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 3

Effects of feeding an organic acid blend (OAB) and bacitracin methylene disalicylate (BMD) at different dose levels on performance traits and carcass characteristics in broiler chicken ^†.

	Dietary treatments					Pooled SE	Contrast $P$ value
Measurements	Control (Basal diet)	OAB		BMD			Dose effect		Between treatments
		1 g/kg diet	2 g/kg diet	0.5 g/kg diet	1.0 g/kg diet		OA	BMD
Live performance and gross carcass traits
Final live weight g	1510	1686	1773	1740	1717	13.2	^***L	^**LQ	^***
Total gain g	1471	1648	1735	1702	1678	13.1	^***L	^** LQ	^***
Overall FCR ^‡	2.03	1.69	1.73	1.79	1.85	0.02	^***LQ	^**LQ	^***
Dressing percentage	56.9	58.7	57.9	57.1	59.6	0.26	NS	^**L	*
Breast g	220	290	261	283	310	9.3	*L	*L	NS
Thigh g	123	152	144	153	167	3.9	^$	*L	NS
Drumstick g	125	151	146	166	187	4.4	NS	^**L	*
Chemical composition (g/100 g meat on fresh basis) and nutrient accretion (g)
Moisture	72.2	73.9	73.8	73.6	72.8	0.31	NS	NS	NS
Ash	3.59	6.89	5.41	3.66	3.92	0.15	^**LQ	NS	^**
Protein	21.9	22.1	22.1	20.4	21.8	0.21	NS	^$	NS
Protein accretion	321.8	384.9	383.9	347.6	366.4	4.37	^**L	^$	^***
Ash accretion	50.2	113.4	92.5	60.2	63.7	2.54	^**LQ	NS	^***

^†The birds were on test for 35 days, ^‡Feed conversion ratio, calculated by dividing total feed intake by total live weight gain in 35 days. ${}_{}{}^{\text{L}}\text{s}$ignificant linear effect, ${}_{}{}^{\text{Q}}\text{s}$ignificant quadratic effect, *at $P<.05\text{,}$^**at $P<.01\text{,}$^***at $P<.001\text{,}$^$$P<.1$.