Table 8.

Effects of different levels of dietary crude protein on nutrient digestibility in weaning pigs¹⁾

Criteria	Treatment2)						SEM	p-value3)
	CP16	CP17	CP18	CP19	CP20	CP21		L	Q
Nutrient digestibility (%)
Dry matter	94.20	94.3	95.24	95.04	94.48	94.18	0.301	0.97	0.31
Crude protein	93.47	93.14	93.52	93.80	93.00	92.07	0.407	0.46	0.47
Crude ash	84.54	84.82	84.71	84.29	84.49	82.74	0.894	0.64	0.71
Crude fat	82.40	80.68	80.50	80.10	80.05	81.33	1.019	0.76	0.57
Nitrogen retention (g/d)
N intake	12.15	12.22	13.24	14.04	14.56	15.07	-
Fecal N	0.75	0.83	1.20	1.23	1.33	1.33	0.114	<0.01	0.64
Urinary N	3.03	2.93	3.50	4.18	4.63	5.13	0.029	<0.01	0.21
N retention4)	8.38	8.47	8.54	8.63	8.60	8.62	0.079	<0.01	0.50

SEM, standard error of the mean.

¹⁾A total of 18 barrows (initial body weight, 8.41±0.371 kg).

²⁾CP16, corn-SBM-based diet (early weaning CP 16%/late weaning CP 15%); CP17, corn-SBM-based diet (early weaning CP 17%/late weaning CP 16%); CP18, corn-SBM-based diet (early weaning CP 18%/late weaning CP 17%); CP19, corn-SBM-based diet (early weaning CP 19%/late weaning CP 18%); CP20, corn-SBM-based diet (early weaning CP 20%/late weaning CP 19%); CP21, corn-SBM-based diet (early weaning CP 21%/late weaning CP 20%).

³⁾L, linear; Q, quadratic.

⁴⁾N retention = N intake (g) – fecal N (g) – urinary N (g).