Table 3.

Requirements for arginine and its endogenous synthesis in gestating gilts

	Amounts of arginine (g/d)
	Days 0 to 30	Days 30 to 60	Days 60 to 90	Days 90 to 114
Body weight of sows (kg)	155 to 160	160 to 170	170 to 185	185 to 200
Arginine requirements for maternal metabolism and conceptus growtha	15.48	16.47	17.36	19.86
Uptake of portal vein arginine by maternal liver	0.40	0.40	0.40	0.40
Placental growth	0.13	0.57	0.11	0.12
Embryonic/fetal growth	0.005	0.17	0.85	2.60
Allantoic fluid	0.005	0.005	0.000	0.000
Amniotic fluid	0.000	0.001	0.000	0.000
Arginine utilization for creatine synthesis	8.08	8.46	9.11	9.88
Dietary arginine for metabolism via non-arginase and non-NO synthase pathways in extra-intestinal tissues	5.04	5.04	5.04	5.04
2 kg diet (0.7% arginine)	14.0	14.0	14.0	14.0
Indigestible arginine in the diet (15%)	2.10	2.10	2.10	2.10
Intestinal catabolism (40% of arginine in the lumen)	4.76	4.76	4.76	4.76
Arginine provision from synthesis in mother plus fetus	≥ 3.58	≥ 4.57	≥ 5.46	≥ 7.96
(% of daily requirement for maternal metabolism and conceptus growth)	(23)	(28)	(32)	(40)

Adapted from Wu et al. (2013b). Gilts gestating 12 fetuses are fed daily 2 kg of a typical corn- and soybean meal–based diet (Li et al., 2010).

^aThe small intestine of the gestating sow uses 4.76 g of digestible dietary arginine per day. The rates of maternal arginine catabolism via arginase and NO synthase pathways in tissues other than the liver and gut are 2.0 and 0.10 g/d, respectively.