. 2019 Dec 31;99(3):1483–1490. doi: 10.1016/j.psj.2019.11.006

Table 4.

Effect of experimental diets on the eggshell ultrastructure of laying hens during the late laying period (52- to 60-week-old).

Items²	Treatments¹			SEM	P-value
Items²	CON	ITM	TRT	SEM	P-value
Palisade layer (μm)	241.42^a	217.58^b	241.10^a	4.75	<0.05
Mammillary layer (μm)	52.66	58.25	52.73	2.30	0.108
Total thickness (μm)	294.08^a	275.83^b	293.83^a	4.80	<0.05
Palisade layer (%)	82.02^a	78.97^b	82.22^a	0.80	<0.05
Mammillary layer (%)	17.98^b	21.03^a	17.78^b	0.80	<0.05
Mammillary knob width (μm)	89.89^a	88.91^a	61.53^b	4.57	<0.05

^a,bValues with different superscripts in the same row are different (P < 0.05).

CON (control), basal diet + inorganic trace minerals at commercial level; ITM, basal diet + inorganic trace minerals at 1/3 commercial level; TRT, basal diet + proteinated trace minerals at 1/3 commercial level.

Data are mean and SEM, calculated for 18 scanning electron microscope photographs of 9 eggs per treatment.