Abstract Growing evidence from human studies and rodent animal models demonstrate that the maternal gut microbiome during gestation influences immune, metabolic, and neurodevelopmental programming in the offspring from early embryonic stages, supporting its role in the Developmental Origins of Health and Disease (DOHaD) framework. However, whether the bovine maternal microbiome similarly influences calf microbiome development, health, and feed efficiency remains unknown. Therefore, this study evaluated the impact of altering maternal microbiome via feeding high-forage (HF) or high-concentrate (HC) diets during pregnancy on offspring calf gut microbiome development from birth to maturity. For this,119 beef heifers were assigned to one of two treatments and received a diet based on 75% forage (HF group; n = 24) or 75% concentrate (HC group; n = 22) from 15 days pre-breeding through parturition, and immediately after calving a common diet was fed to both groups of dams. All heifers were bred with male-sexed semen from a single sire and managed to gain 0.45 kg/day during early to mid-gestation and 0.79 kg/day in late gestation. Individual feed intake and feeding behavior were monitored, and ruminal fluid, fecal, and vaginal, and deep nasopharyngeal swabs were collected from these heifers at pre-breeding (d-30, d-15 d-2), post-breeding (d28, d56, d91, d180, d238), at calving, and 160 days postpartum. Calves born from HF (n = 22) and HC (n = 19) dams were monitored for growth performance and gut microbiome development from birth to finishing stage. Body weight measurements, ruminal fluid and fecal samples were collected from calves at birth and at 14, 30, 120, 160, 260, 330, and 372 days old. The 16S rRNA gene (V3–V4) sequencing was performed on the dam and calf’s microbiota samples. Average daily gain was not different between HF and HC heifers (P = 0.50), but feed intake and feeding behavior were different between the two groups (P 0.05). Significant differences in the ruminal, fecal, vaginal, and nasopharyngeal microbiota were observed between HF and HC dams starting from day-2 pre-breeding (13 days after the final treatment diets were fed) and continuing up to calving, with altered ruminal and fecal communities still evident at 160 days post-calving (PERMANOVA: P 0.05). No differences (P 0.05) were observed in birth weight or in body weight during suckling, pre-weaning, or post-weaning between HF and HC calves. However, the ruminal microbiota at days 14, 30, 60, and 120, and the fecal microbiota at days 14 and 30, differed between HF and HC calves (P 0.005), indicating that diet-induced shifts in the maternal microbiome influenced early-life microbial development in the offspring. Overall, our study provides the first evidence in cattle that maternal microbiome alterations contribute to developmental programming and shape offspring gut microbiome trajectory.
Aryee et al. (Wed,) studied this question.