Table 4. Influence of dietary Na levels with or without microbial phytase on feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR) of broilers fed from day 0 to 35.

Na level1)	Phytase2)	FI (g/bird)			BWG (g/bird)			FCR
		1–10 d	1–24 d	1–35 d	1–10 d	1–24 d	1–35 d	1–10 d	1–24 d	1–35 d
Low	None	248.9	1,644.5	3,486.3	216.7	1,230.0	2,400.7	1.15	1.33	1.45
	Plus	257.9	1,688.8	3,502.3	219.7	1,256.5	2,405.5	1.17	1.34	1.46
Mid	None	250.0	1,631.9	3,432.4	222.2	1,246.4	2,367.7	1.13	1.32	1.45
	Plus	240.2	1,677.8	3,460.2	216.7	1,332.9	2,291.0	1.11	1.26	1.51
High	None	244.5	1,640.0	3,418.2	213.6	1,262.1	2,295.2	1.14	1.30	1.49
	Plus	238.3	1,662.5	3,339.8	222.9	1,303.9	2,312.0	1.12	1.27	1.45
SEM		11.5	59.58	109.27	11.05	48.67	89.58	0.02	0.06	0.04
Main effects
Na level
Low		253.4	1,666.6	3,494.3	218.2	1,243.2	2,403.1	1.16a	1.34	1.46
Mid		245.1	1,654.9	3,446.0	219.4	1,289.7	2,329.3	1.12b	1.29	1.48
High		241.4	1,651.3	3,379.0	213.3	1,283.0	2,303.6	1.13ab	1.29	1.47
Phytase
	Phytase
	None	247.8	1,638.8	3,445.6	217.5	1,246.1	2,354.5	1.14	1.32	1.46
	Plus	245.5	1,676.4	3,434.1	216.4	1,298.0	2,336.2	1.14	1.30	1.47
Source of variation
Na		ns	ns	ns	ns	ns	ns	*	ns	ns
Phytase		ns	ns	ns	ns	ns	ns	ns	ns	ns
Na × phytase		ns	ns	ns	ns	ns	ns	ns	ns	ns

Means were obtained from 6 replicates (6–8) birds per cage.

^a,bMeans within a column without common superscript are statistically different (p < 0.05).

¹⁾Low, 1.5 g Na/kg; Mid, 2.5 Na/kg; High, 3.5 g Na/kg.

²⁾None, without phytase; plus, with (500 U/kg) phytase.

^nsp > 0.05; ^* p < 0.05.

FI, feed intake; BWG, body weight gain; FCR, feed conversion ratio.