Beyond Antibiotics: The Future of Livestock Disease Control

Antibiotics remain an essential part of livestock medicine, but their widespread and repeated use has accelerated the emergence of antimicrobial resistance (AMR). As preserving antibiotic effectiveness becomes a priority, veterinary medicine is increasingly exploring strategies that prevent disease, target pathogens more precisely, or reduce dependence on conventional antimicrobials. Several emerging technologies, including antimicrobial peptides, gene-editing tools, next-generation vaccines, and bacteriophage therapy, offer promising alternatives that could reshape future livestock disease management¹. 

Antimicrobial Peptides: Nature's Defense Against Pathogens 

Antimicrobial peptides (AMPs) are naturally produced by many organisms as part of their innate defense against infection. Unlike conventional antibiotics, AMPs possess broad-spectrum activity against bacteria, fungi, parasites, and viruses while acting through non-specific mechanisms on bacterial membranes, making the development of antimicrobial resistance less likely^2,3,4. 

Another advantage of AMPs is that bacteria appear to adapt to them more slowly than they do to conventional antibiotics⁴. Their biodegradable nature also makes them an attractive option for future antimicrobial strategies. 

However, clinical application is not without challenges. Their biodegradability may reduce stability within the animal's body, limiting therapeutic persistence in conditions such as bovine mastitis². 

One practical example is the use of bovine lactoferrin in chickens as an alternative to antibiotics for preventing Clostridium perfringens type A/G-induced avian necrotic enteritis, particularly in the context of restrictions on antibiotic use in poultry⁵. 

Precision Treatment Through CRISPR Technology 

Gene-editing technology using CRISPR/Cas systems offers an entirely different approach to combating AMR. 

Rather than broadly targeting bacteria, CRISPR-based tools can be programmed to selectively eliminate antimicrobial-resistant bacteria based on their genetic sequences while sparing beneficial commensal microorganisms. They may also reduce bacterial colonization when delivered through phage capsids and can restore bacterial susceptibility to antibiotics by removing plasmids carrying resistance genes⁶. 

Despite these promising capabilities, practical implementation remains challenging. Public acceptance of in vivo gene editing and the need for advanced delivery systems continue to influence wider adoption of this technology⁶. 

Vaccines as a Preventive Strategy 

Preventing disease before antibiotic treatment becomes necessary is another important approach to reducing antimicrobial use. 

DNA and mRNA vaccines aim to decrease disease transmission within livestock populations, thereby reducing the need for antimicrobial therapy. DNA vaccines work by introducing a gene of interest into a plasmid that enables antigen production and stimulates an immune response^7,8. 

Current livestock vaccines are predominantly directed against viral diseases, although bacterial vaccines have been developed or are under development for pathogens including Mycoplasma hypopneumoniae in swine and Salmonella and Pasteurella in poultry^1,7. 

DNA vaccines may face limitations related to in vivo efficacy, stability, and the frequent requirement for booster doses⁸. In contrast, mRNA vaccines offer several potential advantages, including rapid production, natural degradation, non-infectious characteristics, and the ability to stimulate both B-cell and T-cell immune responses⁹. 

Bacteriophages: Targeting Bacteria with Precision 

Bacteriophages are viruses that specifically infect bacteria and have attracted considerable interest as targeted antimicrobial agents. 

Their high specificity enables them to attack particular bacterial pathogens while avoiding broader disruption of beneficial microbial populations. Phages also multiply at the site of infection and are considered relatively economical compared with some other emerging technologies¹⁰. 

Encouraging applications have already been reported. Phage therapy has shown promising activity against Staphylococcus aureus, an important cause of bovine mastitis. In neonatal pigs, phage therapy reduced Salmonella colonization by more than 99%^1,11. 

Despite these advantages, important limitations remain, including the need for careful matching between phages and bacterial strains, challenges related to in vivo stability, immune responses, phage resistance, and scalability for broader use¹. 

Practical Clinical Insights 

• Antimicrobial peptides provide broad-spectrum antimicrobial activity and appear less likely to promote resistance, although in vivo stability remains a challenge. 

• CRISPR/Cas technology offers precision targeting of resistant bacteria while preserving beneficial microorganisms and may restore antibiotic susceptibility by eliminating resistance plasmids. 

• DNA and mRNA vaccines focus on disease prevention, reducing the need for antimicrobial treatment through improved immunity. 

• Bacteriophage therapy provides highly specific antibacterial activity and has demonstrated encouraging results against pathogens affecting poultry, swine, and dairy cattle. 

The future of livestock disease control is unlikely to depend on a single replacement for antibiotics. Instead, it is expected to involve a combination of preventive, targeted, and innovative approaches that complement responsible antimicrobial use. As these technologies continue to evolve, veterinarians will play a central role in evaluating where and how they can be integrated into livestock health programs while supporting long-term antimicrobial stewardship.

References 

1. Enshaie E, Nigam S, Patel S, Rai V. Livestock antibiotics use and antimicrobial resistance. Antibiotics. 2025 Jun 19;14(6):621. https://www.mdpi.com/2079-6382/14/6/621 

2. Robles Ramirez O, Osuna G, Plisson F, Barrientos-Salcedo C. Antimicrobial peptides in livestock: a review with a one health approach. Frontiers in Cellular and Infection Microbiology. 2024 Apr 24;14:1339285. https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2024.1339285/pdf 

3. Mookherjee N, Anderson MA, Haagsman HP, Davidson DJ. Antimicrobial host defence peptides: functions and clinical potential. Nature reviews Drug discovery. 2020 May;19(5):311-32. https://www.research.ed.ac.uk/files/138110044/Mookherjee_Anderson_Haagsman_Davidson_NRDD_2020_accepted.pdf 

4. Assoni L, Milani B, Carvalho MR, Nepomuceno LN, Waz NT, Guerra ME, Converso TR, Darrieux M. Resistance mechanisms to antimicrobial peptides in gram-positive bacteria. Frontiers in Microbiology. 2020 Oct 21;11:593215. https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.593215/pdf 

5. Wong TW, Rai V, Dong F, Tkalcic S, Aguilar JS, Dawes ME. Research Note: Bovine lactoferrin in chickens: An investigation into its viability as an antibiotic alternative. Poultry Science. 2024 Jun 1;103(6):103658. https://www.sciencedirect.com/science/article/pii/S0032579124002372 

6. Bikard D, Barrangou R. Using CRISPR-Cas systems as antimicrobials. Current opinion in Microbiology. 2017 Jun 1;37:155-60. https://pasteur.hal.science/pasteur-01911231/document 

7. Dors A, Panek R, Łużyński W, Janeczko K, Augustyniak A, Turlewicz-Podbielska H, Czyżewska-Dors E, Pomorska-Mól M. Effect of Vaccination Against E. coli, C. perfringens Type A/C on Piglet Productive and Clinical Parameters Under Field Conditions. Vaccines. 2024 Oct 17;12(10):1185. https://www.mdpi.com/2076-393X/12/10/1185 

8. Jazayeri SD, Poh CL. Recent advances in delivery of veterinary DNA vaccines against avian pathogens. Veterinary research. 2019 Oct 10;50(1):78. https://link.springer.com/content/pdf/10.1186/s13567-019-0698-z.pdf 

9. Zhang C, Maruggi G, Shan H, Li J. Advances in mRNA vaccines for infectious diseases. Frontiers in immunology. 2019 Mar 27;10:594. https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.00594/pdf 

10. Ferriol-González C, Domingo-Calap P. Phage therapy in livestock and companion animals. Antibiotics. 2021 May 11;10(5):559. https://www.mdpi.com/2079-6382/10/5/559 

11. Ngassam-Tchamba C, Duprez JN, Fergestad M, De Visscher A, L’Abee-Lund T, De Vliegher S, Wasteson Y, Touzain F, Blanchard Y, Lavigne R, Chanishvili N. In vitro and in vivo assessment of phage therapy against Staphylococcus aureus causing bovine mastitis. Journal of global antimicrobial resistance. 2020 Sep 1;22:762-70. https://www.sciencedirect.com/science/article/pii/S221371652030165X