Effects of heat stress on pullet cloacal and body temperature

Abstract

One measure of the thermal status of poultry is cloacal temperature measured with a cloacal thermometer; however, this method requires handling the bird, is invasive, and can be stressful. Infrared thermography is an alternative means for assessing bird thermal status. The objective of this study was to investigate the body temperature response of pullets subjected to different environmental air temperatures during the growing phase and to evaluate the relationship between the cloacal temperature and the body parts surface temperature. A total of 648 chicks (Lohmann LSL Lite) were used in 2 different phases, phase I (day 1 through 6 wk of age) and phase II (week 7 through 17). During phase I, chicks were reared at 1 of 3 different thermal environments: thermal comfort (35°C–19°C), mild heat stress (38°C–22°C), or mild cold stress (28°C–17°C). In phase II, pullets were randomly redistributed to 1 of 4 daytime temperature treatments: 20°C; 25°C; 30°C; and 35°C, all with night time temperature of 20°C. Cloacal temperature and body surface temperature for 8 parts (head, eye, comb, chest, back, wing, leg, head area, and body area) were obtained weekly from 4 to 2 birds per treatment, respectively, during phase II. There were no effects for the interactions between the 2 experimental phases for cloacal and body parts surface temperature. There was a strong correlation ( P < 0.001) between cloacal temperature and each body part temperature; cloacal temperature followed a quadratic response to environmental air temperature treatments. Pullets subjected to 35°C/20°C and 30°C/20°C had the highest body parts temperatures compared with the other 2 treatments ( P < 0.05). The leg surface temperature was greatest in all treatments, and the chest the lowest. Regression between cloacal and body parts temperature had a 95% predictive accuracy of better than 0.4°C, suggesting a useful alternative to direct cloacal temperature measurement.

Avaliação Dos Parâmetros Ambientais E Fisiológicos Para Frangos De Corte Linhagem Caipira Em Diferentes Fases De Criação Na Amazônia Ocidental

“…Temperatura (°C) cloacal (CLO), cabeça (CAB), pescoço (PESC), dorso (DOR), perna (PER) e de asa (ASA) e frequência respiratória (movimentos/min) de frangos de corte linhagem caipira nas fases inicial (1-21 dias), crescimento (22-42 dias) e final (43-63 dias), considerando os três períodos do dia (manhã, tarde e noite). À medida que a temperatura ambiente e a umidade relativa ultrapassam a zona de conforto térmico as aves tornam-se mais sensíveis ao estresse calórico, como consequência ocorre prejuízos aos processos de dissipação de calor, promovendo elevação da temperatura corporal da ave (Cândido et al, 2020). O aumento das temperaturas superficiais, constituem um dos principais mecanismos fisiológicos utilizados pelas aves em decorrência de condições ambientais desfavoráveis, sendo uma resposta adaptativa que a curto prazo pode auxiliar no processo de perda de calor (Nascimento et al, 2014).…”

Efficacy and Function of Feathers, Hair, and Glabrous Skin in the Thermoregulation Strategies of Domestic Animals

“…These observations show the role that feathers have during heat or cold stress. In the first case, the insulator property of feathers hinders heat loss during hot temperatures, while in the latter, feathers contribute to heat insulation [ 51 ]. Peguri and Coon [ 52 ] investigated the presence or absence of feathers in 59-week-old chickens from the white leghorn strain.…”

Changes in facial surface temperature of laying hens under different thermal conditions

“…When the environmental temperature exceeds 30℃°C , the difficulty of body heat dissipation given to thick feathered hens increases, leading to high temperature stress. In this situation, the FST of laying hens has the advantage of being closer to the core body temperature [16] and being easier to access and measure than the surface temperature of other areas such as wings, legs,…”

“…A c c e p t e d A r t i c l e therefore, the variations in environmental temperature could rapidly be manifested in skin surface temperature, which makes it an important parameter in monitoring the comfort or thermal stress of chickens using infrared thermography [14,15,16]. For skin temperature measurement using infrared thermography in poultry studies, bare areas such as the eye, comb and wattle, earlobes, or nose are the potential zones for detection of temperature differences as thermal stressor intensity changes.…”