The use of antibiotics as growth promoters in livestock production has contributed to the emergence and spread of antimicrobial resistance (AMR), posing a significant global public health threat specifically from the projected mortality burden. Although many countries have restricted the non-therapeutic use of antibiotics, practical and effective alternatives are still required to maintain livestock productivity. This scoping review examines the current evidence on non-antibiotic compounds evaluated as growth-promoting agents in livestock production. The primary objective of this search was to generate a comprehensive list of commonly applied alternatives to antibiotics used as growth promoters in livestock systems. A search was conducted in the CAB Abstracts, Web of Science Core Collection, and AGRICOLA databases. Prior to the scoping review, an initial list of alternatives to antibiotic components was generated through a screening of selected scientific sources and subsequently verified using Google Scholar for the period 2010–2025. This list included brief descriptions of each component, which were used to inform the keyword strategy for the scoping review. Eligible studies were screened in accordance with PRISMA-ScR guidelines, and data were extracted on compound type, livestock species, geographic region, and reported performance outcomes. The alternatives identified included probiotics and prebiotics, phytogenic compounds and essential oils, enzymes and organic acids, vaccines and immunostimulants, bacteriophages, and competitive exclusion products. A total of 1230 records were retrieved and imported into Zotero for reference management. After removal of duplicate records using Zotero’s built-in deduplication tool, 377 unique records remained for screening. Overall, these compounds demonstrated variable effects on feed efficiency, weight gain, and gut health. However, most studies were limited in scale, duration, and methodological consistency. As a result, comprehensive comparative trials and large-scale field evaluations are needed to support evidence-based policy recommendations and the sustainable implementation of alternatives to antibiotics in livestock production systems. Our findings identified six major categories that represent the most frequently reported alternatives to antibiotic growth promoters. Although probiotics, phytogenic, and organic acids were the most extensively studied, substantial heterogeneity in trial design, dosage, and production systems limited meaningful cross-comparisons. In addition, most studies focused on poultry and swine, with comparatively fewer investigations involving ruminant species. This scoping review was not intended to evaluate the efficacy or practical applicability of these alternatives; such assessments require further standardized and extensive studies before recommendations for their widespread application can be made.

Antimicrobial resistance (AMR) is a global public health issue, causing an estimated 1.27 million deaths in 2019. This systematic review and meta-analysis aim to assess the burden of AMR in food animals in Pakistan, identify resistant microbes, and highlight emerging trends in multidrug resistance (MDR). The major databases were searched for articles published between 2016 and 2020 on the prevalence of AMR in food animals in Pakistan. A random-effects model was employed to pool the prevalence of antibiotic-resistant Enterobacteriaceae and non-Enterobacteriaceae pathogens. Among 1,145 studies, 35 met the inclusion criteria as evidence of AMR in food animals. Escherichia coli showed the highest resistance to ampicillin (59.5%), ciprofloxacin (49%), oxytetracycline (39%), and chloramphenicol (35%); Salmonella to ampicillin (78.4%), amoxicillin (53.9%), chloramphenicol (40%), tetracycline (39.3%), and ciprofloxacin (39%); Staphylococci to cefoxitin (53.8%) and penicillin (34.8%); and Campylobacter and Klebsiella to ciprofloxacin (50.4% and 83.3%, respectively). MDR was observed in E. coli (12/12 studies), Salmonella (7/10), Staphylococci (3/8), Campylobacter (3/3), and Klebsiella (1/3), with extensive drug resistance in E. coli (3/12), Salmonella (4/10), Campylobacter (1/3), and Klebsiella (2/2). Enterobacteriaceae showed significant resistance to tetracyclines (pooled prevalence/PPr = 0.75) and aminopenicillins (PPr = 0.74), whereas non-Enterobacteriaceae showed resistance to cephalosporins (PPr = 0.67) and aminopenicillins (PPr = 0.59), both with substantial heterogeneity. This review shows the existence of bacteria resistant to commonly used antimicrobials in food animals, potentially a threat to both human and animal health. The findings suggest the continuous monitoring of AMR and antimicrobial use (AMU) and the regulation of AMU in the food and agriculture sectors.

Irrational use of antimicrobials in humans, livestock, and poultry is often cited as the key driver of the accelerated emergence of antimicrobial resistance (AMR) in humans and animals. In Pakistan, the use of antimicrobials in livestock and poultry is not well-regulated, owing to limited and/or ineffective implementation of existing legislations and lack of coordination amongst the key stakeholders. To gather data and information pertinent to the supply chain mapping and the usage of antibiotics in the livestock and poultry sectors of Pakistan, a national workshop for selected influential stakeholders was held in Islamabad, Pakistan during March 2020 to map the supply chain and the usage of antibiotics in the country. Participants from all relevant organizations identified the supply chain and discussed the status, challenges, and the way forward to enhance data collection and monitoring of antimicrobial usage (AMU) in livestock and poultry sectors to contain the emergence of AMR. The pre-workshop questionnaire was designed to gather relevant information on AMU and its distribution among diverse markets and users from the workshop participants, utilizing open-ended questions. A chart depicting the relative magnitude of an antimicrobial use (AMU) supply chain was constructed to illustrate the flow of antimicrobials from import and production to end-use at the farm level. This chart was shared with participants to gather their professional opinions and potential corrections. It also presented a list of agencies and their roles in regulating AMU, along with the types of AMU data available at each level. Specific recommendations were made at the end of the workshop to review and update legislation to cover the entire AMU supply chain, enhance regulations to restrict the use of antimicrobial growth promoters, build an integrated national AMU database system, and raise awareness about the responsible use of antimicrobials in the livestock and poultry sectors. It was concluded that the AMU supply chain in the veterinary sector of Pakistan is fragmented and is co-regulated by various federal and provincial stakeholders. There are some drugs, such as antibiotic growth promoters, which are not regulated at all. The approach and findings from this study can serve as a model to validate the use and management of antibiotics in other, similar countries currently grappling with serious antimicrobial resistance (AMR) crises.

Irrational use of antimicrobials in humans, livestock and poultry are often cited as the key drivers of accelerated emergence of antimicrobial resistance (AMR) in humans and animals. In Pakistan, the use of antimicrobials in livestock and poultry is not well-regulated owing to limited and/or ineffective implementation of existing legislations and lack of coordination amongst the key stakeholders. To gather data and information pertinent to the supply chain mapping and the usage of antibiotics in the livestock and poultry sectors of Pakistan, a national workshop among selected influential stakeholders was held in Islamabad, Pakistan during March 2020 to map the supply chain and usage of antibiotics in country. Participants from all relevant organizations identified the supply chain and discussed the status, challenges, and way forward to enhance data collection and monitoring of antimicrobials usage (AMU) in livestock and poultry sectors to contain emergence of AMR. The pre-workshop questionnaire was designed to gather relevant information on AMU and its distribution among diverse markets and users from the workshop participants, utilizing open-ended questions. A chart depicting the relative magnitude of an antimicrobial use (AMU) supply chain was constructed to illustrate the flow of antimicrobials from import and production to end-use at the farm level. This chart was shared with participants to gather their professional opinions and potential corrections. It also presented a list of agencies and their roles in regulating AMU, along with the types of AMU data available at each level. Specific recommendations were made at the end of the workshop to review and update legislation to cover the entire AMU supply chain, enhance regulations to restrict the use of antimicrobial growth promoters, build an integrated national AMU database system, and raise awareness about the responsible use of antimicrobials in the livestock and poultry sectors. It was concluded that the AMU supply chain in veterinary sector of Pakistan is fragmented and is co-regulated by various federal and provincial stakeholders. There are some drugs such as antibiotic growth promoters which are not regulated at all. The approach and findings from this study can serve as a model to validate the use and management of antibiotics in other similar countries currently grappling with serious antimicrobial resistance (AMR) crises.

Background: Antimicrobial resistance (AMR) is a critical global health threat, with AMR Salmonella enterica serovar Typhimurium strains being a major foodborne pathogen. Integrons, a type of mobile genetic element, capture and transfer resistance genes, thereby playing a role in the spread of AMR. Objectives: This study aimed to characterize the locations of integrons carrying AMR genes within the whole genomes of 32 Salmonella Typhimurium isolates collected from dairy cattle by two U.S. Veterinary Diagnostic Laboratories between 2009 and 2012. Methods: Class I integrons were sequenced from PCR-amplified products. DNA was extracted, quantified, barcoded, and sequenced on the Illumina MiSeq platform. Whole genome sequences were trimmed and assembled using the SPAdes assembler in Geneious Prime^®, and plasmids were identified with the PlasmidFinder pipeline in Linux. Integron locations were determined by aligning their sequences with whole genome contigs and plasmids, while AMR genes were identified through BLAST with the MEGARes 3.0 database and confirmed by alignment with isolate, plasmid, and integron sequences. Statistical analysis was applied to compare the proportions of isolates harboring integrons on their chromosome versus plasmids and also to examine the associations between integron presence and AMR gene presence. Results: Seven plasmid types were identified from all isolates: IncFII(S) (n = 14), IncFIB(S) (n = 13), IncC (n = 7), Inc1-I(Alpha) (n = 3), and ColpVC, Col(pAHAD28), and Col8282 (1 isolate each). Of the 32 isolates, 16 (50%) carried at least one size of integron. Twelve of them carried both 1000 and 1200 bp; 3 carried only 1000 bp and 1 carried 1800 bp integrons. Of the 15 isolates that carried 1000 bp integron, 12 harbored it on IncFIB(S) plasmids, 2 on IncC plasmids, and 1 on the chromosome. The 1200 bp integrons from all 12 isolates were located on chromosomes. There were significant positive associations between the presence of integrons and the presence of several AMR genes including sul1, aadA2, blaCARB-2, qacEdelta1, tet(G), and floR (p < 0.05). AMR genes were located as follows: aadA2 on IncFIB(S) and IncC plasmids; bla_CMY-2 on IncC plasmid; qacEdelta1 on IncFIB(S), IncC, and chromosome; bla_CARB-2, floR, tet(A) and tet(G) on the chromosome. Conclusions: The findings highlight the genomic and plasmid complexity of Salmonella Typhimurium which is impacted by the presence and location of integrons, and this study provides genomic insights that can inform efforts to enhance food safety and protect both animal and public health.