 vs. 1,001.84â ±â 669.01 pg/mL, respectively) and heifers consuming INT diet vs. HG diet (2,886.77 vs. 1,001.84â ±â 669.01 pg/mL, respectively); however, there were no significant differences in IP10 concentrations between HF and INT heifers. There was a tendency for interleukin-1 family member 5 (IL1F5) concentrations to be lower for heifers consuming the HG diet compared to INT diet (Pâ =â 0.08). Results suggest that heifers consuming a high-concentrate diet have lower concentrations of IP10 and IL1F5. Additional research is necessary to better understand the dietary influence on the immune system in developing heifers.
RESUMEN
Advancements in 16S rRNA gene amplicon community sequencing have vastly expanded our understanding of the reproductive microbiome and its role in fertility. In humans, Lactobacillus is the overwhelmingly dominant bacteria within reproductive tissues and is known to be commensal and an indicator of fertility in women and men. It is also known that Lactobacillus is not as largely abundant in the reproductive tissues of domestic livestock species. Thus, the objective of this review is to summarize the research to date on both female and male reproductive microbiomes in domestic livestock species (i.e., dairy cattle, beef cattle, swine, small ruminants, and horses). Having a comprehensive understanding of reproductive microbiota and its role in modulating physiological functions will aid in the development of management and therapeutic strategies to improve reproductive efficiency.