Table 1. Effect of rice hull bedding depths on growth performance of White Pekin ducks until 42 days of age

Items	Bedding depths (cm)				SEM	p-value
Items	4	8	12	16	SEM	p-value
Body weight (g)
Day 1	47.95	48.09	47.86	48.05	0.117	0.908
Day 7	254.87^a	253.17^a	256.41^ab	263.87^b	1.341	0.014
Day 14	678.00^a	684.67^a	686.57^a	734.07^b	6.671	0.003
Day 21	1,266.45^a	1,272.43^ab	1,287.38^ab	1,322.84^b	7.910	0.040
Day 28	1,627.76^a	1,630.32^a	1,693.41^a	1,806.77^b	18.874	0.000
Day 35	2,169.34^a	2,174.67^a	2,219.42^ab	2,353.29^b	24.635	0.017
Day 42	2,717.03^a	2,727.91^a	2,797.57^ab	3,057.29^b	44.906	0.013
Average daily gain (g/d)
Day 7	36.16^a	36.41^a	36.63^ab	37.69^b	0.191	0.015
Day 14	64.64^a	60.45^a	61.45^a	67.17^b	0.821	0.007
Day 21	73.47	73.55	75.10	73.59	0.771	0.874
Day 28	59.65	60.21	67.67	80.65	2.388	0.148
Day 35	77.76	77.46	75.145	78.07	2.285	0.973
Day 42	79.03	78.14	82.59	100.57	3.745	0.503
Day 1–21	174.90	174.07	177.07	182.11	0.993	0.239
Day 22–42	207.92	207.22	215.74	247.77	0.185	0.558
Day 1–42	382.83	381.29	392.81	429.89	5.294	0.222
Average daily feed intake (g/d)
Day 7	34.36^a	34.86^a	38.65^ab	41.82^b	0.814	0.001
Day 14	79.60	76.80	80.33	85.29	1.392	0.185
Day 21	132.88	131.89	138.98	145.95	2.208	0.078
Day 28	156.54	156.88	157.02	159.18	1.336	0.909
Day 35	145.20	151.07	152.86	171.65	3.800	0.067
Day 42	179.37^a	181.87^a	191.73^ab	222.15^b	5.229	0.006
Day 1–21	243.55	246.85	257.96	273.10	2.138	0.279
Day 22–42	489.82	481.13	501.61	551.01	6.023	0.907
Day 1–42	733.38	727.98	759.57	824.11	6.915	0.479
Feed conversion ratio (g/g)
Day 7	0.94^a	0.96^a	1.05^ab	1.11^b	0.020	0.003
Day 14	1.18	1.14	1.21	1.21	0.014	0.258
Day 21	1.26	1.24	1.26	1.33	0.015	0.184
Day 28	1.66	1.64	1.61	1.59	0.009	0.057
Day 35	1.75	1.69	1.71	1.70	0.014	0.544
Day 42	1.86	1.84	1.81	1.75	0.019	0.219
Day 1–21	1.11	1.12	1.17	1.21	0.039	0.755
Day 22–42	1.72	1.75	1.71	1.68	0.028	0.975
Day 1–42	1.41	1.44	1.44	1.44	0.067	0.514
Mortality (%)	2.77	4.16	4.16	1.38	0.840	0.628
Footpad dermatitis (%)	0.66	0.16	0	0	0.840	0.234

Means in the same row with different superscripts are significantly different (p < 0.05).