Performance of chicks subjected to thermal challenge

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

Desempenho de pintinhos submetidos a estresse térmico

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.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

Methodology to determine the soil sampling grid for precision agriculture in a coffee field

The objective of this study was to develop and propose a methodology to evaluate the quality of different sampling grids. In addition, it allows us to choose the sampling grid that better suits one or a set of variables. The structure and magnitude of the spatial dependence were characterized by semivariogram. It allowed us to apply validation techniques that worked as a base to create an index to evaluate the grid quality and to develop an indicator that points out the best sampling grid. To test the proposed methodology, an experiment was performed at the Brejão farm, in Brazil. We have developed and compared twenty sampling grids, which were applied to four soil variables sampled in georeferenced locations. An accuracy index (AI), a precision index (PI) and the optimum grid indicator (OGI) were developed and proposed, which allowed us to choose the best grid among the sampling grids.El objetivo de este estudio fue desarrollar y proponer una metodología para evaluar la calidad de las diferentes cuadrículas de muestreo. Además, es posible elegir la cuadricula de muestreo que mejor se adapte a una o un conjunto de variables. La estructura y la magnitud de la dependencia espacial fueron caracterizadas por semivariograma. Esto nos permitió utilizar las técnicas de validación que funcionaron como base para crear una clasificación para evaluar la calidad de la cuadricula y para desarrollar un indicador que apunta la mejor cuadricula de muestreo. Un experimento fue realizado en la hacienda Brejão en Brasil, para probar la metodología propuesta. Hemos desarrollado y comparado veinte muestras que fueran aplicadas en cuatro variables de suelo muestreados en los puntos georeferenciados. Un índice de exactitude (AI), un índice de precisión (PI) y el indicador de cuadricula óptima (OGI), fueron desarrollados y propuestos lo que nos permitió elegir la mejor muestra cuadricula de muestreo (cuadricula 5) entre las cuadrículas de muestreo

Blocos de solo-cimento: uma alternativa sustentável para o reaproveitamento de resíduos sólidos industriais

Objetivou-se, com o presente estudo, analisar potenciais resíduos sólidos industriais que possam ser adicionados a blocos de solo-cimento. Foi realizada uma revisão bibliográfica narrativa por meio da base acadêmica Scopus, utilizando-se como critérios de busca palavras-chave ligadas ao tema, como: solo-cimento, materiais de construção, blocos de solo-cimento, tijolos solocimento, propriedades físicas e mecânicas, resíduos sólidos, análise de ciclo de vida e construção civil. Observou-se a versatilidade de resíduos sólidos industriais que podem ser incorporados em blocos de solo-cimento, como resíduos de rochas ornamentais, lodo de estações de tratamento de água, serragem de madeira, fibras de politereftalato de etileno, fibras vegetais de bucha, fibras de cânhamo, cascas de arroz, capim braquiária, cascas de ovos aviários, bagaço de cana-de-açúcar, palha de trigo e cevada, escória de soldagem, areia de fundição, rejeitos de mineração de quartzito, de construção e demolição, tornearia mecânica, grãos de indústria de celulose e coprodutos siderúrgicos. Entre os resíduos incorporados que contribuíram para a melhoria nas propriedades físicas e mecânicas dos blocos de solo-cimento estiveram: grãos da indústria de celulose, casca de arroz, capim braquiária, subprodutos siderúrgicos com blocos de solo-cimento granulado e escória de alto forno. Os resíduos sem resultados satisfatórios foram lodo de estação de tratamento de água, bagaço de cana-de-açúcar e bucha vegetal. Por meio desta pesquisa foi possível verificar que o comportamento dos blocos de solo-cimento é influenciado por diversos fatores em sua fabricação, principalmente no que diz respeito ao tipo e ao percentual de resíduos incorporados. Entretanto, é importante a preocupação com a sua aplicação de modo a não potencializar os impactos ambientais em longo prazo.This study aimed to analyze potential industrial solid waste that can be added to soil-cement blocks. A narrative literature review was conducted in the Scopus academic database, using as the search criteria keywords related to the topic, such as soil-cement, building materials, soil-cement blocks, soil-cement bricks, physical and mechanical properties, solid waste, life cycle analysis, and civil construction. A variety of industrial solid waste that can be incorporated into soil-cement blocks was observed, such as waste rock, sludge from water treatment plants, wood sawdust, polyethylene terephthalate fibers (PET), vegetable fibers from loofah, hemp fibers, rice husks, brachiaria grass, poultry eggshells, sugar cane bagasse, wheat and barley straw, welding slag, foundry sand, waste from quartzite mining, construction, and demolition, mechanical turning, pulp industry grains, and steel mill co-products. Among the investigated wastes, those that improved the physical and mechanical properties of the soil-cement blocks were grains from the cellulose industry, rice husks, Brachiaria grass, steel by-products with granulated soil-cement blocks and blast furnace slag. The waste that produced no satisfactory results was sludge from a water treatment plant, sugarcane bagasse, and vegetable loofah. Through this research, it was possible to verify that the behavior of soil-cement blocks is influenced by several factors in their manufacture, mainly regarding the type and percentage of incorporated waste. However, it is important to be concerned with its application in waste blocks so as not to increase the environmental impacts in the long term

Predicting chick body mass by artificial intelligence‑based models

The objective of this work was to develop, validate, and compare 190 artificial intelligence‑based models for predicting the body mass of chicks from 2 to 21 days of age subjected to different duration and intensities of thermal challenge. The experiment was conducted inside four climate‑controlled wind tunnels using 210 chicks. A database containing 840 datasets (from 2 to 21‑day‑old chicks) – with the variables dry‑bulb air temperature, duration of thermal stress (days), chick age (days), and the daily body mass of chicks – was used for network training, validation, and tests of models based on artificial neural networks (ANNs) and neuro‑fuzzy networks (NFNs). The ANNs were most accurate in predicting the body mass of chicks from 2 to 21 days of age after they were subjected to the input variables, and they showed an R² of 0.9993 and a standard error of 4.62 g. The ANNs enable the simulation of different scenarios, which can assist in managerial decision‑making, and they can be embedded in the heating control systems.O objetivo deste trabalho foi desenvolver, validar e comparar 190 modelos baseados em inteligência artificial, para predizer a massa corporal de pintinhos de 2 a 21 dias de vida, submetidos a diferentes períodos e intensidades de estresse térmico. O experimento foi realizado com 210 pintinhos, em quatro túneis de vento climatizados. Um banco de dados com 840 conjuntos de dados (de aves de 2 a 21 dias) – com as variáveis temperatura de bulbo seco do ar, duração do estresse térmico (dias), idade das aves (dias) e a massa corporal diária dos pintinhos – foi utilizado para treinamento de rede, validação e testes dos modelos baseados em redes neurais artificiais (RNA) e redes “neuro-fuzzy” (RNF). As RNA mostraram-se mais precisas para se predizer a massa corporal de pintinhos de 2 a 21 dias de idade, submetidos às variáveis de entrada, e apresentaram R² de 0,9993 e erro‑padrão de 4,62 g. As RNA propiciam a simulação de diversos cenários, que podem auxiliar na tomada de decisões em relação ao manejo, e podem ser incorporadas nos sistemas de controle de aquecimento

Evaluation of the physical properties of bedding materials for dairy cattle using fuzzy clustering analysis

The bedding materials used in dairy cow housing systems are extremely important for animal welfare and performance. A wide range of materials can be used as bedding for dairy cattle, but their physical properties must be analysed to evaluate their potential. In the present study, the physical properties of various bedding materials for dairy cattle were investigated, and different fuzzy clustering algorithms were employed to cluster these materials based on their physical properties. A total of 51 different bedding materials from various places in Europe were collected and tested. Physical analyses were carried out for the following parameters: bulk density (BD), water holding capacity (WHC), air-filled porosity (AFP), global density (GD), container capacity (CC), total effective porosity (TEP), saturated humidity (SH), humidity (H), and average particle size (APS). These data were analysed by principal components analysis (PCA) to reduce the amount of data and, subsequently, by fuzzy clustering analysis. Three clustering algorithms were tested: k-means (KM), fuzzy c-means (FCM) and Gustafson–Kessel (GK) algorithms. Furthermore, different numbers of clusters (2−8) were evaluated and subsequently compared using five validation indexes. The GK clustering algorithm with eight clusters fit better regarding the division of materials according to their properties. From this clustering analysis, it was possible to understand how the physical properties of the bedding materials may influence their behaviour. Among the materials that fit better as bedding materials for dairy cows, Posidonia oceanica (Cluster 6) can be considered an alternative material

Redes neuronales artificiales para la predicción de la masa corporal de pollos

The thermal environment inside a broiler house has a great influence on animal welfare and productivity during the production phase. Thus, the aim of this study was to predict body mass of chicks from 2 to 21 days of age when subjected to different intensities (27, 30, 33 and 36°C) and duration (1, 2, 3 and 4 days starting on the second day of life) using artificial neural networks (ANN). This experiment was conducted at Lavras, MG, Brazil. It was used 210 chicks of both sexes, from 1st to 22nd days of life. The chicks were raised inside four climate-controlled wind tunnels. Daily the weight of all the chicks was measured to know the daily body masses. The input variables were dry-bulb air temperature, duration of thermal stress, chick age, and the output variable was the daily body mass of chicks. A database containing 840 records was used to train (70% of data), validate (15%) and test (15%) of models based on artificial neural networks (ANN). Between these models, the ANN was accurate in predicting the BM of chicks from 2 to 21 days of age after they were subjected to the input variables, and it had an R² of 0.9992 and a standard error of 5,23 g. This model enables the simulation of different scenarios that can assist in managerial decision-making, and it can be embedded in the heating controlsDentro de un galpón avícola el ambiente térmico ejerce una gran influencia en el bienestar y la productividad de los animales. De esta manera, el propósito de este trabajo fue predecir la masa corporal de polluelos de 2 a 21 días de vida, sujetos a condiciones de confort y estrés calórico en diferentes intensidades (27; 30; 33 y 36 °C) y períodos de duración (1; 2; 3 y 4 días a partir del 2º día de vida) a través de redes neuronales artificiales (RNA). El experimento se llevó a cabo en Lavras, MG, Brasil. 210 pollitos de ambos sexos se utilizaron del 1 al 22 día de vida alojados en cuatro túneles de viento climatizados. Todos los días, todos los polluelos fueron pesados para acompañar su masa corporal. Las variables de entrada fueron: temperatura de bulbo seco del aire, duración del estrés térmico, edad de las aves y como variable de salida, la masa corporal diaria de los pollitos. Se obtuvo una base de datos de 840 observaciones, siendo 70% utilizado para el entrenamiento de la red, un 15% para la validación y un 15% para pruebas de modelos basados en RNA. Se demostró que las RNAs eran precisas para predecir la masa corporal de los pollitos sometidos a diferentes intensidades y duraciones de condiciones térmicas presentando un R² de 0,9992 y error estándar de 5,23 G. Además, las RNAs propiciaron la simulación de varios escenarios, que pueden ayudar en la toma de decisiones con relación a la gestión, y pueden ser incorporados a los sistemas de control de calefacció

Performance of chicks subjected to thermal challenge

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.This article is published as Ferraz, Patrícia Ferreira Ponciano, Tadayuki Yanagi Junior, Renato Ribeiro de Lima, and Hongwei Xin. "Performance of chicks subjected to thermal challenge." Pesquisa Agropecuária Brasileira 52, no. 2 (2017): 113-120. Posted with permission.</p

Agricultural Residues of Lignocellulosic Materials in Cement Composites

Lignocellulosic material residues in cement composites are a favourable option for new fibre cement formulations in building materials, because they combine good mechanical properties with low density. This study aimed to evaluate the chemical, physical, anatomical, and mechanical properties of five cement panels reinforced with the following lignocellulosic materials: eucalyptus, sugarcane bagasse, coconut shell, coffee husk, and banana pseudostem. Lignocellulosic cement panels were produced with each lignocellulosic material residue, and three replicates of each type of lignocellulosic material were examined (15 panels in total). The lignin, extractives, ash, and holocellulose were examined. After 28 days of composite curing, the following physical properties of the panels were evaluated: density, porosity, water absorption after immersion for 2 and 24 h, and thickness swelling after immersion for 2 and 24 h. Mechanical tests (compression strength, internal bonding, modulus of rupture, and modulus of elasticity) were performed before and after the accelerated ageing test with a universal testing machine. Scanning electron microscopy and supervised image classification were performed to investigate the morphologies of the different materials and the filler/matrix interfaces. Eucalyptus and sugarcane panels had the best results in terms of the evaluated properties and thus, could potentially be used as non-structural walls. However, banana pseudostem, coconut shell, and coffee husk panels had the worst results and therefore, under these conditions, should not be used in building

Effect of the Spatial Distribution of the Temperature and Humidity Index in a New Zealand White Rabbit House on Respiratory Frequency and Ear Surface Temperature

The objective of this study was to characterize and evaluate the temperature and humidity index (THI) of New Zealand white (NZW) rabbits kept in a rabbit house using geostatistical techniques. Furthermore, we sought to evaluate its relationship with respiratory frequency (RF) and ear surface temperature (EST). The experiment was conducted at the Federal University of Lavras, Brazil. A total of 52 NZW rabbits were used. For the characterization of the thermal environment, the dry bulb temperature (tdb, °C), relative humidity (RH, %), and dew point temperature (tdp, °C) were collected at 48 points in the rabbit house at 6:00 a.m., 12:00 p.m., and 6:00 p.m. for seven days. The RF and EST of the animals was monitored. Subsequently, the THI was calculated and the data were analyzed using geostatistical tools and kriging interpolation. In addition, the RF and EST data were superimposed on the rabbit house’s THI data maps. The magnitude of the variability and structure of the THI inside the rabbit house were characterized and the heterogeneity was visualized. Critical THI points inside the rabbit house and in locations where animals with high RF and ESTs were housed were identified, thus providing information about improving the production environment