Ecotoxicological effects of untreated pig manure from diets with or without growth-promoting supplements on Eisenia andrei in subtropical soils.

This study aimed to evaluate the effects of untreated pig manure from diets incorporating growth-promoting supplements (antibiotics and Zn oxide) on the survival and reproduction of Eisenia andrei earthworms. The tested manures were obtained from four different groups of pigs fed with four different diets: CS, a diet based on corn and soymeal; TR, a diet based on corn, soymeal, and ground wheat (15%); CSa, a diet based on corn and soymeal + 100 ppm of doxycycline + 50 ppm of colistin + 2500 ppm of Zn oxide; and TRa, a diet based on corn, soymeal, and ground wheat (15%) + 100 ppm of doxycycline + 50 ppm of colistin + 2500 ppm of Zn oxide. The study used two soils representative of the Southern region of Brazil (Oxisol and Entisol). In general, there were no significant differences between the different manures tested in each soil. However, there were differences in the toxicity manure on E. andrei between the soils, and the magnitude of this effect was dependent on the applied dose. In Oxisol, LC50 values were higher than 80 m3 ha-1, and EC50 varied from 9 to 27 m3 ha-1. In Entisol, the LC50 values were below the lowest dose tested (< 25 m3 ha-1), and EC50 remained around 5 m3 ha-1. It may be possible that the effects observed were attributed to an excess of nitrogen, copper, and zinc, promoted by the addition of the untreated manure and how these factors interacted with soil type.

Different diets with and without inclusion of antimicrobial additives alter the toxicity of swine manure to springtails and earthworms? / Diferentes dietas com e sem inclusão de aditivos antimicrobianos alteram a toxicidade do esterco de suíno para colêmbolos e minhocas?

The objective of this study was to measure the impact on part of soil fauna of application of non-stabilized (fresh) manure from post-weaning pigs fed diets, formulated with or without the use of dual-purpose wheat (15% inclusion), and with or without the use of antimicrobial growth-promoting additives (100 mg kg-1 doxycycline + 50 mg kg-1 colistin + 250 mg kg-1 Zn oxide). Two species of edaphic organisms were evaluated, the springtails Folsomia candida and the earthworms Eisenia andrei, using ecotoxicological avoidance behavior tests. The treatments were swine manure from: RR: Reference Ration; WR: Wheat Reference; RA: Reference Ration + Antimicrobial Additives; WA: Wheat Reference + Antimicrobial Additives. The doses of waste used for treatments were as follows: 0 (control), 5, 10, 20, 30, 40, 65 and 100 m³ ha-1 for the springtails, and 0 (control), 5, 10, 20, 30, 40 and 65 m³ ha-1 for the earthworms, applied in the Oxisol. The experimental design was completely randomized with four replicates. The use of non-stabilized swine manure did not affect the avoidance behavior of F. candida at any dose, regardless of the use of antimicrobial additives or wheat. For E. andrei, there was avoidance behavior at all treatments and doses used. These avoidance behaviors were related to the sensitivity of each species of soil organism. The avoidance behavior for earthworms was related to the doses of non-stabilized swine manure in soil and not to the various diets and/or the use of growth-promoting additives

O estudo foi realizado com objetivo de mensurar o impacto sobre parte da fauna do solo de aplicações de dejetos sem estabilização (frescos), provenientes de suínos na fase de creche arraçoados com diferentes dietas, formuladas com ou sem o uso do trigo de duplo propósito (15% de inclusão), e com ou sem o uso de aditivos antimicrobianos promotores de crescimento (100 mg kg-1 de doxiciclina + 50 mg kg-1de colistina + 250 mg kg-1 de óxido de Zn). Foram avaliadas duas espécies de organismos edáficos, colêmbolos Folsomia candida e minhocas Eisenia andrei, com o uso de ensaios ecotoxicológicos de comportamento de fuga. Os tratamentos foram dejetos de suínos provenientes de: RR: Ração Referência; WR: Trigo Referência; RA: Ração Referência + Aditivos Antimicrobianos; WA: Trigo Referência + Aditivos Antimicrobianos. As doses de dejetos utilizadas para os tratamentos foram: 0 (controle), 5, 10, 20, 30, 40, 65 e 100 m³ ha-1 para os colêmbolos, e 0 (controle), 5, 10, 20, 30, 40 e 65 m³ ha-1 para as minhocas, aplicadas em Latossolo Vermelho distrófico. O delineamento experimental foi inteiramente casualizado com quatro réplicas. A utilização de dejetos de suínos não estabilizados não afetou a fuga de F. candida em nenhuma das doses, independente do uso ou não de aditivos antimicrobianos ou de trigo. Já para E. andrei o comportamento foi inverso e houve fuga em todos os tratamentos e doses utilizados. Os comportamentos de fuga foram relacionados à sensibilidade de cada espécie de organismo edáfico. O comportamento de fuga para minhocas foi relacionado com as doses dos dejetos de suínos não estabilizados no solo e não às várias dietas e/ou ao uso dos aditivos promotores de crescimento

Toxicity of four veterinary pharmaceuticals on the survival and reproduction of Folsomia candida in tropical soils.

This study aimed to evaluate the effect of veterinary pharmaceuticals (VPs) used to control endo- and ectoparasites in ruminants, on the survival and reproduction of the collembolan species Folsomia candida. Standard ecotoxicological tests were conducted in Tropical Artificial Soil and the treatments consisted of increasing dosages of four commercial products with different active ingredients: ivermectin, fipronil, fluazuron and closantel. Ecotoxicological effects were related to the class and mode of action of the different compounds. Fipronil and ivermectin were the most toxic compounds causing a significant reduction in the number of juveniles at the lowest doses tested (LOECreprod values of 0.3 and 0.2 mg kg-1 of dry soil, respectively) and similar low EC50 values (fipronil: 0.19 mg kg-1 dry soil, CL95% 0.16-0.22; ivermectin: 0.43 mg kg-1 dry soil, CL95% 0.09-0.77), although the effects observed in the former compound were possibly related to a low adult survival (LC50 of 0.62 mg kg-1 dry soil; CL95%: 0.25-1.06). For the latter compound no significant lethal effects were observed. Fluazuron caused an intermediate toxicity (EC50 of 3.07 mg kg-1 dry soil, CL95%: 2.26-3.87), and also here a decrease in adult survival could explain the effects observed at reproduction. Closantel, despite showing a significant reduction on the number of juveniles produced, no dose-response relationship nor effects higher than 50% were observed. Overall, all tested compounds, especially ivermectin, when present in soil even at sub-lethal concentrations, can impair the reproduction of collembolans and possibly other arthropods. However, the actual risk to arthropod communities should be further investigated performing tests under a more realistic exposure (e.g., by testing the dung itself as the contaminated matrix) and by deriving ecotoxicologically relevant exposure concentration in soil derived from the presence of cattle dung.

Ecotoxicology of Glycerol Monolaurate nanocapsules.

Glycerol Monolaurate (GML) is a compound with known antimicrobial potential, however it is not much used due to its low solubility in water and high melting point. The nanoencapsulation of some drugs offers several advantages such as improved stability and solubility in water. The present study aimed to produce, characterize, and evaluate the ecotoxicity of GML nanocapsules. The nanocapsules were produced and presented a mean diameter of 210nm, polydispersity index of 0.044, and zeta potential of -23.4mV. The electron microscopy images showed the nanometric size and spherical shape. The assay in soil showed that GML has a high toxicity while the GML nanocapsules showed decreased toxic effects. Nanostructuration also protected the Rhamdia quelen against the toxic effects of GML. Concluding, the formulation shows positive results and is useful to predict the success of development besides not damaging the soil.

Ecotoxicological effects of pig manure on Folsomia candida in subtropical Brazilian soils.

The effects of pig manure, from diets incorporating veterinary pharmaceuticals, on survival and reproduction of Folsomia candida were evaluated. Manures derived from the following diets: corn and soymeal (CS); 85% CS diet+15% wheat meal (TR); CS diet+100ppm doxycycline+50ppm colistin+2500ppm Zn oxide (CSa); TR diet+100ppm doxycycline+50ppm colistin+2500ppm Zn oxide (TRa). Manures were tested in two subtropical soils representative of southern (Oxisol and Entisol). Despite the antibiotics no significant differences were found between the four manures within each soil. However, strong differences were found on the toxicity between soils. In Oxisol, LC50 values were around 100m(3)ha(-1), and EC50 values around 80m(3)ha(-1). In Entisol these were much lower, with LC50 values oscillating around 20m(3)ha(-1) and EC50 values between 10-15m(3)ha(-1). The observed toxicity on both soils was attributed to excess of nitrogen, Cu and Zn in the highest doses. The strong difference between soils could be explained by soil properties, namely CEC, organic matter, and clay contents that were lower in Entisol, indicating a poor ability to retain contaminants increasing their availability in soil. Results suggest that the application of these residues should be regulated not only using a volume-based criterion, but should incorporate data on soil properties, complemented by an ecotoxicological assessment.

Influence of cypermethrin on avoidance behavior, survival and reproduction of Folsomia candida in soil.

Cypermethrin is a pyrethroid widely used in agriculture and in control of animal ectoparasites, being effective against a large number of insects. Therefore, this study aimed to evaluate the effects of cypermethrin on soil fauna using reproduction and behavior ecotoxicological tests with the springtail Folsomia candida. The surface layer of a soil characteristic of the western region of the Santa Catarina State, classified as Typic Dystrupept, was used as test substrate. The treatments on both tests consisted of five concentrations of cypermethrin (0, 7.5, 15.0, 22.5, and 30.0mgkg(-)(1)) corresponding to 0, 1.5, 3.0, 4.5, and 6.0gm(-2), respectively. This range was chosen according to technical instruction for the use of this product in broilers beds (that are used afterwards as organic fertilizer in soil) that recommends 15mgkg(-1) (3.0gm(-2)). The results obtained with tests for F. candida showed toxicity at all doses tested, following a dose-related response resulting in reduction in survival rate (LC50 of 18.41mgkg(-1), equivalent to 3.8gm(-2)), in the number of juveniles (EC50 of 15.05mgkg(-1), corresponding to 3.01gm(-2)), and an increase in avoidance response (AC50 of 29mgkg(-1), corresponding to 5.8gm(-2)). Although more studies are needed focusing on the fate of cypermethrin in soil when the poultry beds are used as fertilizer and how it may affect soil fauna, data obtained in this study, by showing effects within the range of the doses that are recommended implies that caution and possible mitigation measures should be taken when using this compound.