Sensitivity of field isolates of Eimeria acervulina and E. maxima from three regions in Brazil to eight anticoccidial drugs
| Autor: | D. V. J. Nascimento, Alda Maria Backx Noranha Madeira, A. L. Kraieski, A. J. Lima Neto, G. B. C. Salles, E. C. Muniz, I. L. Santos |
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| Rok vydání: | 2021 |
| Předmět: |
Veterinary medicine
anticoccidial drug Narasin SF1-1100 Feed conversion ratio anticoccidial resistance 03 medical and health sciences chemistry.chemical_compound IMMUNOLOGY HEALTH AND DISEASE medicine Animals Salinomycin Poultry Diseases 030304 developmental biology Lasalocid 0303 health sciences biology Coccidiosis 0402 animal and dairy science 04 agricultural and veterinary sciences General Medicine anticoccidial sensitivity test biology.organism_classification medicine.disease 040201 dairy & animal science Animal culture Eimeria acervulina broiler chicken chemistry Pharmaceutical Preparations Nicarbazin Coccidiostats Animal Science and Zoology Eimeria OÓCITOS Decoquinate Chickens Brazil |
| Zdroj: | Poultry Science Poultry Science, Vol 100, Iss 8, Pp 101233-(2021) Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1525-3171 |
| Popis: | Rotation with different active ingredients is among the most effective and recommended strategies to preserve the efficacy of anticoccidial drugs and reduce the emergence of resistance. Tools such as anticoccidial sensitivity tests (ASTs) are ideally used to make rational rotation programs and bring benefits to production. The objective of this study was to evaluate the sensitivity of E. acervulina (EA) and E. maxima (EM) from 3 different regions in Brazil, by using four ASTs. Feces samples weighing 6 to 7 kg were collected in the regions of São Paulo, Paraná, and Minas Gerais. Prevalent oocysts from feces were filtered, identified, and quantified to conduct 2 ASTs with EA and 2 with EM. The same experimental design was used in every AST (4 replicates per treatment, with 6 birds each, for a total of 240 birds). Treatment groups were a nonchallenged and nonmedicated control group (T1), a challenged and nonmedicated control group (T2), and the other groups challenged and treated with the following compounds: lasalocid (90 ppm – T3), maduramycin (6 ppm – T4), decoquinate (30 ppm – T5), nicarbazin+semduramicin (66 ppm – T6), monensin (110 ppm – T7), salinomycin (66 ppm – T8), narasin+nicarbazin (100 ppm – T9), and nicarbazin (125 ppm – T10). At the end of each AST (20 d), the percent change (delta value) between the treated group (T3 to T10) and the control group (T2) was calculated for the following variables: body weight gain, feed conversion ratio, lesion score, and an indicator of percentage of optimal anticoccidial activity (POAA) that included T2. Different sensitivity levels of EA and EM isolates could be identified. As a whole, drugs from T5 and T3 groups showed higher delta values when compared to other compounds, whereas the lowest sensitivity levels of these isolates were observed in groups T4 and T7. Despite some limiting factors, ASTs can be a good tool for strategic selection of anticoccidial drugs in order to maintain efficacy and extend the lifespan of these molecules. |
| Databáze: | OpenAIRE |
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