Prevention Of Coccidiosis In Chickens Research Articles

Construction of constitutive expression of Eimeria tenella eukaryotic initiation factor U6L5H2 on the surface of Lactobacillus plantarum and evaluation of its immunoprotective efficiency against chicken coccidiosis

Lactobacillus strains exhibit preferable properties that make them attractive candidates for vaccine delivery systems because of their ability to regulate intestinal mucosal immunity in the body. To date, live Lactobacillus delivery vaccines reported for the defense against Eimeria tenella have been inducer-dependent systems whose applications are significantly limited due to their unattainable induction conditions in vivo. Here, a constitutive expression of Lactobacillus plantarum NC8 surface display system was constructed. Then, this system was used to prepare a live oral vaccine to constitutively express the E. tenella U6L5H2 (EtU6) protein on the NC8 surface and to evaluate its protective efficacy against E. tenella challenge in chickens. The results showed that the heterologous protein (EGFP or EtU6) was successfully expressed on the surface of L. plantarum NC8 without any inducer. The immunoprotection of EtU6 with constitutive expression in L. plantarum NC8 system (NC8/Pc-EtU6) was significantly stronger than that of EtU6 with induced expression of L. plantarum NC8 system (NC8/Pi-EtU6) (ACI: 168.28 vs. 152.74) as evidenced by increased body weight, decreased oocyst output and lesion scores. Furthermore, the constitutive system NC8/Pc-EtU6 produced higher levels of specific cecal SIgA, serum IgG, transcription of cytokines IFN-γ and IL-2, and lymphocyte proliferation than the induced system NC8/Pi-EtU6. These results indicate that, compared to the inducible system, the constitutive surface display system of L. plantarum has the advantages of continuously expressing antigens in vivo and stimulating the host immune system. It could be an ideal platform for vaccine expression. The live vector vaccine for coccidiosis constructed by this constitutive system greatly improves the application potential in chicken production and provides a novel platform for the prevention of coccidiosis in chickens.

Protective potential of diclazuril-treated oocysts against coccidiosis in layer chicks

Diclazuril, which is widely used for the prevention of coccidiosis in chickens, has a lethal effect on asexual and sexual stages of Eimeria spp. However, little is known about its effect on the exogenous stages of Eimeria spp. In this study, we evaluated the effect of in vitro treatment with 0.2% diclazuril on unsporulated and sporulated oocysts of Eimeria spp. For this purpose, a total of 180 male layer chicks aged one day were randomly divided into 5 experimental groups. Each group was divided into 3 replicates of 12 chicks each. Group 1 (G1) and Group 2 (G2) were negative (non-immunized and non-challenged) and positive (non-immunized and challenged) controls, respectively. Group 3 (G3) was immunized per os with 1.0 × 104 non-diclazuril treated-sporulated oocysts. Groups 4 (G4) was immunized per os with 0.2% diclazuril treated-unsporulated oocysts (1.0 × 104) in which diclazzuril didn't affect sporulation. Group 5 (G5) was immunized per os with 0.2% diclazuril treated-sporulated oocysts (1.0 × 104). Chicks of G2, G3, G4, and G5 were challenged with 7.5 × 104 untreated sporulated oocysts at the age of 21 days, while the group 1 chicks remained unchallenged. G4 and G5 animals immunized with 0.2% diclazuril-treated oocysts showed a significant decrease in bloody diarrhea severity, lesion scores, and oocyst counts in comparison to those immunized with untreated oocysts. Furthermore, histopathologic findings showed a low number of parasitic stages in cecal tissues in G4 and G5. A significant increased body weight gain was observed in Gs 4 and 5 in comparison to G2. In addition, expression levels of IL-2, IL-12, and IFN-γ were significantly increased in G4 and G5. In conclusion, diclazuril is effective in attenuating Eimeria oocysts and thus provides an alternative approach for using diclazuril-treated oocysts to protect chicks against Eimeria challenge.

Safety and efficacy of Deccox® (decoquinate) for chickens for fattening.

Deccox®, containing decoquinate as the active substance, is a feed additive intended to be used for the prevention of coccidiosis in chickens for fattening at a dose range of 20–40 mg/kg complete feed. Decoquinate from Deccox® is safe for chickens for fattening at the highest applied concentration in complete feed of 40 mg/kg. No practically relevant interactions with other additives or veterinary drugs exist except with bentonite. Decoquinate does not have antibacterial action. Decoquinate is not genotoxic and not carcinogenic. Deccox® is safe for the consumer under the proposed conditions of use. No withdrawal period is required to ensure consumer safety. No maximum residue limits are considered necessary. The inhalation risk for users is considered negligible since inhalation toxicity and exposure are very low. Deccox® is not an irritant to skin and eyes and has no sensitisation potential. The ratios predicted environmental concentration/predicted no effect concentration (PEC/PNEC) for terrestrial, aquatic compartment and sediment are below 1, indicating that decoquinate used in chickens for fattening up to the highest proposed dose, does not pose a risk for these compartments; as well, no risk is expected neither for secondary poisoning nor for groundwater contamination. Due to insufficient evidence, the potential of decoquinate to prevent coccidiosis in chickens for fattening cannot be established.

Safety and efficacy of Coxiril® (diclazuril) for chickens reared for laying

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Coxiril® (diclazuril) for chickens reared for laying. Coxiril®, containing 0.5% diclazuril, is intended for the prevention of coccidiosis in chickens reared for laying at a dose range of 0.8–1.2 mg diclazuril/kg of complete feed up to a maximum age of 12 weeks. Derived from data already assessed for chickens and turkeys for fattening, diclazuril from Coxiril® is safe for chickens reared for laying up to 1.2 mg/kg complete feed when applied until 12 weeks of age. The FEEDAP Panel extended its previous assessment of consumer safety for the use of diclazuril from Coxiril® in chickens for fattening to chickens reared for laying. No measurable diclazuril residues were found in the first eggs laid from chickens reared for laying fed diclazuril from Coxiril® at 1.2 mg/kg complete feed until 12 weeks of age. Coxiril® was considered as a non‐irritant to eyes and skin. It is not a potential skin sensitiser. User inhalation exposure to Coxiril®, as a result of normal handling, is unlikely to cause respiratory or systemic toxicity. The use of diclazuril from Coxiril® in chickens reared for laying at the highest proposed feed concentration would not pose a risk to the environment for neutral/alkaline soils (pH ≥ 7). A final conclusion on the risk resulting from the use of diclazuril in acid soil from Coxiril® cannot be done due to the high uncertainties related to potential accumulation of diclazuril over time. Derived from data already assessed for chickens for fattening, diclazuril from Coxiril® has the potential to control coccidiosis in chickens reared for laying at a minimum concentration of 0.8 mg/kg complete feed.

A Review of Approaches Targeting the Replacement of Coccidiostat Application in Poultry Production

The classical and the most commonly used approach for the prevention of coccidiosis in chickens is the incorporation of synthetic coccidiostats into their feed during the first weeks of their life. This approach has been challenged by consumers, objecting against residual antimicrobials and drug resistant microorganisms that may contaminate poultry products. Moreover, the coccidiostat application approach has been challenged in the last decade by the emerging regulations in the developed world, targeting the cessation of such a practice. The pressures from the consumers as well as from regulation agencies resulted in a great need for alternative methods to reduce, or completely replace the use of coccidiostats in modern chicken production. This replacement requires seeking for safer products that do not have any negative impact on the consumer’s health. Such products are very much in demand, especially in organic poultry farming. The purpose of this review is to present approaches for the replacement of coccidiostat application in chickens through improvements in poultry house management, research in vaccine developments, and application of holistic natural products for the prevention of the economic losses resulting from coccidiosis.

Validation of a Method for the Determination of Narasin in the Edible Tissues of Chickens by Liquid Chromatography

Maxiban and Monteban are 2 products marketed by Elanco Animal Health. They contain narasin and are used for the prevention of coccidiosis in chickens. Products used in the European market must be regularly re-registered with new data to support label claims. This study was undertaken as part of such a re-registration effort. A method for the determination of narasin in poultry tissue was previously registered with the authorities; however, a method with more environmentally friendly solvents was desired. The Canadian Food Inspection Agency accomplished this goal and published an improved method. In order to register the method with European authorities as the official Elanco method for determination of narasin, Elanco scientists were required to provide validation data for all edible poultry tissues. This paper shows the validation of the method to detect residues of narasin using solid-phase extraction followed by liquid chromatographic analysis utilizing post-column derivatization.

The Efficacy of 2-Chloro-4-Nitrobenzamide for the Prevention and Control of Coccidiosis in Chickens

COCCIDIOSIS prevention and control persists as one of the major problems which plague the poultry industry. Coccidiostats have been widely accepted and one of a variety of these products is used in most chick starter feeds today. However, since coccidiostats on the market today are not entirely satisfactory and because the list of properties of an ideal coccidiostat is becoming more detailed, there remains a great need for research on the development of coccidiostats for the prevention and control of coccidiosis in chickens.A series of experiments was designed to study substituted benzamides for the prevention of coccidiosis in chickens. Certain benzoic acid derivatives, including 3,5-dinitrobenzamide, were reported as effective for the prevention and control of coccidiosis by Morehouse and McGuire (1957, 1958, 1959). Hymas and Stevenson (1960) found 2-methyl-3,5-dinitrobenzamide to be effective against coccidiosis in chickens.The present investigation revealed that 2-chloro-4-nitrobenzamide, further referred to in this report by …

Reproductive Studies on Chickens Fed Glycarbylamide

GLYCARBYLAMIDE (4,5-imidazoledicarboxamide, see Cuckler et al., 1958) is a medicant in use for prevention of coccidiosis in chickens. The drug is not recommended for use in adult birds, yet the possibility exists that it may inadvertently be fed to them. This raises the question of its effect on the reproductive performance of adult chickens and the possibility of its deposition in eggs. To obtain these data the following experiments were conducted. PROCEDURE AND METHODSTen White Leghorn hens and one rooster were housed in each of 15 wire-floored cages in a frame building. They were fed a commercial breeder ration for a 10-day period (Control Period), then diets containing glycarbylamide at levels ranging from 0.02 to 0.16% for 21 days (Experimental Period No. 1), and finally refed non-medicated diets for 21 days (Recovery Period). The cages were randomly reassigned to the treatments and the birds again fed the diets containing…

Studies on Drug Toxicity in Chicks: 3. The Influence of Various Levels of Nicarbazin on Growth and Development of Chicks

NICARBAZIN (2-hydroxy-4,6-dimethylpyrimidine-HDP-and 4,4’ dinitro carbanilide-DCN-) is a drug that was developed specifically for the prevention of coccidiosis in chickens. Cuckler et al. (1955) reported on the antiparasitic activity of selected molecular complexes and later those authors (1956) reported specifically on the antiparasitic activity of Nicarbazin. These data indicate a wide range of safety and a high degree of efficiency for Nicarbazin. In these investigations Nicarbazin effectively prevented mortality from inoculations of Eimeria tenella and Eimeria necatrix in chickens and Eimeria gallapavonis and Eimeria meleagrimitis in turkeys. Nicarbazin was also effective against Eimeria acervulina, a pathogenic but non-lethal species of coccidia found in chickens.Porter and Gilfillan (1955) reported on methods for detection of both compounds of Nicarbazin in the blood and tissues. Their data indicate that the drug is excreted rapidly and that very little Nicarbazin or its metabolites can be detected in the tissues of birds 48 hours or …