scholarly journals Excess dietary leucine in diets for growing pigs reduces growth performance, biological value of protein, protein retention, and serotonin synthesis1

2019 ◽  
Vol 97 (10) ◽  
pp. 4282-4292 ◽  
Author(s):  
Woong B Kwon ◽  
Kevin J Touchette ◽  
Aude Simongiovanni ◽  
Kostas Syriopoulos ◽  
Anna Wessels ◽  
...  

Abstract An experiment was conducted to test the hypothesis that excess dietary Leu affects metabolism of branched-chain amino acids (BCAA) in growing pigs. Forty barrows (initial body weight [BW]: 30.0 ± 2.7 kg) were housed individually in metabolism crates and allotted to 5 dietary treatments (8 replicates per treatment) in a randomized complete block design. The 5 diets were based on identical quantities of corn, soybean meal, wheat, and barley and designed to contain 100%, 150%, 200%, 250%, or 300% of the requirement for standardized ileal digestible Leu. Initial and final (day 15) BW of pigs were recorded. Daily feed consumption was also recorded. Urine and fecal samples were collected for 5 d following 7 d of adaptation to the diets. At the end of the experiment, blood and tissue samples were collected to analyze plasma urea N (PUN), plasma and hypothalamic serotonin, tissue BCAA, serum and tissue branched-chain α-keto acids, and messenger ribonucleic acid abundance of genes involved in BCAA metabolism. Results indicated that acid detergent fiber, average daily feed intake, and gain-to-feed ratio decreased (linear, P < 0.05) as dietary Leu increased. A trend (linear, P = 0.082) for decreased N retention and decreased (linear, P < 0.05) biological value of dietary protein was also observed, and PUN increased (linear, P < 0.05) as dietary Leu increased. A quadratic reduction (P < 0.05) in plasma serotonin and a linear reduction (P < 0.05) in hypothalamic serotonin were observed with increasing dietary Leu. Concentrations of BCAA in liver increased (linear, P < 0.001), whereas concentrations of BCAA in skeletal muscle decreased (linear, P < 0.05) as dietary Leu increased. Concentration of α-ketoisovalerate was reduced (linear and quadratic, P < 0.001) in liver, skeletal muscle, and serum, and α-keto-β-methylvalerate was reduced (linear, P < 0.001; quadratic, P < 0.001) in skeletal muscle and serum. In contrast, α-keto isocaproate increased (linear, P < 0.05) in liver and skeletal muscle and also in serum (linear and quadratic, P < 0.001) with increasing dietary Leu. Expression of mitochondrial BCAA transaminase and of the E1α subunit of branched-chain α-keto acid dehydrogenase increased (linear, P < 0.05) in skeletal muscle as dietary Leu increased. In conclusion, excess dietary Leu impaired growth performance and nitrogen retention, which is likely a result of increased catabolism of Ile and Val, which in turn reduces availability of these amino acids resulting in reduced protein retention, and excess dietary Leu also reduced hypothalamic serotonin synthesis.

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 65-66
Author(s):  
Woong B Kwon ◽  
Kevin J Touchette ◽  
Aude Simongiovanni ◽  
Kostas Syriopoulos ◽  
Anna Wessels ◽  
...  

Abstract The hypothesis that excess dietary Leu affects growth performance and metabolism of branched-chain amino acids (BCAA) in growing pigs was tested. Forty barrows (30.0 ± 2.7 kg) were placed in metabolism crates and randomly allotted to 5 diets that contained 100, 150, 200, 250, or 300% of the requirement for standardized ileal digestible Leu. Initial and final body weight of pigs and daily feed provisions were recorded. Urine and fecal samples were collected for 5 d to measure N balance and biological value of diets. At the conclusion of the experiment, blood, brain, liver, and muscle samples were collected and average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F) were calculated. Orthogonal polynomial contrasts were used to determine linear and quadratic effects of increasing Leu in the diets. Results indicated that ADG, ADFI, and G:F decreased (linear, P < 0.05) as dietary Leu increased (Table 1). A trend (linear, P = 0.082) for decreased N retention and decreased (linear, P < 0.05) biological value of protein was also observed. Plasma urea N increased (linear, P < 0.05) and a quadratic reduction (P < 0.05) in plasma serotonin and a linear reduction (P < 0.05) in cerebral serotonin were observed with increasing dietary Leu. Concentrations of BCAA in liver increased (linear, P < 0.001), concentrations of BCAA in muscle decreased (linear, P < 0.05), concentration of α-keto-isovalerate was reduced (linear and quadratic, P < 0.001) in liver, muscle, and serum, and α-keto-β-methylvalerate was reduced (linear and quadratic, P < 0.001) in muscle and serum, whereas α-keto-isocaproate increased (linear, P < 0.05) in liver and muscle, and in serum (linear and quadratic, P < 0.001) with increasing dietary Leu. In conclusion, excess dietary Leu reduced growth performance and cerebral serotonin and tended to reduce protein synthesis.


2020 ◽  
Vol 98 (11) ◽  
Author(s):  
Woong B Kwon ◽  
Jose A Soto ◽  
Hans H Stein

Abstract 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 &lt; 0.05) N retention and biological value of protein and increased (P &lt; 0.001) plasma urea N (PUN), but PUN was reduced (P &lt; 0.05) as dietary Val increased. Concentrations of Leu in the liver were greater (P &lt; 0.001) in pigs fed excess Leu diets than in pigs fed adequate Leu diets, but concentrations of BCAA in muscle were greater (P &lt; 0.05) in pigs fed low-Leu diets. Increasing dietary Ile increased (P &lt; 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 &lt; 0.001). Plasma concentrations of Val and the Val metabolite α-keto isovalerate increased (P &lt; 0.001) with increasing dietary Val in diets with adequate Leu, but not in diets with excess Leu (interaction, P &lt; 0.001). Increasing dietary Leu increased (P &lt; 0.001) plasma-free Leu and plasma concentration of the Leu metabolite, α-keto isocaproate (KIC). In contrast, increased dietary Val reduced (P &lt; 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.


1985 ◽  
Vol 40 (1) ◽  
pp. 153-160 ◽  
Author(s):  
S. J. Taylor ◽  
D. J. A. Cole ◽  
D. Lewis

ABSTRACTThe response of the growing female pig (25 to 55 kg live weight) to increasing dietary isoleucine supplies at two levels of dietary leucine was assessed by measurement of growth rate, food utilization, tissue deposition as indicated by ham dissection and changes in plasma urea concentration. A range of isoleucine concentrations from 3·7 g/kg to 5T g/kg of the diet was derived from a basal diet and seven increments of L-isoleucine. Synthetic L-leucine was added to the basal diet to increase the concentration from 12 g/kg to 15 g/kg to achieve the two levels. The basal diet was formulated using barley, maize, blood meal, yeast protein, fat and tapioca with synthetic amino acids included to maintain at least 9·5 g/kg lysine and adequate concentrations of other essential amino acids and non-essential nitrogen. The 16 diets were replicated four times and fed to 64 female growing pigs once daily according to a restricted feeding scale. Blood samples were taken from each pig at 40 kg live weight for the determination of plasma urea nitrogen.The addition of synthetic leucine to the basal diet had no consistent effect on growth performance or carcass quality, although it did result in elevated levels of plasma urea nitrogen. The response of growth performance and the composition of the ham joint to increasing dietary isoleucine concentration was interpreted by broken line functions which indicated an isoleucine requirement of 4·4 to 4·5 g/kg of the diet.


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 33-33
Author(s):  
Woong B Kwon ◽  
Jose A Soto ◽  
Hans H Stein

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 &lt; 0.05) N retention and biological value of diets and increased (P &lt; 0.05) plasma urea N (PUN). However, PUN was reduced (P &lt; 0.05) as dietary Val increased. Concentrations of BCAA in liver were greater (P &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 &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.


2000 ◽  
Vol 84 (2) ◽  
pp. 157-163 ◽  
Author(s):  
T. Obitsu ◽  
D. Bremner ◽  
E. Milne ◽  
G. E. Lobley

The effect of abomasal infusion of glucose (120 kJ/d per kg body weight (BW)0·75, 758 mmol/d) on urea production, plasma alanine-N flux rate and the conversion of alanine-N to urea was studied in sheep offered a low-N diet at limited energy intake (500 kJ/d per kg BW0·75), based on hay and grass pellets. Glucose provision reduced urinary N (P= 0·040) and urea (P= 0·009) elimination but this was offset by poorer N digestibility. Urea-N production was significantly reduced (822v. 619 mmol/d,P= 0·024) by glucose while plasma alanine-N flux rate was elevated (295v. 342 mmol/d,P= 0·011). The quantity of urea-N derived from alanine tended to be decreased by glucose (127v. 95 mmol/d) but the fraction of urea production from alanine was unaltered (15 %). Plasma urea and alanine concentrations (plus those of the branched chain amino acids) decreased in response to exogenous glucose, an effect probably related to enhanced anabolic usage of amino acids and lowered urea production.


2021 ◽  
Vol 100 (1) ◽  
Author(s):  
Olufemi Oluwaseun Babatunde ◽  
Olayiwola Adeola

Abstract Two experiments were carried out to determine a time-series effect of phytase on phosphorus (P) utilization in growing and finishing pigs using growth performance, apparent total tract digestibility (ATTD) of nutrients, P excretion, and plasma concentrations of minerals as the response criteria for evaluation. In both experiments, treatments were arranged as a 3 × 4 factorial in a randomized complete block design with 3 corn–soybean meal-based diets including a P-adequate positive control (PC), a low-P negative control (NC; no inorganic P), and NC supplemented with phytase at 1,000 FYT/kg (NC + 1,000); and 4 sampling time points at days 7, 14, 21, and 28 in experiment 1, and days 14, 26, 42, and 55 in experiment 2. In both trials, 96 growing pigs with average body weight (BW) of 19.8 ± 1.16 and 49.8 ± 3.21 kg, respectively, were allocated to the 3 diets with 8 replicates pens (4 barrows and 4 gilts) and 4 pigs per pen. In experiment 1, pigs fed the PC had higher (P &lt; 0.01) BW, average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F) when compared with pigs fed the NC. There was an interaction (P &lt; 0.01) between time and diet on the BW and ADG of pigs while a linear and quadratic increase (P &lt; 0.01) was observed with the ADFI and G:F, respectively, over time. Phytase supplementation improved (P &lt; 0.01) all growth performance responses. Pigs fed the PC had greater (P &lt; 0.01) ATTD of P and Ca than pigs fed the NC. There was no interaction effect on the ATTD of nutrients. Phytase addition improved the ATTD of P and Ca over pigs fed the NC. There was an interaction (P &lt; 0.01) between diet and time on the total and water-soluble P (WSP) excreted. There was a quadratic decrease (P &lt; 0.01) in plasma concentration of Ca in pigs over time. In experiment 2, there was a quadratic increase (P &lt; 0.01) in BW, ADG, and G:F of pigs over time. Similarly, the inclusion of phytase improved (P &lt; 0.05) all growth performance parameters except ADFI. A linear increase (P &lt; 0.05) in the ATTD of DM, P, and Ca occurred over time. Phytase inclusion improved (P &lt; 0.01) the ATTD of P and Ca. Plasma concentrations of P were improved by phytase addition. Phytase supplementation of the NC reduced WSP excretion by 45%, 32%, and 35% over the growing, finishing, and entire grow-finish period, respectively. In conclusion, phytase improves the utilization of P in growing and finishing pigs; however, the magnitude of effect on responses may vary over time.


2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 23-23
Author(s):  
Henrique S Cemin ◽  
Mike D Tokach ◽  
Steve S Dritz ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
...  

Abstract Excess of a branched-chain amino acid (BCAA), particularly Leu, may result in increased degradation of the others due to common catabolic steps. Moreover, large neutral amino acids (LNAA) and BCAA have common brain transporters. Therefore, excessive BCAA may decrease the absorption of AA that serve as precursors of neurotransmitters. We hypothesize that practical diets with high levels of feed-grade AA can potentially create BCAA imbalances and impact performance. A meta-regression was conducted to evaluate the effects of BCAA and their interactions with LNAA to develop prediction equations for ADG, ADFI, and G:F. Data from 25 papers for a total of 44 trials were recorded in a database. Diets were reformulated using NRC (2012) nutrient values. Amino acids were expressed on standardized ileal digestible basis. A step-wise manual forward selection was used to evaluate predictor variables. Predictors had to be significant (P < 0.05) as a single variable predictor and provide a BIC improvement of at least 2 points to be included in the model. Observations were weighted using the inverse of the squared SEM. The resulting predictor equations were: ADG, g = – 985.94 + (15.2499 × average BW (kg)) – (0.08885 × average BW × average BW) + (1.063 × Leu:Lys) + (20.2659 × Ile:Lys) – (0.1479 × Ile:Lys × Ile:Lys) + (9.2243 × (Ile+Val):Leu) – (0.03321 × (Ile+Val):Leu × (Ile+Val):Leu) – (0.4413 × Ile:Trp); G:F = 648.3 – (6.2974 × average BW (kg)) + (0.02051 × average BW × average BW) + (0.5396 × Ile:Lys) + (1.7284 × Val:Lys) – (0.00795 × Val:Lys × Val:Lys) – (1.7594 × Met:Lys); and ADFI, kg = predicted ADG/predicted G:F. The equations suggest that increasing Leu:Lys negatively affects ADG due to a reduction in ADFI and G:F. The addition of Val, Ile, and Trp, alone or in combination, has the potential to counteract the negative effects of high Leu on growth performance.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 642-642
Author(s):  
Glory Madu ◽  
Olasunkanmi Adegoke

Abstract Objectives Branched-chain amino acids (BCAAs) are essential amino acids that are crucial for skeletal muscle anabolism. Thus, alterations in their levels are associated with muscle atrophic diseases such as cancer, chronic inflammatory and neurological disorders. Others have linked impairments in BCAA metabolism to the development of insulin resistance and its sequelae. Compared to the effects of theses amino acids, much less is known on how impairment in BCAA catabolism affects skeletal muscle. BCAA catabolism starts with the reversible transamination by the mitochondrial enzyme branched-chain aminotransferase 2 (BCAT2). This is followed by the irreversible carboxylation, catalyzed by branched-chain ketoacid dehydrogenase (BCKD) complex. We have shown that BCAT2 and BCKD are essential for the differentiation of skeletal myoblasts into myotubes. Here, we investigated the effect of depletion of BCAT2 or of E1a subunit of BCKD in differentiated myotubes. Methods On day 4 of differentiation, L6 myotubes were transfected with the following siRNA oligonucleotides: scrambled (control), BCAT2, or E1a subunit of BCKD. Results Forty-eight hours after transfection, compared to control or BCAT2 siRNA group, we observed improved myotube structure in BCKD-depleted cells. BCKD depletion augmented myofibrillar protein levels: myosin heavy chain (MHC, 2-fold) and tropomyosin (4-fold), P &lt; 0.05, n = 3. To further analyze the increase in myofibrillar protein content, we examined signaling through mTORC1 (mechanistic target of rapamycin complex 1), a vital complex necessary for skeletal muscle anabolism. BCKD depletion increased the phosphorylation of mTORC1 upstream activator AKT (52%, P &lt; 0.05, n = 3), and of mTORC1 downstream substrates by 25%-86%, consistent with the increase in myofibrillar proteins. Finally, in myotubes treated with the catabolic cytokine (tumor necrosis factor-a), BCKD depletion tended to increase the abundance of tropomyosin (a myofibrillar protein). Conclusions We showed that depletion of BCKD enhanced myofibrillar protein content and anabolic signaling.  If these data are confirmed in vivo, development of dietary and other interventions that target BCKD abundance or functions may promote muscle protein anabolism in individuals with muscle wasting conditions. Funding Sources MHRC, NSERC York U.


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