TITLE:
The Effect of Postbiotic Supplementation on Body Weight Changes, Blood Metabolic Profiles, Rumen Microbiome Changes, and Immune Responses in Dairy Calves
AUTHORS:
Byeng Ryel Min, Mariline Hilaire, Honghe Wang, Anthony Kumi, Santoshes Chaudhary, Vivian Kanyi, Isaac Min, EunYoo Kim, Isaac Ha, Heba Abdo, Hosaam Ismael, Sean Yang, Richard Puchala
KEYWORDS:
Postbiotic, Animal Performance, Animal Health, Immune Response
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.16 No.3,
May
27,
2026
ABSTRACT: Limited information exists about the effects of postbiotic supplementation (dried Lactobacillus Fermentation Product) on animal performance, blood metabolites, immune responses, and changes in the rumen microbiome in pre- and post-weaning dairy calves. This study aims to clarify how postbiotic supplementation (in non-viable cells) affects growth performance, blood metabolites, rumen microbiome dynamics, immune response, and immune-related gene expression in pre-weaned dairy calves over a 95-day period. The experiment involved 30 male healthy pre-weaned Holstein (Bos taurus) calves (5 days old, weighing 40 - 50 kg), randomly divided into three groups. The control group received no postbiotics (preferred as a control [0.0 mg]), while the other groups received 1.75 g/d and 3.5 g/d postbiotic supplements in their diet for 50 days (period I). During the post-weaning period, calves in the control group received increasing postbiotic doses (0.0%, 3.5 g/d, and 7.0 g/d per calf) for 45 days, for a total of 95 days of the study (period II). Calves were housed individually in pens with free access to water. Data were analyzed using the Mixed procedure of SAS (version 9.4). Results showed that, with postbiotic supplementation, animal body weight and cell-mediated immune response were significantly higher in the higher-dose group than in the control group (P P P P α, IL-6, and IFN genes. In conclusion, postbiotic feeding improved animal health, strengthened immune responses, caused minor changes in rumen microbiome diversity, and affected blood chemistry in dairy calves compared to controls.