. 2019 Jun 28;97(8):3472–3486. doi: 10.1093/jas/skz213

Table 6.

Nitrogen intake and utilization of dietary N (in % of intake) in sows fed increasing dietary SID CP levels

	Treatment, % SID CP							Week				P-value¹
	11.8	12.8	13.4	14	14.7	15.6
Item²	1	2	3	4	5	6	SEM	1	2	3	SEM	Trt³	Week	Linear	Cubic
No. sows	11	12	12	11	12	12		72	72	72		-	-	-	-
Realized N intake, g/d	141.2^c	151.6^bc	157.3^ab	165.7^ab	156.9^ab	173.9^a	4.99	105.2^C	156.7^B	212.0^A	3.15	<0.001	<0.001	***	NS
Realized SID N intake, g/d	124.0^c	131.7^bc	138.4^ab	142.6^ab	136.6^ab	147.8^a	4.00	90.6^C	137.7^B	182.5^A	2.63	<0.001	<0.001	***	NS
Milk N utilization	77.8^a	69.5^ab	68.2^ab	66.3^b	71.0^ab	63.1^b	3.54	72.0^A	78.3^A	57.4^B	2.96	<0.01	<0.001	***	*
Urine N excretion	18.5^b	17.4^b	23.4^ab	23.4^ab	27.4^a	24.7^ab	2.38	27.0^A	23.1^B	17.1^C	1.85	<0.01	<0.001	***	*
Fecal N excretion	13.0^a	12.1^ab	12.2^ab	11.6^bc	10.6^c	10.8^c	0.35	9.53^C	12.0^B	13.6^A	0.24	<0.001	<0.001	***	NS
Total N output	110.7	101.9	108.1	103.8	110.2	98.9	5.37	111.8^A	116.4^A	88.4^B	4.24	0.31	<0.001	NS	NS
Corrected milk N utilization⁴	68.6	67.3	64.7	63.5	61.6	64.2	2.51	61.6^B	64.3^B	68.8^A	1.90	0.22	<0.01	*	NS

^a,b,cTreatment means with different superscript letters differ significantly (P < 0.05).

^A-CWk means with different superscript letters differ significantly (P < 0.05).

¹No quadratic effects were observed P > 0.05. P-values for linear and cubic treatment effects: NS = not significant, * < 0.05, ** < 0.01, *** < 0.001.

²Items are presented as % of N intake unless otherwise is noted.

³Dietray treatment.

⁴Milk N utilization corrected for N retention was calculated for individual sows each week as milk N utilization divided by total N output relative to N intake.