Table 5. Effects of age (AG) and weight (WT) of gilts at first mating on blood metabolites of sows over three consecutive parities

		AG (days)			WT (kg)			SEM	p-value
		< 220	220–240	241 ≤	< 140	140–149	150 ≤	SEM	AG	WT	AG × WT
Plasma IGF-1 (ng/mL)
Breeding		171.8	165.1	162.9	175.6^a	165.9^b	158.3^b	3.7	0.077	0.011	0.236
Parity 1	Farrowing	158.7	153.2	154	155.9	156.4	153.6	2.67	0.344	0.625	0.347
Parity 1	Weaning	161.9	156.3	157.7	159.4	158.6	157.9	1.96	0.181	0.822	0.522
Parity 2	Farrowing	154.6	151.3	150.2	153.6	151.1	151.4	1.92	0.317	0.612	0.311
Parity 2	Weaning	159.9^a	155.1^ab	153.3^b	161.2^a	153.6^b	153.5^b	1.54	0.034	< 0.01	0.289
Parity 3	Farrowing	144.7	142.1	140.7	142.9	142.6	142	2.34	0.526	0.796	0.451
Parity 3	Weaning	147.9	146.8	147.1	146.8	148.1	146.9	2.13	0.944	0.866	0.417
Plasma leptin (ng/mL)
Breeding		2.93^b	3.17^ab	3.29^a	2.81^c	3.12^b	3.46^a	0.07	0.014	< 0.01	0.111
Parity 1	Farrowing	2.74^b	2.91^ab	2.99^a	2.61^c	2.89^b	3.14^a	0.05	0.010	< 0.01	0.185
Parity 1	Weaning	2.63^b	2.72^ab	2.87^a	2.56^b	2.67^b	2.99^a	0.05	0.025	< 0.01	0.298
Parity 2	Farrowing	2.85^b	2.92^ab	3.07^a	2.72^b	2.81^b	3.31^a	0.05	0.026	< 0.01	0.328
Parity 2	Weaning	2.73	2.82	2.91	2.64^b	2.91^a	2.91^a	0.05	0.083	0.01	0.587
Parity 3	Farrowing	2.71	2.73	2.78	2.72	2.75	2.75	0.03	0.396	0.622	0.622
Parity 3	Weaning	2.75	2.82	2.85	2.73	2.81	2.88	0.04	0.112	0.089	0.349

Means in column are significantly different (p < 0.01).
IGF, insulin-like growth factor.