One of the most worrying problems in poultry production is coccidiosis and how to deal with it without using antibiotics. It is a challenge that, we know, lies in prevention. Furthermore, it is impossible to think in terms of prevention and not to link this to sustainable action.
Thinking sustainably is to link the human population, animals and the environment into every decision or action. It is believing that the world is entirely interconnected.
Continue reading Dealing with coccidiosis by reducing the use of antibiotics: is it sustainable? (Part I)
Depending on the type of production or government rules relating to antibiotic-free product labelling and trade, there will be restrictions on the use of certain products, especially for the treatment of infections or coccidiosis control. Sick flocks should be treated or sacrificed, in order to comply with welfare regulations.
The OIE list contains the classification for antimicrobial agents of veterinary importance. Drugs for human consumption only are not in this list.
Continue reading Antibiotic-free: what does it mean and what to deal with coccidiosis in Poultry? (Part II)
The meaning of antibiotic free products can cause some confusion, mainly because there is no official or international accepted description of what it is and how to classify different types of “antibiotic-free” products or production. Further complications come with anticoccidials for prevention of coccidiosis in poultry. In fact, in some countries they are classified as antimicrobials and as such they have to be withdrawn from “antibiotic-free” productions.
Continue reading Antibiotic free: what does it mean and what to deal with coccidiosis in Poultry? (Part I)
Prevention of coccidiosis in chickens with live vaccines means suspending the use of anticoccidials, but a reduction in other antibiotics has also been observed. Reduction in antibiotic use in animal production is currently one of the aims of the poultry industry. Antimicrobial resistance has become a global public health problem in humans and livestock and plans to reduce the use of antibiotics are being implemented by the authorities in most countries.
Obviously, chemicals and ionophores used to control coccidiosis should be considered as antibiotics because the parasites that are intended to be controlled with these products can develop resistance with prolonged use of these substances.
Continue reading Is it possible to rear broilers without antibiotics? First step to achieve the goal: vaccination against coccidiosis in chickens
The fight against coccidiosis in chickens means the adoption of different strategies depending of the type of bird. If we are managing long life cycle birds, we have to pay special attention to clinical Eimeria species that are able to generate a real coccidiosis process with macroscopic lesions and symptoms that will reduce the healthy status of the birds and will compromise the development of immunity against other diseases or cause the death of the birds.
However, when we are rearing standard, certified or even free-range broilers, the focus needs to be a different one. In these cases it will be difficult to find real clinical coccidiosis. Otherwise, the “silent” species – such as Eimeria praecox among others – will affect the intestinal mucosa and will reduce the capacity of a broiler for nutrient absorption. Dealing with subclinical species is essential in coccidiosis in chickens with a high growth rate.
Continue reading Coccidiosis in chickens: the role of subclinical species of Eimeria
Within the scope of assessing new strategies for the control of coccidiosis in poultry, the first factors to consider are always immunological and physiological but also include less objective factors such as the management. However, when these new strategies come to be assessed, the exercise has to be carried out in perspective by evaluating those indicators that are the most critical in order to decide whether maintaining such strategies or to replacing them with others. In the production of broiler chickens, these indicators are solely productive.
Live precocious attenuated vaccines for coccidiosis in poultry like HIPRACOX® have been used in numerous countries and situations, and these experiences serve to support the implementation of vaccine rotation programmes for the control of coccidiosis in poultry.
Continue reading Coccidiosis in poultry: an objective assessment of the incorporation of a rotation programme using precocious attenuated vaccines
EVALON® is a live coccidiosis vaccine against avian coccidiosis in poultry composed of E. acervulina, E. brunetti, E. maxima, E. necatrix and E. tenella. All the strains have been selected to maximize immunogenicity. Avian Eimeria have a complex life cycle with a combination of exogenous and endogenous stages that trigger the immune system of the host. However, Eimeria parasites have also been described as being highly elusive to the immune system as well as producing chemokines than can slow or inhibit the immune response (Jang 2011, Schmid 2014, Miska 2013).
Although it is well known that live vaccines can induce an adequate immunity, we strongly believe that immune modulation is crucial in providing a strong, fast and long-lasting immunity (Dalloul 2005). This could be essential in the prevention of coccidiosis in poultry.
Continue reading How an adjuvant can modulate the immune response against coccidiosis in poultry
The cellular and molecular mechanisms leading to immune protection against coccidiosis in chickens are complex and include multiple aspects of innate and adaptive immunity. Innate immunity is mediated by subpopulations of immune cells that recognize pathogen-associated molecular patterns. Adaptive immunity, which is important in conferring protection against secondary infections, involves subtypes of T and B lymphocytes that mediate antigen specific immune response. Experimental studies in coccidiosis in chickens now support the role of lymphocytes and their secreted products (Lillehoj et al. 2011)
Eimeria parasites have a long and complex biological cycle with exogenous and endogenous phases that trigger the immune system of the host. These parasites that cause coccidiosis in chickens can produce substances (chemokines) than can inhibit the immune response.
Continue reading Immunology in coccidiosis in chickens: The role of cytokines IL-2 and IFN-gamma
From the very beginnings of this type of animal production, control of digestive diseases in the poultry industry has been one of the most significant health challenges. Moreover, among digestive diseases, coccidiosis in poultry continues to pose a challenge for the poultry farming worldwide. The incorporation of new tools provides new resources for safe and effective control.
Where are we coming from?
The housing conditions of birds used in production constitute a trigger factor for digestive diseases, with coccidiosis in poultry being one of the most prevalent, caused by parasites of the Eimeria genus.
Continue reading New strategies for the control of coccidiosis in poultry: rotation programmes with vaccines against Eimeria
When we think about the prevention of coccidiosis in chickens raised for a long cycle (breeders and layers) we cannot imagine any treatment other than vaccines. Apart from cost considerations, the use of coccidiostats has been always a handicap in birds that usually have restrictions on feed consumption. This is the reason why the protection conferred by a vaccine applied in the first days of life should be high enough to give a level of immunity that is able to protect them throughout the cycle.
Lesion scores of mid-intestine at 6 days post-challenge with E. necatrix. Lesion scoring grading 0-4 according to Johnson and Reid, 1970. Control vs EVALON® + HIPRAMUNE®T.
Layers and breeders have a production cycle of not less than 60 weeks in most cases. One of the main characteristics of these birds is that the rearing period in a normal poultry house is different to that in a production house.
Continue reading The importance of the length of immunity in the prevention of coccidiosis in chickens raised for a long cycle