Table 4.

Effect of Bacillus subtilis and its delivery routes on relative weight of immune organs and serum immunoglobulin concentrations in broiler chickens.

Parameters	Treatments1					SEM2	P value3
	Negative control	In-feed antibiotic	In-feed probiotic	In ovo probiotic 1	In ovo probiotic 2
Bursa weight (g/Kg BW)	1.81	1.80	1.64	1.76	1.93	0.06	0.645
Spleen weight (g/Kg BW)	0.70	0.76	0.73	0.73	0.69	0.02	0.920
Immunoglobulin G (Mg/mL)	10.3a	4.75ab	2.71bc	0.96cd	0.06d	0.31	<0.001
Immunoglobulin M (Mg/mL)	2.37	0.61	0.35	0.19	0.15	0.05	0.333

¹Treatments include— (1) Negative Control treatment- chicks fed a basal corn-soybean meal-wheat–based diet; (2) In-feed antibiotics- chicks fed NC + 0.05% bacitracin methylene disalicylate; (3) In-feed probiotics- chicks fed NC + 0.005% Bacillus subtilis containing 1 × 10⁸ CFU/kg of feed; (4) In ovo probiotics group 1- eggs injected with 10 × 106 CFU of Bacillus subtilis fermentation extract/0.2 mL saline diluent; and (5) In ovo probiotics group 2- eggs injected with 20 × 10⁶ CFU of Bacillus subtilis fermentation extract/0.2 mL saline diluent.

²SEM = Standard error of means.

³Means within a row with different superscripts.

^a,b,c,dSignificantly differ.