. 2022 Jan 27;9:233–239. doi: 10.1016/j.aninu.2022.01.001

Table 3.

Effects of different dietary protein levels and protein sources on nitrogen deposition in growing pigs.

Item	Factors and treatments								SEM	P-value
	Protein content		Protein source		Dietary treatment					P-value
	Normal (N)	Low (L)	CAS	CGM	N.CAS	L.CAS	L.CGM	N.CGM		PC	PS	PC × PS
NI, g/d	41.49^m	36.23ⁿ	38.24^x	39.77^y	40.61^b	35.88^d	37.41^c	42.36^a	0.16	<0.001	<0.001	0.150
UN, g/d	7.74^m	5.92ⁿ	6.18^y	7.65^x	6.83^ab	5.52^b	6.44^b	8.65^a	0.28	0.005	0.023	0.429
FN, g/d	8.84^m	6.88ⁿ	7.33	8.53	8.03^ab	6.62^b	7.19^b	9.64^a	0.29	0.003	0.074	0.374
NE, g/d	16.58^m	12.82ⁿ	13.50^y	16.18^x	14.86^b	12.14^b	13.63^b	18.30^a	0.37	<0.001	0.003	0.201
ND, g/d	24.67	23.77	24.59	23.85	25.42	23.73	23.77	24.07	0.42	0.194	0.383	0.355
NDR, %	59.96ⁿ	64.97^m	64.63^x	59.69^y	63.10^a	66.15^a	63.55^a	56.81^b	0.93	0.016	0.027	0.332
ABV, %	76.17^m	79.99ⁿ	79.94^x	75.86^y	78.79^ab	81.08^a	78.70^ab	73.54^b	0.87	0.045	0.040	0.418

N.CAS = diet with casein at normal protein levels; L.CAS = diet with casein at low protein levels; N.CGM = diet with corn gluten meal at normal protein levels; L.CGM = diet supplemented with corn gluten meal at low protein levels; SEM = standard error of the mean; PC = effect of protein content; PS = effect of protein source; PC × PS = interaction effect between protein content and source; NI = nitrogen intake; UN = urine nitrogen; FN = fecal nitrogen; NE = nitrogen excretion; ND = nitrogen deposition; NDR = nitrogen deposition rate; ABV = apparent biological value.

^a,b,c,d Different letters denote significant differences between experimental diets within each nitrogen deposition variable (P < 0.05).

^m,n Different letters denote significant differences between the normal and low protein groups within each nitrogen deposition variable (P < 0.05).

^x,y Different letters denote significant differences between the CAS and CGM groups within each nitrogen deposition variable (P < 0.05).