Table 2.

Effects of IQ supplementation on the growth performance of heat-stressed broiler chickens.

Parameters	Thermoneutral		Heat stress		SEM	Significance of effects
	Control	IQ	Control	IQ		Diet	Treatment	Diet × treatment
Days 0–14
BW (g)	530	516	-	-	3.7	0.11	-	-
BWG (g)	487	474	-	-	3.1	0.12
FI (g)	-	-	-	-	-	-	-	-
FCR (g/g)	-	-	-	-	-	-	-	-
Days 15–21
BW (g) at day 21	950	973	855	861	12.7	0.256	<0.001	0.527
BWG (g)	429	465	316	336	13.7	0.049	<0.001	0.565
FI (g)	668	696	591	625	11.2	0.012	<0.001	0.791
FCR (g/g)	1.46	1.40	1.84	1.84	0.044	0.714	<0.001	0.875
Days 22–42
BW (g) at day 42	3,031a	3,114a	2,428c	2,647b	25.2	<0.001	<0.001	0.013
BWG (g)	2,081a	2,140a	1,572c	1,785b	36.4	<0.001	<0.001	0.008
FI (g)	4,059	4,150	3,186	3,383	47.5	0.006	<0.001	0.281
FCR (g/g)	1.95	1.94	2.03	1.96	0.024	0.219	0.028	0.439
Days 15–42
BWG (g)	2,510a	2,606a	1,889c	2,121b	25.7	<0.001	<0.001	0.015
FI (g)	4,726	4,846	3,777	4,008	49.5	0.002	<0.001	0.275
FCR (g/g)	1.88b,c	1.86c	2.00a	1.89b	0.015	<0.001	<0.001	0.008

Data are presented as means of 6 replicates (15 birds per replicate). Means within a row marked with different superscript letters are significantly different (^a,b,cP < 0.05). Data on BW and BWG during day 0–14 were analyzed using Student t test.

Abbreviations: BWG, BW gain; FI, feed intake; FCR, feed conversion ratio; IQ, isoquinoline alkaloids.