Heat loss in one day old pullets inside a hatchery

Abstract

After hatching, pullets are transported to brooding area and vaccinated. One day old chicks have not already developed thermoregulation ability; thus, brooding temperature variations may affect pullet quality leading to broiler meat production losses. This research aimed to calculate sensible heat loss in one day old pullets in hatching area and vaccination room. Ten one day old pullets were randomly selected from hatching area of a commercial hatchery. Infrared images were used to calculate bird surface temperature. Exposure areas for the two conditions were quantified, and both air temperature and wind speed was recorded. Total sensible heat loss was calculated as heat loss by radiation plus heat loss by convection. It was found that heat transfer occurs in different ways at different bird body parts. Total heat loss found for hatching baskets was equivalent to 0.81 J s -1 while for vaccination room was 1.16 J s -1. Pullet nutrition is based on energy loss from brooding to farm, and the overall pullet heat loss from hatchery to farm accepted is 13.95 J s -1 . Thus, "starter feed" has relevant excess of energy input. These findings indicate that less energy can be used in initial feed, once heat loss is lower than assumed nowadays. Improved knowledge on these conditions may enhance broiler farm feeding strategies and economics during first rearing week.KEYWORDS: sensible heat, post-hatching, infrared thermography. PERDA DE CALOR EM PINTAINHOS DE UM DIA EM INCUBATÓRIO RESUMO:Após o nascimento, pintainhos são transportados para a sala de pintos e vacinados. Pintainhos de um dia ainda não desenvolveram a habilidade de termorregulação, portanto a variação da temperatura na sala de pintos pode afetar a qualidade dos pintainhos, levando a perdas na produção de carne de frangos de corte. Esta pesquisa visou a calcular a perda de calor sensível em pintos de um dia, na sala de pintos e na de vacinação. Dez pintainhos de um dia foram selecionados ao acaso na área de nascimento de um incubatório comercial. Foram utilizadas imagens termográficas infravermelho, para calcular a temperatura superficial das aves. As áreas de exposição das aves foram quantificadas nos dois ambientes, e ambas as temperatura e a velocidade do ar foram registradas. A perda de calor sensível total foi calculada como o calor perdido por radiação somado à perda de calor por convecção. Foi encontrado que a transferência de calor ocorre em diferentes formas, nas várias partes do corpo da ave. A perda de calor total encontrada nas cestas do nascedouro era equivalente a 0,81 J s -1 , enquanto na área de vacinação foi de 1,16 J s -1. A nutrição de pintainhos é baseada na energia perdida desde o nascimento até a chegada à granja e, geralmente é aceito o valor de 13,95 J s -1 , como um valor total de perda de calor do incubatório até a granja; portanto, a ração inicial de pintainhos tem um valor excessivo de insumo de energia. Estes resultados indicam que menos energia poderia ser usada na ração inicial, uma vez que a perda de calor é menor do que...

Prediction of mean surface temperature of broiler chicks and load microclimate during transport

“…Studies on chick surface temperature are extremely important due to their similarity to ambient temperature, which explains the reduced ability o f birds to lose thermal energy in sensible form at elevated temperatures (LIN et al, 2005;NÄÄS et al, 2014). However, it is known that the Prediction of mean surface temperature of broiler chicks and load microclimate during transport Eng.…”

“…Additionally, the air temperature inside chick boxes has most influence on this formula since such environment surrounds closely the chicks, biasing bird surface temperature. For LIN et al (2005) andNÄÄS et al (2014), such fact is related to the reduced ability of chicks in losing thermal energy appreciably under high temperatures. GILOH et al (2012) observed a high correlatio n coefficient between chick surface temperatures and environmental variables, confirming that air temperature, relative humidity and air circulation are major factors affecting poultry performance.…”

“…For day-old chicks, the ideal average surface temperature ranges from 31.6 to 36.9 °C (MARCHINI et al, 2007;ABREU et al, 2012;NASCIMENTO et al, 2013). According to LIN et al (2005) and NÄÄS et al (2014), chick surface temperature is similar to the environment one, which explains its reduced ability to lose thermal energy in sensible form under high temperatures. In this context, artificial neural networks (ANN) can be a tool to assist in a microclimatic assessment of day-old chicks load and its effect on animal mean surface temperature.…”

Thermal gradients of container and mean surface temperature of broiler chicks transported on different shipments

“…According to MARCHINI et al (2007), ABREU et al (2012) and NASCIMENTO et al (2013), the ideal mean surface temperature of day-old chicks ranges from 31.6 to 36.9 °C. The surface temperature of chicks is similar to the ambient temperature, which explains the reduced ability for chicks in losing thermal energy in a sensible form at elevated temperatures (LIN et al, 2005;NÄÄS et al, 2014). However, some studies have shown that the existing thermal gradient between the body surface temperature and the air temperature in cold condition are considerably extended due to the day-old chick low thermoregulatory capacity and its ease in losing thermal energy to a cooler environment (GUSTIN, 2003).…”