Table 3.

Impacts of IUGR on growth and feed efficiency decrease with increasing age in pigs

Body weight	Total variance in ADG accounted for by BBW	Difference in ADG between IUGR pigs (1-kg BBW) and and large-birth-weight pigs (2-kg BBW)			Daily feed intake		Difference in gain: feed ratio between IUGR pigs (1-kg BBW) and large-birth-weight pigs (2-kg BBW)
		Gilts	Barrows	Both sexes	IUGR pigs with 1-kg BBW	Large-birth weight pigs with 2-kg BBW	Gilts	Barrows	Both sexes
kg	%	g/d			kg/d		(kg/kg)
46.7	12–13	83.4	81.4	82.4	1.62	1.63	0.051	0.050	0.050
64.6 kg	8–9	72.9	69.7	71.3	2.02	2.05	0.036	0.034	0.035
83.5 kg	4.7–5.3	39.7	53.0	46.4	2.30	2.34	0.017	0.023	0.020
102.5 kg	2.0–2.4	41.8	44.3	43.1	2.47	2.52	0.017	0.018	0.017

Adapted from Schinckel et al. [71]. This study involved 991 gilts and 977 barrows. BBW accounted for 14.4 and 13.0% of the variation in 158-d body weight in gilts and barrows, respectively. BBW accounted for 10.8 and 10.4% of the variation in 125-kg body weight in gilts and barrows, respectively. At 158-d body weight, gilts with 1-kg BBW had 10.6 kg less body weight than gilts with 2-kg BBW, whereas barrows with 1-kg BBW had 10.9 kg less body weight than barrows with 2-kg BBW. At the market weight (125-kg body weight), pigs with 1-kg BBW had 1% less lean tissue than pigs with 2-kg BBW. Gilts with 1-kg BBW require 13.3 more days to reach 125-kg body weight than gilts with 2-kg BBW, whereas barrows with 1-kg BBW require 12.6 more days to reach 125-kg body weight than barrows with 2-kg BBW. At the same body weight, daily feed intake did not differ between pigs with 1- and 2-kg BBW

ADG average daily gain; BBW birth body weight; DFI daily feed intake