Table 7.

Hen weight, internal organ weight and serum uric acid level.

Hen age, wk	Variable	SP 1	RP2	RP-Arg3	RP-GAA3	RP-Cit3	SEM	P-value
20	Hen BW, g	1,924	1,941	1,941	1,939	1,932	13.24	0.994
30	Hen BW, g	2,015	1,988	1,936	1,875	1,947	16.54	0.076
40	Hen BW, g	2,078c	1,974bc	1,893b	1,699a	1,908b	20.88	<0.001
40	Liver weight, g	41.75	42.08	38.84	35.06	38.42	1.30	0.432
40	Liver weight per BW, g/kg	19.55	20.79	21.15	19.59	21.15	0.56	0.806
40	Ovary weight, g	42.53b	41.49b	36.54ab	27.98a	35.14ab	1.38	0.003
40	Ovary weight per BW, g/kg	19.91ab	20.53b	19.82ab	15.61a	19.32ab	0.57	0.041
40	Oviduct weight, g	70.00	54.48	64.38	56.61	64.55	2.39	0.228
40	Oviduct weight per BW, g/kg	32.55	27.17	35.12	32.65	35.90	1.26	0.208
40	Oviduct length, cm	67.50	66.60	67.10	58.75	66.20	1.11	0.062
40	Oviduct length per BW, cm/kg	31.75	33.06	36.67	33.47	37.61	0.77	0.071
40	Serum uric acid, mg/dL	3.744b	2.698ab	2.849ab	2.547a	2.665ab	0.114	0.043

GAA = guanidinoacetic acid; Cit = citrulline; BW = body weight.

^{a, b} Differing superscripts indicate significant differences between means.

¹SP: standard protein diet with 17% CP.

²RP: reduced protein diet with 13% CP.

³l-Arg, GAA and l-Cit were added on top of the RP diets at 0.35%, 0.46% and 0.35% in diets, RP-Arg, RP-GAA and RP-Cit, respectively, to the level of Arg in SP.