. 2021 Sep 23;12:713485. doi: 10.3389/fimmu.2021.713485

Table 4.

Effects of dietary treatment on immune indicators in the sera of 7- and 14-day-old broilers.

Items	GML levels (mg/kg feed)					SEM	P-value
Items	CON	300	600	900	1200	SEM	Linear	Quadratic
7 d of age (pg/mL)
IL-1β	597.46^a	559.36^ab	531.91^ab	541.96^ab	525.78^b	8.42	0.004	0.197
IL-6	29.05	28.90	28.62	29.73	29.57	0.36	0.530	0.693
TNF-α	81.37^a	79.03^ab	78.27^ab	75.44^ab	72.75^b	0.92	0.001	0.707
IgG	1934.38	1911.25	1832.50	1953.13	1829.38	24.29	0.331	0.993
14 d of age (pg/mL)
IL-1β	641.47^a	590.74^ab	566.23^b	531.36^b	560.10^b	9.25	<0.001	0.014
IL-6	29.49	29.63	29.63	30.96	30.20	0.37	0.336	0.891
TNF-α	76.90	73.69	78.36	77.96	78.21	0.84	0.254	0.792
IgG	1832.13^b	1813.13^b	1941.88^ab	1939.38^ab	2115.00^a	32.09	0.002	0.315

IL-1β, interleukin 1β; IL-6, interleukin 6; TNF-α, tumor necrosis factor α; IgG, immunoglobulin G; SEM, total standard error of mean.

Values were expressed as least squares means ± SEM (n = 12).

^a,bDifferent superscripts in the same line indicate significant differences according to Tukey’s multiple comparisons (P < 0.05).