Resumo: No Brasil, milhões de pessoas vivem em áreas de risco para a esquistossomose, uma doença negligenciada, de caráter crônico e com elevada morbidade. O helminto Schistosoma mansoni está presente em todas as macrorregiões, incluindo o Estado de Minas Gerais, um dos mais endêmicos. Por essa razão, a identificação de potenciais focos é fundamental para subsidiar políticas públicas de cunho educativo e profilático no controle desse desfecho. Nesse contexto, o objetivo do trabalho consiste em modelar dados de esquistossomose em relação aos aspectos espaciais e temporais, além de avaliar a importância de algumas variáveis exógenas socioeconômicas e a presença das principais espécies de Biomphalaria. Como trabalhar com casos incidentes, uma variável discreta de contagem, exige uma modelagem apropriada, foi escolhida a modelagem GAMLSS por considerar conjuntamente uma distribuição mais adequada à variável resposta devido à inflação de zeros e à heterocedasticidade espacial. Verificaram-se valores elevados de incidência em diversos municípios de 2010 a 2012 e uma tendência de queda até 2020. Também foi identificado que a distribuição da incidência se comporta de maneira diferente no espaço e no tempo. Municípios com barragem apresentaram risco 2,25 vezes maior do que os que não a continham. A presença de B. glabrata foi relacionada ao risco de ocorrência da doença. Por outro lado, a presença de B. straminea refletiu em menor risco de ocorrência da esquistossomose. Conclui-se que o controle e o acompanhamento dos caramujos da B. glabrata podem ser fundamentais para a contenção e a eliminação da esquistossomose e o modelo GAMLSS foi eficaz para tratamento e modelagem de dados espaçotemporais.

Resumen: En Brasil, millones de personas viven en áreas de riesgo de esquistosomiasis, una enfermedad crónica desatendida y con alta morbilidad. El helminto Schistosoma mansoni está presente en todas las macrorregiones, incluido el Estado de Minas Gerais, uno de los más endémicos del país. Por ello, la identificación de potenciales brotes es fundamental para promover políticas públicas de carácter educativo y profiláctico en el control de este desenlace. En este contexto, el objetivo de este trabajo es modelar datos sobre esquistosomiasis con respecto a aspectos espaciotemporales, además de evaluar la importancia de algunas variables socioeconómicas exógenas y la presencia de las principales especies de Biomphalaria. Dado que en el trabajo con casos incidentes una variable de conteo discreta requiere un adecuado modelado, se eligió el modelo GAMLSS, ya que en conjunto considera una distribución más adecuada para la variable de respuesta debido a la inflación de ceros y la heterocedasticidad espacial. Se encontraron valores de alta incidencia en varios municipios en el periodo evaluado de 2010 a 2012 y una tendencia a descenso hasta 2020. También se verificó que existe una distribución de incidencia de manera diferente en el espacio y el tiempo. Los municipios con represas presentaban 2,25 veces más riesgo que los que no las tenían. La presencia de B. glabrata estuvo relacionada con el riesgo de la enfermedad. Por otro lado, la presencia de B. straminea ocasionaba un menor riesgo de padecer la enfermedad. Se concluye que el control y seguimiento de caracoles B. glabrata puede ser fundamental para el control y eliminación de la esquistosomiasis y que el modelo GAMLSS resultó ser efectivo para el tratamiento y modelado de datos espaciotemporales.

Abstract: In Brazil, millions of people live in areas with risk of schistosomiasis, a neglected chronic disease with high morbidity. The Schistosoma mansoni helminth is present in all macroregions of Brazil, including the State of Minas Gerais, one of the most endemic states. For this reason, the identification of potential foci is essential to support educational and prophylactic public policies to control this disease. This study aims to model schistosomiasis data based on spatial and temporal aspects and assess the importance of some exogenous socioeconomic variables and the presence of the main Biomphalaria species. Considering that, when working with incident cases, a discrete count variable requires an appropriate modeling, the GAMLSS modeling was chosen since it jointly considers a more appropriate distribution for the response variable due to zero inflation and spatial heteroscedasticity. Several municipalities presented high incidence values from 2010 to 2012, and a downward trend was observed until 2020. We also noticed that the distribution of incidence behaves differently in space and time. Municipalities with dams presented risk 2.25 times higher than municipalities without dams. The presence of B. glabrata was associated with the risk of schistosomiasis. On the other hand, the presence of B. straminea represented a lower risk of the disease. Thus, the control and monitoring of B. glabrata snails is essential to control and eliminate schistosomiasis; and the GAMLSS model was effective in the treatment and modeling of spatio-temporal data.

Abstract: In Brazil, millions of people live in areas with risk of schistosomiasis, a neglected chronic disease with high morbidity. The Schistosoma mansoni helminth is present in all macroregions of Brazil, including the State of Minas Gerais, one of the most endemic states. For this reason, the identification of potential foci is essential to support educational and prophylactic public policies to control this disease. This study aims to model schistosomiasis data based on spatial and temporal aspects and assess the importance of some exogenous socioeconomic variables and the presence of the main Biomphalaria species. Considering that, when working with incident cases, a discrete count variable requires an appropriate modeling, the GAMLSS modeling was chosen since it jointly considers a more appropriate distribution for the response variable due to zero inflation and spatial heteroscedasticity. Several municipalities presented high incidence values from 2010 to 2012, and a downward trend was observed until 2020. We also noticed that the distribution of incidence behaves differently in space and time. Municipalities with dams presented risk 2.25 times higher than municipalities without dams. The presence of B. glabrata was associated with the risk of schistosomiasis. On the other hand, the presence of B. straminea represented a lower risk of the disease. Thus, the control and monitoring of B. glabrata snails is essential to control and eliminate schistosomiasis; and the GAMLSS model was effective in the treatment and modeling of spatio-temporal data.

Resumen: En Brasil, millones de personas viven en áreas de riesgo de esquistosomiasis, una enfermedad crónica desatendida y con alta morbilidad. El helminto Schistosoma mansoni está presente en todas las macrorregiones, incluido el Estado de Minas Gerais, uno de los más endémicos del país. Por ello, la identificación de potenciales brotes es fundamental para promover políticas públicas de carácter educativo y profiláctico en el control de este desenlace. En este contexto, el objetivo de este trabajo es modelar datos sobre esquistosomiasis con respecto a aspectos espaciotemporales, además de evaluar la importancia de algunas variables socioeconómicas exógenas y la presencia de las principales especies de Biomphalaria. Dado que en el trabajo con casos incidentes una variable de conteo discreta requiere un adecuado modelado, se eligió el modelo GAMLSS, ya que en conjunto considera una distribución más adecuada para la variable de respuesta debido a la inflación de ceros y la heterocedasticidad espacial. Se encontraron valores de alta incidencia en varios municipios en el periodo evaluado de 2010 a 2012 y una tendencia a descenso hasta 2020. También se verificó que existe una distribución de incidencia de manera diferente en el espacio y el tiempo. Los municipios con represas presentaban 2,25 veces más riesgo que los que no las tenían. La presencia de B. glabrata estuvo relacionada con el riesgo de la enfermedad. Por otro lado, la presencia de B. straminea ocasionaba un menor riesgo de padecer la enfermedad. Se concluye que el control y seguimiento de caracoles B. glabrata puede ser fundamental para el control y eliminación de la esquistosomiasis y que el modelo GAMLSS resultó ser efectivo para el tratamiento y modelado de datos espaciotemporales.

Resumo: No Brasil, milhões de pessoas vivem em áreas de risco para a esquistossomose, uma doença negligenciada, de caráter crônico e com elevada morbidade. O helminto Schistosoma mansoni está presente em todas as macrorregiões, incluindo o Estado de Minas Gerais, um dos mais endêmicos. Por essa razão, a identificação de potenciais focos é fundamental para subsidiar políticas públicas de cunho educativo e profilático no controle desse desfecho. Nesse contexto, o objetivo do trabalho consiste em modelar dados de esquistossomose em relação aos aspectos espaciais e temporais, além de avaliar a importância de algumas variáveis exógenas socioeconômicas e a presença das principais espécies de Biomphalaria. Como trabalhar com casos incidentes, uma variável discreta de contagem, exige uma modelagem apropriada, foi escolhida a modelagem GAMLSS por considerar conjuntamente uma distribuição mais adequada à variável resposta devido à inflação de zeros e à heterocedasticidade espacial. Verificaram-se valores elevados de incidência em diversos municípios de 2010 a 2012 e uma tendência de queda até 2020. Também foi identificado que a distribuição da incidência se comporta de maneira diferente no espaço e no tempo. Municípios com barragem apresentaram risco 2,25 vezes maior do que os que não a continham. A presença de B. glabrata foi relacionada ao risco de ocorrência da doença. Por outro lado, a presença de B. straminea refletiu em menor risco de ocorrência da esquistossomose. Conclui-se que o controle e o acompanhamento dos caramujos da B. glabrata podem ser fundamentais para a contenção e a eliminação da esquistossomose e o modelo GAMLSS foi eficaz para tratamento e modelagem de dados espaçotemporais.

Abstract: A germination test is required by Brazilian standards for seed commercialization. The use of an adequate methodology that expresses the real physiological quality of seeds and minimizes possible phytotoxicity by chemicals is important for the production chain. In this context, the aim was to evaluate and validate the paper roll plus vermiculite (PR+V) germination test methodology for use in corn seeds. Two hybrids, one sensitive and the other tolerant to seed treatment, both with different vigor levels and under different chemical treatments, were used. Ten laboratories accredited by the Ministério da Agricultura e Pecuária (MAPA) were selected to perform and evaluate the PR+V germination tests. The data were subjected to statistical procedures to estimate the repeatability and reproducibility and check the accuracy and robustness of the test. The data were accurate, robust, and precise within the critical limits of 1 and 5%. The statistical results for repeatability, reproducibility, and bounds of the Mandel test were also accurate and precise at the critical limits of 1 and 5% for the normal seedlings evaluated by the PR+V methodology. Thus, the methodology can be used routinely to test corn seeds, especially those treated with phytosanitary products.

Resumo: O teste de germinação é exigido pelas normas brasileiras para a comercialização de sementes. O uso de metodologia adequada, que expresse a real qualidade fisiológica das sementes e minimize possível fitotoxidez por produtos químicos é importante para a cadeia produtiva. Nesse contexto, objetivou-se avaliar e validar a metodologia de germinação rolo de papel mais vermiculita (RP+V) para uso em sementes de milho. Utilizou-se dois híbridos, sendo um sensível e outro tolerante ao tratamento de sementes, ambos com diferentes níveis de vigor e tratamentos químicos. Dez laboratórios credenciados pelo Ministério da Agricultura e Pecuária (MAPA) foram selecionados para realização e avaliação do teste de germinação RP+V. Os dados foram submetidos a procedimentos estatísticos para estimar a repetibilidade e a reprodutibilidade e verificar a precisão e robustez do teste. Os dados apresentaram acurácia, robustez e precisão dentro dos limites críticos de 1 e 5%. Os resultados estatísticos para repetibilidade, reprodutibilidade e padrões do teste de Mandel apresentaram exatidão e precisão que estão dentro dos limites críticos de 1 e 5% para plântulas normais avaliadas pela metodologia rolo de papel mais vermiculita. Assim, a metodologia pode ser usada rotineiramente para testar sementes de milho, principalmente para aquelas tratadas com produtos fitossanitários.

Abstract: Bone quality is an important issue in dentistry. Low bone density may be associated with more severe periodontitis, and may influence implant therapy success. Recent evidence suggests that physical activity can improve alveolar bone quality. Irisin is an exercise-mediated peptide that might be involved in this process. We assessed the effect of exercise and that of intra-peritoneal irisin administration on bone quality in healthy and osteoporosis-induced rodents. This study was registered at PROSPERO (CRD42020184140), and followed PRISMA guidelines. A search by two independent examiners was conducted in five databases and gray literature up to July 2021, without restrictions regarding language or date of publication. Initially, they analyzed retrieved titles and abstracts (n=3,844) based on eligibility criteria. Of this total, 19 studies remained for full-text reading, and 16 proceeded to the data extraction and quality assessment phases. Meta-analyses were conducted (n= 6 studies) to establish the effects of irisin administration on cancellous bone mineral density (BMD). Exercise or irisin administration enhanced bone quality, but the meta-analysis showed that BMD increased only slightly in osteoporotic rodents (BMD: mean difference 0.03 mg/cm3 - 95% CI 0.01-0.05). This indicates that they had no significant benefits on the bones of healthy animals. Implications of key findings evidence the potential of irisin as an agent able to mitigate bone loss caused by osteoporosis, an outcome that could favor dental rehabilitation. More studies investigating the effect of irisin on alveolar bone are needed to elucidate its therapeutic viability and implications.

Resumo: O objetivo deste trabalho foi comparar o modelo comitê de redes neurais e o modelo de regressão linear múltipla ponderada (RLMP), para estimar a energia metabolizável aparente corrigida por nitrogênio (EMAn) de alimentos para aves. A equação de predição foi ajustada por RLMP e pelo princípio da meta-análise. Os modelos foram comparados tendo-se considerando as percentagens de acerto de predição, com base em intervalos de predição clássicos e intervalos de credibilidade da máxima densidade de probabilidade, e utilizado um teste para comparação de proporções. A acurácia dos modelos foi avaliada com base nos valores de erro médio quadrático, coeficiente de determinação, desvio médio absoluto, erro percentual absoluto médio e viés. Dados provenientes de ensaios metabólicos foram utilizados na comparação dos modelos selecionados. O comitê de redes neurais é o modelo que forneceu predições mais acuradas, sendo recomendado como o de maior acurácia, para prever os valores de EMAn de alimentos concentrados utilizados na indústria alimentícia para aves.

Abstract: The objective of this work was to compare the committee neural network (CNN) and weighted multiple linear regression (WMLR) models, in order to estimate the nitrogen-corrected apparent metabolizable energy (AMEn) of poultry feedstuffs. The prediction equation was adjusted by using a WMLR model and the meta-analysis principle. The models were compared by considering the correct prediction percentages, based on the classic prediction intervals and on the highest-probability density intervals, and by using a comparison test for proportions. The accuracy of the models was evaluated based on the values of the mean squared error, coefficient of determination, mean absolute deviation, mean absolute percentage error, and bias. Data from metabolic trials were used to compare the selected models. The committee neural network is the model that showed the highest accuracy of prediction, being recommended as the most accurate model to predict AMEn values for energetic concentrate feedstuffs used by the poultry feed industry.

ABSTRACT The objective of this study was to evaluate the effect of replacing ground corn (402 g kg−1 of dry matter) with rehydrated corn grain silage (RCGS; 425 g kg−1 of dry matter) in a flushing diet on follicular development in tropical Santa Inês ewes. Fifteen ewes were randomly assigned to one of two treatment groups: a diet with ground corn (control, n = 7) or a diet with RCGS (n = 8). The first day of the diets was designated d0, and the diets were fed for 30 days, up to two days after the end of the estrus synchronization protocol. The estrus synchronization protocol (intravaginal progestogen sponge for 11 days plus 300 IU eCG and 37.5 µg d-cloprostenol IM two days before sponge removal) started on d17 of the diets. The number and diameters of ovarian follicles ≥3 mm were assessed by ultrasound on the day before the diets were provided (d−1), on d14, and then daily from two days before sponge removal until ovulation or up to the eighth day after sponge removal. Blood samples were collected on days −1, 0, 6, 12, 18, 24, and 30 for glucose and urea analyses. There was no effect of the treatments on dry matter intake, plasma glucose, and urea nitrogen concentrations, or on the percentage of ewes that ovulated and on the number of ovulations. The number of follicles ≥3 mm did not differ between treatment groups; the number increased between d−1 and d14 and did not differ between d14 and d28. The diameter of ovulatory follicles at sponge removal, the interval from sponge removal to estrus, and the growth rate of the ovulatory follicles were greater in the RCGS group than in the control group, resulting in larger follicles at ovulation. Replacement of ground corn by RCGS in the flushing diet does not increase the number of ovulations but results in delayed onset of estrus and ovulation of larger follicles.

ABSTRACT This study aimed to evaluate the determinant profitability indexes of typical dairy farms located in Brazil. The empirical sample included detailed technical and financial information of 61 Brazilian dairy farms across a longitudinal data set (10 years). Numerous technical and economic indexes were estimated, and Pearson’s correlation coefficients were calculated to determine the relationship between each index and profitability. After selecting the significant indexes, regression equations were generated to determine the relationship between each index and profitability. The results of the analysis revealed significant interactions between different combinations of technical and financial indexes. Milk production per lactating cow and area were the indexes most positively correlated with profitability. In contrast, total unit cost in relation to the price of milk, total operating cost in relation to total revenues, and total unit operating cost in relation to the price of milk were the indexes most negatively correlated with profitability. Overall, these results indicate that profits could significantly increase if dairy farm production is conducted with more intensive use of inputs and production factors and better combinations of inputs and outputs.

Resumen El desempeño de pollos de engorde sometidos a estrés térmico en las primeras semanas de vida puede ser perjudicado, una vez que el sistema termorregulador del ave no está completamente desarrollado. El objetivo de este trabajo fue analizar los efectos de diferentes desafíos térmicos sobre el desempeño de pollos de engorde. Doscientos cuarenta pollos de engorde fueron sometidos a diferentes temperaturas de bulbo seco del aire deseada (tbs: 24, 27, 30 y 33°C) y a duraciones de estrés (DE: 1, 2, 3 y 4 días) en la segunda semana de vida. El consumo de ración (CR), ganancias de peso (GP) y conversión alimenticia (CA) fueron evaluadas a los 21 días de edad de las aves. A pesar de que las diferencias fueron verificadas para CR (p<0,05), ninguna diferencia fue observada para GP (p>0,05). Reducciones de CA para las tbs de 24, 27 y 33°C fueron de 14,8, 8,6, y 10,1%, respectivamente. El CA más pequeño se observó a 30°C, lo cual se caracterizó como condición de confort.

Abstract The performance of broilers submitted to thermal discomfort in the first weeks of life may be impaired, since the thermoregulatory system of the bird is not fully developed. The objective of this study was to analyze the effects of different thermal challenges on the performance of broilers. Two hundred and forty broilers were submitted to different desired dry-bulb temperatures (tdb: 24, 27, 30 and 33°C) and stress duration (SD: 1, 2, 3 and 4 days) in the second week of life. Feed intake (FI), weight gain (WG) and feed conversion (FC) were evaluated at 21 days of age. Although differences were verified for FI (p <0.05), none were observed for WG (p> 0.05). Reductions of FC for the 24, 27 and 33°C tdb were 14.8, 8.6 and 10.1%, respectively. The smallest FC was observed at 30°C, indicating comfort condition.

Resumo Na Fazenda Experimental da Universidade Federal de Lavras (FE-UFLA), Minas Gerais, Brasil, no dia do nascimento, bezerras da raça holandesa foram sorteadas de forma aleatória para compor um dos dois grupos, formados por 15 animais cada: Tratamento Estratégico-Seletivo (TE-S) ou Tratamento Convencional (TC). No TE-S, as bezerras foram tratadas após exames coproparasitológicos de acordo com critérios previamente estabelecidos pelos pesquisadores. No TC, as bezerras foram tratadas conforme orientação do veterinário da FE-UFLA. Em ambos grupos, as bezerras foram monitoradas a cada 14 dias, do nascimento até os 12 meses de idade, por meio de exames coproparasitológicos. Para análise estatística, considerou-se a frequência (%) de amostras fecais com contagem de ovos por grama de fezes (OPG) ≥300, contagem de oocistos por grama de fezes (OoPG) ≥500, e amostras fecais com contagem de cistos de Giardia spp. ≥1. A frequência média global de amostras fecais com contagem de OPG ≥300, OoPG ≥500 e cistos de Giardia spp. ≥1, respectivamente, foi similar (p >0,05) entre TE-S (20,3%; 17,3%; e 31,5%) e TC (26,4%; 23,9%; e 37,3%). O custo operacional efetivo, por animal, em 12 meses, foi R$ 784,58 (US$ 241.40) e R$ 83,90 (US$ 25.81) para TE-S e TC, respectivamente. O TE-S necessita de ajustes para que possa ser indicado como uma alternativa, tecnicamente eficiente e economicamente viável, no controle das parasitoses gastrointestinais em bezerras leiteiras.

Abstract In the Experimental Farm of the Universidade Federal de Lavras (EF-UFLA), state of Minas Gerais, Brazil, on their day of birth, female Holstein calves were randomly selected and placed into two groups containing fifteen animals each: Strategic-Selective Treatment (S-ST) or Conventional Treatment (CT). In the S-ST, calves were treated after coproparasitological examinations according to criteria established previously by the researchers. Calves in the CT were treated according to the opinion of the veterinarian of EF-UFLA. For statistical analysis, the frequency (%) of fecal samples with count of eggs per gram of feces (EPG) ≥300, count of oocysts per gram of feces (OoPG) ≥500 and fecal samples with count of cysts of Giardia spp. ≥1 were conducted. The overall average frequency of fecal samples with EPG ≥300, OoPG ≥500 and Giardia spp. cysts ≥1, respectively, was similar (p >0.05) between S-ST (20.3%; 17.3%; and 31.5%) and CT (26.4%; 23.9%; and 37.3%). The effective operational cost, per animal, in 12 months, was of R$ 784.58 (US$ 241.41) and R$ 83.90 (US$ 25.81) in S-ST and CT, respectively. The S-ST requires adjustments to be used as a technically efficient and economically viable alternative for the control of gastrointestinal parasitosis in female Holstein calves.

Resumo: O objetivo deste trabalho foi avaliar o efeito do estresse térmico em diferentes intensidades e durações sobre as respostas produtivas de frangos de corte de 3 a 21 dias de idade. Duzentos e dez pintinhos Cobb foram submetidos às temperaturas do bulbo seco (tbs) de 27, 30, 33 ou 36°C durante 0, 1, 2, 3 ou 4 dias, a partir do segundo dia de vida. O experimento foi conduzido em quatro túneis de vento climatizados idênticos. Dados de massa corporal (MC), consumo de ração (CR) e consumo de água (CAg), todos em gramas, foram coletados diariamente; e ganho de massa corporal (GMC), em gramas, e conversão alimentar (CA) também foram calculados. O efeito da duração não foi estatisticamente significativo. Modelos empíricos foram ajustados para estimar MC, CR e CAg em função da tbs e da idade das aves. O desempenho dos pintinhos aos 21 dias de idade foi analisado a partir dos valores de MC, CR, CAg, GMC e CA. Em geral, o desenvolvimento de pintinhos a 33 e 36°C foi melhor que o dos submetidos às menores tbs, de 30 e 27°C. A exposição de pintos de corte ao frio nos primeiros dias de vida pode causar efeito residual em suas respostas produtivas até 21 dias de idade.

Abstract: The objective of this work was to evaluate the effect of thermal challenge at different intensities and durations on the production responses of 3 to 21-day-old broiler chickens. Two hundred and ten Cobb chicks were subjected to dry-bulb temperatures (tdb) of 27, 30, 33, or 36°C for the duration of 0, 1, 2, 3, or 4 days from the second day of life onwards. The experiment was carried out in four identical environmentally-controlled wind tunnels. Data on body mass (BM), feed intake (FI), and water intake (WI), all in grams, were monitored daily; and body weight gain (BWG), in grams, and feed conversion (FC) were also calculated. The effect of duration was not statistically significant. Empirical models were adjusted to relate BM, FI, and WI with tdb and bird age. The performance of chicks at 21 days of age was analyzed using the BM, FI, WI, BWG, and FC values. Overall, the development of chicks at 33 and 36°C was better than that of those subjected to the lower tdb of 30 and 27°C. The exposure of chicks to cold thermal challenge in early life can have a carry-over negative effect on their production performance up to 21 days of age.

ABSTRACT The objective of this study was to examine the effects of suckling schemes (continued, controlled, and total separation) and the type of pregnancy on performance and serum cortisol concentration in lambs. A total of 29 Santa Inês ewes and 40 lambs were used, and the randomized block design was applied in a split-plot scheme with a 3 × 2 factorial arrangement in the plot and time in the subplot. For controlled suckling, the diet was supplied twice daily during one hour, starting on their 10th day of life. Total and average daily intakes of concentrate dry matter of lambs that underwent total separation was higher than those of lambs under continued suckling. Lambs subjected to total separation demonstrated higher concentrate dry matter intake/weight gain ratio, lower total weight gain, lower average daily weight gain, and lower weaning weight than those subjected to continued and controlled suckling. Lambs from single pregnancy demonstrated higher weight gain and obtained higher weight at weaning. Lambs subjected to total separation have a developmental delay. However, the lower performance of lambs subject to total separation cannot be attributed to stress because there is a decrease in the serum cortisol concentration over time.

This study aimed at evaluating the effect of ractopamine (RAC) on metabolism, zootechnical performance, body composition, and behavior in Wistar rats submitted to acute and chronic restrain stress. The oral dose of 5 mg/kg of RAC was administered in periods of 0, 7, 14, 21, and 28 days. The elevated plus-maze test (EPMT) was used for behavioral assessment. Blood, carcass and viscera characteristics were evaluated. Insulin-dependent glucose transporters (GLUT-4) were semi-quantified by Western Blot in epididymal adipocytes. RAC periods associated with chronic stress increased the GLUT-4 protein expression in adipose tissue in a time-dependent manner (P=0.01), i.e., the longer the RAC addition period, the higher the GLUT-4 concentration in chronically stressed animals (0=1.42; 7=1.19; 14=2.03; 21=1.59; 28=2.35). The stress periods combined with RAC increased the time spent in the opened arms of the maze (Chronic stress: 0=10.6; 7=8.7; 14=5.9; 21=12.3; 28=4.0; Acute stress 0=3.1; 7= 4.7; 14=7.5; 21=0.0; 28=2.8) (P=0.04). Chronic (entries on the closed arms [ECA]=3.60) and acute (ECA=3.80) stress reduced locomotive activity in the maze (P=0.03). The results suggested that stress could negatively affect the possible benefits offered by the RAC, mainly impairing the adipose tissue metabolism and behavior in the animals.

A utilização de antimicrobianos melhoradores de desempenho na criação de frangos de corte é uma prática comum na indústria avícola e, no Brasil, seu uso deve ser feito de acordo com os limites determinados pelo Ministério da Agricultura Pecuária e Abastecimento (MAPA).Objetivou-se com o presente trabalho determinar o efeito da utilização da bacitracina de zinco, dentro dos níveis recomendados pelo Ministério da Agricultura Pecuária e Abastecimento (MAPA), em dietas para frangos de corte sobre o desempenho de aves e criadas de 1 a 42 dias de idade. Utilizou-se o delineamento inteiramente casualizado, com 5 tratamentos, distribuídos em 10 repetições de 25 pintos machos de corte da linhagem Cobb 500®, totalizando 1250 aves. Os tratamentos experimentais foram constituídos de cinco níveis de inclusão de bacitracina de zinco (0, 10, 25, 40 e 55ppm). As variáveis analisadas foram consumo de ração, ganho de peso, conversão alimentar e avaliação econômica das dietas. Para o período total de criação, avaliou-se também a viabilidade dos frangos de corte. A bacitracina de zinco foi eficiente como beneficiador do desempenho de frangos de corte criados no período de 1 a 21, 1 a 35 e 1 a 42 dias. Para o período de 1 a 21 dias, o uso de 55 e 29,3ppm de bacitracina de zinco resultou em menor consumo de ração e maior ganho de peso, respectivamente. No geral, a melhor conversão alimentar foi obtida quando se adicionou 55ppm de bacitracina de zinco na ração de frangos de corte.

The use of growth promoters in the broilers production is a common practice in the poultry industry and its use must be made accordance with limits in Brazil set by the Ministry of Agriculture, Livestock and Supply (MAPA).The main objective of this study was to verify the effect of the use of zinc bacitracin, within the levels recommended by the Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA), in broiler diets for the performance of birds from 1 to 42 days old. We used a randomized design with five treatments in 10 replications of 25 male chicks from Cobb cut 500®, totaling 1250 birds. The treatments consisted of five inclusion levels of zinc bacitracin (0, 10, 25, 40 and 55ppm). The variables studied were feed intake, weight gain, feed conversion and economic evaluation of feed. For the breeding period as a whole, this study also evaluated the viability of broilers. Zinc bacitracin was effective as growth promoter of broilers reared during 1 to 21, 1 to 35 and 1 to 42 days. For the period 1-21 days, using 55 and 29.3ppm of zinc bacitracin resulted in a lower feed intake and increased weight gain, respectively. In general, the best feed conversion was obtained when 55ppm of zinc bacitracin was added to the feed of broilers.

The objective of this study was to evaluate the morphometric growth and weight gain of strains of tilapia (Thai, Red, UFLA and Commercial) by nonlinear models. Initially, 500 male fingerlings of each strain, at 85 (Red and UFLA) and 86 (Thai and Commercial) days of age, were stocked separately in raceways with 56 m³. Twenty fish of each strain were randomly sampled, weighed and measured monthly. Five nonlinear models (Brody, von Bertalanffy, Gompertz, logistic and exponential) were tested, choosing one that best fit to the data. The variables studied were: weight, standard length (SL), head length (HL), height 1 (H1), height 2 (H2), height 3 (H3), first distance (D1), second distance (D2), first width (W1), second width (W2) and third width (W3). The exponential model had the best fit to weight and morphometric data, with the exception of W2, in which the best fitted model was von Bertalanffy. The convergence of the exponential model to data indicates that the cultivation period studied was not enough for the strains to reach maturity weight. The UFLA strain presented the lowest value for parameter "a" (initial weight estimate), 8.71 g, and the highest for parameter k (specific growth rate), 0.0127, when compared with other evaluated strains. However, the highest k of UFLA was not enough to overcome the final weight observed for the Commercial strain (603.1 g), which was higher than all other strains. Regarding the morphometric measurements, the UFLA strain also had the highest k for the variables SL, HL, HH, H1, H2, H3 and D2, and similar k to Commercial and Thai strains for the variables D1 and W3 respectively. The strains differ as to weight gain and morphometric growth.

Neste estudo, foi proposta a utilização da análise de componentes principais, na formação de grupos homogêneos de artigos científicos, a serem considerados em uma meta-análise. Nessa meta-análise, foram utilizados resultados referentes à composição química e energia metabolizável aparente corrigida pelo balanço de nitrogênio (EMAn) de alimentos para aves, na obtenção de equações de predição da EMAn. Foram considerados 293 experimentos com resultados já publicados. Dados provenientes de ensaios metabólicos foram utilizados na validação das equações de predição obtidas, sendo que estas apresentaram resultados semelhantes às disponíveis na literatura. No procedimento de meta-análise, a formação de grupos homogêneos de resultados experimentais, que é uma das maiores dificuldades, foi facilitada com a utilização de componentes principais, uma vez que não houve a necessidade de determinar variáveis ou fatores a serem considerados nessa classificação. Assim, tem-se uma forma rápida e eficiente de definir tais grupos.

The purpose of this study was to develop a meta-analysis study by using the principal components analysis to obtain homogeneous groups of experimental results. In the process of the meta-analysis, it was considered data from 293 experiments carried out in Brazil. Prediction equations were obtained to estimate the nitrogen-corrected apparent metabolizable energy (AMEn) of poultry feedstuffs. Data from metabolic trials were used to validate the prediction equations obtained, which were similar than other available equations in the literature. One of the problems in meta-analysis is the determination of the homogeneous groups of experiments and, this problem was eliminated by using principal components, since there was no need to establish variables or factors to be considered in this classification.