Control Of Coccidiosis In Chickens Research Articles

Effects of Six Natural Compounds and Their Derivatives on the Control of Coccidiosis in Chickens.

Chicken coccidiosis costs the poultry industry over GBP 10 billion per year. The main method of preventing and controlling coccidiosis in chickens continues to be the use of drugs. Unfortunately, the prevalence of drug resistance in the field reduces or even eliminates the effectiveness of drugs, and drug residues in the food supply chain can also can be harmful to humans. Therefore, safe and effective anticoccidial drugs are urgently needed. Natural products have many advantages such as being safe, effective and inexpensive and are a sustainable way to control coccidiosis. In this study, the anticoccidial effects of six natural compounds were tested by Eimeria tenella infection. Oocyst production, cecum lesion, body weight gain, feed conversion ratio, and intestinal microbiota were measured. The results showed that nerolidol had a moderate effect on maintaining both body weight gain and feed conversion ratio. Silymarin and dihydroartemisinin showed significant anticoccidial effects by reducing total oocyst output. Dihydroartemisinin also significantly reduced the cecum lesion caused by Eimeria infection, but this compound may be toxic to the host at such informed doses because it decreases growth and survival rates. In addition, both silymarin and dihydroartemisinin partly restored the microbiota after challenge. This indicates that silymarin, dihydroartemisinin, and nerolidol are effective in the control of chicken coccidiosis. Our data provide basic knowledge about the anticoccidial effects of such natural compounds/derivates.

Construction of recombinant SAG22 Bacillus subtilis and its effect on immune protection of coccidia

Avian coccidiosis causes huge economic losses to the global poultry industry. Vaccine is an important means to prevent and control coccidiosis. In this study, Bacillus subtilis was selected as the expression host strain to express anti Eimeria tenella surface protein SAG22. The synthesized surface protein SAG22 gene fragment of E. tenella was ligated with Escherichia coli-bacillus shuttle vector GJ148 to construct the recombinant vector SAG22-GJ148. And then the recombinant Bacillus strain SAG22-DH61 was obtained by electrotransfer. The results of SDS-PAGE and Western Blot showed that the recombinant protein SAG22 was successfully expressed intracellularly. The immunoprotective effect of recombinant Bacillus strain SAG22-DH61 on broiler chickens was evaluated in 3 identically designed animal experiments. The birds were infected with E. tenella on d 14, 21, and 28, respectively. Each batch of experiments was divided into 4 groups: blank control group (NC), blank control group+infected E. tenella (CON), addition of recombinant SAG22-DH61 strain+infected with E. tenella (SAG22-DH61), addition of recombinant empty vector GJ148-DH61 strain+infected with E. tenella (GJ148-DH61). The animal experiments results showed that the average weight gain of the SAG22-DH61 group was higher than that of the infected control group, and the difference was significant in the d 14 and 28 attack tests (P < 0.05); the oocyst reduction rate of the SAG22-DH61 group was much higher than that of the GJ148-DH61 group (P < 0.05); the intestinal lesion count score of the SAG22-DH61 group was much lower than that of the GJ148-DH61 group (P < 0.05). In addition, the SAG22-DH61 group achieved highly effective coccidia resistance in the d 14 attack test and moderately effective coccidia resistance in both the d 21 and 28 attack tests. In summary, recombinant SAG22 B. subtilis has the potential to become one of the technological reserves in the prevention and control of coccidiosis in chickens in production.

Knowledge, Attitude, and Practices of Poultry Farmers Regarding the Control of Chicken Coccidiosis in Lagos State, Nigeria

Background: Coccidiosis, caused by coccidia of the genus Eimeria, accounts for significant production loss-es in the global poultry industry. This study evaluated commercial poultry farmers’ knowledge, attitude, and practices (KAPs) on chicken coccidiosis and its control in Lagos State, Nigeria. Methods: Semi-structured questionnaires assessing KAPs relating to chicken coccidiosis and its control were administered to 157 poultry farmers. Summary statistics were performed on the collated data using the Statis-tical Package for the Social Sciences (SPSS) software. The relationship between respondents’ knowledge and demographic features was analysed using the Chi-square test of independence on SPSS. Results were consid-ered significant at p &lt; 0.05. Results: The majority of the respondents were males (91, 58%), married (108, 68.7%), and between 31 and 50 years old (106, 67.5%). Most have had tertiary education (84, 53.5%) and farming experience between 1 and 5 years (97, 61.8%). All the respondents have heard about coccidiosis previously, and of these, 57 (36.3%), 45 (28.7%), and 37 (23.6%) sourced this information from veterinarians, fellow farmers, and during training/workshops, respectively. Ingestion of faecally contaminated feed and water by chickens was opined as the cause of coccidiosis by 48 (30.6%) respondents, followed by bacteria (30, 19.1%) and poor hygiene and sanitation (27, 17.2%). Most mentioned that ingesting faecally contaminated feed and water (126, 80.2%) is the mode of coccidiosis transmission, and 76 (48.4%) identified bloody and watery diarrhea as the major clinical sign. The gender of the farmers and their educational status were significantly associated with the level of coccidiosis knowledge. Of the study participants, 150 (95.5%) have experienced an outbreak of coccidiosis on their farms before, and the majority observed bloody diarrhea (90, 60.0%) as the major clinical sign. None of the farmers used ionophore drugs. Embazin-forte® (Sulphaquinoxaline) was the drug most reportedly used to prevent and treat coccidiosis. Few farmers (11, 7%) adopted anticoccidial vaccines for coccidiosis prevention using either Immucox®, Livacox®, or both. Conclusion: This study showed that poultry farmers in Lagos State have adequate knowledge of chicken coccidiosis. Chemical anticoccidials were the only drugs used for prevention and treatment, and vaccines were not adopted. There is a need for veterinarians and poultry extension workers to enlighten farmers in the study area about the proper, safe, and effective use of anticoccidial drugs and vaccines.

Exploration of the Mechanism of the Control of Coccidiosis in Chickens Based on Network Pharmacology and Molecular Docking With the Addition of Modified Gegen Qinlian Decoction.

Gegen Qinlian Decoction is a long-established Chinese herbal compound for the treatment of diarrhea and dysentery, while Magnolia officinalis has been demonstrated to have some anthelmintic activity. The preliminary screening of this study showed that the addition of Modified Gegen Qinlian Decoction has some effective on the prevention and treatment of coccidiosis in chickens. However, the mechanism of its treatment of chicken coccidiosis is not clear. The network pharmacology study was based on the screening of chemical components and related targets from TCMSP and PharmMapper server databases. Genes related to chicken coccidiosis were obtained from the SRA database, and those genes that intersected with the target genes of Modified Gegen Qinlian Decoction were screened. By exploring the target interactions through the String system and enrichment analysis by the Metascape system, the mechanism of action of Modified Gegen Qinlian Decoction in chicken coccidiosis was identified. Using real-time quantitative polymerase chain reaction (RT-qPCR) to analyze the mRNA levels of the relevant factors in chicken coccidiosis, molecular docking was used to reveal the extent of binding of the key target genes predicted in the network pharmacology by the action of Modified Gegen Qinlian Decoction. Compound and target screening suggested that the 99 chemical targets of Modified Gegen Qinlian Decoction were involved in chicken coccidiosis, and the enrichment results of KEGG pathway suggested that Modified Gegen Qinlian Decoction was significantly associated with PI3K/AKT signaling pathway in chicken coccidiosis. The Hubba gene module in Cytoscape_v3.7.1 software was used to analyze the network topology to obtain the Hubba gene SRC, STAT3, and PPARG, etc. The molecular docking results showed that SRC, STAT3, and PPARG were key targets in the treatment of coccidiosis in chickens by Modified Gegen Qinlian Decoction, which was in agreement with the RT-qPCR results. Through network pharmacology, molecular docking and in vitro experiments, it was confirmed that Modified Gegen Qinlian Decoction fights against chicken coccidiosis through key targets such as SRC, STAT3, and PPARG.

A Novel Whole Yeast-Based Subunit Oral Vaccine Against Eimeria tenella in Chickens.

Cheap, easy-to-produce oral vaccines are needed for control of coccidiosis in chickens to reduce the impact of this disease on welfare and economic performance. Saccharomyces cerevisiae yeast expressing three Eimeria tenella antigens were developed and delivered as heat-killed, freeze-dried whole yeast oral vaccines to chickens in four separate studies. After vaccination, E. tenella replication was reduced following low dose challenge (250 oocysts) in Hy-Line Brown layer chickens (p<0.01). Similarly, caecal lesion score was reduced in Hy-Line Brown layer chickens vaccinated using a mixture of S. cerevisiae expressing EtAMA1, EtIMP1 and EtMIC3 following pathogenic-level challenge (4,000 E. tenella oocysts; p<0.01). Mean body weight gain post-challenge with 15,000 E. tenella oocysts was significantly increased in vaccinated Cobb500 broiler chickens compared to mock-vaccinated controls (p<0.01). Thus, inactivated recombinant yeast vaccines offer cost-effective and scalable opportunities for control of coccidiosis, with relevance to broiler production and chickens reared in low-and middle-income countries (LMICs).

Prevalence of Eimeria parasites in the Hubei and Henan provinces of China.

Coccidiosis is an intestinal parasitic disease that causes huge economic losses in the poultry industry globally. Henan and Hubei, as important poultry production provinces in China, have great pressure for the prevention and control of chicken coccidiosis. In order to obtain information on the local prevalence of Eimeria species, we used an internal transcribed spacer 1 (ITS1) sequence of ribosomal DNA to identify the species from 318 fresh fecal samples. The fecal samples and the data relating to farm information were collected from 137 farms in Hubei and Henan provinces. As shown by genus-specific PCR results, the positivity rate of Eimeria was 97.17% (309/318), and the most common species were Eimeria mitis (66.67%), E. tenella (46.86%), and E. necatrix (41.51%). Then, we analyzed the correlation between the background information of each sample and the PCR identification results, which showed that indigenous farms in Henan province were at the greatest risk of harboring highly pathogenic Eimeria species and a larger proportion of such farms were positive for E. necatrix, the most pathogenic species. The results of this study showed that chicken coccidia was widespread, which provides important insights into the control of chicken coccidiosis in this region.

Understanding the interactions between Eimeria infection and gut microbiota, towards the control of chicken coccidiosis: a review.

The gastrointestinal tract in poultry harbours a diverse microbial community that serves a crucial role in digestion and protection. Disruption of the gut environment due to Eimeria spp. parasite infection causes an imbalance in intestinal homeostasis, driving the increment of pathogens such as Clostridium species. Coccidiosis infection affects the composition and integrity of gut microbiota, resulting in elevated susceptibility to diseases that pose a serious threat to the overall health and productivity of chickens. Anticoccidial drugs have proven effective in curbing coccidiosis but with concerning drawbacks like drug resistance and drug residues in meat. The exploration of natural alternative strategies such as probiotics and phytochemicals is significant in controlling coccidiosis through modification and restoration of gut microbiota, without inducing drug resistance. Understanding the interaction between Eimeria parasites and gut microbiota is crucial for the control and prevention of coccidiosis, and the development of novel alternative treatments.

AVIAN COCCIDIOSIS: RECENT ADVANCES IN ALTERNATIVE CONTROL STRATEGIES AND VACCINE DEVELOPMENT

Coccidiosis induces huge economic losses to poultry production. Its control through anticoccidial live vaccines and drugs has been very successful with some limitations because of the cost of production of live vaccines, drug resistance, and residues representing public health concerns. Consequently, there is a crucial need for drug-free production of foods. Useful strategies include environmental, immunological, and genetic approaches; feed additives are recent attitudes involving probiotics, synbiotics, organic acids, phytobiotics as essential oils, antioxidants, and nanobiotics (nanoparticles). A combination of such additives is a recent useful trend. Transgenic Eimeria parasite could fill in the gap in the control of chicken coccidiosis as an efficient anticoccidial vaccine with improved protective efficacy using multiple vaccine antigens. Alternatives justify further studies as therapeutic or prophylactic anticoccidial agents. Full biological and toxicology profiles are crucial for the promising materials which deserve to be applied on a larger scale.

Investigation of Eimeria oocyst concentrations and species composition in litter from commercial broiler farms

Coccidiosis is one of the major economically important diseases of poultry industry worldwide. In Bangladesh, coccidiosis is one of the major threats for commercial poultry industry as well. Successful control of chicken coccidiosis in Bangladesh mainly depends on the application of anticoccidial drugs (ACD) in a poultry house during grow-out. There are some reports on the occurrence of coccidiosis in broiler chickens in Bangladesh, but information on track changes in Eimeria oocysts levels and species composition in commercial broiler farms over time during ACD program is very scarce. The purpose of this study was to investigate the oocyst concentrations and species composition of Eimeria in litter from commercial broiler houses during ACD control programs. Litter samples were collected from a total of 22 different broiler farms during at least one complete grow-out cycle. Samples were collected at 0, 1, 2, 3 and 4 week (wk) of grow-out of the ACD cycle. We succeeded for isolation of Eimeria oocysts from the litter samples of 14 broiler farms and coccidian species were identified by previously described morphological characteristics using standard shape index method under microscopy. Eimeria oocyst concentration in litter was found to be reached in peak levels at 3–4 wk of grow-out cycle. However, sudden peak level of oocysts of Eimeria spp in 8 farms indicated to develop some drug resistance. E. tenella, E. necatrix and E. acervulina were generally found be to present in the most of the samples. Findings of this study will be helpful to develop an appropriate control strategy against chicken coccidiosis in Bangladesh.

Control of Coccidiosis in Chickens Through Herbal Medicine

Coccidiosis caused by Eimeria sp. is an important disease in poultry industry. In Indonesia, the morbidity due to this disease in poultry reaches up to 90%. The clinical symptoms of coccidiosis vary depending on the age of poultry and the species of Eimeria. If coccidiostat is not properly used in control and eradication program, it will cause resistance and residue in meat and egg. This paper aims to describe the optimal control of coccidiosis without chemical substances by using natural herbs. Resistance cases to Eimeria sp. cause the anti-coccidia ineffective therefore a safe and effective coccidiostat is needed. Currently, coccidiosis control using natural medicines from herbs was reported to be effective, safe, free of side effects and cheaper. An integrated coccidiosis control program can be applied along with biosecurity, vaccination, prebiotics and coccidiostat from herbs. Control of coccidiosis in chickens with herbal medicines can increase immunity, appetite and reduce stress so that it can suppress Eimeria sp. infestation.

Appraisal of a new patented method for control of chicken coccidiosis

ABSTRACT The aim of this research is to appraise a newly patented method for control of chicken coccidiosis in comparison to a classical approach. The new method implements an invented Disinfectant (WSD) for decontamination of rearing surfaces, and a developed drinking water-herbal coccidiostat (EOBWE) supplement. The experimental design has 8 treatments (TRTs), with four pens/TRT, and 25 broiler chicks/pen. The floors of TRT1 to TRT7 are contaminated with 4.0 × 105 sporulated oocysts/m2 of each of E. acervulina, E. maxima, and E. tenella, while TRT8-floor is left uncontaminated. The floors of TRTs 1 and 2 are disinfected with chlorine, while that of TRTs 3–6 are disinfected by WSD. Floors of TRTs 7 and 8 are deprived of disinfection. Birds in TRTs 1, 6, 7, and 8 are deprived of coccidiostat, while birds in TRTs 2 and 3 are fed salinomycin in their feed; birds of TRT 4 are administered EOBWE in drinking water, while birds of TRT 5 are administered simultameously both, the salinomycin and EOBWE. Birds in TRT 4 (WSD/EOBWE treated) and TRT 5 (WSD/salinomycin + EOBWE) had improved protection (lowest oocyst output and intestinal lesions) and enhanced production (lowest mortality, lowest feed conversion ratio, and highest live body weight) compared to the other five challenged treatments, associated with significant improvements compared to positive controls (TRT 7) (P < 0.05).

Diagnosis and control of chicken coccidiosis: a recent update.

Coccidiosis is a deadly disease that hampers chicken's productivity and welfare. Thus, the disease is a major menace to the global poultry industry. Coccidiosis which is caused by the apicomplexan parasite of the genus Eimeria has seven known species which affect the different parts of the intestinal tract of chickens. The disease which occurs by ingestion of sporulated oocyst has been associated with poor poultry management system. Mixed infection among the species of this parasite contributes to both pathogenicity and misdiagnosis of the disease. A progress in identification and diagnosis approach which cuts across pathological, morphological and molecular has been reported for this parasite. Control measures which include anticoccidial drugs, vaccines and natural products have dominated literature for this disease. However, the emergence of genetic and antigenic diversity with implication on resistance to anticoccidials among different strains of Eimeria parasite has generated concerns on the effectiveness of the current anticoccidial vaccines. A new look on the control strategy therefore becomes imperative. This study reviews the current trends on the identification and control of chicken coccidiosis with focus on (1) Avian coccidiosis (2) Epidemiology of chicken coccidiosis (3) Eimeria parasite and distribution in poultry (4) Diagnosis of Eimeria parasite (5) Control measures of coccidiosis (6) Threats posed by genetic and antigenic diversity of Eimeria parasite on coccidiosis control. Genomic study on diversity of Eimeria parasite becomes imperative for effective vaccine design against coccidiosis.

Applied strategies for the control of coccidiosis in poultry.

Abstract Apicomplexan parasites of the genus Eimeria are widespread in poultry flocks and if present in sufficient numbers can cause the intestinal disease coccidiosis. For many years, the disease has been controlled either by incorporating drugs in the feed (prophylaxis) or by immunization with live parasites (vaccination). Efficacy of anticoccidial drugs has been compromised by the acquisition of resistance which has been documented for all drugs introduced including those most widely used, the ionophorous antibiotics. A consequence of limited efficacy is that these drugs permit some parasite development thus allowing the acquisition of immunity. Combined with improvements in management, this may explain the continued use of drugs for the control of coccidiosis in broiler and turkey production. In recent years vaccination, utilizing live attenuated or non-attenuated parasites has made a significant contribution to the control of coccidiosis in chickens. Vaccines are administered on a single occasion by a variety of methods to newly hatched chicks and initiate an immune response in the bird. Full protective immunity requires secondary exposure to vaccinal oocysts in the litter, an aspect of vaccination over which the producer has little control. Exposure to wild-type parasites already present in the litter may cause clinical coccidiosis, as evident by characteristic intestinal lesions in birds, before protective immunity has time to fully develop. Several vaccines comprise parasites that have never been exposed to anticoccidial drugs and it has been shown that their use in a commercial setting may replace drug-resistant organisms resulting in a restoration of drug-sensitivity. Programs involving alternation of chemotherapy and vaccination have been introduced with the objective of prolonging the life of anticoccidial drugs that have been compromised by drug-resistance. This is the only known example of restoration of drug sensitivity in veterinary parasitology. So-called 'natural' products that include herbs, herbal and fungal extracts, and probiotics are claimed to alleviate Eimeria infections in poultry, but few have been thoroughly investigated. Advances have been made in our knowledge of the structure of proteins released during parasite invasion of host cells and may eventually result in novel vaccines based upon molecular technology. Hens immunized with proteins isolated from gametocyte stages of the life cycle of one species of Eimeria pass antibodies to developing embryos and this may provide short-term passive protection to young chickens' post-hatch. As with other approaches to vaccination, protection is dependent upon exposure to wild-type parasites present in the environment.

Scientific Opinion on the safety and efficacy of Coxiril® (diclazuril) as a feed additive for chickens for fattening

Coxiril®, containing 0.5 % diclazuril, is intended for use in the control of coccidiosis in chickens for fattening at a dose range of 0.8 to 1.2 mg diclazuril/kg complete feed. The highest proposed use level (1.2 mg diclazuril/kg feed) is considered safe for chickens for fattening, although the value of the tolerance study is limited owing to weaknesses in the design. However, none of the parameters measured showed an adverse effect of the three-fold use level of diclazuril. Diclazuril has no substantial antibacterial activity. Diclazuril from Coxiril ® is considered toxicologically equivalent to the other currently authorised diclazuril. The use of Coxiril® at the highest proposed use level of 1.2 mg diclazuril/kg complete feed in chickens for fattening is safe for the consumer since Maximum Residue Limits are not exceeded. Coxiril® is considered non-irritant to eyes and skin. It is not a potential skin sensitiser. User exposure to Coxiril®, as a result of normal handling, is unlikely to cause respiratory or systemic toxicity. Based on a Phase I assessment, the use of diclazuril in chickens for fattening at the high use level does not pose a risk to the environment. Diclazuril from Coxiril® has the potential to control coccidiosis in chickens for fattening at a minimum dose of 0.8 mg/kg complete feed. This conclusion is derived from literature data, and from recent studies (five floor pen studies, two field trials and two sensitivity tests) performed with Coxiril®.

Designing strategies for the control of coccidiosis in chickens on poultry farms using modern diagnostic tools

Correspondence: Michael Wallach The iThree Institute and the School of Medical and Molecular Biosciences, University of Technology, PO Box 123, Broadway, Sydney, New South Wales 2007, Australia Tel +61 2 9514 4082 Fax +61 2 9514 4026 Email michael.wallach@uts.edu.au Abstract: Coccidiosis is caused by the intracellular protozoan parasite Eimeria and is a major worldwide problem in the poultry industry today. The current strategies to control the disease still rely heavily on anticoccidial drugs and on the use of shuttle programs to periodically introduce attenuated live parasites onto poultry farms. Recently, because of the improved performance of broiler chickens, farmers are able to raise chickens for market within a period of only 5–6 weeks. This short growth period enables the development of strategies for coccidiosis control either by ensuring an even exposure of chickens to parasites in the litter, inducing immunity against reinfection, or by keeping parasite numbers below a threshold level wherein only subclinical infections will occur. Therefore, the development and use of new diagnostic tools to precisely identify the Eimeria species and strain and to measure the number of oocysts in the feces and litter can be very helpful in predicting exposure and designing strategies for the control of coccidiosis in the field. The purpose of this study was to describe recently developed methods of diagnosis in terms of their sensitivity and usefulness, describe ways in which litter oocyst numbers can be quantitated, and start to develop an analytical tool that can be used for designing strategies for the control of coccidiosis. A multiplex polymerase chain reaction–based assay has been developed that enables the identification of all seven Eimeria species in a single reaction tube. Previous reports have shown it is possible to detect one oocyst using a polymerase chain reaction–based assay; however, other reports have found that under both laboratory and field conditions the minimal level of sensitivity is only 20 oocysts. In addition, the present authors’ studies have found that when using spiked mixed samples, the level of detection of a contaminating Eimeria species is only 5%. Therefore, it is imperative that a new method be developed with a tenfold higher level of sensitivity for field-testing. Once this test is developed and validated, it can be used to monitor the litter and assess the parameters (climate, hygiene, breed of chicken, etc) that govern coccidial outbreaks on farms.

Role of antibody in immunity and control of chicken coccidiosis

Research has been carried out worldwide to try to elucidate the mechanism of protective immunity against coccidiosis. It was concluded from early studies that cellular immunity is the key to protection against Eimeria, whereas humoral immunity plays a very minor role in resistance against infection. By contrast, other studies have pointed towards the ability of antibody to block parasite invasion, development and transmission and to provide passive and maternal immunity against challenge infection. Herein, recent results demonstrate the ability of antibodies (raised by live immunization or against purified stage-specific Eimeria antigens) to inhibit parasite development in vitro and in vivo and readdress the question of the role of antibody in protection against coccidiosis.

From the editors

From the editors

Progress in Control Measures for Chicken Coccidiosis

For many years, prophylactic use of anticoccidial drugs has been the primary means of controlling chicken coccidiosis in broiler industry and has played a major role in the growth of this industry. Also the use of live vaccines is well established in the control of the disease. Three groups of live vaccines can be distinguished based on the characteristics of the Eimeria species included in the product: vaccines based on live virulent strains, vaccines based on live attenuated strains, vaccines based on live strains that are relatively tolerant to the ionophores, and non-live subunit vaccines. The mounting problem of drug resitance of Eimeria species has prompted major research efforts to seek alternative means of control through increased knowledge of understanding the immunomodulation, natural-product feed additives, advances in live and recombinant vaccines. This article reviews the above mentioned methods in control of chicken coccidiosis.

Control of coccidiosis in chickens by vaccination

Control of coccidiosis in chickens has relied upon managerial measurements and the prophylactic use of coccidiostatic drugs. With the emergence of Eimeria strains that are resistant to these drugs the use and number of commercially available vaccines has increased. In this review various aspects that contribute to the development of coccidiosis are discussed, and an overview of the currently marketed coccidiosis vaccines is presented. Three groups of vaccines can be distinguished based on the characteristics of the Eimeria species included in the products: vaccines based on live virulent strains, vaccines based on live attenuated strains, and vaccines based on live strains that are relatively tolerant to the use of ionophores. These latter vaccines combine the early protective effect of ionophore treatment with the late protective effect of vaccination. The impact of future developments such as recombinant-DNA vaccines and changes in consumer’s attitude towards broiler production are discussed.

Detection of coccidiostats by immunoassay

Coccidiosis is a complex disease that affects many farm animals, but which can be especially serious in poultry. Control of coccidiosis is essential for efficient, modern poultry productions; thus coccidiostats are extensively used to control this disease. The most commonly used coccidiostats in poultry are the polyether monocarboxylic ionophores including monensin and salinomycin. Polyether ionophores also improve feed utilization by ruminants. However, the quantity of such ionophores for effective control of coccidiosis in chickens may prove highly toxic to other agriculturally important animals. Over the past few years, we have developed monoclonal antibody‐based immunoassays for both salinomycin and monensin. In addition, we have developed immunoassays for dimetridazole and for halofuginone, the latter being a heavily used non‐ionophore coccidiostat. The advantages of the immunoassays over the conventional analytical methods are discussed as well as the characteristics of the individual immunoassays.