Table 4. Effects of dietary energy and crude protein levels in the diets of gestating sows on reproductive performance and litter performance

Energy CP (%)	ME 13.40 MJ /kg (%)			ME 13.82 MJ/kg (%)			SEM	p-value
	10.5	12	13.5	10.5	12	13.5		ME	CP	M × C
No. of sows	10	10	10	10	9	10
Litter size, no. of piglets
Total born	12.90	10.40	12.90	13.80	13.44	13.50	0.426	0.07	0.30	0.44
Born alive	12.90	10.40	12.30	13.30	13.22	12.40	0.395	0.17	0.39	0.31
After cross-fostering	11.40	11.80	11.80	11.50	11.56	11.88	0.093	0.81	0.31	0.75
No. of deaths upon weaning	0.20c	0.60b	0.50b	0d	1.00a	0.88a	0.508	0.48	0.03	0.48
Weaning pigs (d 21)	11.20b	11.20b	11.30ab	11.50a	10.56c	11.00bc	0.127	0.43	0.34	0.31
Litter weight (kg)
At birth	18.58	16.44	19.55	19.34	18.64	18.31	0.477	0.55	0.35	0.35
After cross-fostering	17.41	19.06	18.96	17.18	16.66	17.96	0.289	0.04	0.23	0.28
Day 21 of lactation	66.38	72.95	69.55	69.32	66.96	64.89	1.286	0.33	0.65	0.32
Weight gain (d 0–21, kg)	48.97	53.89	50.59	52.14	50.30	46.94	1.200	0.58	0.53	0.43
Piglet weight (kg)
At birth	1.47	1.62	1.54	1.41	1.39	1.41	0.028	0.02	0.75	0.31
After cross-fostering	1.53	1.61	1.61	1.50	1.44	1.52	0.022	0.03	0.63	0.43
Day 21 of lactation	5.94	6.51	6.14	6.02	6.33	5.86	0.084	0.41	0.06	0.63
Weight gain (d 0–21, kg)1)	4.41	4.90	4.53	4.53	4.89	4.34	0.080	0.81	0.04	0.71

Quadratic response (p < 0.05) to dietary CP levels when a significant CP effect was detected.
Means with different superscripts in the same row differ significantly (p < 0.05).
CP, crude protein; ME, metabolizable energy; SEM, Standard error of means.