Coccidiosis in poultry industry

Abstract

Coccidiosis is a permanent health problem in poultry industry especially in intensive production systems. It is the most important poultry disease as far as economy is concerned since yearly costs of prophylaxis, as well as of therapy exceed 2 billion Euros, at the global level. In Serbia the disease has the highest prevalence in chicken, less in turkeys, gees, ducks and pheasants. The causes of the infection are protozoa belonging to the Eimeridae family, spore oocists being the infective form. The source of the infection are already infected birds, whereas the disease can spread in the sussceptible bird population by direct and indirect contact such as dust, objects on the farm, people, rodents, wild birds, as well as insects. The incidence of the disease depends on the lack of space on the farm, high temperature and high relative humidity, improper feeding, other diseases and all factors that can compromise bird immunity and general resistance to infectious diseases. Coccidiosis is the disease of the spring and fall, i.e. humid seasons with plenty of rain. The parasite development takes place in epithelial cells of the intestine of all bird species. The parasite can develop also in epithelial cells of the kidney glomerully in gees whereas merozoits and shizonts (as a developing form of the parasite) cause severe lesions and desquamation of the mucus. Local symptoms are accompanied with general health disturbance and typical diarrhea which is the characteristic symptom. Diagnosis is on the basis of the general symptoms, gross and microscopic findings as well as feces sample testing. To control coccidiosis in poultry, there is a vaccine or the disease is controlled by anticoccidials in the feed. Coccidiosis is possible to treat with anticoccidials (coccidiostatics and coccidiocides). Economical consequences of the coccidiosis in poultry are decreased feed conversion, smaller weight gain, inadequate feed conversion, smaller body weight at the end of the fattening period, prolonged fattening period, as well as therapy costs. Body weight gain is reduced, as well as accumulation of abdominal fat. The disease has a negative impact on chemical and sensory meat appearance. One of the problems as far as coccidiosis is concerned is drug resistance. Today, coccidiosis control strategies are the 'shuttle' and 'switch' program of the prophylactic medication, good manufacturing praxis and proper sanitation. .

Kokcidioza je oboljenje koje predstavlja stalan zdravstveni problem, naročito u uslovima intenzivnog uzgoja živine. Najznačajnija je bolest živine u ekonomskom pogledu, jer godišnji troškovi za profilaksu i terapiju kokcidioze prevazilaze dve milijarde eura na globalnom nivou. U našoj zemlji najzastupljenija je kod kokošaka, a ređe se javlja kod ćuraka, gusaka, pataka i fazana. Uzročnici oboljenja su protozoe iz familije Eimeridae, a infektivni oblik predstavljaju sporulisane oociste. Izvor infekcije su inficirane jedinke, a bolest se prenosi direktnim i indirektnim kontaktom - pribor, oprema, prašina, ljudi, glodari, divlje ptice i insekti. Na rasprostranjenost bolesti utiču: nedovoljan prostor, visoka temperatura i relativna vlažnost vazduha, neadekvatna ishrana, pojava drugih oboljenja i svi faktori koji smanjuju otpornost organizma. Najčešće se javlja u proleće i jesen, odnosno u kišnim periodima. Razvoj parazita odigrava se u epitelnim ćelijama creva svih ptica, odnosno epitelu bubrežnih kanalića gusaka, a razvojni oblici (merozoiti i šizonti) dovode do teških oštećenja i deskvamacije sluznice, praćenih promenom opšteg stanja i karakterističnim prolivom. Dijagnoza oboljenja postavlja se na osnovu kliničke slike, koprološkog, patomorfološkog i patohistološkog nalaza. Profilaksa oboljenja sprovodi se vakcinacijom ili primenom antikokcidijala u smešama za ishranu, dok se terapija sprovodi antikokcidijalima, koji mogu biti kokcidiostatici i kokcidiocidi. Ekonomski gubici ogledaju se u povećanom utrošku hrane, smanjenom prirastu, nižoj konverziji hrane, manjoj prosečnoj telesnoj masi na kraju tova, produženom trajanju tova i troškovima lečenja. Prinos trupova i deponovanje abdominalnog masnog tkiva su manji, a oboljenje negativno utiče i na hemijske i senzorne parametre kvaliteta mesa. Problem u suzbijanju oboljenja je brz razvoj rezistencije na lekove, a kontrolne strategije u suzbijanju kokcidioze su 'shuttle' i 'switch' program profilaktičke medikacije, dobra proizvođačka praksa i sanitacija. .