. 2018 Nov 30;97(1):43–54. doi: 10.1093/jas/sky416

Table 5.

Effects of line (LRFI vs. HRFI¹) and diet sequence (control vs. complex) on longitudinal sampling of plasma concentration of NEFA, urea, glucose, and insulin of weaned pigs

		Line and dietary program					P ⁴
		LRFI		HRFI			P ⁴
Trait	Day³	Control	Complex	Control	Complex	SEM	Line	Diet	L × D
NEFA², µmol/L	Day −1	283^y	284^yz	303^y	317^y	9	0.82	0.33	0.87
	Day 6	263^c,y	316^{bc, y}	165^{ab, x}	157^a,x	13
	Day 19	57^x	49^x	36^w	61^w	3
	Day 42	293^{a, y}	516^{a, z}	589^b,z	874^c,z	36
Urea, mg/L	Day −1	178^b	180^ab,y	164^ab,xy	144^a,y	4	0.32	0.72	0.31
	Day 6	178^c	120^b,x	151^bc,xy	79^{a, x}	5
	Day 19	146^b	73^a,x	116^b,x	63^a,x	6
	Day 42	169	186^y	169^y	208^z	6
Glucose, mg/L	Day −1	1,484^z	1,455^z	1,378^z	1,374^z	15	0.02	0.99	0.69
	Day 6	1,114^y	1,066^y	1,121^y	1,133^y	12
	Day 19	1,021^x	968^x	967^x	975^x	14
	Day 42	1,108^c,xy	947^b,x	911^ab,w	820^a,w	18
Insulin, µU/L	Day −1	8.37^z	7.00^y	9.12^z	7.56^y	0.59	0.72	0.85	0.53
	Day 6	7.73^ab,z	7.94^b,y	6.63^ab,yz	4.91^a,y	0.30
	Day 19	6.78^y	7.92^y	6.20^xy	6.57^y	0.41
	Day 42	5.77^b,x	3.95^ab,x	3.13^a,x	2.56^a,x	0.36

^a,b,cFor a given day, means with different letters differed (P < 0.05) across treatments (line × diet combinations).

^w,x,y,zWithin a given combination of line and dietary treatment (column), means with different letters differed with time (P < 0.05).

¹LRFI = line selected for low residual feed intake; HRFI = line selected for high residual feed intake.

²NEFA = non-esterified fatty acid.

³Day −1 = day before weaning; day 6 = 6 d after weaning; day 19 = 19 d after weaning; day 42 = 42 d after weaning.

⁴ P-values of linear mixed models applied to each measure with the batch, the dietary program, the line, the day of sample collection as fixed effects, together with the interactions diet program × line, diet program × time, line × time, and diet program × line × time, the animal as a random factor, and BW at weaning as covariate. n = 33 pigs per combination of line and dietary sequence (total of 132 pigs). P-values for BW was P < 0.01 for NEFA, glucose, and insulin, and P = 0.09 for urea. The P-value for day of plasma collection was P < 0.0001 for NEFA, glucose, and insulin, and P = 0.08 for urea. The P-value for the interaction line × day of plasma collection was P < 0.01 for NEFA, glucose, and insulin, and not significant for urea (P = 0.45). The P-value for the interaction diet × day was P < 0.001 for urea, P = 0.07 for NEFA and insulin, and not significant for glucose (P = 0.15). Data for NEFA and insulin were log transformed before statistical analyses.