Efeitos da temperatura e da umidade relativa sobre o desempenho e o rendimento de cortes nobres de frangos de corte de 1 a 49 dias de idade

Abstract

RESUMO -Foram utilizados 180 pintos machos de 1 dia de idade, da linhagem Ross (peso inicial 43,0 ± 0,2 g) para avaliação dos efeitos de diferentes ambientes sobre o desempenho e as características de carcaça. As aves foram criadas no período de 1 a 49 dias de idade em um delineamento experimental inteiramente casualizado, com três ambientes (conforto térmico, calor seco e calor úmido), seis repetições por tratamento e dez aves por unidade experimental. As rações e a água foram fornecidas à vontade. O monitoramento da temperatura e da umidade relativa do ar de cada ambiente foi feito por meio de termômetros de bulbo seco e de globo negro. Os valores obtidos foram convertidos em valor único -Índice de Temperatura de Globo e Umidade (ITGU), para caracterização do ambiente. As temperaturas que caracterizaram os ambientes de conforto, de calor seco e de calor úmido foram, respectivamente, 25,1 ± 2,99; 35,0 ± 0,14 e 31,2 ± 1,82 o C e as umidades relativas registradas nos ambientes de calor seco e calor úmido foram, respectivamente, de 40 e 75%. Foram avaliados o consumo de ração, o ganho de peso e a conversão alimentar nos períodos de 1 a 21, 1 a 41 e 1 a 49 dias de idade. Ao final do experimento, as aves foram abatidas para avaliação dos pesos absolutos e do rendimento de carcaça e de cortes nobres (coxa, sobrecoxa e peito). O ambiente de calor influenciou negativamente o consumo de ração e o ganho de peso das aves em todos os períodos estudados, mas esse efeito foi mais acentuado nas aves mantidas em ambiente de calor úmido. O calor também influenciou negativamente os pesos absolutos de coxa, sobrecoxa e peito. Altas temperaturas prejudicam o desempenho e o rendimento de cortes nobres de frangos de corte de 1 a 49 dias de idade, de modo que esses efeitos são mais acentuados pelo aumento da umidade relativa do ar. Palavras-chave: ambiente, aves, calor, carcaçaEffects of temperature and relative humidity on performance and yield of noble cuts of broilers from 1 to 49 days old ABSTRACT -One hundred and eighty male Ross 1-d chicks averaging initial weight of 43.0 ± 0.2 g were used to evaluate the effects of different environments on performance and carcass characteristics. The experiment was analyzed as a completely randomized design with three environments (thermal comfort, dry heat and wet heat), six replicates of ten birds per experimental unity reared from 1 to 49 days old. Diets and water were fed ad libitum. The temperature and relative humidity control in each environment were measured by dry bulb and black globe thermometers. The values obtained were converted in a single valueBlack Globe Humidity and Temperature Index (BGHI) to characterize the environment. The temperatures that characterize the comfort, dry heat and wet heat were respectively: 25.1 ± 2.99, 35.0 ± 0.14, 31.2 ± 1.82ºC. The relative humidity recorded in dry and wet heat environments were respectively 40 and 75%. Feed intake, weight gain, feed:gain ratio in the periods from 1 to 21, 1 to 41 and 1 to 49 days of old were evaluated. In the end of th...

Effect of thermal environment on performance of broiler chickens using fuzzy modeling

“…The results of this work are similar to those found by Oliveira et al (2006), working with 1-21-day-old broilers, observed a 14% reduction in FI in birds kept in hightemperature environments. Silva et al (2009), evaluating the performance of 1-21-day-old broilers raised at different temperatures, concluded that the high temperature in stage 1-7 days old increased FC, which presented the best values in control , respectively, corresponding to the percentage error measured of 1.20, 0.02, and 2.17% (Table 3).…”

“…For this reason, the thermal environment must adapt to the ideal conditions of welfare for younger birds. According to Oliveira et al (2006), the ideal temperature range for broilers is, in the first weeks of life, between 32-34°C , reducing gradually to reach 27 °C in the final phase of the experiment, at 21 days of age. Overall, as can be seen from Table 3, the best results, WG and, FC were observed during the first two weeks of life in conditions of 30-33 °C.…”

Cassava root scrapings for 22 to 42-day-old broilers in high-temperature environments

“…The inclusion levels of cassava scraping did not affect (P<0.05) percentage of carcass, beast, back, thighs, chicken chops, wings, wingettes, heart, liver or gizzard (P>0.05) ( Table 4). This finding is contrary to the results obtained by Oliveira Neto et al (2000) and Oliveira Neto et al (2006), as they conclude that broilers from 1 to 49 days of age, subjected to high temperature environments (32 o C), have the performance and yield of prime cuts compromised. This study was conducted in an environment with temperature ranging from 27.5±1.2 and 31.8±1.9 o C, and the percentage of vegetable oil, at the 20% CRS inclusion level was around 5.9% in the two feeding programs, which may have contributed to yield drop in carcass and prime cuts.…”

Thermal environment in two broiler barns during the first three weeks of age

“…The temperature humidity index (THI) introduced by Thom (1959) only requires measurement of T db and wet bulb temperature (T wb ). In Brazil, as in most of South America, THI is the most widely used index due to its simplicity (Medeiros et al, 2005;Furtado et al, 2006;Oliveira et al, 2006;Jácome et al, 2007;Menegali et al, 2009;Nascimento et al, 2011;Menegali et al, 2013).…”