## 4 Conclusions  
In this study, a 14-day experiment was conducted with two groups of newborn calves, the control group, and the MP group, which received an MP supplement fermented with \(L\)_uvarum_ LUHS245. After 14 days of treatment, there were no significant differences between the MP14 and CON14 groups in blood parameters, growth performance, and faecal pH. However, there were significantly higher numbers of live LAB (by 17.02%), a lower TCE (by 10.38%), and a higher content of dry matter in the faeces after 14 days in the MP group compared with the CON group (\(p<0.05\)). The variety and composition of microbial species in the faeces of calves in the MP group differed significantly from the CON group in that there were more probiotic bacteria (particularly LAB) and a 1.7-fold greater variety of species. The profiles of FA (with the exceptions of C4:0 and C16:1) and VCs (with the exceptions of indole, hexanoic acid, 2-nonanone, and nonanoic acid) differed significantly between the two groups. The predominant SCFA in the faeces of both groups were acetic, propionic, and butyric acids, the concentrations of which were significantly higher in the faeces of the MP14 group compared with the CON14 group by 34.3%, 57.3%, and 22.3%, respectively. The results suggest that supplementing the feed of newborn calves with fermented MP has a positive effect on some parameters, which may potentially affect health, although blood parameters and growth performance were not influenced by the treatment.  
**Supplementary Materials:** The following are available online at [[https://www.mdpi.com/article/10.3390/anil1092544/s1](https://www.mdpi.com/article/10.3390/anil1092544/s1)]([https://www.mdpi.com/article/10.3390/anil1092544/s1](https://www.mdpi.com/article/10.3390/anil1092544/s1)), Table S1: pH, total titratable acidity (TTA), and total lactic acid bacteria (LAB) count in the milk permeate (MP) samples; Table S2: Antimicrobial activities of the nonfermented and fermented milk permeate (MP) against 15 pathogenic and opportunistic microbial bacteria in liquid medium (+ indicates pathogen growth)--indicates that pathogen growth was not established); Table S3: Galactooligosaccharides (GOS) (mgGOS/100 mLsample) concentration in nonfermented and fermented milk permeate (MP) samples; Table S4: Bacterial genera in the faeces of calves fed with fermented milk permeate (MP group) after 14 days of the experiment; Table S5: Bacterial genera in the faeces of calves fed with milk replacer only (CON group) after 14 days of the experiment; Table S6: Bacterial species in the faeces of calves fed with fermented milk permeate (MP group) after 14 days of the experiment; Table S7: Bacterial species in the faeces of calves fed with milk replacer only (CON group) after 14 days of the experiment; Table S8: Volatile compound percentage profiles of faeces in the control (CON) and supplemented with fermented milk permeate (MP) groups.  
**Author Contributions:** Conceptualisation and methodology E.B., R.G., and A.S.; formal analysis L.V., S.B., E.Z., V.S., E.M., J.K., V.L., A.D., and D.C.; investigation L.V., S.B., E.Z., P.Z., V.S., E.M., J.K., V.L., A.D., and D.C.; writing--original draft preparation M.R., D.C., D.K., and E.B.; writing--review and editing D.K., M.R., and D.C.; supervision, E.B., R.G., and A.S. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** The calves were housed indoors and were individually tethered and cared for in accordance with the Lithuanian State Food and Veterinary Service Requirements. Research was carried out in accordance with both the Republic of Lithuania Act (6 November 1997) regulating animal care and maintenance and its subsequent legal amendment (Act 8-500).  
**Informed Consent Statement:** Not applicable.