Table 3.
Effect of dietary available phosphorus levels with or without supplementation of phytase on egg quality of laying hens

Parameters	% of AP without phytase			% of AP with phytase			SEM	P-value
	0.20	0.25	0.30	0.20	0.25	0.30
Egg shell thickness (mm)
44 weeks	0.353	0.355	0.349	0.349	0.354	0.354	0.002	0.943
48 weeks	0.364	0.369	0.365	0.362	0.360	0.357	0.002	0.583
52 weeks	0.345	0.364	0.356	0.352	0.361	0.354	0.002	0.340
56 weeks	0.342	0.346	0.356	0.348	0.351	0.349	0.001	0.423
60 weeks	0.349	0.364	0.361	0.358	0.354	0.359	0.002	0.408
Egg shell breaking strength (kg/cm2)
44 weeks	2.66	2.80	2.75	2.74	2.74	2.63	0.04	0.872
48 weeks	2.68	2.62	2.81	2.74	2.67	2.58	0.04	0.551
52 weeks	2.47	2.53	2.56	2.40	2.47	2.32	0.05	0.701
56 weeks	2.48	2.43	2.68	2.35	2.44	2.61	0.04	0.246
60 weeks	2.82	2.87	2.92	3.09	2.94	3.07	0.07	0.832
Albumen height (mm)
44 weeks	8.46	8.32	8.57	8.51	8.22	8.20	0.08	0.708
48 weeks	8.09	8.04	8.20	8.03	7.93	8.19	0.08	0.927
52 weeks	7.84	7.44	7.83	7.48	7.76	7.43	0.09	0.489
56 weeks	8.80	8.85	8.83	8.75	8.80	8.35	0.08	0.425
60 weeks	8.21	8.02	8.28	8.47	8.22	8.03	0.09	0.738
Haugh unit score
44 weeks	91.20	90.10	91.73	90.74	89.64	90.01	0.44	0.744
48 weeks	88.52	88.63	89.46	87.65	88.02	89.17	0.45	0.872
52 weeks	88.06	85.61	87.29	85.44	87.67	85.95	0.50	0.503
56 weeks	92.69	92.88	93.20	93.26	93.94	91.24	0.44	0.630
60 weeks	89.62	88.60	89.66	91.08	89.94	87.93	0.52	0.596