Efficiency of cooling systems in broiler houses during hot days / Eficiência dos sistemas de resfriamento em aviários durante dias quentes

This study evaluated: (1) the vulnerability of broiler houses with different cooling systems, and (2) the spatial distribution of environmental variables during hot days. Four potentially vulnerable commercial broiler houses in southern Brazil were selected according to the following parameters: absence or presence of different cooling systems, broilers older than 28 days, and outside air dry-bulb temperature over 30°C. Broiler house vulnerability was classified according to the cooling and mechanical ventilation system: cellulose pad cooling (CPC), sprinkling (SPK), fogging (FOG), and mechanical ventilation without evaporative cooling system (VTL). The air dry-bulb temperature (Tdb, °C) and relative humidity (RH, %) were recorded every 10 min. For each broiler house, we evaluated: (1) relative cooling efficiency (RCE) and (2) inside spatial distribution of microclimate variables using a geostatistical technique. The CPC and SPK did not differ (P<0.05) in RCE (81.6% and 80.7%, respectively), but both differed from FOG (23.8%) and VLT (1.87%) systems. The highest variations in indoor Tdb were recorded in the FOG (7 °C), followed by the SPK (4 °C) and CPC (3 °C). In the CPC, there was an increase in RH from the middle to the end of the broiler house near the exhaust fans. In conclusion, the relative cooling efficiency and the inside spatial distributions of environmental variables in the broiler houses were influenced by the existing cooling system.

Os objetivos deste estudo foram (1) comparar a vulnerabilidade de aviários com diferentes sistemas de resfriamento, e (2) avaliar a distribuição espacial interna das variáveis ambientais durante dias quentes. Quatro aviários comerciais potencialmente vulneráveis no sul do Brasil foram selecionados de acordo com os seguintes parâmetros de elegibilidade: ausência ou presença de diferentes sistemas de resfriamento; frangos de corte com mais de 28 dias de idade; e temperatura de bulbo seco do ar externa acima de 30 °C. A vulnerabilidade do aviário foi classificada de acordo com o sistema de resfriamento e ventilação mecânica, sendo: resfriamento por pad cooling (CPC), aspersão (SPK), nebulização (FOG) e ventilação mecânica sem sistema de resfriamento evaporativo (VTL). A temperatura de bulbo seco do ar (Tbs, °C) e a umidade relativa do ar (UR, %) foram coletadas por registradores de dados autônomos a cada 10 min. Para cada aviário foram avaliados: (1) eficiência relativa de resfriamento (RCE) e (2) distribuição espacial interna das variáveis ambientais por técnica de geoestatística. O CPC e SPK não diferiram (P>0,05) na RCE (81,6% e 80,7% respectivamente), mas ambos diferiram do FOG (23,8%) e VLT (1,87%). As maiores variações na Tbs do ar interno foram registradas no FOG (7 °C), seguido pelo SPK (4 °C) e CPC (3 °C). No CPC, houve um aumento da umidade relativa do meio para o final do aviário, próximo aos exaustores. Em conclusão, a eficiência relativa de resfriamento, assim como a distribuição espacial das variáveis ambientais internas foram influenciadas pelo sistema de resfriamento de cada aviário.

Efficiency of cooling systems in broiler houses during hot days / Eficiência dos sistemas de resfriamento em aviários durante dias quentes

ABSTRACT: This study evaluated: (1) the vulnerability of broiler houses with different cooling systems, and (2) the spatial distribution of environmental variables during hot days. Four potentially vulnerable commercial broiler houses in southern Brazil were selected according to the following parameters: absence or presence of different cooling systems, broilers older than 28 days, and outside air dry-bulb temperature over 30°C. Broiler house vulnerability was classified according to the cooling and mechanical ventilation system: cellulose pad cooling (CPC), sprinkling (SPK), fogging (FOG), and mechanical ventilation without evaporative cooling system (VTL). The air dry-bulb temperature (Tdb, °C) and relative humidity (RH, %) were recorded every 10 min. For each broiler house, we evaluated: (1) relative cooling efficiency (RCE) and (2) inside spatial distribution of microclimate variables using a geostatistical technique. The CPC and SPK did not differ (P<0.05) in RCE (81.6% and 80.7%, respectively), but both differed from FOG (23.8%) and VLT (1.87%) systems. The highest variations in indoor Tdb were recorded in the FOG (7 °C), followed by the SPK (4 °C) and CPC (3 °C). In the CPC, there was an increase in RH from the middle to the end of the broiler house near the exhaust fans. In conclusion, the relative cooling efficiency and the inside spatial distributions of environmental variables in the broiler houses were influenced by the existing cooling system.

RESUMO: Os objetivos deste estudo foram (1) comparar a vulnerabilidade de aviários com diferentes sistemas de resfriamento, e (2) avaliar a distribuição espacial interna das variáveis ambientais durante dias quentes. Quatro aviários comerciais potencialmente vulneráveis no sul do Brasil foram selecionados de acordo com os seguintes parâmetros de elegibilidade: ausência ou presença de diferentes sistemas de resfriamento; frangos de corte com mais de 28 dias de idade; e temperatura de bulbo seco do ar externa acima de 30 °C. A vulnerabilidade do aviário foi classificada de acordo com o sistema de resfriamento e ventilação mecânica, sendo: resfriamento por pad cooling (CPC), aspersão (SPK), nebulização (FOG) e ventilação mecânica sem sistema de resfriamento evaporativo (VTL). A temperatura de bulbo seco do ar (Tbs, °C) e a umidade relativa do ar (UR, %) foram coletadas por registradores de dados autônomos a cada 10 min. Para cada aviário foram avaliados: (1) eficiência relativa de resfriamento (RCE) e (2) distribuição espacial interna das variáveis ambientais por técnica de geoestatística. O CPC e SPK não diferiram (P>0,05) na RCE (81,6% e 80,7% respectivamente), mas ambos diferiram do FOG (23,8%) e VLT (1,87%). As maiores variações na Tbs do ar interno foram registradas no FOG (7 °C), seguido pelo SPK (4 °C) e CPC (3 °C). No CPC, houve um aumento da umidade relativa do meio para o final do aviário, próximo aos exaustores. Em conclusão, a eficiência relativa de resfriamento, assim como a distribuição espacial das variáveis ambientais internas foram influenciadas pelo sistema de resfriamento de cada aviário.

Efficiency of cooling systems in broiler houses during hot days / Eficiência dos sistemas de resfriamento em aviários durante dias quentes

This study evaluated: (1) the vulnerability of broiler houses with different cooling systems, and (2) the spatial distribution of environmental variables during hot days. Four potentially vulnerable commercial broiler houses in southern Brazil were selected according to the following parameters: absence or presence of different cooling systems, broilers older than 28 days, and outside air dry-bulb temperature over 30°C. Broiler house vulnerability was classified according to the cooling and mechanical ventilation system: cellulose pad cooling (CPC), sprinkling (SPK), fogging (FOG), and mechanical ventilation without evaporative cooling system (VTL). The air dry-bulb temperature (Tdb, °C) and relative humidity (RH, %) were recorded every 10 min. For each broiler house, we evaluated: (1) relative cooling efficiency (RCE) and (2) inside spatial distribution of microclimate variables using a geostatistical technique. The CPC and SPK did not differ (P<0.05) in RCE (81.6% and 80.7%, respectively), but both differed from FOG (23.8%) and VLT (1.87%) systems. The highest variations in indoor Tdb were recorded in the FOG (7 °C), followed by the SPK (4 °C) and CPC (3 °C). In the CPC, there was an increase in RH from the middle to the end of the broiler house near the exhaust fans. In conclusion, the relative cooling efficiency and the inside spatial distributions of environmental variables in the broiler houses were influenced by the existing cooling system.(AU)

Os objetivos deste estudo foram (1) comparar a vulnerabilidade de aviários com diferentes sistemas de resfriamento, e (2) avaliar a distribuição espacial interna das variáveis ambientais durante dias quentes. Quatro aviários comerciais potencialmente vulneráveis no sul do Brasil foram selecionados de acordo com os seguintes parâmetros de elegibilidade: ausência ou presença de diferentes sistemas de resfriamento; frangos de corte com mais de 28 dias de idade; e temperatura de bulbo seco do ar externa acima de 30 °C. A vulnerabilidade do aviário foi classificada de acordo com o sistema de resfriamento e ventilação mecânica, sendo: resfriamento por pad cooling (CPC), aspersão (SPK), nebulização (FOG) e ventilação mecânica sem sistema de resfriamento evaporativo (VTL). A temperatura de bulbo seco do ar (Tbs, °C) e a umidade relativa do ar (UR, %) foram coletadas por registradores de dados autônomos a cada 10 min. Para cada aviário foram avaliados: (1) eficiência relativa de resfriamento (RCE) e (2) distribuição espacial interna das variáveis ambientais por técnica de geoestatística. O CPC e SPK não diferiram (P>0,05) na RCE (81,6% e 80,7% respectivamente), mas ambos diferiram do FOG (23,8%) e VLT (1,87%). As maiores variações na Tbs do ar interno foram registradas no FOG (7 °C), seguido pelo SPK (4 °C) e CPC (3 °C). No CPC, houve um aumento da umidade relativa do meio para o final do aviário, próximo aos exaustores. Em conclusão, a eficiência relativa de resfriamento, assim como a distribuição espacial das variáveis ambientais internas foram influenciadas pelo sistema de resfriamento de cada aviário.(AU)

Data mining as a hatchery process evaluation tool

The hatchery is one of the most important segments of the poultry chain, and generates an abundance of data, which, when analyzed, allow for identifying critical points of the process . The aim of this study was to evaluate the applicability of the data mining technique to databases of egg incubation of broiler breeders and laying hen breeders. The study uses a database recording egg incubation from broiler breeders housed in pens with shavings used for litters in natural mating, as well as laying hen breeders housed in cages using an artificial insemination mating system. The data mining technique (DM) was applied to analyses in a classification task, using the type of breeder and house system for delineating classes. The database was analyzed in three different ways: original database, attribute selection, and expert analysis. Models were selected on the basis of model precision and class accuracy. The data mining technique allowed for the classification of hatchery fertile eggs from different genetic groups, as well as hatching rates and the percentage of fertile eggs (the attributes with the greatest classification power). Broiler breeders showed higher fertility (> 95 %), but higher embryonic mortality between the third and seventh day post-hatching (> 0.5 %) when compared to laying hen breeders eggs. In conclusion, applying data mining to the hatchery process, selection of attributes and strategies based on the experience of experts can improve model performance.

Data mining as a hatchery process evaluation tool

The hatchery is one of the most important segments of the poultry chain, and generates an abundance of data, which, when analyzed, allow for identifying critical points of the process . The aim of this study was to evaluate the applicability of the data mining technique to databases of egg incubation of broiler breeders and laying hen breeders. The study uses a database recording egg incubation from broiler breeders housed in pens with shavings used for litters in natural mating, as well as laying hen breeders housed in cages using an artificial insemination mating system. The data mining technique (DM) was applied to analyses in a classification task, using the type of breeder and house system for delineating classes. The database was analyzed in three different ways: original database, attribute selection, and expert analysis. Models were selected on the basis of model precision and class accuracy. The data mining technique allowed for the classification of hatchery fertile eggs from different genetic groups, as well as hatching rates and the percentage of fertile eggs (the attributes with the greatest classification power). Broiler breeders showed higher fertility (> 95 %), but higher embryonic mortality between the third and seventh day post-hatching (> 0.5 %) when compared to laying hen breeders eggs. In conclusion, applying data mining to the hatchery process, selection of attributes and strategies based on the experience of experts can improve model performance.(AU)

Glycemic response of poultries in different feeding systems

The management of poultry feed is an important welfare promoter and the glycemic index a noninvasive evaluation. The aim was to evaluate the glycemic response of broiler breeders in restricted feeding system, and broilers receiving ad libitum feeding. Two experiments were carried out: I) 39-weekoldbroiler breeders, fed with three sources of fiber, in a completely randomized design in factorial scheme (3 fiber diets x 7 collection periods); and II) broilers, 42 days old, housed in different light systems, in a completely randomized design in factorial design (2 sexes x 2 lighting conditions x 13 collection periods). Blood glucose levels were measured at random collecting one blood drop from foot, with three replicates in each condition and treatment. In broiler breeder different fiber sources had no effect on glycemia, but the period affected circulating glucose levels, presenting a minimum of 184.3 mg dL-1 before feed and, a maximum of 242.5 mg dL-1 four hours after feeding. In broilers, there was a significant effect in glycemia for collection period and for sex, and interaction between lighting conditions and collection period. Further studies are needed to establish reference values to compare blood glucose levels in poultry.(AU)

Glycemic response of poultries in different feeding systems

The management of poultry feed is an important welfare promoter and the glycemic index a noninvasive evaluation. The aim was to evaluate the glycemic response of broiler breeders in restricted feeding system, and broilers receiving ad libitum feeding. Two experiments were carried out: I) 39-weekoldbroiler breeders, fed with three sources of fiber, in a completely randomized design in factorial scheme (3 fiber diets x 7 collection periods); and II) broilers, 42 days old, housed in different light systems, in a completely randomized design in factorial design (2 sexes x 2 lighting conditions x 13 collection periods). Blood glucose levels were measured at random collecting one blood drop from foot, with three replicates in each condition and treatment. In broiler breeder different fiber sources had no effect on glycemia, but the period affected circulating glucose levels, presenting a minimum of 184.3 mg dL-1 before feed and, a maximum of 242.5 mg dL-1 four hours after feeding. In broilers, there was a significant effect in glycemia for collection period and for sex, and interaction between lighting conditions and collection period. Further studies are needed to establish reference values to compare blood glucose levels in poultry.

Caracterização e previsão de ondas de calor com impacto na mortalidade de frangos de corte / Characterization and estimation of occurrence of heat waves with impact on broiler mortality

Com o aumento da produção de frangos de corte no Brasil surge a necessidade de otimização do sistema de produção, principalmente devido a um mercado competitivo, sendo necessária a aplicação de recursos de tecnologia que reduzam perdas. Perdas produtivas decorrentes de ondas de calor (OC) são comuns na produção de frangos de corte em clima tropical e a solução é um problema complexo. A previsão precoce destes eventos climáticos com impacto na mortalidade permite reduzir perdas. Bancos de dados zootécnicos e meteorológicos podem conter padrões úteis para a previsão da mortalidade de frangos de corte, possíveis de se extrair por técnicas como a Mineração de Dados. Este trabalho teve por objetivo geral predizer a mortalidade de frangos de corte com um mínimo de 24 horas de antecedência. Os objetivos específicos foram: 1) Caracterizar OC com impacto sobre a mortalidade de frangos de corte; 2) Gerar modelos de previsão aplicável a sistemas de suporte à decisão durante o processo produtivo de frangos de corte prevendo a ocorrência de mortalidade alta em frangos de corte devido a OC; 3) Indicar ações mitigadoras para a amenização do impacto de OC. As OC com impacto na mortalidade de frangos de corte apresentaram características que dependem do tipo construtivo e da idade da ave. A condição mínima para a ocorrência de OC afetando aviários sem climatização foi: temperatura máxima do dia > 32º C; temperatura média do dia > 24º C; Índice de Temperatura e Umidade (ITU) médio > 23º C; Velocidade média do vento _ 1,4 m s-1. Para aviários com climatização mínima, a mortalidade ocorreu de forma diferente entre as idades, não havendo mortalidade por OC para idade até 31 dias. Para as demais idades as condições para o desencadeamento de mortalidade alta foram: entre 31 e 40 dias: ITU máximo > 30,6º C e temperatura máxima > 34,4º C; entre 41 dias e o abate: ITU máximo > 30,6º C; temperatura máxima > 34,4º C; ITU mínimo _ 15,5º C; hora da temperatura máxima > 15h00min. A magnitude média de OC com impacto na mortalidade de frangos de corte, medida em ITU horas grau acumulado (ITUhga) > 24º C, foi de 367º C acumulados no dia. As previsões com 48 horas (precisão de 91,12% do modelo e 66,9% para a mortalidade alta) e 24 horas (precisão de 97,2% do modelo e 93,3% para a mortalidade alta) de antecedência permitem o desencadeamento de ações mitigadoras para a redução da mortalidade em frangos de corte. Dias de OC apresentam uma pior condição térmica, uma menor umidade relativa do ar nos horários de pico de calor, no turno da tarde, o que permite estratégias de mitigação com a intensificação do uso dos ventiladores e resfriamento evaporativo iniciando operação entre 09h00min e 10h00min, perdurando até as 20h00min. A previsão da mortalidade alta em frangos de corte a partir de dados meteorológicos com 24 e 48 horas de antecedência pode auxiliar na tomada de decisão precoce para se evitar esta mortalidade

As broiler production increases in Brazil it appears the need of optimizing production system mainly due to the market competitiveness, and technological resources application are required for reducing losses. Productive loss decurrently from heat wave (HW) incidence is quite common in broiler rearing under tropical conditions, and the solution for this is a rather complex problem. The early forecast of these climate events with impact on animal mortality may allow losses reduction. Data base on animal production and meteorology may enclose useful pattern for broiler mortality prediction, and it can be possible to extract them by techniques such as Data Mining. This research had the general objective of predicting broiler chicken mortality with a minimum period of 24 hours prior to heat wave exposure. The specific objectives were: 1) To characterize HW with impact on broiler mortality; 2) To generate forecast models applied to decision making systems during the broiler productive process, estimating the high mortality occurrence due to HW exposure; 3) To indicate mitigation actions to reduce HW impact on broiler chicken production. The HW with impact on broiler mortality presented characteristics that depend on the housing characteristics as well as on the age of the bird. The minimum concomitant climatic condition for HW affecting broiler production reared on housing without acclimatization was: maximum daily environmental temperature > 32º C; average daily temperatures > 24º C; average temperature and humidity index (THI) > 23º C; and average wind speed _ 1.4 m s-1. For housing with the minimum acclimatization equipments mortality occurred in a distinct way for birds with distinct ages, and there was not mortality by HW exposure for birds up to 31 days old. For birds with age different from that, the climate condition for starting the high mortality incidence was distinct such as: between 31 and 40 days old: Maximum THI > 30.6 ºC and maximum environmental temperature above 34.4 ºC; between 41 days old and laughter age: maximum THI > 30.6 ºC; maximum ambient temperature > 34.4º C; minimum THI _ 15.5 ºC; time that the maximum ambient temperature was found > 15h00min. The mean HW magnitude with impact in broiler 31 days old and characterized by THI degrees hour accumulated (THIdha) >24ºC, was of 367 ºC accumulated during the day. The forecast within 48 hours (91.12% accuracy and 0.66 precision for the class High Mortality) and 24 hours (97.2% accuracy of the model, and 0.93 precision for the class High Mortality) of minimum forecast allows the start of mitigation actions for reducing broiler mortality. Days during HW present the worst thermal conditions, with lower air relative humidity during peak of heat during the afternoon; that allows the adoption of mitigation strategies by using fans and evaporative cooling starting between 09h00min and 10h00min up to 20h00min. It was possible to predict high broiler mortality using meteorological data forecast within 24 and 48 hours, and this may help early decision making to avoid economical losses