The epizootiology of Eimeria infections in commercial broiler chickens where anticoccidial drug programs were employed in six successive flocks to control coccidiosis

Abstract

The course of natural Eimeria infections in 6 successive broiler flocks at a commercial farm comprising 4 houses, where different anticoccidial drug programs were employed, was studied by counting the number of oocysts in the litter at weekly intervals. The course of infection in all flocks followed a bell shaped curve in which oocyst numbers, initially low, increased to a peak ranging from 36 × 10(3) to 74 × 10(3) oocysts/g (OPG) of litter around 3 to 4 wk of age. Numbers subsequently declined to 3 × 10(3) to 15 × 10(3) OPG. Oocysts could be detected between flocks when birds were not present. Species of Eimeria identified included E. acervulina, E. maxima, and E. tenella Despite the presence of large numbers of oocysts in the litter, coccidial lesions were not observed in the intestines of the birds. The performance of broilers at the study site was comparable to that of other farms in the area where birds from the same settlement were reared to a similar age using the same drug programs. The results indicate the ubiquitous nature of Eimeria spp. infections in commercial broilers despite prophylactic medication.

Utility of Feed Enzymes and Yeast Derivatives in Ameliorating Deleterious Effects of Coccidiosis on Intestinal Health and Function in Broiler Chickens

“…Caused by protozoan parasites of the phylum apicomplexan, genus Eimeria, coccidiosis is inexplicably linked to the advancement and modernization of poultry production and annual global impact amounts to more than $3 billion in morbidity and mortality losses (2,3). The protozoa invades intestinal cells as part of life cycle leading to impaired digestion and absorption, barrier function and secondary bacterial infections (4)(5)(6). The parasites exhibits remarkable speciesspecific sites of development and foci of pathology within the intestinal tract (5,(7)(8)(9).…”

“…In recognition of the negative effects of coccidiosis in poultry production, the industry has long developed and adopted anticoccidials or live vaccination or combinations of these strategies for control (6,14). However, concerns over Eimeria species resistant to anticoccidials and public concern over drug use in animal production is limiting chemotherapy options (15).…”

Growth performance and gastrointestinal responses of broiler chickens fed corn-soybean meal diet without or with exogenous epidermal growth factor upon challenge with Eimeria

“…Coccidiosis is a disease of significant importance to the global poultry industry accruing more than US$6 billion dollars in morbidity and mortality losses (Chapman, 2014 ; Chapman et al, 2016 ). Pathogenesis entails protozoa Eimeria invading the intestinal cells as part of the life cycle.…”

Differential immune response to Eimeria maxima infection in fast‐ and slow‐growing broiler genotypes

“…Economic loss in the broiler industry results from reduced feed intake, feed conversion and the cost of treatment . Control of coccidiosis in poultry flocks currently requires strict husbandry, the use of anti‐coccidial drugs and vaccination . However, significant resistance to anti‐coccidial drugs has been reported and current concerns over antimicrobial resistance in the human food chain are leading to reduction in metaphylactic antibiotic usage.…”

“…Control of coccidiosis in poultry flocks currently requires strict husbandry, the use of anti‐coccidial drugs and vaccination . However, significant resistance to anti‐coccidial drugs has been reported and current concerns over antimicrobial resistance in the human food chain are leading to reduction in metaphylactic antibiotic usage. Although immunity to Eimeria in chickens is long‐lasting, vaccination against Eimeria requires multiple live‐attenuated species and strains in order to overcome antigenic variation and ensure immune recognition of these .…”