. 2020 Aug 26;99(11):5214–5221. doi: 10.1016/j.psj.2020.08.018

Table 5.

The effects of feeding systems on the oil weight in the preen gland (mean ± SE).

Aged (wk)	Feeding system	Oil weight (g)	Percentage of oil weight in gland weight (%)
Birthday	—	0.01 ± 0.00	12.46 ± 0.63
1	WP	0.14 ± 0.01^A	18.97 ± 0.51^A
	LWP	0.12 ± 0.02^B	17.43 ± 0.33^B
2	WP	0.51 ± 0.01^A	27.05 ± 0.51^A
	LWP	0.39 ± 0.03^B	24.78 ± 0.06^B
3	WP	1.11 ± 0.06^A	48.82 ± 0.28^A
	LWP	0.85 ± 0.01^B	40.05 ± 0.53^B
4	WP	1.33 ± 0.25^A	47.46 ± 1.61^A
	LWP	1.01 ± 0.10^B	42.15 ± 0.36^B
5	WP	1.75 ± 0.20^A	46.61 ± 0.90^A
	LWP	1.10 ± 0.12^B	41.64 ± 0.36^B
6	WP	2.18 ± 0.14^A	46.82 ± 0.23^A
	LWP	1.22 ± 0.07^B	41.07 ± 0.25^B
SEM		0.005	0.307
P-Value	Treatment	<0.001	<0.001
	Age	<0.001	<0.001
	Treatment∗Age	<0.001	<0.001

Mean values with different superscript in column between WP and LWP are significant different (P < 0.05).

Abbreviations: LWP, lack of water pool; WP, providing with water pool.