Maternal administration of octanoate, a medium-chain fatty acid, improves feed efficiency of Japanese black calves through influencing gut bacteriome structure.

Maternal-offspring gut bacteriomes are closely linked to each other; however, the effects of the maternal diet have not been fully elucidated. This study aimed to determine the effect of administration of octanoate, a medium-chain fatty acid as a physiological regulator, on the fecal bacteriome and physiological indices of dams and their calves as a livestock animal model. Twelve Japanese Black cattle were randomly assigned to CON (without Ca-octanoate supplementation, n = 6) or OCT (with Ca-octanoate supplementation, n = 6), 60 days prior to the expected parturition date. A tendency towards enhanced feed efficiency was observed during the suckling period in OCT calves compared to CON calves, although the management of the calves was uniform from birth. Three types of machine learning algorithms computationally selected the feature factors of dams and their calves (30 d and 180 d of age). Based on the feature selection, causal inference estimated that feeding octanoate to dams would establish a positive association with the genus Bacteroides, a producer of short-chain fatty acids, at 30 d and a negative association with the genus Candidatus Stoquefichus, which is involved in colitis, at 180 d. These findings highlight that feeding octanoate to dams may influence the bacteriome of calves, thereby improving their feed efficiency.