Lys Content Research Articles

109 Evaluation of net energy, standardized ileal digestible lysine, and soybean meal content interaction in 13 to 25 kg pigs using a central composite design

Abstract Pigs [n = 4,683; 337 × 1050, PIC; initial body weight (BW) = 13.0 ± 0.01 kg] were used in a 21-d trial to investigate the interaction of net energy (NE), standardized ileal digestible lysine (SID Lys), and soybean meal (SBM) content used at five different levels on growth performance of nursey pigs. Pigs were housed in mixed sex pens with 35 pigs per pen and assigned in a randomized complete block design to 15 dietary treatments using a circumscribed central composite design (CCD). Factorial and axial points had 7 repetitions, and the central points had a total of 24. Eight diets were formulated to various levels of NE, SID Lys, and SBM and blended to create the 15 dietary treatments. The NE ranged from 2,334 to 2,762 kcal/kg, SID Lys from 1.08 to 1.52%, and SBM from 25.5 to 35.9%. Diets were corn-soybean meal based and soy hulls and soybean oil were added to reduce or increase NE content of the diet. Feed grade amino acids and SBM were used to adjust SBM and SID Lys content and to maintain SID Thr, Trp, Met, Val, and Ile ratios relative to SID Lys. For NE, a linear effect (P ≤ 0.052) was observed for average daily gain (ADG) and average daily feed intake (ADFI), and linear and quadratic effect was found (P ≤ 0.047) for gain to feed ratio (G:F) with a reduction in growth performance as NE increased due to reduction in SID Lys:calorie. When increasing SID Lys, ADG (P ≤ 0.044) and G:F (P ≤ 0.020) increased quadratically (Table). Increasing SBM content linearly improved ADG (P = 0.039) and G:F (P < 0.001), respectively. There was also a significant interaction between SID Lys and SBM for G:F (P = 0.082), where SID Lys positively impacted G:F as SBM increased in the diet. When including the significant terms, the resulting models can be used to predict the ADG (kg) response = [0.579392 + (-0.0063389 × NE) + (0.0260796 × Lys) + (0.0067428 × SBM%) + (-0.0065721 × Lys²) adjusted R2 = 0.36], and G:F (kg/kg) response = [0.7013215 + (0.0035198 × NE) + (0.0264389 × Lys) + (0.0060863 × SBM%) + (-0.0048012 × NE²) + (-0.0031838 × Lys²) + (-0.0034413 × Lys × SBM) adjusted R2 = 0.65]. In conclusion, using a CCD, increasing SID Lys resulted in a quadratic improvement in ADG and G:F, with this improvement being greater when SBM also increased. Overall, we observed few interactions between SID Lys, SBM, and NE.

Comparative Analysis of Dehydrins from Woody Plant Species.

We conducted analyses on 253 protein sequences (Pfam00257) derived from 25 woody plant species, including trees, shrubs, and vines. Our goal was to gain insights into their architectural types, biochemical characteristics, and potential involvement in mitigating abiotic stresses, such as drought, cold, or salinity. The investigated protein sequences (253) comprised 221 angiosperms (85 trees/shrubs and 36 vines) and 32 gymnosperms. Our sequence analyses revealed the presence of seven architectural types: Kn, KnS, SKn, YnKn, YnSKn, FSKn, and FnKn. The FSKn type predominated in tree and shrub dehydrins of both gymnosperms and angiosperms, while the YnSKn type was more prevalent in vine dehydrins. The YnSKn and YnKn types were absent in gymnosperms. Gymnosperm dehydrins exhibited a shift towards more negative GRAVY scores and Fold Indexes. Additionally, they demonstrated a higher Lys content and lower His content. By analyzing promoter sequences in the angiosperm species, including trees, shrubs, and vines, we found that these dehydrins are induced by the ABA-dependent and light-responsive pathways. The presence of stress- and hormone-related cis-elements suggests a protective effect against dehydration, cold, or salinity. These findings could serve as a foundation for future studies on woody dehydrins, especially in the context of biotechnological applications.

Nutritional guide to feeding wheat and wheat co-products to swine: a review.

Inclusion of wheat grain can offer feeding opportunities in swine diets because of its high starch, crude protein (CP), amino acid (AA), and phosphorus (P) content. High concentrations of starch within wheat grain makes it a good energy source for swine. Mean energy content of wheat was 4,900 and 3,785 kcal/kg dry matter (DM) for digestible energy and metabolizable energy, respectively. CP concentration can vary based on the class of wheat which include hard red winter, hard red spring, soft red winter, hard white, soft white, and durum. The average CP of all wheat data collected in this review was 12.6% with a range of 8.5% to 17.6%. The AA concentration of wheat increases with increasing CP with the mean Lys content of 0.38% with a standardized ileal digestibility (SID) of 76.8%. As CP of wheat increases, the SID of AA in wheat also increases. Mean P of wheat was 0.27% and median P was 0.30%. Off-quality wheat is often associated with sprouts, low-test weight, or mycotoxin-contamination. Sprouted and low-test weight wheat are physical abnormalities associated with decreased starch within wheat kernel that leads to reductions in energy. The assumed energy value of wheat grain may need to be reduced by up to 10% when the proportion of sprouted to non-sprouted wheat is up to 40% whereas above 40%, wheat's energy may need to be reduced by 15% to 20%. Low-test weight wheat appears to not influence pig performance unless it falls below 644kg/m3 and then energy value should be decreased by 5% compared to normal wheat. Deoxynivalenol (DON) contamination is most common with wheat grain. When content is above the guidance level of 1mg/kg of DON in the complete diet, each 1mg/kg increase in a DON-contaminated wheat-based diet will result in a 11% and 6% reduction in ADG and ADFI for nursery pigs, and a 2.7% and 2.6% reduction in ADG and ADFI, in finishing pigs, respectively. Wheat co-products are produced from the flour milling industry. Wheat co-products include wheat bran middlings, millrun, shorts, and red dog. Wheat co-products can be used in swine diets, but application may change because of differences in the final diet energy concentration due to changes in the starch and fiber levels of each wheat co-product. However, feeding wheat co-products are being evaluated to improve digestive health. Overall, wheat and wheat co-products can be fed in all stages of production if energy and other nutrient characteristics are considered.

Bio-functional and prebiotics properties of products based on whole grain sorghum fermented with lactic acid bacteria.

Products fermented with lactic acid bacteria based on whole grain flours of red or white sorghum (Sorghum bicolor (L.) Moench) added with malted sorghum flour, or with skim milk (SM) were developed. Composition, protein amino acid profile, total acidity, pH, prebiotic potential, and bio-functional properties after simulation of gastrointestinal digestion were evaluated. In all cases, a pH of 4.5 was obtained in approximately 4.5 h. The products added with SM presented higher acidity. Products made only with sorghum presented higher total dietary fiber, but lower protein content than products with added SM, the last ones having higher lysine content. All products exhibited prebiotic potential, white sorghum being a better ingredient to promote the growth of probiotic bacteria. The addition of malted sorghum or SM significantly increased the bio-functional properties of the products: the sorghum fermented products added with SM presented the highest antioxidant (ABTS•+ inhibition, 4.7 ± 0.2 mM Trolox), antihypertensive (Angiotensin converting enzyme-I inhibition, 57.3 ± 0.5%) and antidiabetogenic (dipeptidyl-peptidase IV inhibition, 31.3 ± 2.1%) activities, while the products added with malted sorghum presented the highest antioxidant (reducing power, 1.6 ± 0.1 mg ascorbic acid equivalent/mL) and antidiabetogenic (α-amylase inhibition, 38.1 ± 0.9%) activities. The fermented whole grain sorghum-based products could be commercially exploited by the food industry to expand the offer of the three high-growth markets: gluten-free products, plant-based products (products without SM), and functional foods. © 2023 Society of Chemical Industry.

PSII-12 Growth Performance of Pigs Fed Diets Containing Supplemental Lysine and a Low or High Essential Amino Acid-Nitrogen to Total Nitrogen Ratio

Abstract With the provision of low protein (LP) diets, it is possible that N, or non-essential amino acids (NEAA), become limiting. We have previously shown that the lysine (Lys) requirement for N retention is greater when pigs are fed a diet with sufficient N, as indicated by a low EAA-N:total N ratio (EAA-N:TN). The objective of this study was to investigate the effect of EAA-N:TN and Lys content on growth performance of growing pigs. A total of 240 growing pigs (20.6 ± 2.03 kg initial body weight) were randomly placed into groups of 5 pigs/pen (either 2 barrows and 3 gilts, or 3 barrows and 2 gilts) and randomly assigned to 1 of 4 dietary treatments (n = 12 pens/treatment) in 3 blocks in a 2 × 2 factorial design. Factors consisted of dietary EAA-N:TN [optimal ratio (LR) of 0.48 or high ratio (HR) of 0.55] and dietary Lys level of 1.03% SID or 1.22% SID, representing the NRC (2012) requirement and the requirement as determined previously, respectively. Diets were corn and soybean meal based and formulated to meet or exceed nutrient requirements according to NRC (2012). Pigs were individually weighed and feed intake determined weekly to determine average daily gain (ADG), average daily feed intake (ADFI), and gain:feed (G:F). Fecal samples were collected on d 14 for determination of N output. Data were analyzed using a mixed model with fixed effects of ratio, lysine, and their interaction and block as a random effect. Increasing dietary Lys resulted in increased overall ADG and ADFI, regardless of EAA-N:TN ratio (P < 0.01). Pigs fed the HR diets had improved ADG in week 4 (P < 0.05), whereas pigs fed the LR diets had improved ADG and G:F in week 1 (P < 0.01). There was an interactive effect of ratio and Lys on N output (P < 0.01), where N output decreased in the HR diets with 1.22% Lys. Overall, current Lys requirements may not be sufficient to maximize growth in 20-50 kg pigs, and greater Lys may be beneficial for reducing N output in LP diets.

PSII-10 Ammonium Phosphate is an Appropriate Nitrogen Source in Nitrogen-Limiting Diets for Growing Pigs

Abstract The use of low protein (LP) diets is common in swine production, but there is potential for reduced dietary N for the endogenous synthesis of non-essential amino acids (NEAA), impacting overall animal growth. It has been previously demonstrated that inclusion of non-protein nitrogen (NPN) in a diet with an increased essential amino acid-nitrogen:total nitrogen (EAA-N:TN) ratio (i.e. limiting in total N) reduced the Lys requirement and maximum NR in growing pigs. The objective of this study was to determine the impact of NPN inclusion and Lys content on growth performance of growing pigs. A total of 240 growing pigs (120 gilts and 120 barrows) with an initial body weight (BW) of 20.2 ± 2.18 kg were housed in groups of 5 pigs/pen. Pens were randomly assigned to 1 of 6 dietary treatments over 3 blocks (n = 8 pens/treatment) in a 2 × 3 factorial design, with factors of NPN inclusion (no ammonium phosphate [NAP] or ammonium phosphate inclusion at 1.7% [AP]) and dietary lysine (Lys; 1.03%, 1.15% or 1.27% standardized ileal digestible). The AP and NAP diets were formulated to have an EAA-N:TN ratio of 0.48 and 0.54, respectively. All diets were corn and soybean meal-based and formulated to meet or exceed NRC (2012) nutrient requirements. The experimental period was 28 d, with individual BW and per pen feed intake determined weekly. On d 28, backfat and lean depth were measured on 2 pigs per pen, one male and one female. Data were analyzed using a mixed model with fixed effects of N content, Lys, and their interactions, and block as a random effect. Backfat and lean depth analysis included sex as a fixed effect. Inclusion of NPN reduced feed intake and increased gain:feed compared with pigs fed NAP diets (P < 0.05). Overall ADG and d 28 BW increased with increasing Lys, but were not impacted by dietary NPN content (P > 0.05). Pigs fed AP diets had increased lean depth (P < 0.05) and reduced backfat. Overall, NPN, as ammonium phosphate, can improve feed efficiency and increase lean depth while maintaining similar ADG and final BW.

Establishment of CRISPR-Cpf1-assisted gene editing tool and engineering of 4-hydroxyisoleucine biosynthesis in Corynebacterium glutamicum.

Corynebacterium glutamicum, an important industrial producer, is a model microorganism. However, the limited gene editing methods and their defects limit the efficient genome editing of C. glutamicum. To improve the screening efficiency of second-cross-over strains of traditional SacB editing system, a universal pCS plasmid which harbors CRISPR-Cpf1 system targeting kan gene of SacB system was designed and established to kill the false positive single-cross-over strains remained abundantly after the second-cross-over events. The lethality of pCS plasmid to C. glutamicum carrying kan gene on its genome was as high as 98.6%. In the example of PodhA::PilvBNC replacement, pCS plasmid improved the screening efficiency of second-cross-over bacteria from 5% to over 95%. Then this pCS-assisted gene editing system was applied to improve the supply of precursors and reduce the generation of by-products in the production of 4-hydroxyisoleucine (4-HIL). The 4-HIL titer of one edited strain SC01-TD5IM reached 137.0 ± 33.9 mM, while the weakening of lysE by promoter engineering reduced Lys content by 19.0-47.7% and 4-HIL titer by 16.4-64.5%. These editing demonstrates again the efficiency of this novel CRISPR-Cpf1-assisted gene editing tool, suggesting it as a useful tool for improving the genome editing and metabolic engineering in C. glutamicum.

Impacts of Dietary Lysine and Crude Protein on Performance, Hepatic and Renal Functions, Biochemical Parameters, and Histomorphology of Small Intestine, Liver, and Kidney in Broiler Chickens

The present study aimed to investigate the effects of increasing dietary lysine (Lys) levels with an adequate dietary crude protein (CP) content, as well as the effects of a reduction in dietary CP content with the recommended amino acid (AAs) level, on the performance, blood biochemical parameters, and histomorphology of the duodenum, liver, and kidney in broiler chickens. A total of 500 broiler chickens were randomly distributed into five dietary treatment groups, following a completely randomized design, where, at the beginning, the control group (C) was fed a diet containing the standard CP and Lys levels: 23% CP with 1.44% Lys during the starter period; 21.5% CP with 1.29% Lys during the growing period; and 19.5% CP with 1.16% Lys during the finishing period. The Lys content was increased by 10% above the recommended control basal requirements in the second group (Gr1) and by 20% in the third group (Gr2), while using the same recommended CP percentage as the C group. The fourth group (Gr3) had a 1% lower CP content and the fifth group had a 2% lower CP content than the C group, with the same recommended AA level as the C group. Increasing the Lys content in the Gr1 group improved the broilers' weight gains (p < 0.05) during the starter, growing, and finishing periods. Decreasing dietary CP with the standard AA levels (Gr3 and Gr4) did not significantly affect (p > 0.05) the live weight gain, feed intake, or feed conversion ratio (FCR) of the broilers compared with those fed with the C diet. Blood total bilirubin, direct and indirect bilirubin, triglycerides, cholesterol, low-density lipoprotein (LDL), and very LDL were not different among the experimental groups. However, blood aspartate aminotransferase levels were increased (p < 0.05) in the Gr1 and Gr3 groups compared with the other treatment groups. All dietary treatments decreased the serum creatinine levels (p < 0.05) compared with the C group. The Gr2 broilers had greater serum total protein and globulin (p < 0.05) than those receiving the other treatments. Increasing dietary Lys levels resulted in a significant improvement in duodenum villus height and width (p < 0.05), while the low-CP diets resulted in shorter villi length and width, along with degenerated areas and lymphocytic infiltration. Low dietary CP content induced hepatocyte disorganization and moderate degeneration, along with vacuolated hepatic cells, excessive connective tissue, and lymphocytic infiltration. The cortical regions of the kidney exhibited obvious alterations in the Gr3 and Gr4 groups and large interstitial spaces were found between tubules. Renal tubules in the Gr3 and Gr4 groups were smaller in size and some of these tubules were atrophied. In conclusion, reducing dietary CP levels to 1% or 2% lower than the recommended level did not negatively affect growth performance, inducing minimal influence on the blood metabolic indicators of health status, and resulting in moderate alterations to the histomorphology of the duodenum, liver, and kidney. Furthermore, increasing the Lys content by 10% above the recommended level improved the growth performance, health status, and histomorphology of the duodenum, liver, and kidney in broiler chickens.

Effect of the essential amino acid-nitrogen to total nitrogen ratio on lysine requirement for nitrogen retention in growing pigs.

Low protein diets supplemented with essential amino acids (EAA) fed to pigs reduce the excess supply of EAA and nitrogen (N). However, low protein diets may become limiting in non-essential amino acids (NEAA) and N, thus affecting the utilization of EAA for N retention. It has been suggested that the EAA-N:total N (E:T) ratio can give an indication of dietary N sufficiency. An N-balance study was conducted to determine the effect of E:T ratio on the Lys requirement for maximum N retention. A total of 80 growing barrows (19.3 ± 0.21 kg initial body weight) were randomly assigned to 1 of 10 diets (n = 8) in 8 blocks in a 2 × 5 factorial arrangement. Diets consisted of a low ratio (LR; E:T of 0.33) or a high ratio (HR; E:T of 0.36) with graded Lys content (0.82%, 0.92%, 1.02%, 1.12%, and 1.22% standardized ileal digestible [SID]). After a 7-d adaptation, a 4-d N-balance collection was conducted. Blood samples were obtained on d 2 of the collection period 2 h after the morning meal for plasma urea N (PUN) analysis. Data were analyzed using the MIXED model procedure with fixed effects of ratio (n = 2), Lys (n = 5), and their interactions. The experimental block (room) was included as a random effect (n = 8). The SID Lys requirement was estimated using PROC NLIN linear broken-line breakpoint model. There was a significant interaction between E:T ratio and Lys (P < 0.01), where LR diets had a higher N retention than HR diets, while increasing Lys linearly increased N retention (P = 0.01) in both HR and LR diets. The marginal efficiency of utilizing SID Lys (P < 0.01) reduced with increasing Lys content, while the efficiency of utilizing N (P < 0.05) increased as Lys increased. The SID Lys required to maximize N retention of pigs fed HR diets was estimated at 1.08% (R2 = 0.61) and LR diets at 1.21% (R2 = 0.80). The current results indicate that N may be limiting in diets with a high E:T ratio, limiting N retention. Supplying additional dietary N, as intact protein, can increase N retention, resulting in a greater Lys requirement.

Different dietary ratios of arginine, methionine and lysine for turkeys: effects on whole-body composition and nutrient utilization efficiency in the early growth stage

Abstract The growth rate, tissue development and health status of turkeys are affected by the dietary supply of essential amino acids (AAs) such as lysine (Lys), methionine (Met) and arginine (Arg). According to various guidelines, the diets fed to turkeys in the first 4 weeks of the rearing period should contain 1.60–1.76% Lys, 1.60–1.80% Arg and 0.55–0.70% Met. This study investigated the effects of different ratios of Arg and Met in starter diets with 1.60% of Lys content, i.e. a low level, on the whole-body composition of turkeys and nutrient retention efficiency. The experiment lasted for 28 days and it had a two-factorial randomized design with three levels of Arg (90%, 100% and 110%) and two levels of Met (30% or 45%), relative to the content of dietary Lys, with six groups of eight replicates per group and 18 turkeys per replicate. Different dietary Arg and Met levels, relative to Lys, did not affect AA concentrations in the body protein or the proximate whole-body composition (crude protein, crude fat, gross energy and ash) of turkeys. The higher Met level positively influenced energy, protein and Arg utilization and their retention efficiency as well as the growth performance of turkeys. An increase in the dietary level of Arg to 100% and 110% of Lys content had no influence on the growth performance of turkeys and it reduced the retention efficiency of Arg. Differences in the body weight gain, feed intake and Lys utilization of turkeys fed diets with different Arg levels resulted also from the strong interaction between Met and Arg levels. At the lower level of Met in the diet, a decrease in Arg relative to Lys from 100% to 90% resulted in decreased (P = 0.003) feed intake (from 50.34 g to 46.72 g) and growth rate (from 31.84 g to 29.79 g), which was not noted for the higher Met content (45% relative to Lys). At the lowest level of Arg in the diet (90% of Lys content), a decrease in Met relative to Lys from 45% to 30% caused a decrease in Lys retention efficiency (from 61.51% to 56.29%). The results of this study suggest that the higher content of Met in the diet (45% to Lys) and the Arg level corresponding to 90% of Lys content contribute to optimizing nutrient retention efficiency in turkeys during the first 28 days of their life.

257 Effect of the Essential Amino Acid-Nitrogen to Total Nitrogen Ratio on Lysine Requirement for Nitrogen Retention in Growing Pigs

Abstract Low-protein (LP) diets may become limiting in nitrogen (N), affecting utilization of essential amino acids (EAA) for nitrogen retention (NR). The objective of the present study was to determine the effect of the EAA-N to total N ratio (EAA-N:TN) on lysine (Lys) requirement for NR. A total of 80 growing barrows (21.5±0.89 kg initial BW) were randomly assigned to 1 of 10 dietary treatments (n=8 pigs/treatment) in 8 blocks in a 2 × 5 factorial arrangement with factors of EAA-N:TN (low vs. high) and Lys content (0.82, 0.92, 1.02, 1.12, and 1.22% standardized ileal digestible [SID] Lys). Diets were formulated to meet EAA requirements with the low ratio diet (LR; 16.8% crude protein) having an ideal EAA-N:TN of 0.48 and the high ratio diet (HR; 15.5% crude protein) formulated to be limiting in NEAA with an EAA-N:TN of 0.55. Diets were fed at 2.8 × maintenance metabolizable energy requirements. After a 7-d dietary adaptation, a 4-d N-balance period was conducted where fresh fecal samples were collected daily and quantitative urine samples were collected over a 24-h period. Nitrogen-balance was determined as the difference between N intake minus fecal and urinary N output. Data were analyzed using a MIXED model with fixed effects of ratio, Lys, and their interactions, and block as a random effect. Lysine requirement based on two-phase linear or quadratic modeling was estimated using PROC NLIN. Nitrogen retention increased linearly with increasing Lys levels regardless of ratio (P&amp;lt; 0.01). Quadratic modelling estimated the Lys requirement to maximize NR at 17.83 g/d in pigs fed HR diets at 1.21% SID (R2 = 0.53; P&amp;lt; 0.05), but no breakpoint was achieved for pigs fed LR diets, which showed a linear response (R2 = 0.79; P&amp;lt; 0.05). These results suggest that NR is limited by NEAA or TN in HR diets.

Isolation and characterization of a novel protein from Momordica charantia L. Positively regulates lipid metabolism activity in vivo and in vitro

• MC3-2, A novel anti-hypertriglyceridemic protein was isolated from Momordica charantia L.. • MC3-2 binded to bile acids, and decreased FFA-induced HepG2 steatosis and intracellular TG. • MC3-2 regulated high-fat-diet hypertriglyceridemia in vivo tests. • MC3-2 ameliorated inflammatory cytokines and oxidative stress by regulating related protein. In this study, a novel protein designated MC-2 was isolated from Momordica charantia L. , and the positively regulates lipid metabolism activity was detected by the bile acid binding activity test. Then, the amino acid composition of MC-2 was analyzed, and the total content of Asp, Glu, and Lys is up to 38.96 g/100 g in MC-2. Furtherly, its lipid metabolism activity were explored. In vitro, MC-2 ameliorated FFA-induced HepG2 steatosis phenotypes and intracellular triglycerides level with the promotion of bile acids secretion. In vivo, MC-2 was able to protect rats against NAFLD-induced in response to a high-fat diet through a manner associated with the regulation of inflammatory cytokines and oxidative stress-related factors. The hepatoprotective activity of MC-2 was closely tied to improvements CPT1A, FATP2, ACSL1, and PPAR-α expressions. Together, these data highlight the promise of MC-2 (rich in Asp, Glu, and Lys) as a candidate functional food ingredient.

MTORC1 Mediates the Processes of Lysine Regulating Satellite Cells Proliferation, Apoptosis, and Autophagy.

Lysine (Lys) is essential for skeletal muscle growth and protein synthesis in mammals. However, the regulatory network underlying Lys-regulated skeletal muscle development is unknown. To determine whether any cross-talk occurs among mammalian targets of rapamycin complex 1 (mTORC1) and Lys in the regulation of muscle satellite cells (SCs) proliferation, we applied the treatment rapamycin (a mTORC1 inhibitor) and MHY1485 (a mTORC1 activator) on Lys-added or -deficient SCs. The results show Lys deprivation significantly decreases SCs viability, protein synthesis, and cell cycling, increases autophagy and apoptosis, and inhibits the mTORC1 signaling pathway. Restoration of Lys content significantly attenuates this effect. mTORC1 signaling pathway activation during Lys deprivation or mTORC1 signaling pathway inhibition during Lys addition attenuates the effect of Lys deprivation or addition on SCs viability, protein synthesis, cell cycling, autophagy, and apoptosis. In conclusion, Lys could improve SCs proliferation, and inhibit SCs apoptosis and autophagy, via the mTORC1 signaling pathway.

Effects of Dietary Lysine Levels on Growth Performance, Nutrient Digestibility, Serum Metabolites, and Meat Quality of Baqing Pigs.

Simple SummaryThis study investigated the effects of different standardized ileal digestible (SID) Lys levels on growth performance, nutrient digestibility, serum metabolites, and carcass and meat traits of Baqing pigs. The results revealed that the addition of dietary SID Lys was beneficial for the average daily feed intake (ADFI), gain to feed ratio (G/F), and average daily gain (ADG) of Baqing pigs at the growth phase. The serum concentrations of triglycerides, lysine, and histidine increased by increasing dietary Lys levels. Compared with the treatment three group, dietary SID Lys addition content at treatment four increased the shear force of the longissimus dorsi muscle, but it did not affect the other carcass and meat traits. The SID Lys requirement of 20–40 kg, 40–60 kg, and 60–90 kg of Baqing pigs fed corn–soybean meal-based diets is estimated to be 0.92%, 0.66%, and 0.55% of the diets, respectively.This study was carried out to determine the Lys requirements of Baqing pigs and the effects of different dietary lysine levels on growth performance, apparent nutrient digestibility, serum metabolites, and carcass and meat traits. A total of 120 castrated Baqing pigs were selected by body weight and randomly assigned to five dietary treatments with six replicate pens (4 pigs per pen, castrated) per treatment in a randomized complete block design. Five diets in mash form were formulated to contain SID Lys at 0.56%, 0.68%, 0.80%, 0.92%, and 1.04% of diet in phase 1 (20–40 kg), at 0.45%, 0.54%, 0.63%, 0.72%, and 0.81% of diet in phase 2 (40–60 kg), and at 0.39%, 0.47%, 0.55%, 0.63%, and 0.71% of diet in phase 3 (60–90 kg), respectively. The results showed that the bodyweight of pigs was not affected by dietary SID Lys content during each period. However, the addition of dietary SID Lys linearly reduced F/G in the first period and quadratically increased ADG during the second period (p < 0.05). The digestible energy (DE) was increased linearly and quadratically in the first phases with the dietary increased SID Lys levels, while DE was reduced in the third and second phases (p < 0.05). Increasing SID Lys contents linearly increased the serum TG concentration and quadratically decreased the serum GLU concentration, while linearly reducing the serum HDLC concentration of first period pigs (p < 0.05). Serum concentrations of TP, TG, TC, and LDLC were increased linearly with the increasing dietary SID Lys levels in the second period (p < 0.05). The serum concentrations of Lys increased quadratically, and histidine increased linearly with the increased dietary SID Lys levels (p < 0.05). Compared with the treatment three group, dietary SID Lys addition content at treatment four increased the shear force of the longissimus dorsi muscle (p < 0.05), but it did not affect the other carcass and meat traits. The optimal SID Lys requirement of 20–40 kg, 40–60 kg, and 60–90 kg of Baqing pigs fed corn–soybean meal-based diets is estimated to be 0.92%, 0.66%, and 0.55% of the diets by the quadratic curve models, respectively.

The effect of the application of diets with varied proportions of arginine and lysine on biochemical and antioxidant status in Turkeys

Abstract The aim of the study was to determine the effect of two proportions of arginine (95% and 105%) relative to lysine (Lys), where Lys content in the diet is in accordance with NRC (1994) recommendations or 10% higher, on the metabolism, antioxidant status, and growth performance of turkeys. The experiment had a 2x2 factorial design with two levels of Lys and Arg. The diets with a low level of Lys were according to the NRC (1994) requirements. In the diets with a high level of Lys, the content of Lys was increased by 10% relative to the low level Lys. The two Arg levels in the experimental diets were determined so as to provide 95% and 105% Arg relative to the content of dietary Lys. An increase in the amount of Lys in the diet of turkeys by 10% relative to NRC nutritional recommendations (1994) was not shown to improve growth performance, but had beneficial effects on the metabolism and antioxidant status of the birds, as evidenced by the improvement of hepatic indices (reduction of AST and ALT activity at 9th week of life) and renal indices (reduction of UREA at 9th week of life and reduction of TP and increase level of ALB levels at 16th week of life), as well as an increase in the level of glutathione with strong antioxidant properties at 16th week of life. In comparison to the lower level of Arg in the diet, an increase in the amount of this amino acid to 105% Lys did not improve growth performance, metabolism, or antioxidant status. An Arg level of 95% Lys can be used in a diet for turkeys containing 10% more Lys than the level recommended by the NRC (1994).

Dynamic control of 4-hydroxyisoleucine biosynthesis by multi-biosensor in Corynebacterium glutamicum.

4-hydroxyisoleucine (4-HIL) has a potential value in treating diabetes. The α-ketoglutarate (α-KG)-dependent isoleucine dioxygenase (IDO) can catalyze the hydroxylation of L-isoleucine (Ile) to form 4-HIL by consuming O2. In our previous study, the ido gene was overexpressed in an Ile-producing Corynebacterium glutamicum strain to synthesize 4-HIL from glucose. Here, a triple-functional dynamic control system was designed to regulate the activity of IDO, the supply of α-KG, O2, and Ile and the synthesis of by-product L-lysine (Lys) for promoting 4-HIL synthesis. Firstly, the codon-optimized ido was positively regulated by seven Ile biosensors Lrp-PbrnFEN with different intensities, and the resulting seven D-NI strains produced 38.7-111.1mM 4-HIL. Then on the basis of D-NI, odhI and vgb were simultaneously regulated by three PbrnFEN with different intensities to synergistically control α-KG and O2 supply. The 4-HIL titer of twelve D-NINONV strains was more than 90mM, with D-0I7O7V generating the highest titer of 141.1 ± 15.5mM. Thirdly, ilvA was negatively regulated by an Ile attenuator PilvBNC on the basis of D-NI strains and some D-NINONV strains to balance the synthesis and conversion of Ile. The resulting D-NIPA strains produced 73.6-123.2mM 4-HIL, while D-7I7O1VPA accumulated 127.1 ± 20.2mM 4-HIL. Finally, dapA was negatively regulated by a Lys-OFF riboswitch and Lys content decreased by approximately 70% in most D-RS-NIPA strains. A strain D-RS-5IPA with the highest 4-HIL titer (177.3 ± 8.9mM) and the lowest Lys concentration (6.1 ± 0.6mM) was successfully obtained. Therefore, dynamic regulation of main and branch pathway by three functional biosensors can effectively promote 4-HIL biosynthesis in C. glutamicum. KEY POINTS: • Three biosensors were coordinated for dynamic 4-HIL biosynthesis in C. glutamicum • Bidirectional regulation of Ile synthesis and conversion promoted 4-HIL synthesis • Negative regulation of Lys synthesis further increased 4-HIL production.

Standardized ileal digestible amino acids and digestible energy contents in two modified soy protein concentrates and soybean meal fed to growing pigs.

Six ileal-cannulated barrows (28.0 ± 1.3 kg initial BW) were used in a replicated 3 × 3 Latin square design with one additional period (n = 7 or 6) to determine standardized ileal digestible (SID) AA and digestible energy of two modified soy protein concentrates [MSPC1 and MSPC2] and soybean meal (SBM). Pigs were fed one of three cornstarch-based diets with either MSPC1 or MSPC2 or SBM as the sole source of AA at a rate of 2.8 times the estimated maintenance energy requirement. In each period, pigs were adapted to diets for 7 d followed by 2 d of fecal collection and subsequently, 2 d of continuous ileal digesta collection for 8 h. The SID of AA was calculated using basal endogenous losses from a previous study for pigs fed a nitrogen-free diet. The digestible energy of the ingredients was calculated according to the difference method using a nitrogen-free diet that contained the same cornstarch:sucrose:oil ratio as the three test diets. The total Lys content was 33% and 38% greater for MSPC1 vs. MSPC2 and SBM, respectively. The SID of crude protein was greater for MSPC1 (96.9%) than for SBM (91.3%; P < 0.05), whereas an intermediate value was observed for MSPC2 (94.3% ± 1.2%). The SID of Ile (93.8%), Leu (93.6%), Lys (93.9%), Phe (96.7%), and Val (93.2%) were not different between MSPC1 and MSPC2 but greater than for SBM (88.8% ± 1.3%, 87.8% ± 1.2%, 84.5% ± 1.7%, 92.9% ± 1.0%, 86.5% ± 1.7% for Ile, Leu, Lys, Phe, and Val, respectively; P < 0.05). The SID of His and Thr was greater for MSPC1 than MSPC2 and SBM (P < 0.05), which were not different. The SID of Met was greater for MSPC1 and SBM vs. MSPC2 (P < 0.05). The SID of Arg was greater for MSPC1 than MSPC2 and SBM (P < 0.05), and greater for MSPC2 than SBM (P < 0.05). The digestible energy was greater for MSPC1 (4,677 kcal/kg) than MSPC2 and SBM (average; 3,896 ± 239 kcal/kg; P < 0.05), which were not different. Therefore, the MSPC1 was a better source of SID Lys and digestible energy than either MSPC2 or SBM and could be used as a highly digestible protein ingredient in swine rations.

Assessing Amino Acid Metabolism in Splanchnic Tissues and Mammary Glands to Short-Term Graded Removal of Lys From an Abomasal-Infused Amino Acid Mixture in Lactating Goats.

To investigate the responses of amino acid metabolism in portal-drained viscera (PDV), liver, and mammary glands (MGs) to a graded gradual decrease of post-ruminal Lys supply, four multi-catheterized lactating goats were used in a 4 × 4 Latin square experiment. Goats were fasted for 12 h and then received a 33-h abomasal infusion of an amino acid mixture and glucose. Treatments consisted of a graded decrease of Lys content in the infusate to 100 (complete), 60, 30, or 0% as in casein. Lys-removed infusions decreased the production of milk, milk protein, fat, and lactose linearly and also decreased arterial Lys concentrations linearly (p < 0.05). Net PDV uptake decreased linearly (p < 0.05) with decreasing PDV loss ratio (p < 0.05). Although liver removal of Lys decreased linearly (p < 0.05), the removal ratio relative to portal absorption changed small, which was about 10% in all four treatments. Reduced Lys supply resulted in a linear decrease in the utilization of Lys in the peripheral tissues (except mammary, p < 0.05) and the release of more Lys in MGs. Although net mammary uptake of Lys declined linearly (p < 0.05), lactating goats can partially offset the negative effect of decreased circulating Lys concentrations by increasing mammary affinity (p < 0.05) and increasing mammary blood flow (p < 0.05). Graded removal of Lys from the infusate linearly decreased mammary uptake-to-output ratios of Lys (p < 0.05) suggesting that mammary catabolism of Lys decreased. Meanwhile, the treatments linearly increased circulating concentrations of glucagon and linearly decreased prolactin (p < 0.05). In conclusion, the results of the present study indicated that there were several mechanisms used to mitigate a Lys deficiency, including reduced catabolism of Lys in PDV and peripheral tissues (including MGs) and linearly increased mammary blood flow and mammary affinity together with increased mammary uptake and U:O of branched-chain amino acids (BCAA). Given these changes, the decline in milk protein production could be attributed to the combined effect of mass action with Lys and hormonal status.

Selected metabolic, epigenetic, nitration and redox parameters in turkeys fed diets with different levels of arginine and methionine

Abstract The amino acid guidelines formulated by British United Turkeys postulate higher levels of lysine (Lys) in turkey diets than those recommended by the National Research Council. However, any modifications in the Lys content of turkey diets should be accompanied by changes in the inclusion rates of other amino acids, including methionine (Met) and arginine (Arg). The research hypothesis postulates that the appropriate inclusion levels and ratios of arginine and methionine in turkey diets with high lysine content can improve the antioxidant status of turkeys without compromising their metabolism. The aim of this study was to determine the influence of different Arg and Met ratios in Lys-rich diets on biochemical indicators, redox status and epigenetic changes in turkeys. The turkeys were assigned to six groups with eight replicates per group and 18 birds per replicate. Six feeding programs, with three dietary Arg levels (90%, 100% and 110%) and two dietary Met levels (30% and 45%) relative to dietary Lys content were compared. During each of the four feeding phases, birds were fed ad libitum isocaloric diets with high Lys content. Our results show that in growing turkeys fed diets with high Lys content, the inclusion rate of Arg can be set at 90% of Lys content with no negative effects on their antioxidant status, metabolism or performance. Diets with high Arg content (110% Lys) are not recommended due to the risk of lipid and protein damage, and an undesirable increase in insulin and T4 levels. Regardless of dietary Arg levels, an increase in the Met inclusion rate from 30% to 45% of Lys content minimizes the oxidation of lipids, proteins and DNA, and increases the antioxidant defense potential of turkeys.

Comparative transcriptome analysis of global effect of ddh and lysE deletion on 4-hydroxyisoleucine production in Corynebacterium glutamicum

4-hydroxyisoleucine (4-HIL) is a potential drug for diabetes and weight control. 4-HIL was produced by expressing ido gene in L-isoleucine (Ile)-producing Corynebacterium glutamicum. But L-lysine (Lys) was also accumulated as the main by-product in this recombinant strain SN02. To attenuate Lys synthesis, two genes in Lys synthetic pathway, i.e., ddh encoding the diaminopimelic acid dehydrogenase and lysE encoding the specific Lys exporter were deleted in SN02. However, the deletion of ddh increased 4-HIL titer by 28.1%, but did not decrease Lys content; while the deletion of lysE significantly reduced Lys content by 66.7%, but 4-HIL titer also decreased by 19.3%. Therefore, we carried out transcriptome analysis to reveal the global variation in these mutants. Deletion of ddh and lysE (especially lysE) enhanced the transcription of key enzymes in succinylase branch of Lys synthesis pathway (DapD and DapC) and several enzymes involved in succinyl-CoA accessibility (SucC, SucD and OdhI), suggesting the compensatory synthesis of Lys via succinylase branch. In addition, the transcription of ilvBN in Ile synthesis pathway was improved, while the transcription of some genes in the 2-methylcitrate cycle and inositol metabolism pathway was weakened in these mutants. Mere deletion of ddh enhanced the transcription of aceA, ppc and pck, thus promoting oxaloacetate supply and 4-HIL synthesis. Deletion of lysE affected the transcription of some stress-related genes and transporter genes, suggesting that this mutant would be under stress, thus attenuating its 4-HIL synthesis. These findings will be helpful for systematic microbiology and bio-manufacturing of C. glutamicum.