Valine and isoleucine requirement of 20- to 45-kilogram pigs1,2

Abstract

Three experiments were conducted to determine the Val and Ile requirements in low-CP, corn-soybean meal (C-SBM) AA-supplemented diets for 20- to 45-kg pigs. All experiments were conducted for 26 to 27 d with purebred or crossbred barrows and gilts, which were blocked by initial BW. Treatments were replicated with 5 or 6 pens of 3 or 4 pigs per pen. At the beginning of Exp. 1 and the end of all experiments, blood samples were obtained from all pigs to determine plasma urea N (PUN) concentrations. All diets were C-SBM with 0.335% supplemental Lys to achieve 0.83% standardized ileal digestible (SID) Lys, which is the Lys requirement of these pigs. In Exp. 1, 0, 0.02, 0.04, 0.06, 0.08, or 0.10% L-Val was supplemented to achieve 0.51, 0.53, 0.55, 0.57, 0.59, or 0.61% dietary SID Val, and Thr, Trp, Met, and Ile were supplemented to maintain Thr:Lys, Trp:Lys, TSAA:Lys, and Ile:Lys ratios of 0.71, 0.20, 0.62, and 0.60, respectively. Also, supplemental Gly and Glu were added to all diets to achieve 1.66% Gly + Ser and 3.28% Glu, which is equal to the Gly + Ser and Glu content of a previously validated positive control diet that contained no supplemental AA. Treatment differences were considered significant at P < 0.10. Valine addition increased ADG, ADFI, and G:F in pigs fed 0.51 to 0.59% SID Val (linear, P < 0.08), but ADG and ADFI were decreased at 0.61% SID Val (quadratic, P ≤ 0.10). On the basis of ADG and G:F, the SID Val requirement is between 0.56 and 0.58% in a C-SBM diet supplemented with AA. In Exp. 2 and 3, 0, 0.02, 0.04, 0.06, or 0.08% L-Ile was supplemented to achieve 0.43, 0.45, 0.47, 0.49, or 0.51% dietary SID Ile, and Thr, Trp, Met, and Ile were supplemented to maintain Thr:Lys, Trp:Lys, TSAA:Lys, and Val:Lys ratios of 0.71, 0.20, 0.62, and 0.74, respectively. Also, supplemental Gly and Glu were added to achieve 1.66% Gly + Ser and 3.28% Glu as in Exp. 1. Data from Exp. 2 and 3 were combined and analyzed as 1 data set. Daily BW gain, ADFI, and G:F were not affected by Ile additions to the diet; however, ADFI was decreased among pigs fed the diet with 0.45% SID Ile (P < 0.10) compared with pigs fed the 0.43% SID Ile diet. Broken-line analysis requirements could not be estimated for the combined data from Exp. 2 or 3. The results of this research indicate that the SID Val requirement is between 0.56 to 0.58% (0.67 to 0.70 SID Val:Lys), and the Ile requirement is adequate at 0.43% SID Ile (0.52 SID Ile:Lys) for 20- to 45-kg pigs.

Requirement of standardized ileal digestible valine to lysine ratio for 8- to 14-kg pigs

“…There are not many experiments reporting the optimum SID Val : Lys ratio for the maximum growth performance of piglets. However, recent investigations indicate that the optimum SID Val : Lys ratio for piglets is ranging from 0.63 to 0.70 (Gaines et al, 2011;Gloaguen et al, 2011;Waguespack et al, 2012). The results of the present study showed that the maximum ADFI, ADG and G : .…”

Estimation of the standardized ileal digestible valine to lysine ratio required for 25- to 120-kilogram pigs fed low crude protein diets supplemented with crystalline amino acids1

“…Gaines et al (2011) concluded that the SID Val:Lys ratio for 21.4-to 32.6-kg growing pigs was approximately 0.65 based on a linear broken-line model and using growth performance as the response criteria. Waguespack et al (2012) demonstrated that for 20-to 45kg pigs, the SID Val:Lys ratio was about 0.67 to 0.70. In the present experiment, the dietary SID Val:Lys ratios required for 26-to 46-, 49-to 70-, 71-to 92-, and 94-to 119kg pigs were 0.62, 0.66, 0.67, and 0.68, respectively, using a linear broken-line model, which are similar to the NRC (2012) recommendations of 0.65, 0.65, 0.66, and 0.67 for 25-to 50-, 50-to 75-, 75-to 100-, and 100-to 130-kg pigs, respectively.…”

“…Much of the literature on the Val requirement summarized by NRC (2012) focused on weaned piglets. However, research on the requirements for Val for growing and finishing pigs is scarce and the results vary among the different studies (Lewis and Nishimura, 1995;Gaines et al, 2011;Waguespack et al, 2012). Therefore, the aim of this study was to evaluate the SID Val:Lys ratio required for growing and finishing pigs fed low CP diets supplemented with crystalline AA.…”

Amino acid requirement of growing and finishing pigs

“…A 10% reduction in the isoleucine concentration (below the requirement) resulted in a 15% reduction in feed intake and a 21% reduction in daily gain (Van Milgen et al, 2012). Waguespack et al (2012) investigated the SID isoleucine to lysine ratio in 20-45 kg pigs, fed low crude protein diets supplemented with crystalline AA ad libitum. They used corn-soybean meal diets without blood products.…”