Table 2.

Productive performance of slow-growing broiler chickens injected in ovo with GOS in response to heat stress.

	Treatment (Tr)1		Temperature (T)2			Significance
	C	GOS	TN	HS	SEM	Tr	T	TrxT
Chick body weight (g, d 0)	40.7	39.8	39.9	40.6	0.1	**	*	NS
Final body weight (g, d 50)	2,041	1,996	2,158	1,879	37.9	NS	***	NS
Daily weight gain (g/bird/d)
d 0–14	16.4	16.9	16.8	16.6	0.15	NS	NS	NS
d 15–36	46.8	45.0	46.2	45.5	0.8	NS	NS	NS
d 37–50	52.8	52.4	62.0	43.2	1.7	NS	***	NS
d 0–50	40.0	39.1	42.4	36.8	0.8	NS	**	NS
Daily feed intake (g/bird/d)
d 0–14	26.7	26.9	26.4	27.3	0.3	NS	NS	NS
d 15–36	88.3	86.8	88.1	87.0	0.6	NS	NS	NS
d 37–50	140.0	137.2	154.6	122.6	2.2	NS	***	NS
d 0–50	82.8	81.5	86.4	77.9	0.8	NS	***	NS
FCR3
d 0–14	1.63	1.59	1.57	1.65	0.01	NS	**	NS
d 15–36	1.90	1.94	1.91	1.92	0.03	NS	NS	NS
d 37–50	2.72	2.69	2.52	2.89	0.06	NS	**	NS
d 0–50	2.28	2.30	2.25	2.33	0.04	NS	NS	NS
Mortality (%)
d 0–14	0.58	0.86	0.29	1.15	0.30	NS	NS	NS
d 15–36	0.63	0.62	0.93	0.32	0.30	NS	NS	NS
d 37–50	0.62	0.00	0.31	0.31	0.22	NS	NS	NS
d 0–50	1.73	1.44	1.44	1.73	0.43	NS	NS	NS

¹C = Control (untreated); GOS = in ovo injected with GOS.

²TN = thermoneutral conditions; HS = heat stress conditions (on d 36–50).

³Abbreviation: FCR, feed conversion ratio. Significance: NS = P > 0.05; * P < 0.05; ** P < 0.01; *** P < 0.001.