Antibiotics In Livestock Production Research Articles

Prudent Use of Antibiotics in Dairy Cows: The Nordic Approach to Udder Health.

Global concerns regarding bacterial antibiotic resistance demand prudent use of antibiotics in livestock production. Dairy production in the Nordic countries has a low consumption of antibiotics, while animal health, productivity and milk quality are at high levels. Here, we describe the basis of Nordic mastitis control and treatment strategies, as a model for production of high-quality milk with prudent use of antibiotics. We hope this will be beneficial for dairy producers and advisors in other countries and regions that consider limiting antibiotic use in cattle herds. In this perspectives paper we describe the dairy sector in the Nordic countries, and present regulatory aspects of antibiotic use, diagnostics and current guidelines for treatment of clinical mastitis as well as dry cow therapy. We also show summary statistics of udder health indicators in Denmark, Finland, Norway and Sweden, to illustrate the effects of the implemented udder health management practices.

Meat Consumers' Opinion Regarding Unhealthy Pigs: Should They Be Treated with Antibiotics or Euthanized on Farm?

The aim of this study was to investigate the opinions of meat consumers (n = 1780) on on-farm management of unhealthy pigs, whether support for treatment with antibiotics varies according with chance of recovery, and the effect of knowledge on the use of antibiotics on these opinions. Most participants believed that the use of antibiotics was the best solution for unhealthy pigs, and this was associated with a low level of knowledge about antibiotics. Increasing the probability of recovery after treatment increased support for treating pigs with antibiotics. However, the majority of participants rejected the consumption of meat from animals housed in “hospital pens”. After price, concern with food safety was the second main factor that influenced participants’ choice when buying meat. Support for the use of antibiotics to deal with unhealthy pigs in “hospital pens”, as well as for consumption of the meat from these animals, was higher among participants involved in agriculture. This shows that consumers are unaware of the potential negative repercussions for animal welfare associated with banning or reducing the use of antibiotics in livestock production, which is an important concern for the industry.

Fermented traditional Chinese medicine alters the intestinal microbiota composition of broiler chickens

For a long time, phytogenic resources have been widely used as substitutes for antibiotics in livestock production. However, few studies have examined the relationship between the intestinal microbiota and fermented herbal medicines. Here, 252 Arbor Acres broiler plus broiler chickens were randomly assigned to a control group, which was fed a basal diet; an unfermented healthy chicken powder group (JJS) fed a basal diet containing 20 g/kg JJS; or one of 5 fermented JJS groups, which were fed a basal diet containing 20 g/kg JJS, fermented with by 5 different bacterial strains for 42 days. The growth performances of the different groups were measured and the changes in the intestinal microbiota were analyzed. The body weight gain in the Bacillus subtilis group (Bs) was the highest among the 6 groups, while the feed conversion ratio (FCR) was best with Z. rouxii fermentation. The result indicated that products of JJS fermentation products of JJS by B. subtilis and Z. rouxii had important effects on chicken growth performance. The foregut and hindgut microbial communities of Bs, Zr, the control group and the JJS group, were collected for 16S rDNA sequencing. The results showed that JJS and its fermentation products mainly acted on the foregut and had little effect on the hindgut, and Z. rouxii fermentation products can increased the diversity in the foregut microbial community. In addition, the relative abundance of Bifidobacterium in the foregut of the Z. rouxii group was significantly increased, which may be an important factor in promoting growth.

The growth performance and carcass characteristics of broiler guinea fowls (Numida meleagris) fed on diets containing RE3™ probiotics

The increasing abuse of antibiotics in production of food animals has led to development of resistant strains of bacteria (and other microbiota) which are responsible for several infectious diseases in animals and in humans. This study was conducted to investigate the effects of RE3TM, a third-generation probiotic used in place of a conventional antibiotics (to minimise incidence of antimicrobial resistance in livestock and human consumers), on growth performance and some carcass characteristics of guinea fowls. One hundred and twenty guinea fowl keets of mixed sexes with an average weight of 28.3±0.364g were used for the study conducted in a Completely Randomised Design. There were 4 treatments in which RE3TMwas incorporated at; 0.0ml/kg feed (Diet 1; Control), 1.0ml/kg feed (Diet 2) ,1.5ml/kg feed (Diet 3) and 2.0ml/kg feed (Diet 4); each treatment had 30birds. The feeding trial covered the entire meat production phase (starter, grower and finisher) which lasted for 84 days. Feed and water were given ad libitum.At maturity (12 weeks old), a total of thirty-six (36) birds (9 from each treatment, comprising 5 males and 4 females across the treatments) were selected, weighed and slaughtered.Carcass and viscera weights were taken, carcasses were then sectioned into primal cuts after 24-hour chilling at 4°C. Breast muscles from sampled carcasses were grilled for sensory evaluation by a trained panel, whilst the thigh muscles were subjected to proximate analyses. Data obtained were analysed for statistical significance using the one-way Analysis of Variance (ANOVA) Test, of the GenStat Statistical Package (Discovery Edition,VSN, 2012). Results obtained showed higher (p<0.05) growth rates and lower feed conversion ratio for birds on the diets with 1.0 ml of RE3TM per Kg feed. The carcass and body parts characteristics assessed however, showed no significant differences (p>0.05), except for the thighs which were heavier (p<0.05) in birds on the RE3TM supplemented diets, compared with those on the control diets.The use of RE3™ probiotics, up to 2.0ml/kg feed for guinea fowls, had no adverse effects on the growth of the birds, but it reduced the cost of providing medication for the birds. Fat content in the meat reduced, as inclusions of RE3TMincreased in the diets. It is recommended that relevant Government authorities and other stakeholders should aid in promoting the use of probiotics, instead of antibiotics in livestock production to minimise possible antibiotic residue in meat.

Assessing antibiotic residues in piglet liver and kidney samples: How to manage the results obtained

The use of antibiotics in livestock production has become a common practice. In the EU, the use of antibiotics as growth promoters is forbidden. However, the (mis)use of antibiotics may lead to antimicrobial resistance, which adversely affects humans, animals and the environment. Thus, the present study, using a previously validated multiclass and multi-residue UHPLC-ToF-MS methodology for the determination of 43 antibiotics, presents an assessment of data obtained from 60 piglets, using their livers and kidneys as samples. Eleven antimicrobials from different families were detected, which included ciprofloxacin, danofloxacin, doxycycline, enrofloxacin, oxytetracycline, spiramycin, sulfisomidine, sulfachloropyridazine, sulfadiazine, tilmicosin, and trimethoprim. The obtained concentrations ranged from 0.3 to 438.7 μg kg−1, confirming that both kidney and liver matrices are relevant in monitoring drug residue control programs.

Microcin J25 Exhibits Inhibitory Activity Against Salmonella Newport in Continuous Fermentation Model Mimicking Swine Colonic Conditions.

Microcin J25 (MccJ25), a 21-amino acid bacteriocin produced by Escherichia coli (E. coli), is a potent inhibitor of Enterobacteriaceae, including pathogenic E. coli, Salmonella, and Shigella. Its lasso structure makes it highly stable and therefore of interest as a possible antimicrobial agent in foods or as an alternative to antibiotics in livestock production. In the present study, we aimed to evaluate in vitro the inhibitory activity of MccJ25 against Salmonella enterica subsp. enterica serovar Newport ATCC 6962 (Salmonella Newport) used as a model pathogen under conditions simulating those of the swine proximal colon. The growth inhibition activity of MccJ25 against Salmonella Newport was examined in lysogeny broth (LB) and in modified MacFarlane medium that allows miming the swine colonic conditions. The MccJ25 activity was further determined using the Polyfermentor intestinal model (PolyFermS), an in vitro continuous fermentation model that permits deciphering the activity of any antimicrobial molecule in real colon fermentation conditions using selected microbiota. It was set up here to simulate the porcine proximal colon fermentation. In these conditions, the inhibition activity of MccJ25 was compared to those of two antimicrobial agents, reuterin and rifampicin. The minimal inhibitory concentration (MIC) of MccJ25 was determined at 0.03 μM in LB medium, compared to 1,079 and 38 μM for reuterin and rifampicin, respectively, showing a significantly higher potency of MccJ25. Total inhibition of Salmonella Newport was observed in LB medium over 24 h of incubation at concentrations starting from the MIC. In the PolyFermS model, MccJ25 induced a significantly stronger inhibition of Salmonella Newport growth than reuterin or rifampicin. A specific and sensitive LC-MS method allowed to detect and quantify MccJ25 in the PolyFermS fermentation system, showing that MccJ25 remains stable and active against Salmonella in conditions mimicking those found in swine colon. This study paves the way for further exploring the potential of this bacteriocin as an alternative to antibiotics in livestock.

Antibiotics in Crop Production

This new 5-page article presents an overview of the use of antibiotics in agriculture. Several of the most severe bacterial diseases of tree fruit and other crops are discussed and their integrated management, which includes the use of antibiotics, is described. Antibiotic use for plant disease protection is compared with the use of antibiotics in livestock production, and their future and limitations in plant production are discussed. Written by Leigh Archer, Ute Albrecht, and Pamela Roberts, and published by the UF/IFAS Horticultural Sciences Department.

Does reduced usage of antibiotics in livestock production mitigate the spread of antibiotic resistance in soil, earthworm guts, and the phyllosphere?

The overuse of antibiotics in animal husbandry is widespread and believed to significantly contribute to the selection of antibiotic resistance genes (ARGs) in animals. Thus, there is a global drive to reduce antibiotic use in the agricultural sector. However, it has not been established whether a reduction in the use of antibiotics in livestock production would be effective in reducing the spread of ARGs. A microcosm approach was used to determine how the addition of manure with either reduced antibiotic levels or with typical antibiotic levels could affect the spread of antibiotic resistance genes between soil, earthworms and the phyllosphere. When compared to the control soil, earthworm and phyllosphere samples had the greater increase in ARG abundance in conventional manure treatments (P < 0.05). Reduced antibiotic manure also enriched the abundance of ARGs in the phyllosphere and soil but not earthworm guts when compared to the control (P < 0.05). In both soil and earthworm guts, the enrichment of ARGs was lower in reduced antibiotic manure than in conventional manure. This study has identified bacterial transfer through the soil-earthworm-phyllosphere system as a potential means to spread ARGs between habitats after fertilization with livestock derived manures.

Compound- and context-dependent effects of antibiotics on greenhouse gas emissions from livestock.

The use of antibiotics in livestock production may trigger ecosystem disservices, including increased emissions of greenhouse gases. To evaluate this, we conducted two separate animal experiments, administering two widely used antibiotic compounds (benzylpenicillin and tetracycline) to dairy cows over a 4- or 5-day period locally and/or systemically. We then recorded enteric methane production, total gas production from dung decomposing under aerobic versus anaerobic conditions, prokaryotic community composition in rumen and dung, and accompanying changes in nutrient intake, rumen fermentation, and digestibility resulting from antibiotic administration. The focal antibiotics had no detectable effect on gas emissions from enteric fermentation or dung in aerobic conditions, while they decreased total gas production from anaerobic dung. Microbiome-level effects of benzylpenicillin proved markedly different from those previously recorded for tetracycline in dung, and did not differ by the mode of administration (local or systemic). Antibiotic effects on gas production differed substantially between dung maintained under aerobic versus anaerobic conditions and between compounds. These findings demonstrate compound- and context-dependent impacts of antibiotics on methane emissions and underlying processes, and highlight the need for a global synthesis of data on agricultural antibiotic use before understanding their climatic impacts.

Knowledge, attitudes and practices of livestock and aquaculture producers regarding antimicrobial use and resistance in Vietnam.

The use of antibiotics in livestock production is considered a major driver of antibiotic resistance on a global scale. In Vietnam, small- and medium-scale livestock producers dominate the domestic market and regulatory pushes have done little to decrease antibiotic use. In order to inform future policy directions, this study aims to explore knowledge, attitudes, and practices amongst livestock producers to identify their perspectives on antibiotic use and resistance. A total of 392 small- and medium-scale producers specialized in pig, poultry and aquaculture production participated in the study. The results showed that the primary reason for antibiotic use reported by producers was for the treatment of infections (69%). However, prophylactic use was also evident, with farmers reporting other reasons for antibiotic use such as “animals display abnormal symptoms or behaviour” (55%), the “weather is about to change” (25%), or “animals on neighboring farms fall ill” (27%). Only one-fifth of producers demonstrated favorable attitudes towards antibiotic use and preventing antibiotic resistance. Moreover, administering antibiotics remained the preferred countermeasure directly applied by farmers at the first indication of disease (17%), compared to enacting hygiene (10%) or quarantine (5%) measures. The results showed divergent trends amongst producers, with pig producers demonstrating higher levels of knowledge, more favorable attitudes, and higher self-reported utilization of good practice. Better knowledge, attitudes, and practices were also associated with producers who engaged in efforts to explore information on antibiotic use and resistance, which improved incrementally with the number of sources consulted and hours invested. However, there were some areas where increased knowledge or more favorable attitude scores did not translate into better practices. For instance, producers with higher levels of formal education performed significantly better than those with lower education in terms of knowledge and attitude, though both groups reported similar practices. The findings of this study may support future interventions to prevent both antibiotic misuse and the development of antimicrobial resistance.

69 The effects of feeding a novel saccharomyces cerevisiae feed additive on the prevalence and abundance of antimicrobial resistance genes in the microbiome(s) of receiving beef calves

Abstract Antimicrobial resistance (AMR) is a growing worldwide health threat. Increases in AMR are preventing the success of therapeutic treatment(s), which leads to diminished animal well-being. Innovative research is needed to explore alternatives (i.e. feed supplementation) to reduce the dependencies of antibiotics in livestock production. Diet composition has previously been shown to play a large role in altering microbial communities. The objective of this project was to evaluate the effect a novel Saccharomyces cerevisiae feed additive on the abundance and prevalence of AMR genes present in beef cattle microbiomes (nasal, deep nasopharyngeal cavities, and fecal matter). Samples were collected from weaned steers (n = 32). Steers were fed four different dietary treatments (Control, 12 g/hd/day, 18 g/hd/day, post-transportation 18/g/hd/day). Analyses performed evaluated if AMR gene abundance or prevalence was reduced due to treatment. DNA samples were extracted and whole genome shotgun sequencing was conducted by Illumina Technologies. Sequences were mapped to the UMD 3.1 Bovine reference genome and the National Database of Antibiotic Resistant Organisms (NDARO) (n2= 4,187) to annotate and quantify microbial AMR genes. Hundreds of AMR genes were detected across fecal (371), nasal (363), and deep nasopharyngeal (121) samples. Nasal and deep nasopharyngeal samples primarily aligned to the bovine genome and were not analyzed further. DNA from fecal samples aligned predominantly with microbial genes and were the primary focus of the research. Linear models and treatment contrast analyses were implemented to test for nominally significant treatment differences (P &lt; 0.05). Dietary treatment significantly impacted AMR genes, predominantly Mef(EN2) and Lnu(AN2). On average, Lnu(AN2) and Mef(EN2) AMR gene read abundances were reduced due to dietary treatments by 57% and 55%. In conclusion, feeding this novel Saccharomyces cerevisiae feed additive did significantly reduce AMR gene read abundances. However, further research will increase our understanding of dietary treatment impacts within the fecal microbiome.

The effects of different doses of onion (Allium cepa. L) extract on leptin, ghrelin, total antioxidant capacity, and performance of suckling lambs

Application of antibiotics in livestock production has been a big concern in the recent years since they can have a vital role in the emergence of antibiotic resistant bacteria. Therefore, scientists and nutritionists have been searching for alternative agents to alter ruminal metabolism and improve feed efficiency and animal productivity. In this respect, the aim of the present study was to evaluate the effects of onion extract on leptin, ghrelin, total antioxidant capacity (TAC), and the performance of suckling lambs. Eighteen Torki Qashqai suckling lambs with 30 days of age were randomly divided into three groups, including (1) control group; basement diet without onion extract + sheep milk, (2) T150 group; basement diet containing 150 mg/kg onion extract + sheep milk, (3) T250 group; basement diet containing 250 mg/kg onion extract + sheep milk. The trial lasted for 60 days and the blood samples were taken on days 30 and 60 of the experiment. The results showed that the addition of onion extract led to an increase in the feed intake and daily weight in lambs. Moreover, onion extract was able to increase the level of ghrelin and reduce leptin hormone in the treatment groups (T150 and T250). In conclusion, it could be said that onion extract has a promising effect as a feed additive in ruminant nutrition and has the ability to improve feed intake in these animals. Moreover, onion extract has a positive effect on concentrations of leptin, ghrelin, TAC, and the performance in lambs.

Reducing the use of antibiotics in livestock production: adaptations to manage risk at different scales

Reducing the use of antibiotics in livestock production: adaptations to manage risk at different scales

Safety and Growth Optimization of Lactic Acid Bacteria Isolated From Feedlot Cattle for Probiotic Formula Design.

In order to eliminate the widespread use of antibiotics in livestock production, the research for alternatives has increased lately. This study examined the safety of 40 lactic acid bacteria (LAB) isolated from bovine feedlot environment and previously selected as potential probiotics. A high sensitivity prevalence to ampicillin (AMP, 100%), gentamicin (GEN, 96.3%), kanamycin (KAN, 96.3%), clindamycin (CLI, 85.2%), chloramphenicol (CHL, 92.6%) and streptomycin (STR, 88.9%) while moderate and high resistance against erythromycin (ERY, 48%) and tetracycline (TET, 79%) respectively, were determined. Feedlot enterococci and pediococci displayed high resistance to CLI, ERY, GEN and TET (73, 100, 54.5, and 73%, respectively). Among fifteen resistance genes investigated, seven were identified in lactobacilli; their presence not always was correlated with phenotypic resistance. STR resistance genes, aadA and ant(6) were observed in 7.4 and 3.7% of isolates, respectively; genes responsible for aminoglycosides resistance, such as bla (7.4%), and aph(3”)-III (3.7%) were also recognized. In addition, resistance cat and tetS genes (3.7 and 7.4%, respectively) were harbored by feedlot lactobacilli strains. The presence of ermB gene in 22.3% of isolates, including two of the six strains phenotypically resistant to ERY, exhibited the highest prevalence among the assessed antibiotics. None of the feedlot lactobacilli harbored virulence factors genes, while positive PCR amplification for ace, agg, fsrA, and atpA genes was found for enterococci. With the objective of producing large cell biomass for probiotic delivery, growth media without peptone but containing glucose and skim milk powder (Mgl and Mlac) were selected as optimal. Lactobacillus acidophilus CRL2074, L. amylovorus CRL2115, L. mucosae CRL2069, and L. rhamnosus CRL2084 were strains selected as free of antibiotic resistance and virulence determinants, able to reach high cell numbers in non-expensive culture media and being compatible among them.

Resistance to Metals Used in Agricultural Production.

Metals and metalloids have been used alongside antibiotics in livestock production for a long time. The potential and acute negative impact on the environment and human health of these livestock feed supplements has prompted lawmakers to ban or discourage the use of some or all of these supplements. This article provides an overview of current use in the European Union and the United States, detected metal resistance determinants, and the proteins and mechanisms responsible for conferring copper and zinc resistance in bacteria. A detailed description of the most common copper and zinc metal resistance determinants is given to illustrate not only the potential danger of coselecting antibiotic resistance genes but also the potential to generate bacterial strains with an increased potential to be pathogenic to humans. For example, the presence of a 20-gene copper pathogenicity island is highlighted since bacteria containing this gene cluster could be readily isolated from copper-fed pigs, and many pathogenic strains, including Escherichia coli O104:H4, contain this potential virulence factor, suggesting a potential link between copper supplements in livestock and the evolution of pathogens.

Tackling antimicrobial resistance in food-producing animals

Tackling antimicrobial resistance in food-producing animals

Dietary modulation of endogenous host defense peptide synthesis as an alternative approach to in-feed antibiotics.

Traditionally, antibiotics are included in animal feed at subtherapeutic levels for growth promotion and disease prevention. However, recent links between in-feed antibiotics and a rise in antibiotic-resistant pathogens have led to a ban of all antibiotics in livestock production by the European Union in January 2006 and a removal of medically important antibiotics in animal feeds in the United States in January 2017. An urgent need arises for antibiotic alternatives capable of maintaining animal health and productivity without triggering antimicrobial resistance. Host defense peptides (HDP) are a critical component of the animal innate immune system with direct antimicrobial and immunomodulatory activities. While in-feed supplementation of recombinant or synthetic HDP appears to be effective in maintaining animal performance and alleviating clinical symptoms in the context of disease, dietary modulation of the synthesis of endogenous host defense peptides has emerged as a cost-effective, antibiotic-alternative approach to disease control and prevention. Several different classes of small-molecule compounds have been found capable of promoting HDP synthesis. Among the most efficacious compounds are butyrate and vitamin D. Moreover, butyrate and vitamin D synergize with each other in enhancing HDP synthesis. This review will focus on the regulation of HDP synthesis by butyrate and vitamin D in humans, chickens, pigs, and cattle and argue for potential application of HDP-inducing compounds in antibiotic-free livestock production.

Rhubarb Supplementation Promotes Intestinal Mucosal Innate Immune Homeostasis through Modulating Intestinal Epithelial Microbiota in Goat Kids.

The abuse and misuse of antibiotics in livestock production pose a potential health risk globally. Rhubarb can serve as a potential alternative to antibiotics, and several studies have looked into its anticancer, antitumor, and anti-inflammatory properties. The aim of this study was to test the effects of rhubarb supplementation to the diet of young ruminants on innate immune function and epithelial microbiota in the small intestine. Goat kids were fed with a control diet supplemented with or without rhubarb (1.25% DM) and were slaughtered at days 50 and 60 of age. Results showed that the supplementation of rhubarb increased ileal villus height (P = 0.036), increased jejujal and ileal anti-inflammatory IL-10 production (P < 0.05), increased jejunal and ileal Claudin-1 expression at both mRNA and protein levels (P < 0.05), and decreased ileal pro-inflammatory IL-1β production (P < 0.05). These changes in innate immune function were accompanied by shifts in ileal epithelial bacterial ecosystem in favor of Blautia, Clostridium, Lactobacillus, and Pseudomonas, and with a decline in the relative abundance of Staphylococcus (P < 0.001) when rhubarb was supplemented. Additionally, age also affected (P < 0.05) crypt depth, cytokine production, Claudin-1 expression and relative abundances of specific genera in epithelial bacteria. Collectively, the supplementation of rhubarb could enhance host mucosal innate immune homeostasis by modulating intestinal epithelial microbiota during the early stages of animal development.

Bacterial Whack-a-Mole: Reconsidering the Public Health Relevance of Using Carbadox in Food Animals.

ABSTRACTCarbadox is an antibiotic used to control dysentery and promote growth in swine in the United States; however, the drug also causes tumors and birth defects in laboratory animals. Despite this and because the drug has no analogs in human medicine, it is not considered “medically important” and can be used in livestock without veterinarian oversight. In their recent study, T. A. Johnson et al. (mBio 8:e00709-17, 2017, https://doi.org/10.1128/mBio.00709-17) demonstrated that carbadox has profound effects on the swine gut microbiome, including the induction of transducing phage carrying tetracycline, aminoglycoside, and beta-lactam resistance genes. In swine production, carbadox can be used in conjunction with other antibiotics (e.g., oxytetracycline) that could fuel the emergence of strains carrying phage-encoded resistance determinants. Johnson et al.’s findings underscore the potential unforeseen consequences of using antibiotics in livestock production and call into question our current methods for classifying whether or not a veterinary drug has relevance to human health.

Public Acceptance of Antibiotic Use in Livestock Production Canada and Germany

The use of antibiotics in livestock production has repeatedly been in the dock over the last few years. However, reducing antibiotic treatments without increasing the suffering of animals requires changes in animal husbandry practices which will likely come at a cost. The objective of the paper is to investigate the factors influencing consumers’ willingness to consume products of animals that have been treated with antibiotics, their willingness to pay for a considerable reduction in the use of antibiotics and their willingness to consider animal welfare in the context of ‘antibiotic free’ livestock production. The study is based on an online survey of citizens in Germany and Canada, conducted in October 2016. The results reveal differences in the individual’s willingness to consume livestock products from animals treated with antibiotics between Canada and Germany with lower acceptance rates in the latter. Results also show that in both countries individuals with higher concerns about the treatment of animals more strongly reject the use of antibiotics in livestock production. This might indicate that consumers are not aware that banning antibiotics in livestock production might have negative repercussions for animal welfare.