The effect of thermal environment on the digestion of broilers

Abstract

Summary Two experiments were conducted to determine the effect of thermal environment on the digestion of broilers. In both experiments the birds were exposed to three temperatures: 5, 21, and 32° C, and relative humidity was maintained at 60%. In experiment one, the amount of chyme in the whole digestive tract was decreased by the cold environment (5° C, 60% relative humidity) and increased by hot environment (32° C, 60% relative humidity), compared with control environment (20° C, 60% relative humidity). The expelling of digesta from the crop or small intestine was suppressed by high temperature (32° C) (p < 0.01). In experiment two, the activities of trypsin, chymotrypsin, and amylase were affected significantly by different environmental temperatures (p < 0.01). Compared to normal environment, the activities of the three kinds of enzymes in intestinal juice were decreased by the hot environment: trypsin (p < 0.01), chymotrypsin (p < 0.05), and amylase (p < 0.01), respectively. The activities of the three kinds of digestive enzyme were not influenced by the cold environment.

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

“…Também não está de acordo com a redução das atividades das enzimas proteolíticas (tripsina e quimotripsina) no intestino delgado de aves expostas ao calor verificada por Hai et al (2000).…”

Influence of Coenzyme Q10 Supplementation in High Energy Broiler Diets on Production Performance, Hematological and Slaughter Parameters under Higher Environmental Temperature

“…The broilers exposed to an environmental temperature of 32°C were subjected to heat stress, which resulted in decreased feed intake by 14%, as compared to those kept at thermo neutral zone temperature; this reduction in feed intake is to reduce metabolic heat production (Sahin et al, 2009). Hai et al (2000) reported that the activities of digestive enzymes trypsin, chymotrypsin and amylase were significantly reduced when animals were kept at high temperature (32°C) conditions. Heat stress also decreases the serum and liver concentrations of vitamins (C, E and A) and minerals (Fe, Zn, Se and Cr) and also influence the immune response of poultry (Donker et al, 1990).…”

Evaluation of cold water and vitamin C on broiler growth during hot-dry season in sw Nigeria

“…They lack sweat glands as in ruminant animals. There is consequential reduction in voluntary feed intake, so as to limit metabolic heat production (Hai et al, 2000) in order to lower the metabolic heat production. Moreover, they divert energy and other nutrients intended for growth, immunity and reproduction to thermoregulation, thereby limiting their productivity (Brake, 1987).…”