Resumo

Nitrogen (N) is essential to the fertilization of coffee. The fertilizer most used to meet this demand is urea, although it has high rates of N loss due mainly to ammonia volatilization. To reduce this loss, fertilizers with increased efficiency have emerged. Thus, the aim was to select the most appropriate nonlinear regression model to describe N loss attributable to ammonia volatilization in slow- and controlled-release fertilizers applied to coffee plants and to compare the different fertilizers based on the parameters of the selected model. The data studied are controlled-release fertilizers: urea + sulfur + polymer (U+S+P), urea + plastic resin (U+PR), urea + polymer insoluble in water (U+PIW) and slow-release fertilizer: urea formaldehyde (UF) applied to coffee. The Gompertz, Brody, and von Bertalanffy Logistics models were fit by the least squares method. The goodness of fit was assessed using the adjusted coefficient of determination, mean absolute deviation, and Akaike's information criterion. The von Bertalanffy model was the most appropriate for describing the data in most cases. After selecting the best model for the means, the parameters of the von Bertalanffy model were estimated again for each repetition of treatments. With the repetitions of the parameter estimates of these models, the F test of analysis of variance (ANOVA) and Tukey's test were applied. In the F test, p < 0.05 for all parameters. In the Tukey's test, the UF fertilizer reached the asymptote more quickly and presented a lower accumulated loss of N in the coffee tree. The fertilizers U+S+P and U+PIW have later inflection points (IP).

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Ensilage of rehydrated corn kernels (RC) has been used to improve nutritional value and facilitate on-farm storage. This study evaluated the effects of chitosan and lactic acid microbial inoculants on rehydrated corn silage microbiology, fermentation profile and losses, chemical composition, in vitro degradation, and aerobic stability. Forty experimental silos were used in a completely random design to evaluate the following treatments: 1) Control (CON): RC silage without additives; 2) Chitosan (CHI): RC silage with 6 g/kg dry matter (DM) of chitosan; 3) Lactobacillus buchneri (LB): RC ensiled with 5 × 105 colony forming units (CFU) of L. buchneri per gram fresh weight; and 4) Lactobacillus plantarum and Pediococcus acidilactici (LPPA): RC ensiled 1.6 × 105 of L. plantarum and 1.6 × 105 P. acidilactici per gram fresh weight. Additives increased lactic acid bacteria and concentration of lactic and propionic acid, decreased mold and yeast count and gas and fermentative losses, and improved DM recovery. The CHI-silos had lower silage pH, Ammonia-N concentration, fermentative losses, and higher acetic acid concentration compared to microbial inoculated-silos. In addition, CHI and LB decreased silage pH and temperature after aerobic exposure. Although, treatments showed slight effects on the nutritional value of RC, CHI improved aerobic stability and decreaseds fermentation losses.

A ensilagem de grãos de milho reidratados (RC) tem sido usada para melhorar o valor nutricional e facilitar o armazenamento na fazenda. Este estudo teve como objetivo avaliar os efeitos de inoculantes microbianos de quitosana e ácido lático na microbiologia de silagem de milho reidratada, perfil e perdas de fermentação, composição química, degradação in vitro e estabilidade aeróbia. Quarenta silos experimentais foram utilizados em delineamento inteiramente casualizado para avaliar os seguintes tratamentos: 1) Controle (CON): silagem RC sem aditivos; 2) Quitosana (CHI): silagem de RC com 6 g/kg de matéria seca (MS) de quitosana; 3) Lactobacillus buchneri (LB): RC ensilados com 5 × 105 unidades formadoras de colônias (UFC) de L. buchneri por grama na alimentação; e 4) Lactobacillus plantarum e Pediococcus acidilactici (LPPA): RC ensilado 1,6 × 105 de L. plantarum e 1,6 × 105 P. acidilactici por grama na alimentação. Os aditivos aumentaram as bactérias láticas e a concentração de ácido lático e propiônico, diminuíram a contagem de fungos e leveduras e as perdas gasosas e fermentativas e melhoraram a recuperação da MS. Os silos CHI apresentaram menores pH da silagem, concentração de N amoniacal, perdas fermentativas e maior concentração de ácido acético em comparação com silos inoculados microbianos. Além disso, CHI e LB reduziram pH e temperatura da silagem após a exposição ao ar. Embora os tratamentos mostrem pequenos efeitos sobre o valor nutricional do RC, a CHI melhoroua a estabilidade aeróbia e diminui as perdas por fermentação.

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Quantification and evaluation of the spatiotemporal changes in soil quality is important to understand soil degradation mechanisms and restore the damaged land productivity. However, the effects of coal mining subsidence on the spatial and temporal characteristics of soil quality are not well understood. We investigated the contents of pH, organic matter (OM), total nitrogen (TN), nitrate nitrogen (NN), ammonia nitrogen (AN), total phosphorus (TP), available phosphorus (AP), available potassium (AK), total potassium (TK), cation exchange capacity (CEC), sucrase activity (SA), urease activity (UA), phosphatase activity (PA), catalase activity (CA) and dehydrogenase activity (DA) in the coal mining subsided area. The results showed that the contents of TN, NN, AN, TP, AK, TK, SA, UA, PA, CA and DA exhibited significant (P < 0.05) differences among the four seasons. Compared with the upper layer (0-20 cm), the lower layer (20-40 cm) contained higher contents of AN, NN, TN, TP and TK but lower contents of SA, UA, PA, CA and DA. The NN, AP, TP, AK and UA were identified as key indicators in the minimum dataset using principal component analysis. The seasonal changes of soil quality index (SQI) were in the following order: winter (0.707), spring (0.681), summer (0.616), and autumn (0.563). The spatial changes of SQI were highest for middle slope position 3 (0.508), followed by lower slope position 4 (0.507), top slope position 1 (0.446), upper slope position 2 (0.442), and bottom slope position 5 (0.437). Based on these spatiotemporal changes in soil quality, it was suggested that the application of multiple land use types may be a useful method for land reclamation and the interest of local farmers in the coal mining subsided area.

A quantificação e avaliação das mudanças espaço-temporais na qualidade do solo são importantes para compreender os mecanismos de degradação do solo e restaurar a produtividade da terra danificada. Contudo, os efeitos da subsidência da mineração de carvão nas características espaciais e temporais da qualidade do solo não são bem compreendidos. Foram investigados os teores de pH, matéria orgânica (MO), nitrogênio total (NT), nitrogênio nitrato (NN), nitrogênio amoniacal (AN), fósforo total (TP), fósforo disponível (FA), potássio disponível (AK), total potássio (TK), capacidade de troca catiônica (CEC), atividade de sacarase (SA), atividade de urease (UA), atividade de fosfatase (PA), atividade de catalase (CA) e atividade de desidrogenase (DA) na área subsidiada de mineração de carvão. Os resultados mostraram que os teores de TN, NN, AN, TP, AK, TK, SA, UA, PA, CA e DA apresentaram diferenças significativas (P < 0,05) entre as quatro estações. Comparada com a camada superior (0-20 cm), a camada inferior (20-40 cm) continha maiores teores de AN, NN, TN, TP e TK, mas menores teores de SA, UA, PA, CA e DA. Os NN, AP, TP, AK e UA foram identificados como indicadores-chave no conjunto mínimo de dados utilizando análise de componentes principais. As mudanças sazonais no índice de qualidade do solo (IQS) ocorreram na seguinte ordem: inverno (0,707), primavera (0,681), verão (0,616) e outono (0,563). O valor do IQF foi mais alto para a posição 3 do declive médio (0,508), seguido pela posição 4 do declive inferior (0,507), posição 1 do declive superior (0,446), posição 2 do declive superior (0,442) e posição 5 do declive inferior (0,437). Com base nestas mudanças espaço-temporais na qualidade do solo, foi sugerido que a aplicação de múltiplos tipos de uso da terra pode ser um método útil para a recuperação de terras e o interesse dos agricultores locais na área subsidiada de mineração de carvão.

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Nitrogen compounds, particularly ammonium, nitrite and nitrate, are a major problem in shrimp production systems. These compounds can accumulate in the aquatic environment and reach harmful or even lethal levels. Thus, monitoring the levels of nitrogenous compounds such as ammonia and studying their effects on the animals are essential. One tool used for this purpose is acute toxicity testing based on the evaluation of LC50 values. Furthermore, tools that can help improve the performance of aquatic organisms in culture are needed. The present study aimed to evaluate the effect of salinity on the toxicity of total ammonia to postlarvae of the freshwater prawn Macrobrachium rosenbergii. For this purpose, acute toxicity testing (LC50-96h) was performed using 540 postlarvae with a mean weight of 0.13 g and a mean total length of 2.47 cm, divided into 54 experimental units of two liters each. A completely randomized design in a 3×6 factorial scheme was used, combining three salinities (0, 5, and 10 g.L-1) and six total ammonia concentrations (0, 8, 16, 32, 64, and 128 mg.L-1), with three replicates per combination. The LC50 values for M. rosenbergii postlarvae at 24, 48, 72, and 96 h and their respective confidence intervals (95%) were estimated using the trimmed Spearman-Karber method. The results showed that salinities of 5 or 10 g.L-1 did not reduce the acute toxicity of total ammonia.

Compostos nitrogenados, particularmente amônia, nitrito e nitrato, são um grande problema nos sistemas de produção de camarão. Esses compostos podem se acumular no meio aquático e atingir níveis nocivos ou mesmo letais. Assim, monitorar os níveis de compostos nitrogenados como a amônia e estudar seus efeitos nos animais são essenciais. Uma ferramenta utilizada para este fim são os testes de toxicidade aguda baseados na avaliação dos valores de CL50. Além disso, são necessárias ferramentas que possam ajudar a melhorar o desempenho dos organismos aquáticos em cultura. O presente estudo teve como objetivo avaliar o efeito da salinidade na toxicidade da amônia total para pós-larvas do camarão de água doce Macrobrachium rosenbergii. Para tanto, o teste de toxicidade aguda (CL50-96h) foi realizado utilizando-se 540 pós-larvas com peso médio de 0,13 g e comprimento total médio de 2,47 cm, divididas em 54 unidades experimentais de dois litros cada. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 3×6, combinando três salinidades (0, 5 e 10 g.L-1) e seis concentrações de amônia total (0, 8, 16, 32, 64 e 128 mg.L-1), com três repetições por combinação. Os valores de CL50 para pós-larvas de M. rosenbergii em 24, 48, 72 e 96 h e seus respectivos intervalos de confiança (95%) foram estimados pelo método de Spearman-Karber aparado. Os resultados mostraram que salinidades de 5 ou 10 g.L-1 não reduziram a toxicidade aguda da amônia total.

Resumo

In Brazil, urea is the most used nitrogen (N) fertilizer to improve forage production. However, their excessive use can cause environmental impacts through N losses, such as ammonia (NH3) volatilization. Therefore, the current study adjusted and estimated the NH3 volatilization from urea applied on tropical pastures in three rainfall conditions using mathematical models. Data were collected from Marandu grass (Brachiaria brizantha) fertilized with 50 kg N ha-1 during wet, intermediate, and dry conditions. Ammonia volatilization was measured in five semi-open chambers for 21 days. The linear, quadratic, exponential, Gompertz, Groot, and Richards models were tested for fitting and estimating the NH3 volatilization. The Gompertz, Groot, and Richards models generated predictions similar to the observed data, with a high determination coefficient, indicating a better fit of these equations to data, with precision and accuracy. However, the Groot model was selected due to the lowest root mean square error of prediction (0.29 % total N lost as NH3). The greatest N loss as NH3 volatilization occurred in the wet, followed by intermediate and dry conditions (20.2, 17.0, and 11.3 % total N lost as NH3, respectively). Therefore, nitrogen losses as NH3 volatilization after application of 50 kg N ha-1, as urea source, are altered according to the weather conditions, reaching 20% of N added in the wet rainfall period. The Groot model is recommended for fitting and estimating the NH3 volatilization from urea applied on Marandu grass pastures in the wet and dry rainfall conditions.

No Brasil, a ureia é o fertilizante nitrogenado mais utilizado para melhorar a produção de forragem. No entanto, seu uso excessivo pode causar impactos ambientais por meio de perdas de nitrogênio (N), como a volatilização da amônia (NH3). Portanto, o objetivo do presente estudo foi ajustar a volatilização de NH3 da ureia aplicada em pastos tropicais em três condições de chuva utilizando modelos matemáticos. Dados foram coletados de pastos de capim-marandu (Brachiaria brizantha) adubado com 50 kg N ha-1 em condições úmidas, intermediárias e secas. A volatilização da NH3 foi medida em cinco câmaras semiabertas durante 21 dias. Os modelos, linear, quadrático, exponencial, Gompertz, Groot e Richards foram testados para ajuste e estimativa da volatilização do NH3. Os modelos de Gompertz, Groot e Richards geraram predições semelhantes aos dados observados, com alto coeficiente de determinação, indicando um melhor ajuste dessas equações aos dados, com acurácia e precisão. No entanto, o modelo Groot foi selecionado devido ao menor erro quadrático médio das predições (0,29% de N total perdido como NH3). A maior volatilização de NH3 ocorreu em condições climáticas úmida, seguido por intermediária e seca (20,2; 17,0 e 11,3% de N total perdido como NH3, respectivamente). Portanto, as perdas de N como volatilização de NH3 após a aplicação de 50 kg N ha-1, como fonte de ureia, são alteradas de acordo com as condições climáticas, atingindo a 20% do N adicionado nas condições úmidas. O modelo Groot é recomendado para ajuste e estimativa da volatilização de NH3 da ureia aplicada em pastos de capim Marandu em condições úmidas e secas.

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Poultry slaughterhouse wastewater (PSW) has substantial organic load and nutrient contents, which must be removed before discharge due to being sanitary and environmental hazards. The present study is the first to analyze the individual and synergistic influences of combined hydrogen peroxide (H2O2), different ultraviolet lights (UV-A/UV-C), inorganic compound catalysts of titanium and zinc oxides (TiO2/ZnO), and ultrasound (US) processes on ammonia and phosphorus elimination from PSW using a Taguchi L36 orthogonal array. The results showed that, compared to other processes in isolation, the integrated process of H2O2, US, and heterogeneous photocatalysis (HPC) is significantly more effective at treating PSW in terms of N4 + -N removal (52.0%) and PO4-P elimination (59.5%). Furthermore, electrical energy consumption at 2.67 g-1 N4 + -N US$ and 2.14 g-1 PO4-P US$ was determined to be the most significant factor in the operating cost of the system, while the average chemical cost under optimal conditions was 0.34 US$/g. In general, the results indicate that the effectiveness of removing pollutants is directly influenced by the pH, catalyst concentration, and duration of the operation. Additionally, the presence of different types of pollutants in real wastewater might lead to reduced nutrient removal efficiencies.(AU)

Resumo

ABSTRACT The disposal of domestic effluents without an adequate treatment may increase nitrogen and phosphorus levels in natural water bodies. Bioremediation using microalgae is one of the solutions for treating effluents before disposal. We tested the effect of Scenedesmus acuminatus, Chlorella vulgaris and Planktothrix isothrix, as well as the effect of water dilution, on the nutrient concentration in water eutrophicated by domestic effluent in an urban lake in the Brazilian Amazon. We inoculated the three species in monoculture in undiluted water (PW0), and 50% (PW50) and 90% (PW90) diluted water. The experiment lasted 10 days and every 24 hours we removed a bottle of each treatment for nutrient analysis. The three species were equally efficient in removing ammonia in PW0. Nitrate removal rate was highest for Chlorella vulgaris in PW0, and higher for C. vulgaris and P. isothrix in PW50 and PW90. Orthophosphate removal efficiency was higher for S. acuminatus and C. vulgaris in PW0, equally efficient for the three species in PW50, and higher for C. vulgaris and P. isothrix in PW90. We concluded that the three species of microalgae tested are efficient in removing ammonia. Scenedesmus acuminatus was not an ideal species for nitrate removal. Planktothrix isothrix was efficient in removing nutrients when domestic wastewater is diluted. Chlorella vulgaris was efficient in removing nutrients from domestic wastewater whether diluted or not.

RESUMO O descarte de efluentes domésticos sem tratamento adequado pode elevar os níveis de nitrogênio e fósforo em corpos hídricos naturais. A biorremediação com o uso de microalgas é uma solução para o tratamento de efluentes antes do descarte. Nós testamos o efeito de Scenedesmus acuminatus, Chlorella vulgaris e Planktothrix isothrix e o efeito da diluição da água sobre a concentração de nutrientes da água eutrofizada por efluente doméstico de um lago urbano na Amazônia brasileira. Inoculamos as três espécies em monocultura em água não diluída (PW0) e diluída a 50% (PW50) e 90% (PW90). O experimento durou 10 dias e a cada 24 horas retiramos um recipiente de cada tratamento para análise de nutrientes. As três espécies foram igualmente eficientes na remoção de amônia em PW0. A eficiência de remoção de nitrato foi mais alta com C. vulgaris em PW0, e mais alta com C. vulgaris e P. isothrix em PW50 e PW90. A eficiência de remoção de ortofosfato foi mais alta com S. acuminatus e C. vulgaris em PW0, igualmente eficiente para as três espécies em PW50, e mais alta com C. vulgaris e P. isothrix em PW90. Concluímos que as três espécies de microalgas testadas são eficientes na remoção da amônia. Scenedesmus acuminatus não foi ideal para a remoção de nitrato. Planktothrix isothrix foi eficiente na remoção de nutrientes quando a água residual doméstica é diluída. Chlorella vulgaris foi eficiente na remoção de nutrientes de águas residuais domésticas, estando diluída ou não.

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This study evaluated the stability of anaerobic digestion and biogas production from the manure of laying hens fed diets containing different mineral sources and rosemary oil concentrations. Manure was obtained from 288 semi-heavy laying hens, 30 weeks old, and collected for 112 days. A completely randomized design was used in a 2×3 factorial scheme with repeated measures, considering two mineral sources (inorganic and organic) and three concentrations of rosemary oil (0, 100, and 200 mg kg-1). Twelve continuous bench digesters (7.5 kg) were operated with a hydraulic retention time of 30 days and daily loads of 5% total solids, for 90 days. A weekly analysis of influents and effluents was performed by measuring the values of total solids (TS), volatile solids (VS), pH, ammonia nitrogen (ammonia N), intermediary alkalinity (IA), partial alkalinity (PA), and the relationship IA:PA; biweekly analysis of total nitrogen (N) and total phosphorus (P) concentrations; and daily measurement of biogas production data to calculate the biogas production potential of the manure. Manure from laying hens fed with organic minerals has greater potential for biogas production and greater TS and VS reduction than manure from hens supplemented with inorganic minerals. Laying hen diets containing up to 200 mg kg-1 of rosemary oil do not present the risk of anaerobic digestion failure.

O objetivo deste estudo foi avaliar a estabilidade no processo de digestão anaeróbia e a produção de biogás dos dejetos de poedeiras alimentadas com dietas contendo diferentes fontes de minerais e níveis de óleo de alecrim. Os dejetos foram provenientes de 288 poedeiras semipesadas, com 30 semanas de idade, colhidos por 112 dias. Utilizou-se o delineamento inteiramente casualizado com esquema fatorial 2x3, com medidas repetidas no tempo, sendo as dietas com duas fontes minerais (inorgânica e orgânica) e três níveis de óleo de alecrim (0, 100 e 200 mg kg-1). Foram utilizados 12 biodigestores contínuos (7,5 kg), operados com tempo de retenção hidráulica de 30 dias, com cargas diárias com 5% de sólidos totais, por 90 dias. Foram realizadas análises semanais do afluente e efluente mensurando-se os valores de sólidos totais (ST), sólidos voláteis (SV), pH, nitrogênio amoniacal (N amoniacal), alcalinidade parcial (AP), alcalinidade intermediária (AI) e a relação AP:AI; quinzenalmente análises das concentrações de nitrogênio total (N) e de fósforo total (P) e diariamente mensuradas as produções de biogás para calcular o potencial de produção de biogás do dejeto. Dejetos de poedeiras alimentadas com minerais orgânicos apresentam maior potencial de produção de biogás, maiores reduções de ST e SV em relação àquelas alimentadas com minerais inorgânicos. A adição de óleo de alecrim na dieta de poedeiras não oferece riscos de falência para o processo de digestão anaeróbia.

Resumo

The aims of this study were to investigate the different strategies of biofloc addition to zebrafish (Danio rerio) larviculture and to evaluate their growth and biochemical parameters. Three treatments were used: addition of 200 mL biofloc once at the start of the assay (O1), addition of 100 mL biofloc every seven days (1W), and addition of 100 mL biofloc every four days (2W). The 1W and 2W treatments also received 200 mL biofloc at the start of the assay. Regarding water quality, the only difference was the total suspended solid concentration, because the 2W treatment had a higher concentration in the final assay (127.6 ± 24.3 mg·L-1). The final weight, survival rate, and juvenile/larval percentile did not show statistical differences among the treatments. However, the O1 treatment exhibited a higher total length (11.93 ± 0.45 mm) than those in the 2W treatment. The juveniles in the 2W treatment exhibited lower nonprotein thiols and higher thiobarbituric acid reactive substance concentrations than those in the other treatments. Thus, the biofloc system can be a viable alternative to zebrafish larviculture without the use of conventional live food, and the addition of biofloc once (O1) at the beginning of larval rearing achieves good growth and survival results.(AU)

O objetivo deste estudo foi investigar diferentes estratégias de adição de biofloco na larvicultura de zebrafish(Danio rerio), avaliando o crescimento e os parâmetros bioquímicos. Três tratamentos foram utilizados: adição de 200 mL de biofloco uma vez no início do ensaio (O1), adição de 100 mL de biofloco a cada sete dias (1W) e adição de 100 mL de biofloco a cada quatro dias (2W). Os tratamentos 1W e 2W também receberam 200 mL de biofloco no início do ensaio. Em relação à qualidade da água, a diferença ocorreu na concentração de sólidos suspensos totais, pois o tratamento 2W teve maior concentração no fim do experimento (127,6 ± 24,3 mg·L-1). Ao final do ensaio, o peso final, a sobrevivência e a porcentagem de juvenis e larvas não apresentaram diferença entre os tratamentos. Entretanto, no tratamento O1, os peixes apresentaram maior comprimento total (11,93 ± 0,45 mm) do que no tratamento 2W. Os juvenis possuíram menor concentração de tiois não proteicos e maior substâncias reativas ao ácido tiobarbitúrico no tratamento 2W. Assim, o sistema de bioflocos pode ser uma alternativa à larvicultura de zebrafish sem utilizar alimento vivo, e a adição de bioflocos uma vez (O1) no início da larvicultura proporciona bons resultados de crescimento e sobrevivência. (AU)

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This experiment was conducted to evaluate the welfare and production performance of broilers reared under different stocking densities. A total of 1242 one-day-old Cobb500 broiler males were distributed randomly among four treatments with nine replicates each. The treatments consisted of different broiler stocking densities (10.41; 11.45; 12.50 and 13.54 birds/m²). The parameters evaluated were regadring production performance (body weight, body weight gain, feed intake, feed conversion ratio, uniformity, and carcass yield), animal welfare (cortisol, lactate, total protein, albumin, glucose, triglycerides, cholesterol, uric acid seric, and hemogram), and litter quality (temperature, humidity, and volatilized ammonia concentration). The broilers reared at 12.5 birds/m2 presented the best feed conversion ratio at 42 days of age. Neither the carcass traits nor the stress parameters studied were influenced by the stocking densities. It was concluded that the stocking density of 12.50 birds/m² results in the best feed conversion ratio among the studied treatments for the production cycle of 42 days.(AU)

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This study aimed to evaluate different proportions of cactus pear in silage with BRS Capiaçu grass, along with a 10% inclusion of ground corn grain, focusing on aerobic stability, fermentative profile, chemical composition, and digestibility. The treatments included cactus pear (Opuntia spp.) at increasing levels of 0, 15, 30, 45, and 60% of the natural matter in the silage with BRS Capiaçu grass, plus 10% ground corn grain. Additionally, a control silage composed of BRS Capiaçu grass without ground corn was used. A completely randomized design was employed with six treatments and eight replications. The BRS Capiaçu grass was harvested after 100 days of regrowth. For ensiling, experimental PVC silos of known weights and of 50 cm long and 10 cm in diameter were used. The breakdown of aerobic stability of the silage without cactus pear (BRS Capiaçu grass with 10% ground corn) occurred 144 h after opening the silo. The inclusion of cactus pear in the silage with BRS Capiaçu grass and 10% ground corn grain resulted in a linear increase in pH value. Among the silages with cactus pear inclusion, there was no significant difference in gas losses (P = 0.46) and dry matter (DM) recovery (P = 0.43). There was no significant difference between the silages in terms of acetic acid content (P = 0.91). The content of DM and total digestible nutrients was lower in the control silage compared with the other silages. For each percentage unit of cactus pear inclusion, there was a reduction of 0.1195% in DM content. Additionally, for every 1% inclusion of cactus pear in silage with BRS Capiaçu grass, there was an increase of 0.2007 percentage units in DM digestibility. The optimal proportion of cactus pear in silage with BRS Capiaçu grass and 10% ground corn is up to 60% of the natural matter.(AU)

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This study evaluated the growth performance and parasite load of angelfish juveniles Pterophyllum scalare kept at different stocking densities using two rearing systems. The experiment was conducted in a factorial design (4x2) with four stocking densities (0.1, 0.4, 0.7, and 1.0 g/L), two type of aquarium tanks (glass and ceramic aquariums), and four replicates. The experiment lasted 60 days using 148 juvenile fish (3.05 ± 0.09 g) randomly placed in 32 aquariums (50 L) equipped with filters and aeration. All fish received two meals a day ad libitum (8:00 and 16:00). Water quality parameters such as temperature, dissolved oxygen, pH, and total ammonia were measured. At the end of the experiment, all fish were measured and weighed to determine growth performance and then subjected to parasitological analysis. The data were analyzed with a two-way ANOVA with post-hoc Tukey test (p<0.05). No effects on growth performance at different stocking densities were observed. However, there was an increase in Capillaria pterophylli infestation in the high stocking density within ceramic aquariums. Thus, this study recommends the use of 1.0 g/L for the intensive aquaculture system of freshwater angelfish, and applying cleaning management to avoid parasite infestation, particularly in ceramic aquariums.

Este estudo avaliou o desempenho de crescimento e a carga parasitária de juvenis de peixe anjo Pterophyllum scalare mantidos em diferentes densidades de estocagem usando dois sistemas de criação. O experimento foi conduzido em esquema fatorial (4 x 2) com quatro densidades de estocagem (0,1, 0,4, 0,7 e 1,0 g/L), dois aquários (aquários de vidro e cerâmica) e quatro repetições. O experimento durou 60 dias utilizando 148 peixes juvenis (3,05 ± 0,09 g) distribuídos aleatoriamente em 32 aquários (50 L) equipados com filtros e aeração. Todos os peixes receberam duas refeições diárias ad libitum (8h e 16h). Parâmetros de qualidade da água como temperatura, oxigênio dissolvido, pH e amônia total foram medidos. Ao final do experimento, todos os peixes foram medidos e pesados para determinação do desempenho de crescimento e posteriormente submetidos à análise parasitológica. Os dados foram analisados por meio de ANOVA a dois fatores com teste post-hoc de Tukey (p<0,05). Não foram observados efeitos no desempenho do crescimento em diferentes densidades de estocagem. Entretanto, houve um aumento na infestação por Capillaria pterophylli na alta densidade de estocagem dentro dos aquários cerâmicos. Assim, este estudo recomenda o uso de 1,0 g/L para o sistema intensivo de aquicultura de acarás de água doce, e aplicação de manejo de limpeza para evitar a infestação parasitária, principalmente em aquários cerâmicos.

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This study was designed to assess the ichthyofaunal diversity of River Panjkora, Khyber Pakhtunkhwa, Pakistan. For this purpose, a total of 1189 fish from six different sites were collected along the river and identified using standard keys. The fish collected and identified were representing 38 species, belonging to 7 families. The investigation spanned a year, from July 2021 to May 2022. The most dominant family was Cyprinidae 76% (n=906/1189), followed by Nemacheilidae 5.8% (n=69/1189), Channidae 5.2% (n=62/1189), Sisoridae 5.1% (n=61/1189), Mastacembelidae 4.9% (n=58/1189), Salmonidae 2.6% (n=31/1189) and least was Bagridae 0.17 (n=2/1189). The most abundant speices was Schizothorax plagiostomus with relative density of 16.8. Family Cyprinidae was represented by 21 species, Sisoridae by 7 species, Nemacheilidae by 5 species, Channidae by 2 species, while Bagridae, Salmonidae and Mastacembelidae, were each represented by a single species. PAST 3, XLSTAT and EXCEL 2019 were used for principal component analysis to study correlation of fish diversity and richness. Eigenvalue obtained from Kumrat to Busaq were 3.32, 1.01, 0.80, 0.44, 0.31 and 0.10 respectively. The higher value at Kumrat shows higher diversity. The water quality assessment showed average value of water temperature 10.4 ͦC, pH 7.0, electrical conductivity 184 mg/L, dissolved oxygen 7.9 mg/L, turbidity 43.73 mg/L, total dissolved solids 101 mg/L, total suspended solids 34.72 mg/L, total solids 135.53 mg/L, total alkalinity 75.77 mg/L, total hardness 58.37 mg/L, ammonia 0.46 mg/L, sulphate 26.03 mg/L, chloride 14.67 mg/L, calcium 69.11 mg/L, chromium 0.18 mg/L, copper 0.03, cobalt mg/L 0.04, nickel 0.039 mg/L, lead 0.02 mg/L and Zinc 0.35 mg/L. The findings of this study indicated that most of the physicochemical parameters remained within the acceptable limits throughout the study period. Analysis of fish gut contents included; nymphs, insect larvae, the presence of algae, protozoans and macroinvertebrates in the river ecosystem.

Este estudo foi projetado para avaliar a diversidade da ictiofauna do rio Panjkora, Khyber Pakhtunkhwa, Paquistão. Para isso, foram coletados um total de .1189 peixes de seis locais diferentes ao longo do rio e identificados através de chaves-padrão. Os peixes coletados e identificados representavam 38 espécies, pertencentes a 7 famílias. A investigação durou um ano, de julho de 2021 a maio de 2022. A família mais dominante foi Cyprinidae 76% (n=906/1189), seguida por Nemacheilidae 5,8% (n=69/1189), Channidae 5,2% (n=62/ 1189), Sisoridae 5,1% (n=61/1189), Mastacembelidae 4,9% (n=58/1189), Salmonidae 2,6% (n=31/1189), e o mínimo foi Bagridae 0,17 (n=2/1189). A espécie mais abundante foi Schizothorax plagiostomus com densidade relativa de 16,8. A família Cyprinidae foi representada por 21 espécies, Sisoridae por 7 espécies, Nemacheilidae por 5 espécies, Channidae por 2 espécies, enquanto Bagridae, Salmonidae e Mastacembelidae foram representados cada um por uma única espécie. PAST 3, XLSTAT e EXCEL 2019 foram utilizados para análise de componentes principais para estudar a correlação entre diversidade e riqueza de peixes. Os autovalores obtidos de Kumrat para Busaq foram 3,32, 1,01, 0,80, 0,44, 0,31 e 0,10, respectivamente. O valor mais alto em Kumrat mostra maior diversidade. A avaliação da qualidade da água apresentou valor médio de temperatura da água 10,4 ͦC, pH 7,0, condutividade elétrica 184 mg/L, oxigênio dissolvido 7,9 mg/L, turbidez 43,73 mg/L, sólidos totais dissolvidos 101 mg/L, sólidos suspensos totais 34,72 mg/L, sólidos totais 135,53 mg/L, alcalinidade total 75,77 mg/L, dureza total 58,37 mg/L, amônia 0,46 mg/L, sulfato 26,03 mg/L, cloreto 14,67 mg/L, cálcio 69,11 mg/L, cromo 0,18 mg /L, cobre 0,03, cobalto mg/L 0,04, níquel 0,039 mg/L, chumbo 0,02 mg/L e zinco 0,35 mg/L. Os resultados deste estudo indicaram que a maioria dos parâmetros físico-químicos permaneceu dentro dos limites aceitáveis durante todo o período de estudo. Análise do conteúdo intestinal dos peixes incluiu ninfas, larvas de insetos, presença de algas, protozoários e macroinvertebrados no ecossistema fluvial.

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The objective of this study was to evaluate the effects of an essential oil blend (EO), based on cinnamaldehyde and diallyl disulfide, associated or not with antibiotics on intake and nutrient digestibility, ingestive behavior, rumen fermentation, ruminal microbial synthesis, and blood metabolites of feedlot cattle fed a no-forage diet. The study was carried out as a Latin Square with five treatments consisting of a blend of essential oil (EO), monensin (MON) and virginiamycin (VM), both separately and combined as follows: CON (monensin at 30 mg kg­1 DM), VM (virginiamycin at 25 mg kg­1 DM and monensin at 30 mg kg­1 DM), MEO25 (monensin at 30 mg kg­1 DM and EO at 25 mg kg­1 DM), MEO35 (monensin at 30 mg kg­1 DM and EO at 35 mg kg­1 DM) and EO35 (blend of EO at 35 mg kg­1 DM). There were no effects from additives and their combinations on the intake and apparent digestibility of nutrients or ingestive behavior. Furthermore, treatments did not modify the ruminal pH, nor the concentration of short-chain fatty acids and ammonia, nor the microbial protein synthesis. Blood glucose concentration was higher 4 h after morning feeding for all treatments. There was a significant contrast between the VM and EO for the blood concentration of D-Lactate and L-Lactate. There was no difference between the additives in the concentration of cortisol metabolites in the feces. The blend of essential oil studied, containing cinnamaldehyde and diallyl disulfide, associated or not with antibiotics, does not change the nutritional parameters nor the metabolism of feedlot cattle fed a no-forage diet.

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Salmonella Heidelberg is an emerging pathogen in Brazilian poultry production. The traditional methods (quicklime, windrowing and tarpaulin-on-surface) used for disinfecting reused poultry litter between flocks does not guarantee its elimination, thus allowing the transmission of this agent from one flock to another. The new tarpaulinon-surface method with controlled injection of ammonia gas has proven to be effective in its control, however, it is still unknown what dose of ammonia gas is needed to eliminate Salmonella Heidelberg in reused poultry litter. The objective of this study was to evaluate the effect of ammonia gas at different concentrations in sterile poultry litter artificially contaminated with Salmonella Heidelberg. Then, ammonia gas was injected in concentrations of 0.25%, 0.5%, and 1%, and 48 hours later, a sample was collected from each repetition in an entirely randomized design, and bacterial isolation was performed. All treatments, including positive and negative controls, were tested in quadruplicate and the parameters temperature, humidity, pH and water activity were evaluated. In the 0.5% and 1% treated samples the pathogen was not isolated, while in the 0.25% concentration one of the four samples tested was positive. The study reveals that ammonia gas is efficient in killing Salmonella Heidelberg in poultry litter at concentrations of 0.5 % or more within a 48-hour period and that the litter treated with ammonia gas increases its pH and water activity.(AU)

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Fusarium head blight, also known as fusariosis, is caused by a fungus called Fusarium graminearum that produces the mycotoxin deoxynivalenol (DON). This toxin causes problems to human and animal health. Ammonia gas has been shown to be effective in deactivating mycotoxins. The objectives of this study were to evaluate the effectiveness of ammonia gas in the deactivation of DON in wheat grains, the effect of this treatment on its protein composition and the toxicity in rats fed with ammoniated wheat grains. Wheat samples were exposed to ammonia gas at concentrations of 0% (Control), 0.5%, 1% and 1.5%. It was observed that ammonia gas was effective in deactivating DON at concentrations of 1% and 1.5%. There was no difference in crude protein observed in the bromatological analysis of treated wheat grains in relation to the control. Regarding the toxicity of wheat grains treated with ammonia in the feeding of Wistar rats (Rattus norvegicus), no histopathological alterations were observed in the liver, kidneys, intestine and in the hematological profile. The results of this study demonstrated that the treatment of wheat with ammonia gas can contribute to the deactivation of DON without compromising its protein composition and animal health.

A giberela, também conhecida como fusariose, é causada por um fungo chamado Fusarium graminearum, que produz a micotoxina desoxinivalenol (DON). Essa toxina gera problemas à saúde humana e animal. O gás amônia demonstrou ser eficaz na desativação das micotoxinas. Os objetivos deste estudo foram avaliar a eficácia do gás amônia na desativação do DON em grãos de trigo contaminados naturalmente, o efeito desse tratamento na sua composição proteica e a toxicidade em ratos alimentados com os grãos de trigo amonizados. Amostras de trigo foram expostas ao gás amônia nas concentrações de 0% (controle), 0,5%, 1% e 1,5%. Observou-se que o gás amônia foi eficaz na desativação do DON na concentração de 1% e 1,5%. Não houve diferença na proteína bruta observada na análise bromatológica dos grãos de trigo tratados em relação ao controle. Quanto à toxicidade dos grãos de trigo tratados com amônia fornecidos aos ratos Wistar (Rattus norvegicus), não foram observadas alterações histopatológicas do fígado, dos rins e do intestino e no perfil hematológico. Os resultados deste estudo demonstraram que o tratamento de trigo com gás amônia pode contribuir na desativação do DON sem comprometer sua composição proteíca e a saúde dos animais.

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The urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) reduces NH3 losses from urea (UR) surface-applied to soils, but its efficacy may be lower in acidic soils. The period when urease inhibition occurs efficaciously may change with soil pH. This needs to be clarified in tropical soils which are commonly acidic. This study evaluated the effectiveness of NBPT-treated urea to delay and reduce ammonia volatilization in two soils at three pH levels. Two experiments were conducted under laboratory conditions in soils with different textures (sandy-clay and clay). The treatments consisted of three soil pH levels and two N sources (UR and UR + NBPT), with five replicates. The soil pH values were adjusted and reached values of 4.5, 5.6, and 6.4 in the sandy-clay, and 4.5, 5.4, and 6.1 in the clay soil. Ammonia volatilization was measured using glass chambers (1.5 L). In the sandy-clay soil, NH3 losses were 40-47 % of the UR-N. In the clay soil, losses were 26-32 %. The addition of NBPT to UR reduced the NH3 volatilization by 18-53 %; the inhibitor decreased the N losses under all soil pH conditions but was significantly less efficient in acidic soils (pH 4.5). The lower efficiency of the inhibitor under acidic conditions was more evident in the first few days: 50 % of the total NH3 losses occurred in less than four days in soils with pH 4.5, but in 8-11 days in soils with pH above 5.4. The rapid loss in efficiency in more acidic soils is a drawback. Using NBPT in severely acidic soils showed a relatively small advantage over untreated UR as the inhibitor did not provide extra time for fertilizer incorporation and further reduction of NH3 losses.(AU)

Resumo

The urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) reduces NH3 losses from urea (UR) surface-applied to soils, but its efficacy may be lower in acidic soils. The period when urease inhibition occurs efficaciously may change with soil pH. This needs to be clarified in tropical soils which are commonly acidic. This study evaluated the effectiveness of NBPT-treated urea to delay and reduce ammonia volatilization in two soils at three pH levels. Two experiments were conducted under laboratory conditions in soils with different textures (sandy-clay and clay). The treatments consisted of three soil pH levels and two N sources (UR and UR + NBPT), with five replicates. The soil pH values were adjusted and reached values of 4.5, 5.6, and 6.4 in the sandy-clay, and 4.5, 5.4, and 6.1 in the clay soil. Ammonia volatilization was measured using glass chambers (1.5 L). In the sandy-clay soil, NH3 losses were 40-47 % of the UR-N. In the clay soil, losses were 26-32 %. The addition of NBPT to UR reduced the NH3 volatilization by 18-53 %; the inhibitor decreased the N losses under all soil pH conditions but was significantly less efficient in acidic soils (pH 4.5). The lower efficiency of the inhibitor under acidic conditions was more evident in the first few days: 50 % of the total NH3 losses occurred in less than four days in soils with pH 4.5, but in 8-11 days in soils with pH above 5.4. The rapid loss in efficiency in more acidic soils is a drawback. Using NBPT in severely acidic soils showed a relatively small advantage over untreated UR as the inhibitor did not provide extra time for fertilizer incorporation and further reduction of NH3 losses.

Resumo

The aim of the present study was to analyze the histomorphology and histopathology of broiler chicken tracheas submitted to different levels of ammonia gas. The experiment was conducted during different seasons in 2019 in the city of Garanhuns, Brazil. Three sheds with rice hull bedding were used: Shed 1, new bedding; Shed 2, reused bedding; Shed 3, reused bedding with an increase in moisture. Twenty-eight birds were housed per shed for a 42-day production cycle. On days D0 (control group), D7, D21, D35 and D42, seven birds per shed were euthanized. Fragments of the trachea were collected and placed into plastic containers with 10% buffered formalin solution (pH 7) for 24 h, subsequently undergoing routine histological processing. The thickness of the tracheal mucosa was measured using digital images, considering ten equidistant points as being separated by 100 µm. Histopathological lesions were analyzed considering distribution and intensity. The birds in Shed 2 (reused bedding) had greater quantity and severity of histopathological lesions, but the differences did not reach statistical significance. Regarding histomorphometry, birds reared in the higher temperature period had thicker tracheal mucosa at the end of the production cycle (D35 and D42) compared to those raised in the cooler temperature period. In conclusion, the difference in bedding did not significantly alter the tracheal mucosa of the birds, whereas temperature exerted an influence on the thickness of the trachea at the end of the production cycle.(AU)

Resumo

The objective was to examine the effects of supplementing different levels of zeolite in the diet of laying hens during the laying phase, at 54 weeks of age, on production performance, egg quality, ammonia volatilization, excreta pH, blood parameters, weight, and organ morphometry. The treatments consisted of a control diet free of zeolite and five diets including increasing levels of zeolite (0.7, 1.4, 2.1, 2.8, and 3.5%). A completely randomized design was adopted with eight replicates of five birds per plot, totaling 240 laying hens, for four 28-day periods. Results were subjected to ANOVA, Dunnett's test, and regression analysis at 5% probability. The zeolite levels had no significant effect on production performance, egg quality, and blood parameters. The zeolite levels have a significant effect on ammonia volatilization, excreta pH, liver weight, and organ morphometry specifically on the intestinal length. Ammonia and pH reached a linear plateau. Ammoniacal nitrogen levels in the excreta differed from that observed in the control group at all zeolite levels, whereas the pH was lowest at the zeolite inclusion levels of 0.7 and 1.4%. Ammonia volatilization and the pH value of the excreta decreased by 46.9% and 4.6%, when the laying hens consumed diets with 0.93% and 1.19% zeolite, respectively. There was an effect on the relative weight of the organs, with higher liver yield and intestinal length provided by zeolite inclusion. Therefore, zeolite can be included in the diet of commercial layers at up to 0.93% without affecting their production performance or egg quality.(AU)