Comparative Efficacy of an Organic Acid Blend and Bacitracin Methylene Disalicylate as Growth Promoters in Broiler Chickens: Effects on Performance, Gut Histology, and Small Intestinal Milieu

Table 2

Chemical composition (g/kg) and microbiological count (${\text{log}}_{\text{10}}\hspace{0.17em}$ CFU/g) of the experimental diets supplemented with an organic acid blend (OAB) and bacitracin methylene disalicylate (BMD).

	Diet	Dietary treatments					Significance ($P$ value)
		Control	OAB		BMD		Dose effect		Between treatments
Chemical compositin			1 g/kg diet	2 g/kg diet	0.5 g/kg diet	1.0 g/kg diet	OAB	BMD
Crude protein*	Starter	226.6	228.7	230.1	229.2	228.7	NS	NS	NS
	Finisher	197.1	197.7	197.3	198.2	198.8	NS	NS	NS
Crud fiber	Starter	43.9	42.5	42.9	43.2	43.8	NS	NS	NS
	Finisher	37.6	35.4	35.9	36.8	37.2	NS	NS	NS
Ether extract	Starter	29.5	29.3	29.1	29.2	9.3	NS	NS	NS
	Finisher	38.7	38.8	38.6	38.5	8.7	NS	NS	NS
Microbial counts^†
Total coliforms	Starter	18	16	14	13	15	*	*	NS
	Finisher	19	12	14	16	11	*	*	NS
Escherichia coli	Starter	4	2	—	2	2	*	NS	*
	Finisher	4	3	—	2	1	*	*	NS
Clostridium spp.	Starter	210	180	170	200	180	*	*	*
	Finisher	200	180	160	180	160	*	*	*
Aspergillus flavus ^$	Starter	—	—^‡	2	1	—
	Finisher	1	—^‡	—	3	—
Aspergillus fumigatus ^$	Starter	2	—	—^‡	—	—
	Finisher	2	—	—	—	—

^$ Statistical analysis not performed due to lack of sufficient data; ^†Salmonella was negative for all the diets; ^‡ mucoid growths were observed.
* Significance at $P<.05$; NS, not significant.