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

Management and control of coccidiosis in poultry - A review

Poultry coccidiosis is an intestinal infection caused by an intracellular parasitic protozoan of the genus Eimeria. Coccidia-induced gastrointestinal inflammation results in large economic losses, hence finding methods to decrease its prevalence is critical for industry participants and academic researchers. It has been demonstrated that coccidiosis can be effectively controlled and managed by employing anticoccidial chemical compounds. However, as a result of their extensive use, anticoccidial drug resistance in Eimeria species has raised concerns. Phytochemical/herbal medicines (Artemisia annua, Bidens pilosa, and garlic) seem to be a promising strategy for preventing coccidiosis, in accordance with the "anticoccidial chemical-free" standards. The impact of herbal supplements on poultry coccidiosis is based on the reduction of oocyst output by preventing the proliferation and growth of Eimeria species in chicken gastrointestinal tissues and lowering intestinal permeability via increased epithelial turnover. This review provides a thorough up-to-date assessment of the state of the art and technologies in the prevention and treatment of coccidiosis in chickens, including the most used phytochemical medications, their mode of action, and the applicable legal framework in the European Union.

Assessing the effects of a mixed Eimeria spp. challenge on performance, intestinal integrity, and the gut microbiome of broiler chickens

A mixed Eimeria spp. challenge model was designed to assess the effects of challenge on broiler chicken performance, intestinal integrity, and the gut microbiome for future use to evaluate alternative strategies for controlling coccidiosis in broiler chickens. The experimental design involved broiler chickens divided into two groups: a control group (uninfected) and a positive control group, infected with Eimeria acervulina (EA), Eimeria maxima (EM), and Eimeria tenella (ET). At day-of-hatch, 240 off-sex male broiler chicks were randomized and allocated to one of two treatment groups. The treatment groups included: (1) Non-challenged (NC, n = 5 replicate pens); and (2) challenged control (PC, n = 7 replicate pens) with 20 chickens/pen. Pen weights were recorded at d0, d16, d31, d42, and d52 to determine average body weight (BW) and (BWG). Feed intake was measured at d16, d31, d42, and d52 to calculate feed conversion ratio (FCR). Four diet phases included a starter d0-16, grower d16-31, finisher d31-42, and withdrawal d42-52 diet. At d18, chickens were orally challenged with 200 EA, 3,000 EM, and 500 ET sporulated oocysts/chicken. At d24 (6-day post-challenge) and d37 (19-day post-challenge), intestinal lesion scores were recorded. Additionally, at d24, FITC-d was used as a biomarker to evaluate intestinal permeability and ileal tissue sections were collected for histopathology and gene expression of tight junction proteins. Ileal and cecal contents were also collected to assess the impact of challenge on the microbiome. BWG and FCR from d16-31 was significantly (p < 0.05) reduced in PC compared to NC. At d24, intestinal lesion scores were markedly higher in the PC compared to the NC. Intestinal permeability was significantly increased in the PC group based on serum FITC-d levels. Cadherin 1 (CDH1), calprotectin (CALPR), and connexin 45 (Cx45) expression was also upregulated in the ileum of the PC group at d24 (6-day post-challenge) while villin 1 (VIL1) was downregulated in the ileum of the PC group. Additionally, Clostridium perfringens (ASV1) was enriched in the cecal content of the PC group. This model could be used to assess the effect of alternative coccidiosis control methods during the post-challenge with EA, EM, and ET.

Coccidiostats and Poultry: A Comprehensive Review and Current Legislation

Coccidiosis remains one of the major problems of the poultry industry. Caused by Eimeria species, Coccidiosis is a contagious parasitic disease affecting poultry with great economic significance. Currently, in order to prevent health problems caused by this disease, broiler farmers make extensive use of coccidiostats in poultry feed, maintaining animal health and, in some cases, enhancing feed conversion. The presence of unauthorized substances, residues of veterinary products and chemical contaminants in the food industry is of concern, since they may pose a risk to public health. As the use of coccidiostats has been increasing without any requirements for veterinary prescription, research and surveillance of coccidiostat residues in poultry meat is becoming imperative. This review presents an up-to-date comprehensive discussion of the state of the art regarding coccidiosis, the most used anticoccidials in poultry production, their mode of action, their prophylactic use, occurrence and the European Union (EU) applicable legislation.

Anti-Coccidial Effect of Rumex Nervosus Leaf Powder on Broiler Chickens Infected with Eimeria Tenella Oocyst

Simple Summary

Eimeria tenella pathogens belong to the Eimeriidae family and the Apicomplexa phylum, which invades the cecal epithelium of birds, resulting in massive injury and economic loss. We evaluated the ameliorative effect of Rumex nervosus (RN) leaf powder against E. tenella-induced coccidiosis in broiler chickens. Chickens infected with E. tenella were treated with 1, 3, and 5 g/kg RN, respectively. Salinomycin sodium (Sacox^®), an anti-coccidial agent, was used as a reference drug. Results have shown that RN contains Gallic acid and 13 phytochemicals, which require further investigation in vitro or in vivo to ascertain whether the anti-coccidial activity, if there, is a direct or indirect link to reduce the number of fecal oocysts in the bird. The lesion score and bloody diarrhea were also decreased after infection. Moreover, the coccidial challenge adversely affected (p < 0.05) the performance measurements in the RN- and Sacox-treated groups compared with the uninfected–unmedicated control (NC) group. Interestingly, these parameters were positively affected by natural and synthetic treatments compared with infected–unmedicated control (PC); however, the values were not significant. In conclusion, RN at the highest dose is a promising shrub with a moderate anti-coccidial activity when used to cure avian coccidiosis.

Abstract

Coccidiosis a huge economic burden in poultry farms where the pathogen Eimeria harms animal well-being and survival. Besides synthetic anti-coccidial drugs, natural herbs appear to be an alternative way to prevent avian coccidiosis. Rumex nervosus (RN), a phytogenic shrub, has received considerable attention in recent years due to its significant anti-microbial effects; however, limited knowledge exists about its potential anti-coccidial functions. This study was conducted to evaluate the prophylactic and therapeutic activities of RN leaf powder in broilers infected with Eimeria tenella. Infected chickens received a commercial diet containing 1, 3, or 5 g RN powder/kg diet compared to infected broilers that treated with Sacox (PC) or compared to uninfected broilers that received a commercial diet alone (NC). Results showed that RN powder significantly (p < 0.05) reduced the lesion scores and suppressed the output of oocysts per gram (OPG) in chickens’ feces. Although RN was unable to minimize the weight gain loss due to emeriosis, RN at level 1 g improved the feed conversion ratio. Therefore, RN powder, at 5 g, possesses moderate anti-coccidial effects and hence could be used to treat avian coccidiosis in field conditions; however, further studies are required to investigate, in vitro or in vivo, the anti-coccidial potential of active ingredients.