Intensive, excessive, and often unjustified use of antibiotics in livestock farms promotes the development of resistant pathogens, reducing the effectiveness of medicines, causing recurring diseases, and leading to increased antibiotic doses. Scientific studies have shown that bacteria carrying antibiotic resistance genes can be transmitted from animal to animal and from animals to humans. This problem is particularly significant because microbial resistance to antibiotics develops faster than new antimicrobial substances can be discovered or created. Therefore, it is essential to implement more advanced disease prevention and treatment measures that would reduce the use of antibiotics on farms. One of the promising solutions is the inclusion of synbiotics in animal feed. Synbiotics are combinations of biologically active organic substances consisting of probiotics and prebiotics that positively affect the digestive and immune systems, support healthy gastrointestinal microflora, and improve animal health and productivity. Once in the digestive tract, synbiotics suppress pathogenic microorganisms, help restore impaired body functions, stimulate tissue regeneration, and strengthen the immune system. These preparations are developed from microorganisms naturally found in the digestive tract of animals and synthesize important biologically active substances such as vitamins, enzymes, amino acids, and natural antibiotics. Compared to chemical antibacterial products, synbiotics have several advantages: they are non-toxic, do not cause allergic or other side effects, improve feed utilization, support intestinal health, reduce the risk of acidosis, enhance the absorption of microelements, and increase productivity. They are especially beneficial for young cattle, as they strengthen immunity and promote better growth and development. In order to evaluate the effectiveness of synbiotics on the health and productivity of dairy cows and calves, livestock consultants and specialists of the Lithuanian Agricultural Advisory Service (LAAS) carried out eight demonstration trials on dairy farms located in the districts of Plungė, Skuodas, Rokiškis, Utena, Šilutė, Šilalė, Kelmė, and Šiauliai. Sixteen dairy cows and sixteen newborn calves were selected for the study. The animals were divided into control and experimental groups and kept under identical feeding and housing conditions. Experimental group cows received synbiotics with feed for three months, while calves received synbiotics with milk for two months. During the trials, feed nutritional value analyses were performed, blood biochemical parameters and immunoglobulin levels in blood serum were determined, and productivity, milk quality, and feed digestibility were evaluated using manure washing sieves. The animals were tested four times: 14 days after calving, after one month, after two months, and at the end of the trial period. The results confirmed the benefits of synbiotics for animal health and productivity. Conclusions and practical recommendations for the use of synbiotics on farms were prepared based on the trial results.