Maternal Gut Microbiota and Metabolomic Signatures Are Potential Indicators of Neonatal Calf Birth Weight: A Preliminary Pilot Study

ABSTRACT The gut microbiota plays a crucial role in host homeostasis, influencing digestion, metabolism, and immune regulation. Neonatal birth weight is pivotal for early development and long‐term productivity. The study identified distinct maternal gut microbiota and metabolomic profiles associated with neonatal calf birth weight, providing preliminary biomarkers for future microbiota‐driven reproductive strategies. A cohort of periparturient Holstein dairy cows was strategically selected to establish two distinct experimental groups based on neonatal birth weight stratification: a high birth weight cohort (WU) and a low birth weight cohort (WF). WU cows exhibited enrichment of Burkholderiaceae_A , Turicibacter , Romboutsia_B , Blautia_A , Barnesiella , Clostridium_T , and Paraclostridium , while WF cows had higher levels of Elusimicrobiota, Ruminiclostridium_E , Campylobacter_B , and Odoribacter . Metabolomic profiling identified 85 differentially abundant metabolites. WU cows showed higher levels of 4‐imidazoleacrylic acid, 1,2,3,4‐tetrahydroacridin‐9‐ol, 8S‐hydroxy‐4Z,6E,10Z‐hexadecatrienoic acid, 7‐hydroxy methotrexate, sorbitol 6‐phosphate, and captopril. WF cows exhibited elevated d ‐proline, l ‐hydroxy arginine, alanine betaine, sn‐glycerol 3‐phosphoethanolamine, and anthranilic acid. Correlation analysis further revealed strong associations between microbial taxa and key metabolic pathways. In the WU group, the genera Romboutsia_B , Paraclostridium , Clostridium_T , Turicibacter , and Blautia_A were positively correlated with metabolites such as neoabietic acid, 4‐imidazoleacrylic acid, 8 s‐hydroxy‐4Z,6E,10Z‐hexadecatrienoic acid, n ‐acetylcytidine, 7‐hydroxymethotrexate, and O‐succinyl‐l‐homoserine. Conversely, these genera were negatively correlated with alanine betaine, l ‐hydroxy arginine, d ‐proline, anthranilic acid (Vitamin L1), sn‐glycerol 3‐phosphoethanolamine, and 1‐deoxy‐1‐(methylamino)‐d‐galactitol. In the WF group, Campylobacter_B was positively correlated with 1‐myristoyl‐2‐hydroxy‐sn‐glycero‐3‐phosphoethanolamine, sn‐glycerol 3‐phosphoethanolamine, and anthranilic acid (Vitamin L1), and negatively correlated with 4‐imidazole acrylic acid and 7‐hydroxy methotrexate. Additionally, Ruminiclostridium_E and Odoribacter negatively correlated with 7‐hydroxy methotrexate and captopril. These findings suggest a coordinated microbiota‐metabolite interplay influencing fetal development. Identifying maternal specific microbial taxa and metabolic pathways associated with higher‐birth‐weight calves offers potential biomarkers and intervention targets for optimizing neonatal growth and perinatal health management in dairy cattle.