Table 1.

Characteristics of included studies.

Study	Strain	No. of chick/group	Age for experiment (d)	Thermoneutral conditions	Heat stress conditions
Alhenaky et al., 2017	Hubbard classic broiler chicks	24	26	20°C ± 2°C	Chronic: 30°C ± 2°C, 24 h/d for 10 d Acute: 35°C ± 2°C for 4 h and then returned back to the thermoneutral conditions
Aswathi et al., 2019	CARIBRO-Vishal broiler breeder hens	45	Not provided	Normal temperature	37°C ± 1°C for 6 h/d up to 10 d
Awad et al., 2020	Cobb 500 and Ross 308 male broiler chicks	60	22	23°C	34°C, 6 h/d for 13 d
Del Vesco et al., 2017	Cobb 500 male broilers	50	20	34°C for the first 7 d, decreased gradually to 27°C until day 20, and then decreased gradually to 18°C until day 42	38°C for 21 d
Goo et al., 2019	Cobb 500 mixed	285	21	20°C for 14 d	27.8°C for 14 d
Imik et al., 2012	Ross 308 mixed	45	15	24°C for 20 d	34°C, 6 h/D for 20 d
Khatlab et al., 2018	Cobb 500 mixed	60	22	19°C for 19 d	38°C for 19 d
Ma et al., 2018	Arbor Acres male broilers	48	28	22°C for 14 d	32°C for 14 d
Olfati et al., 2018	Broiler chickens	60	22	23.9°C ± 2°C for 22 d	33°C ± 3°C for 22 d
Quinteiro-Filho et al., 2010	Broiler chickens	80	34	21°C ± 1°C for 8 d	31°C ± 1/36°C ± 1°C, 10 h/d for 8 d
Quinteiro-Filho et al., 2012b	Male broiler chickens	60	35	21°C ± 1°C for the entire day	31°C ± 1°C for 10 h in the 35th d
Sohail et al., 2012	Ross-708 broilers mixed sex	90	1	35°C ± 2°C at day 1 and decreased 3°C per week until reached 26°C ± 2°C	35°C ± 2°C for 42 d