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Haemonchus contortus is the most prevalent nematode in Brazil. The objective of this study was to select 6 populations of H. contortus of known or suspected benzimidazole resistance status and characterize these using quantitative real-time polymerase chain reaction (qPCR) for single nucleotide polymorphisms (SNPs) F200Y, F167Y and E198A in the β-tubulin isotype 1 gene. qPCR was performed using DNA from a pool of 10 adult male H. contortus from a single animal per farm. Faecal egg count reduction test (FECRT) and egg hatch test (EHT) were used to determine the resistance status. Samples were obtained from 6 farms located in 5 counties in the Ceará State: Tauá, Boa Viagem, Quixadá, Santa Quitéria and Solonópole. The inbred-susceptible-Edinburgh (ISE) isolate was used as reference for comparative purposes in the qPCR. Benzimidazole resistance was detected by FECRT on all farms with efficacy values ranging from 0 to 51%. EC50 values as determined by EHT were all above 1.49 μg/ml. High frequencies of the resistant SNPs F200Y and F167Y alleles were detected but no resistance was detected at SNP E198A. Our results suggest that the SNPs F167Y and F200Y are both important for benzimidazole resistance in the studied populations.  相似文献   
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This study compares both versions of the nutritional requirement system determined by the National Research Council (NRC) version 1985 (NRC85) and NRC version 2007 (NRC07), for finishing lambs in feedlots. Nineteen crossbred lambs were divided in four groups representing four experimental treatments: one diet according to NRC85 and three diets according to NRC07. The diets recommended by NRC07 considers crude protein intake relative to ruminal undegradable protein at 20, 40, and 60 % levels (NRC07/20, NRC07/40, and NRC07/60). Diets were composed of Brazilian semi-arid native grass silage, soybean meal, corn, annatto byproduct, and limestone. Purchases and sales of lambs were done according to average market prices in Brazil. The economic indicators considered pointed that all treatments were viable but NRC07/20 and NRC07/60 were more profitable with similar net present values (NPVs) and internal return rates (IRRs). NRC07/20 was the best option showing an IRR of 17.20 % and a payback period (PP) of 5.07 considering a fixed annual interest rate of 6 %. Sensitivity analysis considering a 10 % raise in variable costs showed negative NPVs, IRRs inferior to the opportunity cost rates adopted and PPs that exceeded the planning horizon of 7 years for both NRC85 and NRC07/40.  相似文献   
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The focus of this work is to determine the distribution and identify species of Eimeria parasites of dairy goats in the livestock of the National Goat and Sheep Research Center in Sobral, State of Ceará, Northeast Brazil. Results showed the presence of multiple species in 196 of 215 analyzed samples (91.2%). Fifty five out of these were from kids (28%) and 141 from adult goats (72%). Eight different Eimeria species were identified and their prevalence in the herd was: Eimeria alijevi Musaev, 1970 (26.7%), E. arloingi (Marotel, 1905) Martin, 1909 (20.6%), E. hirci Chevalier, 1966 (18%), E. ninakohlyakimovae Yakimoff & Rastegaieff, 1930 (16.2%), E. jolchijevi Musaev, 1970 (8.7%), E. christenseni Levine, Ivens & Fritz, 1962 (6%), E. caprovina Lima, 1980 (2.8%) and E. caprina Lima, 1979 (1%). Moreover, E. ninakohlyakimovae showed higher prevalence in kids (97%), followed by E. arloingi and E. alijevi (88%). On the other hand, E. alijevi (77%) was more common in adult goats followed by E. hirci (74%) and E. ninakohlyakimovae (70%). The species E. caprina had low frequency in both kids (27%) and adult goats (13%). Data indicated that infection was relatively common among kids and adult goats. The implementation of a routine diagnostic strategy can be useful in maintaining Eimeria populations under monitoring and will enable the determination of its potential impact on dairy goat herds in Northeast Brazil.  相似文献   
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