Desempenho e composição da carcaça de frangos de corte submetidos a diferentes períodos de arraçoamento

Abstract

RESUMO -Este trabalho foi realizado com o objetivo de estudar a influência do período de arraçoamento sobre parâmetros zootécnicos, desenvolvimento visceral e composição da carcaça de frangos de corte. Foram utilizados 630 frangos da linhagem Cobb-500, divididos em três programas de alimentação, a partir do 8 o até o 50 o dia de vida: ad libitum (AL -alimento durante 24 horas), arraçoamento diurno (AD -alimento à vontade das 7-19 h e restrito durante o período noturno 19-7 h) e arraçoamento noturno (AN -alimento à vontade das 19-7 h e restrito durante o período diurno 7-19h). A água foi fornecida à vontade para todos os grupos durante o período experimental. O período de arraçoamento (12 horas noturno ou diurno) reduziu significativamente o peso vivo final das aves. No entanto, aves arraçoadas durante o período noturno consumiram menos ração e mostraram melhor índice de conversão alimentar. O uso dos diferentes períodos de arraçoamento não afetou o desenvolvimento do fígado, moela, coração e comprimento do intestino. Aves arraçoadas por 12 horas, tanto no período noturno quanto no diurno, apresentaram maior teor de gordura na carcaça. O teor de cinzas não foi afetado pelo programa alimentar. Os resultados deste experimento sugerem que a adaptação ao novo programa alimentar foi muito lenta. Assim, as aves não foram capazes de manter o consumo de alimento compatível com seu desenvolvimento, ocorrendo com isso prejuízo no desempenho produtivo (peso vivo), bem como na composição da carcaça (gordura).Palavras-chave: frangos de corte, desempenho, composição da carcaça, período de arraçoamento Performance and Carcass Composition of Broiler Chickens Submitted to DifferentFeeding Periods ABSTRACT -This investigation was carried out to study the feeding period influence on broilers performance, viscera development, and carcass composition. A total of 630 broiler chickens, Cobb-500 strain, were allocated in three feeding programs from 8 th day to 50 th day of life: ad libitum (AL -food available 24 hours), diurnal feeding (DF -food provided ad libitum from 7 am to 7 pm and fed restricted from 7 pm to 7 am) and nocturnal feeding (NF-food provided ad libitum from 7 pm to 7 am and fed restricted from 7 am to 7 pm). The water was provided ad libitum for all groups during experimental period. The feeding period (12 hours at nocturnal and diurnal) significantly decreased the broilers' final body weight. However, broilers fed at night showed lower feed intake and had better feed conversion index. The different feeding periods did not affect liver, gizzard, heart and intestine length development. Broilers fed for 12 hours during the night and during the day showed higher carcass fat content. Ash content was not affected by feeding program. The results suggested that the adaptation to feeding program was slow, thus, the broilers were not able to keep the feed consumption compatible with their development, with lower productive performance and higher carcass fat. IntroduçãoA alimentação do frango, além de corresponder a um alto p...

Estimating mortality in laying hens as the environmental temperature increases

“…In the classification tree presented in Figure 3, flock age was more important in the determination of bird mortality, as it occupied the first root node. Chickens between 24 and 28 weeks of age respond differently to environmental weather conditions as older birds are heavier, and therefore, their heat exchange with environment is more difficult as compared to younger birds (Campos, 2000;Furlan & Macari, 2002). In addition to body weight, 28-w-old layers are achieving the peak of lay, according to most genetic line manuals (Dekalb, 2009;Hy-Line, 2009;Lohmman, 2009), which means that they have higher metabolic activity, and require more nutrients, particularly amino acids (Rocha, 2006;Lin et al, 2006) and energy (Rostagno et al, 2005), generating more metabolic heart, and presenting lower capacity of responding to heat stress.…”

“…These high temperature cause high levels of stress in adult birds (Furlan & Macari, 2002), which may cause high mortality due to compromised immune response (Mashaly et al, 2004;Mumma et al, 2006).…”

Protein levels and environmental temperature effects on carcass characteristics, performance, and nitrogen excretion of broiler chickens from 7 to 21 days of age

“…On one hand, feed intake of birds reared at low environmental temperature was not different from birds at thermoneutral temperature, which might be due to bird behavior in order to conserve heat. At low environmental temperatures, the birds spend most of the time in groups as a means to decrease heat dissipation, and therefore the time spent eating or drinking water is reduced (Furlan & Macari, 2002).…”

“…Indeed, high environmental temperatures are essential for chicks in the initial phase. Besides the fact that their thermoregulatory system is not completely developed yet, their area/volume ratio is greater; therefore, more heat is dissipated (Furlan & Macari, 2002).…”

Efeito do enriquecimento sensorial auditivo (música) no bem-estar de matrizes suínas gestantes

“…Para estimular a perda evaporativa e manter o equilíbrio térmico corporal, a frequência respiratória aumenta durante o estresse (FURLAN;MACARI, 2002).…”