Table 3. Effect of the dietary supplementation of different proteases on the growth performance of broilers in each experimental group measured at different growth stages

	PC	NC	PR1	PR2	PR3	SEM	p-value
0–14 days
BW (day 14)	485^ab	493^ab	503^a	501^a	482^b	4.5018	0.0056
BWG (g)	444^ab	452^ab	462^a	460^a	441^b	4.5018	0.0056
FI (g)	430	439	440	440	425	6.4400	0.3688
FCR	0.967	0.972	0.951	0.956	0.963	0.0069	0.2342
14–28 days
BW (day 28)	1,782	1,779	1,813	1,819	1,788	14.1348	0.1583
BWG (g)	1,296	1,286	1,310	1,318	1,306	10.2540	0.2356
F, (g)	1,987	1,937	1,952	1,987	1,952	15.7609	0.0988
FCR	1.532^a	1.506^b	1.490^b	1.508^b	1.495^b	0.0058	< 0.0001
0–32 days
BW (day 32)	2,089	2,103	2,140	2,106	2,072	20.6572	0.2333
BWG (g)	2,048	2,062	2,099	2,065	2,031	20.6572	0.2333
FI (g)	2,821	2,938	2,872	2,911	2,886	35.5427	0.2071
FCR	1.377^b	1.425^a	1.368^b	1.410^a	1.420^a	0.0062	< 0.0001
Adjust. FCR (2.1 kg BW)	1.379	1.424	1.359	1.409	1.426	-	-

Values with different superscripts in the same row were significantly different (p < 0.05).
PC, positive control diet formulated to meet Ross 308 AA requirements; NC, negative control diet reformulated to 3.5% lower digestible AA compared PC; PR1, NC supplemented with 3,000 U/kg (300 mg/kg) of a multi-protease solution, containing 3 different coated proteases produced from Aspergillus niger, Bacillus subtilis and Bacillus licheniformis; PR2, NC supplemented with 15,000 U/kg (200 mg/kg) of a serine protease produced from Bacillus licheniformis; PR3, NC supplemented with 30,000 U/kg (500 mg/kg) of an alkaline protease produced from Bacillus licheniformis; SEM, n = 10 replicates per treatment (20 birds per replicate); BW, body weight; BWG, body weight gain; FI, feed intake; FCR,feed conversion ratio; Adjust. FCR (2.1 kg BW), Adjusted FCR at 2.1 kg of final BW calculated according to Ross Broiler Management Handbook 2014.