Table 5.

Effect of dietary L-serine supplementation on egg composition of laying hens fed the low crude protein diets.¹

Item2	Egg weight, g	Egg composition, %				Albumen solid, %
		Eggshell	Egg yolk	Albumen	Thick white
Wk 5
CON	58.20	10.45	23.80	66.03	36.54	12.44
LCP	57.93	10.53	23.41	66.22	34.50	12.15
LCP + Ser0.114	57.19	10.42	23.60	66.32	34.50	12.51
LCP + Ser0.306	57.34	10.53	23.72	65.75	34.83	12.60
LCP + Ser0.498	58.15	10.80	23.45	65.75	35.17	12.27
SEM	0.394	0.066	0.169	0.174	0.495	0.096
P-value
All groups	0.903	0.406	0.944	0.806	0.666	0.612
CON vs. LCP	0.803	0.500	0.339	0.583	0.210	0.381
LCP groups	0.896	0.084	0.956	0.706	0.967	0.506
Linear	0.795	0.035	0.942	0.290	0.609	0.779
Quadratic	0.747	0.067	0.849	0.576	0.876	0.305
Wk 10
CON	60.60	10.02	24.15	65.83	38.99	12.42
LCP	59.48	10.24	25.08	64.68	35.47	12.68
LCP + Ser0.114	59.56	10.31	25.03	64.66	37.14	12.50
LCP + Ser0.306	58.63	10.37	24.96	64.67	37.06	12.56
LCP + Ser0.498	59.41	10.30	25.35	64.35	38.28	12.68
SEM	0.280	0.064	0.167	0.209	0.447	0.068
P-value
All groups	0.334	0.410	0.145	0.133	0.101	0.688
CON vs. LCP	0.118	0.325	0.129	0.119	0.005	0.384
LCP groups	0.707	0.715	0.588	0.628	0.256	0.792
Linear	0.789	0.212	0.410	0.433	0.065	0.832
Quadratic	0.764	0.289	0.415	0.670	0.177	0.650

¹n = 8 replicates (6 eggs per replicate) per treatment.

²CON, the control diet (16.49% CP); LCP, the low crude protein diets (14.05% CP); LCP + Ser0.114 (0.306 or 0.498), the low crude protein diet supplemented with 0.114% (0.306% or 0.498%) L-serine.