Leu In Diets Research Articles

172 Effects of Dietary Valine, Isoleucine, and Tryptophan Supplementations to Diets Containing Excess Leucine from Corn Protein on Growth Performance of Growing Pigs

Abstract An experiment was conducted to test the hypothesis that addition of Val, Ile, or Trp alone or in combination will reduce the negative effects of excess Leu in diets for growing pigs. A total of 288 growing pigs (28.6 ± 2.5 kg) were randomly assigned to 1 of 9 dietary treatments in a randomized complete block design. There were 2 barrows and 2 gilts in each pen and 8 replicate pens per treatment. A control diet based on corn and soybean meal and 8 diets based on corn and a high-protein corn product (48% crude protein) with 2 levels of crystalline L-Val (0 or 0.10%), L-Ile (0 or 0.10%), and L-Trp (0 or 0.05%) were formulated. The crystalline L-Val, L-Ile, and L-Trp increased standardized ileal digestible (SID) Val:Lys from 70 to 80%, SID Ile:Lys from 53 to 63%, and SID Trp:Lys from 18 to 23%, respectively. All diets were formulated to contain 1.00% SID Lys and the 8 diets containing corn protein contained 171% SID Leu:Lys. Individual pig weights were recorded at the beginning and at the conclusion of the 28-d experiment. Data were analyzed using the PROC MIXED of SAS with a pen as the experimental unit. Diet was the fixed effect and block and replicate within block were random effects. Results indicated that final body weight and average daily gain were not different between pigs fed the control diet and pigs fed the diet with Val and Trp addition, but greater (P < 0.001) than for pigs fed the diet with Val addition, Ile addition, Trp addition, Val and Ile addition, Ile and Trp addition, or Val, Ile, and Trp addition (Table 1). In conclusion, addition of Val and Trp to diets with excess Leu may prevent negative effects of excess Leu in diets for growing pigs.

Improving performance of finishing pigs with added valine, isoleucine, and tryptophan: validating a meta-analysis model.

Based on results of a recent meta-analysis, we hypothesized that increased dietary Val, Ile, or Trp could correct possible amino acid interactions because of excess Leu in diets containing high levels of corn protein, namely dried distiller's grains with solubles (DDGS). A total of 1,200 pigs (PIC TR4 × (Fast LW × PIC L02); initially 33.6 ± 0.6 kg) were used in a 103-d study. The 6 dietary treatments were corn-soybean meal (SBM)-DDGS-based as follows: (1) high SBM and low level of l-Lys HCl (HSBM), (2) high l-Lys HCl and moderate Ile, Val, Trp (AA above NRC 2012 estimates; NC), (3) moderate l-Lys HCl and high Ile, Val, and Trp (PC), and PC with either increased (4) L-Val (PC+Val), (5) L-Ile (PC+Ile), or (6) L-Trp (PC+Trp). Pigs fed the NC diet were predicted to have the poorest average daily gain (ADG), the PC diet to be intermediate, and pigs fed the HSBM, PC+Val, PC+Ile, and PC+Trp have the same and highest predicted ADG. In the grower period (34 to 90 kg), ADG was greater (Ρ < 0.05) for the pigs fed HSBM and PC+Val diets than the NC with pigs fed other diets intermediate. Pigs fed HSBM were more (Ρ < 0.05) efficient (G:F) than the NC and PC with pigs fed other diets intermediate. In the finisher period (90 to 136 kg), ADG was greater (Ρ < 0.05) for pigs fed PC+Ile than that of the NC with pigs fed other diets intermediate. Pigs fed PC+Val had greater (Ρ < 0.05) average daily feed intake (ADFI) than the NC with pigs fed other diets intermediate. However, PC+Ile pigs were more (Ρ < 0.05) efficient than PC+Val with pigs fed other diets intermediate. Overall, ADG was greater (Ρ < 0.05) for pigs fed HSBM, PC+Val, and PC+Ile diets than the NC with pigs fed other diets intermediate. Pigs fed the PC+Val diet had greater (Ρ < 0.05) ADFI than the NC with pigs fed other diets intermediate. No differences were detected between treatments for overall G:F or other carcass characteristics. In conclusion, increasing Val or Ile in high l-Lys-HCl-DDGS-based diets improved growth performance compared with pigs fed diets containing high levels of l-Lys HCl without added Val and Ile. These results present evidence that the recently developed meta-analysis can predict the relative differences in overall ADG for pigs fed the NC, PC, PC+Val, and PC+Ile diets; however, the predicted G:F was less accurate. The data demonstrate that the negative effects of high Leu concentrations in corn-DDGS-based diets can be reversed by increasing the ratios of Val and Ile relative to Lys.

48 Effects of dietary isoleucine and valine supplementation to excess or low leucine diets on nitrogen balance and metabolism of branched-chained amino acids in growing pigs

Abstract An experiment was conducted to test the hypothesis that Ile and Val supplementation may overcome detrimental effects of excess dietary Leu on N balance and metabolism of branched-chained AA (BCAA) in growing pigs. A total of 144 barrows (28.5 ± 2.5 kg) were housed in metabolism crates and randomly assigned to 18 diets. The basal diet contained 0.98% standardized ileal digestible (SID) Lys and had SID Leu, Val, and Ile ratios to SID Lys of 100, 60, and 43%, respectively. Two levels of synthetic L-Leu (0 or 2.0%), 3 levels of synthetic L-Ile (0, 0.1, or 0.2%), and 3 levels of synthetic L-Val (0, 0.1, or 0.2%) were added to the basal diet for a total of 18 diets in a 2 × 3 × 3 factorial. Urine and fecal samples were collected for 5 d after 7 d of adaptation. Blood, skeletal muscle, and liver samples were collected at the conclusion of the experiment. Data were analyzed as a 2 × 3 × 3 factorial using the PROC MIXED of SAS with concentrations of Leu, Val, and Ile, and all interactions as main effects and replicate as random effect. No interactions among main effects were observed, but excess Leu in diets reduced (P &amp;lt; 0.05) N retention and biological value of diets and increased (P &amp;lt; 0.05) plasma urea N (PUN). However, PUN was reduced (P &amp;lt; 0.05) as dietary Val increased. Concentrations of BCAA in liver were greater (P &amp;lt; 0.05) in pigs fed excess-Leu diets than in pigs fed low-Leu diets, but concentrations of BCAA in muscle were greater (P &amp;lt; 0.05) in pigs fed low-Leu diets. In conclusion, excess dietary Leu reduced N retention and biological value of diets and increased PUN in growing pigs, but Val supplementation may help overcome negative effects of excess Leu.

207 Improving Performance of Finishing Pigs with Added Val, Ile, and Trp: Validating a Meta-analysis Model

Abstract Based on a recent meta-analysis, we hypothesized that increased dietary Val, Ile, or Trp could correct possible amino acid interactions caused by high dietary Leu in diets containing high levels of corn protein, namely dried distillers grains with solubles (DDGS). A total of 1,200 pigs (PIC TR4×(Fast LW×PIC L02); initially 33.6±0.63 kg) were used in a 103-d study. The 6 dietary treatments were corn-soybean meal-DDGS-based diets as follow: low level of Lys-HCl (SBM), high Lys-HCl and moderate Ile, Val, Trp (NC; AA above NRC 2012 estimates), moderate Lys-HCl and high Ile, Val, Trp (PC), and PC with either increased L-Val (Val), L-Ile (Ile), or L-Trp (Trp). Diets contained 30% DDGS until pigs reached approximately 100 kg and then 20% DDGS until market. Data were analyzed as a randomized complete block design using lmer function in lme4 package in R with pen considered as the experimental unit, body weight as blocking factor, and treatment as a fixed effect with 10 replicates/treatment. Overall final BW and ADG were greater for pigs fed SBM, Val, and Ile diets than the NC with PC and Trp intermediate. Pigs fed the Val diet had greater (R&amp;lt; 0.05) ADFI than the NC with pigs fed SBM, PC, Ile, and Trp intermediate. No differences were detected between treatments for G:F. In conclusion, increasing Val or Ile in high Lys-HCl-DDGS-based diets improved growth performance and final BW compared with pigs fed diets containing high levels of HCl-Lys without added Val and Ile. These results demonstrate that negative effects of high Leu in corn-DDGS-based diets can be overcome by increasing the ratios of Val and Ile to Lys.

Effects on nitrogen balance and metabolism of branched-chain amino acids by growing pigs of supplementing isoleucine and valine to diets with adequate or excess concentrations of dietary leucine.

Diets based on high levels of corn protein have elevated concentrations of Leu, which may negatively affect N retention in pigs. An experiment was, therefore, conducted to test the hypothesis that Ile and Val supplementation may overcome the detrimental effects of excess dietary Leu on N balance and metabolism of branched-chain amino acids (BCAA) in growing pigs. A total of 144 barrows (initial body weight: 28.5 kg) were housed in metabolism crates and randomly assigned to 1 of 18 dietary treatments. The basal diet contained 0.98% standardized ileal digestible (SID) Lys and had SID Leu, Val, and Ile ratios to SID Lys of 100%, 60%, and 43%, respectively. Crystalline l-Leu (0% or 2.0%), l-Ile (0%, 0.1%, or 0.2%), and l-Val (0%, 0.1%, or 0.2%) were added to the basal diet resulting in a total of 18 dietary treatments that were arranged in a 2 × 3 × 3 factorial. Urine and fecal samples were collected for 5 d after 7 d of adaptation. Blood, skeletal muscle, and liver samples were collected at the conclusion of the experiment. There were no three-way interactions among the main effects. Excess Leu in diets reduced (P < 0.05) N retention and biological value of protein and increased (P < 0.001) plasma urea N (PUN), but PUN was reduced (P < 0.05) as dietary Val increased. Concentrations of Leu in the liver were greater (P < 0.001) in pigs fed excess Leu diets than in pigs fed adequate Leu diets, but concentrations of BCAA in muscle were greater (P < 0.05) in pigs fed low-Leu diets. Increasing dietary Ile increased (P < 0.001) plasma-free Ile and plasma concentration of the Ile metabolite, α-keto-β-methylvalerate, but the increase was greater in diets without excess Leu than in diets with excess Leu (interaction, P < 0.001). Plasma concentrations of Val and the Val metabolite α-keto isovalerate increased (P < 0.001) with increasing dietary Val in diets with adequate Leu, but not in diets with excess Leu (interaction, P < 0.001). Increasing dietary Leu increased (P < 0.001) plasma-free Leu and plasma concentration of the Leu metabolite, α-keto isocaproate (KIC). In contrast, increased dietary Val reduced (P < 0.05) the plasma concentration of KIC. In conclusion, excess dietary Leu reduced N retention and increased PUN in growing pigs, but Val supplementation to excess Leu diets may increase the efficiency of amino acid utilization for protein synthesis as indicated by reduced PUN.

Improving Performance of Finishing Pigs with Added Valine, Isoleucine, and Tryptophan: Validating a Meta-Analysis Model

Based on a recent meta-analysis, we hypothesized that increased dietary Val, Ile, or Trp could correct possible amino acid interactions caused by high dietary Leu in diets containing high levels of corn protein, namely dried distillers grains with solubles (DDGS). A total of 1,200 pigs (PIC TR4 × (Fast LW × PIC L02); initially 74.0 ± 1.38 lb) were used in a 103-d study. The 6 dietary treatments were corn-soybean meal- DDGS-based diets as follows: 1) low level of Lys-HCl (HSBM), 2) high Lys-HCl and moderate Ile, Val, Trp (NC; AA above NRC4 estimates), 3) moderate Lys-HCl and high Ile, Val, Trp (PC), and 4) PC with either increased L-Val (PC+Val), 5) L-Ile (PC+Ile), or 6) L-Trp (PC+Trp). Diets contained 30% DDGS until pigs reached approximately 217 lb, and then pigs were fed diets with 20% DDGS until market. Data were analyzed as a randomized complete block design using the lmer function in the lme4 package in R with pen considered as the experimental unit, body weight, and pen location as a blocking factor, and treatment as a fixed effect with 10 replicates/treatment.

Nutrition, Metabolism, and Fertility in Dairy Cows: 3. Amino Acids and Ovarian Function

Plasma insulin concentrations influence resumption of ovarian activity in postpartum dairy cows, and plasma insulin can be manipulated by changing dietary starch and fat supply. The objective of this experiment was to investigate the role of dietary amino acids in altering peripheral metabolic hormones and ovarian function. Thirty-two cows were fed a standard diet from calving until 40 d in milk (DIM), and then 8 cows were transferred to each of 4 dietary treatments until 70 DIM. The 4 diets were designed to supply either low (diets 1 and 2) or high (diets 3 and 4) levels of metabolizable protein (MP), containing either low (diet 1 and 3) or high (diets 2 and 4) proportions of Leu. Leucine was manipulated with heat-treated lupins and corn gluten meal. Estrus was synchronized at 60 DIM. Between 60 and 70 DIM, energy intake and energy balance were similar among diet groups, although cows receiving high MP containing high Leu had a greater milk yield than other groups (means: 37.8, 37.1, 37.4, 39.4±standard error 0.85 kg/d for diets 1 to 4, respectively). Interactions between MP and Leu were found for insulin, glucagon, and the ratio between them. Insulin was not affected by Leu in diets with low MP but was decreased by greater Leu in diets with high MP (means: 0.37, 0.32, 0.46, 0.39±SE 0.031 ng/mL for diets 1 to 4, respectively). Glucagon was not affected by MP in diets with low Leu but was increased by greater MP in diets with high Leu (means: 92, 81, 88, 95±SE 6.0 pg/mL for diets 1 to 4, respectively). For the low-MP treatments, the insulin-to-glucagon ratio was greater with high Leu; for the high-MP treatments, the insulin-to-glucagon ratio was greater with low Leu (means: 4.28, 5.42, 5.16, 4.22±SE 0.456 for diets 1 to 4, respectively). There was no effect of MP or Leu on ovarian follicle numbers or reproductive hormones. Based on hormonal and ovarian responses, we conclude that altering metabolic hormones through manipulation of amino acid supply and balance is unlikely to have a significant effect on ovarian function in dairy cows.