Understanding the resistance development of
Eimeria
Coccidiosis, a disease caused by the protozoan parasites of the genus Eimeria, is a significant threat to poultry, particularly broilers. These parasites are capable of causing severe intestinal distress, leading to poor nutrient absorption, diarrhea, and in severe cases, death. Eimeria species develop resistance through genetic mutations and adaptive responses to conventional coccidiostats, which include chemical, such as diclazuril, and fermentation-derived substances also called ionophores.
The resistance development process is primarily driven by the overuse and possible misuse of these anticoccidial drugs in broiler production. When coccidiostats are administered in subtherapeutic doses or used continuously without rotation, it creates a selection pressure favoring the survival of resistant strains. These strains undergo genetic mutations that alter the target sites of the drugs, reducing their effectiveness. Additionally, some Eimeria strains may develop mechanisms to decrease drug uptake or increase drug expulsion from their cells, further complicating conventional treatment efforts. This resistance not only undermines the efficacy of existing treatments but also necessitates the search for alternative solutions.
The consequences of resistance on economic performance and
Animal welfare
Regarding the economic impact of coccidiosis resistance, the main direct costs include increased mortality rates and reduced feed conversion ratio. Indirect cost may involve increased veterinary care and enhanced biosecurity measures inside poultry houses. Moreover, coccidiosis resistance outbreaks can lead to significant production losses, due to reduced growth performances, affecting profitability
From a welfare perspective, resistance increases the severity of disease outbreaks inside poultry flocks, leading to greater suffering among infected birds.
The use of natural saponin-based alternative solutions to
Fight resistance
Natural saponin-based solutions appear to be effective alternatives to conventional coccidiostats, offering several advantages when they are properly selected. Saponins are natural glycosides that posses anticoccidial properties. Indeed, saponins have an amphiphilic structure enabling them to bind with sterol, which are fat-soluble, contained in Eimeria cells’ membrane. This interactions between saponins and the sterols disrupts the Eimeria membrane and lead to cellular lysis, resulting in the death of the parasitic cell. But not all saponins have the same efficacy towards Eimeria.
The use of saponin based solutions for coccidiosis management offer several advantages. Firstly, and most importantly, the difference in the mode of action on Eimeria offered by saponins reduces the risk of cross-resistance. Secondly, saponins are found in renewable plant sources, making them a sustainable alternative compared to chemical or fermentation-based coccidiostats. Finally, they do not leave any harmful residues in final poultry products, ensuring food safety and avoiding any withdrawal period.
In conclusion, tackling coccidiosis resistance in broilers requires a comprehensive approach. While understanding and mitigating the mechanisms of resistance are crucial, exploring and adopting natural solutions like saponins can pave the way for a more resilient and sustainable poultry industry.