Effects of peripartal rumen-derived direct-fed microbials supplementation on lactation performance, metabolism, ruminal fermentation, and microbial abundance in dairy cows

• Published in: Journal of dairy science 2024-12
• Main Authors: Bulnes, M., Bonilla, J., Suazo, M., Michelotti, T.C., Paz, A., Lefler, J., Marotz, C., Embree, M., Begalli, G., Halfen, J., Fernandes, T., Trevisi, E., Uddin, M.E., Osorio, J.S.
• Format: Article
• Language: English
• Subjects: direct-fed microbials; feed additive; ruminal microbial abundance; transition cow
• ISSN: 0022-0302; 1525-3198; 1525-3198
• DOI: 10.3168/jds.2024-25058

The objective of this study was to evaluate the effects of a rumen-derived direct-fed microbial (DFM) product on performance, blood biomarkers, ruminal fermentation, and bacterial abundance in dairy cows during the transition period until 100 DIM. Fifty-six Holstein cows were enrolled in a randomized complete block design from −21 to 100 DIM. Cows were blocked based on expected calving date, parity, and previous lactation milk yield for multiparous or genetic merit for primiparous cows. At −21 DIM, cows were randomly assigned to either a basal diet supplemented with 150 g/d ground corn (CON, n = 29) or a basal diet supplemented with ground corn plus rumen-derived DFM product (GF, 150 g/d ground corn + 5g/d of GF, n = 27; Clostridium beijerinckii at 1.0 × 107 cfu; Pichia kudriavzevii at 1.0 × 108 cfu; Ruminococcus bovis at 1.0 × 108 cfu; Butyrivibrio fibrisolvens at 1.0 × 108 cfu; Galaxis Frontier (GF), Native Microbials, San Diego), top-dressed once a day. All cows received the same basal close-up diet from −21 DIM until calving (1.56 Mcal/kg DM and 14.46% CP) and lactation diet from calving to 100 DIM (1.76 Mcal/kg DM and 15.69% CP). Blood samples were collected to measure biomarkers of metabolism, inflammation, and oxidative stress as well as rumen fluid via esophageal tubing for ammonia, VFA, and microbial abundance from a subset of multiparous cows (n = 12/treatment) at various time points from −22 to 100 DIM. Compared with CON, GF cows produced greater milk (+4.1 kg/d) during the post-fresh period (6 – 14 wk). However, GF cows tended to produce more milk (+2.9 kg/d) than CON during the entire trial (0 – 14 wk). Although DMI was not affected by treatment, GF cows had greater feed efficiency (+0.18, milk/DMI) in the post-fresh period. Compared with CON, GF cows had lower blood plasma glucose and higher BHB. Blood biomarkers showed greater concentrations of ceruloplasmin, haptoglobin, and reactive oxygen metabolites (ROM) in GF cows compared with CON. Compared with CON, GF cows had greater ruminal molar proportions of butyrate and tended to have greater valerate and lower acetate. These changes in ruminal VFA were coupled with alterations in ruminal microbial abundance, where compared with CON, GF cows tended to have a greater abundance of lactate-utilizing (Megasphaera elsdenii) but lower abundance of cellulose-utilizing species (Fibrobacter succinogens). Although greater ROM was accompanied by a mild inflammatory condition in GF cows, this was not detr