Sensitivity of field isolates of Eimeria acervulina and E. maxima from three regions in Brazil to eight anticoccidial drugs.

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.

Água salina e biofertilizante bovino na produção de frutos e alocação de biomassa em noni (Morinda citrifolia L. ) / Saline water and bovine biofertilizer on yield and biomass allocation in noni plants (Morinda citrifolia L. )

RESUMO: Têm sido evidenciado que os compostos orgânicos exercem ação mitigadora dos efeitos tóxicos dos sais às plantas, promovendo maior crescimento e desenvolvimento em solos com excesso de sais. Nessa direção, um experimento foi desenvolvido para avaliar os efeitos do biofertilizante bovino na produção de frutos e alocação de biomassa pelos diversos órgãos de plantas de noni, irrigadas com águas salinas. Os tratamentos foram distribuídos em blocos ao acaso, com quatro repetições e duas plantas por parcela, adotando o arranjo fatorial 5 x 2, correspondente a salinidade das águas de irrigação de 0,5; 1,5; 3,0; 4,5; 6,0 dS m-1, em substratos sem e com biofertilizante bovino, aplicado uma única vez, em volume correspondente a 10% do volume do substrato, um dia antes da instalação do experimento. As variáveis avaliadas foram: salinidade do solo, expressa pela condutividade elétrica do extrato de saturação do solo; número de frutos; massa média de fruto; produção de frutos por planta; e alocação de biomassa pelas raízes, caules, folhas e frutos. O aumento da salinidade da água de irrigação elevou o caráter salino do solo desde "não salino" para "fortemente salino" e, inibiu a produção de frutos e a acumulação de biomassa seca das plantas de noni em geral, mas, com maior intensidade nos tratamentos sem o insumo orgânico. O biofertilizante estimula o crescimento e a produção de plantas de noni cultivadas sob irrigação com águas de alta salinidade.

ABSTRACT: Organic compounds have shown to exercise a mitigating action on salts in plants and they promote growth and development in salt stress environments. In this sense, an experiment was carried out in order to evaluate the effects of saline water irrigation and bovine biofertilizer on yield and biomass allocation by the various organs of noni plants. Treatments were arranged in a randomized block design with four replications and two plants per plot using the 5 x 2 factorial design, which correspond to the salinity levels of irrigation water of 0.5, 1.5, 3.0, 4.5 and 6.0 dS m-1 in substrates with and without bovine biofertilizer, applied to the soil once, in the volume corresponding to 10% of the volume of the substrate one day before the implementation of the experiment. The variables evaluated were soil salinity, expressed as electrical conductivity of the soil saturation extract, fruit number, fruit weight and fruit yield per plant, and biomass allocation by roots, stems, leaves and fruit. The increasing salinity of the water for irrigation increased the saline character of the soil from non-saline to saline soil and inhibited the production and accumulation of dry biomass in noni plants in general but with more intensity in the plants of the treatments without bovine biofertilizer applied to the soil in liquid form. The biofertilizer stimulates the growth and production of noni plants grown under irrigation with high salinity water.