Dietary Lysine Research Articles

Limiting Dietary Lysine Increases Body Weight Variability by Restricting Growth Potential of the Lightest Growing Pigs.

Simple SummaryFinding strategies to manage variability in growing pig operations is of major importance to avoid the extra costs associated with inefficient barn usage or penalties at the processing plants when pigs are not correctly sorted. The aim of this study was to determine whether dietary amino acid density can have an impact on body weight variability in a population of growing pigs. Feeding diets with a reduced amino acid density had a negative effect because they increased body weight variability of pens composed of the smallest pigs. For instance, in those pigs, the coefficient of variation, which is used as a measure of variability, increased significantly at the end of the experiment when dietary amino acid density was reduced. It was observed that this effect was explained by a growth restriction that was more severe the lightest the pigs were at the start of the trial. Hypothesizing that posteriorly there would be no differences in growth between those restricted pigs and the normally fed ones, the differences in growth would result in around 5–10 additional days to reach marketing weight. In conclusion, severe nutritional restrictions can negatively affect growing pigs’ body weight variability.The goal of this experiment was to determine the implications of dietary standardized ileal digestible lysine (SID Lys:NE) on body weight variability of growing pigs grouped in three initial body weight categories (BWCAT). Animals (N = 1170) were individually weighed and classified in 3 BWCAT (Lp: 32.1 ± 2.8 kg, Mp: 27.5 ± 2.3 kg, and Sp: 23.4 ± 2.9 kg). Afterward, pens were randomly allocated to five dietary SID Lys:NE treatments (3.25 to 4.88 g/Mcal) that were fed over 47 days. Pen coefficient of variation of Sp at day 47 was linearly increased when reducing SID Lys:NE (p < 0.01), from 9.8% to 15.4% between the two extreme dietary levels. The linear effect was different in Sp compared to Lp (p < 0.05) as no effect of SID Lys:NE was reported in the latter BWCAT (p = 0.992). Further analysis showed that this effect was explained by a growth restriction that was more severe the lightest the pigs were at the start of the trial. To summarize, swine body weight variability can be negatively affected when SID Lys requirements are not fulfilled.

Dietary lysine requirements of Colossoma macropomum (Cuvier, 1818) based on growth performance, hepatic and intestinal morphohistology and hematology.

This study aimed to determine the dietary lysine requirements of juvenile Colossoma macropomum tambaqui based growth performance, hepatic and intestinal morphohistology and hematology. Tambaqui were fed with levels of 6.60, 9.72, 12.84, 15.96, 19.08, and 22.20 g/kg of total lysine and those who received 15.96 g/kg dietary lysine showed higher final weight (p= 0.001) and optimized feed conversion ratio (p= 0.001). Morphohistological modifications (presence of fat droplets) were present in livers of fish fed with low levels of lysine. In the morphohistology of the intestine, the diets influenced the density of the intestinal, cell layers, height and perimeters of the villi and acid mucin secretion by the goblet cells. In the proximal intestine, mucosa layer density was greater at the level of 15.96 g/kg (p= 0.001). In the middle intestine, height (p= 0.001) and perimeter (p= 0.001) of the villi were greater at low levels of lysine (respectively, 9.72 and 12.84 g/kg dietary lysine). No differences were found for the hemoglobin, hematocrit, erythrocytes, MCV, MCH, MCHC, thrombocytes and leukocytes differentiated of fish fed with experimental diets (p>0.05). The biochemical responses were affected by the diet, both in plasma concentration (protein and cholesterol; p<0.05), and in muscle (ash and moisture; p<0.05). In conclusion, the dietary requirement for lysine for tambaqui juveniles was estimated to be 15.4 - 15.6 g/kg of diet (5.7% -5.8% dietary protein).

Effect of Dietary Amino Acids L-Arginine and Lysine on Implant Osseointegration.

Background:Low protein diets have been linked to decreased bone strength in humans. Arginine and lysine can help improve the healing process and stimulate growth factors.Aim:To evaluate if dietary arginine and lysine combination aids in reducing the time frame for osseo-integration process and bone formation in animal models.Materials and Methods:Controls (Group I) and Experimental (Group II) consisted of twelve New Zealand rabbits. Animals in the experimental group were fed a conventional pellet food, water, and the amino acids L-Lysine and L-Arginine (Biovea, USA), whereas those in the control group were offered a standard diet. In both groups of animals, titanium implants measuring 2.5mm* 6mm were implanted in each tibial osteotomy. At the end of two weeks, four weeks, and eight weeks, the animals were euthanized. The tibial bone was removed and preserved in 1% formalin. The samples were analysed histologically for presence or absence of Necrosis, presence or absence of clot formation, Vascularization, Fibroblast, Osteoblasts and Osteoid Bone growth.Results:Histological outcomes on vascularization, fibroblasts, osteoblasts, osteoid bone growth inferred no significant variation between the control and experimental groups after 8 weeks (P>.05).Conclusion:Vascularity, clot organisation, osteoblasts, fibroblasts, and osteoid bone production in the protein fed experimental group animals were better in initial stages of healing when compared to control groups.

Redução temporária de lisina digestível em dietas de leitões em fase de creche: desempenho e viabilidade econômica

ABSTRACT To evaluate the effects of temporary dietary lysine restriction on nursery pigs’ growth performance and its economic viability compared to control diets, 144 piglets (21-d-old) were assigned to randomized blocks, with two treatments and twelve replicates. The treatments were control-lys: lysine level as recommended from 21-32 and 32-42 days and low-lys: 90% of the lysine level of the control-lys diets. From 42 to 62 days, all animals received a control diet. From 21 to 32 days, pigs fed low-lys had worse average daily gain (ADG), feed conversion, and 32-d body weight (BW; P ≤ 0.05). From 32 to 42 days, pigs fed low-lys had lower average daily feed intake, ADG, and 42-d BW (P ≤ 0.05). From 42 to 62 days, pigs had similar performance (P &gt; 0.05). Overall (21 to 62 days), pigs fed the low-lys had lower (P &lt;0.05) ADG and final BW. At 27 and 29 days, pigs fed the low-lys diet had a higher (P≤0.05) incidence of diarrhea. The lowest feed cost and the highest economic efficiency index were recorded for the low-lys treatment. However, pigs fed the control-lys presented a 3.9% higher profitability. In conclusion, a temporary reduction of lysine in the diets of nursery pigs followed by an unrestricted diet in the subsequent period led to worse growth performance and lower economic viability.

Pyridoxine-Dependent Epilepsy and Antiquitin Deficiency Resulting in Neonatal-Onset Refractory Seizures.

Pyridoxine-dependent epilepsy (PDE) is an autosomal recessive neurometabolic disorder due to a deficiency of α-aminoadipic semialdehyde dehydrogenase (mutation in ALDH7A1 gene), more commonly known as antiquitin (ATQ). ATQ is one of the enzymes involved in lysine oxidation; thus, its deficiency leads to the accumulation of toxic metabolites in body fluids. PDE is characterized by persistent, recurrent neonatal seizures that cannot be well controlled by antiepileptic drugs but are responsive clinically and electrographically to daily pyridoxine (vitamin B6) supplementation. Although the phenotypic spectrum distinguishes between typical and atypical, pyridoxine-dependent is true for each. Diagnosis may pose a challenge mainly due to the rarity of the disorder and the fact that seizures may not occur until childhood or even late adolescence. Moreover, patients may not demonstrate an obvious clinical or electroencephalography response to the initial dose of pyridoxine. Effective treatment requires lifelong pharmacologic supplements of pyridoxine, and dietary lysine restriction and arginine enrichment should improve prognosis and avoid developmental delay and intellectual disability. The purpose of this review is to summarize briefly the latest reports on the etiology, clinical symptoms, diagnosis, and management of patients suffering from pyridoxine-dependent epilepsy.

Lysine requirement of the spotted scat Scatophagus argus (Linaeus, 1766)

The study aimed to determine the lysine requirement of young spotted scat Scatophagus argus (Linaeus, 1776) (average body weight = 10.7 g). The feeding trial was conducted for 8 weeks with 5 experimental diets which were isonitrogenous, isocaloric and isolipidic (35% CP, 18.3 MJkg-1, containing lysine levels as treatments containing equal dietary protein (35%) and lipid levels (5%) in 3 replicates. The lysine content was from 1.22 g to 1.94 g lysinekg-1 dry diet (35 to 55 gkg-1 CP) with an average content of 0.18 g lysinekg-1 dry diet per treatment. Results showed that the growth rate, feed conversion and protein efficiency ratios were significantly highest at lysine level of 1.58 gkg dry diet-1(45 gkg-1 CP). Fish survival was not influenced by dietary lysine. Lysine requirement level for juvenile scat was estimated using quadratic regression of the percent weight gain (PWG) and specific growth rate (SGR) against dietary lysine level to have a mean value of 1.64 gkg dry diet-1 (4.75 gkg-1 CP).

The effect of natural feed additive on productive performance of broiler chickens

The effect of natural feed additive on productive performance of broiler chickens

Estimating Amino Acid Requirements in Real-Time for Precision-Fed Pigs: The Challenge of Variability among Individuals.

Simple SummaryPrecision feeding considers the difference in amino acid requirements among pigs and over time by providing daily tailored diets. This practice allows improving environmental and economic performances. Future systems should focus on maximizing nutrient use efficiency to move towards “green” pig production. This study explored a new method of providing amino acids to maximize their use, mainly focusing on understanding variations in the protein metabolism response among individuals to minimize variation in growth response. This study showed that even pigs fed the same amino acid level might use these nutrients differently, especially in protein deposition. Logically, pigs with the greatest protein deposition are the ones that use amino acids the most efficiently, thus exhibiting the lowest nitrogen excretion. This study helped identify some of the factors affecting the efficiency of nitrogen use in pigs. By improving the understanding of pigs’ nutrient response, pig production can become more resource-efficient.This study aimed to measure protein deposition (PD) in pigs fed with daily tailored diets where either dietary lysine (Lys) or threonine (Thr) were provided at independent levels (ignoring an ideal ratio). A total of 95 growing pigs (35 kg body weight (BW)) with electronic ear tags granting them access to automatic feeders were randomly assigned to treatments. The setup was an unbalanced 2 × 5 factorial arrangement with Lys and Thr provided at five levels (i.e., 60%, 80%, 100%, 120%, and 140% of the estimated individual requirements of Lys and Thr), resulting in 25 treatments for 21 days. The observed PD variation to Lys and Thr provisions was large, with Lys and Thr intake explaining only 11% of the variation. Cluster analysis discriminated pigs with low (167 g/d, n = 16), medium (191 g/d, n = 38), and high (213 g/d, n = 37) PD, but with a similar amino acid intake. Differences in PD were associated with differences in nutrient efficiency of utilization. Providing Lys and Thr in a factorial mode, ignoring an ideal ratio, did not decrease the variability in PD. Future research efforts should focus on identifying and investigating the sources of interindividual variability—a necessary step before final recommendations can be made for AA in precision-fed pigs.

Dietary lysine modulates growth performance, haemato‐biochemical indices, non‐specific immune response, intestinal enzymatic activities and antioxidant properties of rainbow trout, Oncorhynchus mykiss fingerlings

The experimental trial was conducted to assess the appropriate utilization of dietary lysine (Lys) required for Oncorhynchus mykiss fingerlings. Six isonitrogenous (450 g/kg CP) and isoenergetic (20.90 kj/g GE) casein–gelatine based diets supplemented with varying concentrations of dietary Lys (14.0, 16.5, 19.0, 21.5, 24.0. and 26.5 g/kg, dry diet) were formulated. For each incremental level, all diets were randomly distributed in triplicate groups of 20 fish (1.79 ± 0.06 g/fish; 5.70 ± 0.42 cm/fish) and were fed in the morning and evening time (08:00 and 17:00 h) at the rate of 5% BW day−1. After the end of the trial, maximum live weight gain (355.21), protein efficiency ratio (1.69 g/kg), better-feed conversion ratio (1.31) and maximum body protein deposition were recorded at 21.50 g/kg increment of Lys in the diet. Highest body protein, lowest moisture and intermediate fat contents were noted in the fish fed 21.50 g/kg of dietary Lys containing diet, while body ash values did not show any significant (p ˃ .05) changes at each increment of Lys in the diets, except at lower increments, where highest ash content was observed. Hepatosomatic index (HSI) value was noted lowest in the fish fed with diets containing 21.50 g/kg Lys level, while haematological variables also exhibit considerable changes with the addition of each Lys inclusion level. Maximum haemoglobin (Hb), haematocrit (Hct) and red blood cell (RBC) count were also noted at 21.50 g/kg Lys fed diet. Significant variations (p < .05) in plasma variables, non-specific immune system, intestinal enzymatic activities and antioxidant status were also observed in the fish fed with varying dietary Lys containing diets. However, cholesterol, triglycerides, amylase, lipase and superoxide dismutase (SOD) did not show any differences with respect to Lys inclusion levels. Our findings suggest that 21.60 g/kg dietary Lys, corresponding to 48.0 g/kg of dietary protein should be incorporated in the diet of rainbow trout for better growth and efficient nutrient conversion of this species, and also for the improvement in fish health. Collectively, this study indicated that an appropriate amount of Lys improve fish growth, haemato-biochemical parameters, immune response and digestive ability, and also up-regulate the antioxidant status.

Requirement of fingerling Channa punctatus (Bloch) for dietary lysine based on growth, feed conversion and lysine retention efficiency, RNA/DNA ratio, haematological parameters and serum antioxidant activity

Dietary lysine requirement of fingerling Channa punctatus (5.64 ± .08g) was determined by feeding isoproteic (450g/kg crude protein) and isoenergetic (14.73 kJ/g digestible energy) diets with graded concentrations of lysine (5, 10, 15, 20, 25, 30 and 35g/kg dry diet) to triplicate groups to apparent satiation at 08:00, 12:30 and 17:30 h for 12-week. Absolute weight gain (AWG), specific growth rate (SGR), feed conversion ratio (FCR), protein gain (PG), lysine retention efficiency (LRE) and RNA/DNA ratio were found to increase with the increasing concentrations of lysine up to 20g/kg dry diet. Carcass protein increased up to 20g/kg dietary lysine, whereas carcass fat decreased significantly. Total serum protein and superoxide dismutase activity responded positively (p < .05), while aspartate aminotransferase and alanine aminotransferase activities negatively up to 20g/kg dietary lysine level. Quadratic regression analysis of AWG, FCR, PRE, LRE, Hb and Hct against dietary lysine levels indicated the lysine requirement ranging between 22.2 and 24.0g/kg dry diet corresponding to 49.4 and 53.4g/kg protein.

A knock-in rat model unravels acute and chronic renal toxicity in glutaric aciduria type I

Glutaric aciduria type I (GA-I, OMIM # 231670) is an autosomal recessive inborn error of metabolism caused by deficiency of the mitochondrial enzyme glutaryl-CoA dehydrogenase (GCDH). The principal clinical manifestation in GA-I patients is striatal injury most often triggered by catabolic stress. Early diagnosis by newborn screening programs improved survival and reduced striatal damage in GA-I patients. However, the clinical phenotype is still evolving in the aging patient population. Evaluation of long-term outcome in GA-I patients recently identified glomerular filtration rate (GFR) decline with increasing age.We recently created the first knock-in rat model for GA-I harboring the mutation p.R411W (c.1231 C>T), corresponding to the most frequent GCDH human mutation p.R402W. In this study, we evaluated the effect of an acute metabolic stress in form of high lysine diet (HLD) on young Gcdhki/ki rats. We further studied the chronic effect of GCDH deficiency on kidney function in a longitudinal study on a cohort of Gcdhki/ki rats by repetitive 68Ga-EDTA positron emission tomography (PET) renography, biochemical and histological analyses.In young Gcdhki/ki rats exposed to HLD, we observed a GFR decline and biochemical signs of a tubulopathy. Histological analyses revealed lipophilic vacuoles, thinning of apical brush border membranes and increased numbers of mitochondria in proximal tubular (PT) cells. HLD also altered OXPHOS activities and proteome in kidneys of Gcdhki/ki rats.In the longitudinal cohort, we showed a progressive GFR decline in Gcdhki/ki rats starting at young adult age and a decline of renal clearance. Histopathological analyses in aged Gcdhki/ki rats revealed tubular dilatation, protein accumulation in PT cells and mononuclear infiltrations.These observations confirm that GA-I leads to acute and chronic renal damage. This raises questions on indication for follow-up on kidney function in GA-I patients and possible therapeutic interventions to avoid renal damage.

28. The anorexigenic effect of dietary lysine could be mediated by increased jejunal cholecystokinin secretion in piglets

28. The anorexigenic effect of dietary lysine could be mediated by increased jejunal cholecystokinin secretion in piglets

Nitrogen retention, nutrient digestibility and growth efficiency of Nile tilapia ( Oreochromis niloticus ) fed dietary lysine and reared in fertilized ponds

Two diets were formulated, a low lysine (LowL) and a balanced lysine diet (BalL), containing 9.10 and 13.10 g lysine kg−1 feed, respectively. Twenty fish (30.2 ± 1.9 g) per tank were stocked in 110-L tanks, mounted in a recycling aquaculture system (RAS), and nine hundred fish (17.2 ± 1.6 g) per pond were stocked in 200 m2 fertilized ponds (FPS). Four replicates in RAS and five replicates in FPS were assigned for each diet tested. Fish were fed with the experimental diets at a feeding rate based on metabolic body weight, twice daily for 70 days. Fish fed the BalL diet in RAS had a higher yield (kg m−3), specific growth rate, nitrogen retention efficiency (%), protein efficiency ratio (g g−1 protein), protein content and essential amino acid content, as well as a better feed conversion ratio (p < .05). Lysine levels did not significantly affect fish survival (%), feed intake and apparent digestibility coefficients of nutrients. In contrast, in FPS, dietary lysine content did not (p > .05) affect the growth indices of nutrient utilization, survival (%), body composition and essential amino acids or nitrogen utilization efficiency. Percentage compositions of plankton in the gut contents and plankton abundances in water were approximately the same between diets. The Pearson correlation coefficient (r) between plankton abundance and growth in fish fed the LowL diet was .761 and −.961 for phytoplankton and zooplankton, respectively, compared with .50 and .54 in fish fed the BalL diet. The contribution of the natural food to nitrogen gain was 30% in fish fed the LowL diet, compared with 21% in fish fed the BalL diet (p < .05). The present study shows that natural food compensated for the deficiency of dietary lysine and improved the protein efficiency ratio by 46%, when compared to Nile tilapia grown in clear-water tanks.

Quantitative lysine requirement for juvenile Florida pompano, Trachinotus carolinus fed plant-based diets

Florida pompano, Trachinotus carolinus is positioned to be an important fish species in US mariculture. If commercial production is to be developed sustainably and with reduced feed costs, it is critical to maximize the level of plant-based proteins in the diet. Thus, an understanding of limiting amino acids is necessary to properly formulate grow out feeds, which include lysine. This work was conducted using eight diets formulated with graded levels of lysine (1.42–2.42% dry weight) and fed to juvenile pompano (mean initial weight 13.07 ± 0.46) for 56 days. Dose responses and significant effects were observed in final weight (FW), percent weight gain (PWG), thermal growth coefficient (TGC) and feed conversion ratio (FCR). Significant differences in mean fish whole body amino acids were observed in aspartic acid, glutamic acid, hydroxyproline, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tyrosine and valine. Regression models, such as broken-quadratic model (BQM), 4-parameter saturation kinetic model (4-SKM), 5-parameter saturation kinetic model (5-SKM), one-slope broken line model (BKL.1) and two-slope broken line model (BKL.2) from R were fitted against different parameters to determine the dietary lysine requirement. Thermal growth coefficient was the parameter utilized to fit a 4-SKM model and determine the quantitative lysine requirement. Based on these results, a minimum lysine requirement of 1.67% dry weight is recommended to meet nutritional requirements for growth in practical feed formulations.

Dietary lysine restriction induces lipid accumulation in skeletal muscle through an increase in serum threonine levels in rats

We previously reported that dietary amino acid restriction induces the accumulation of triglycerides (TAG) in the liver of growing rats. However, differences in TAG accumulation in individual cell types or other tissues were not examined. In this study, we show that TAG also accumulates in the muscle and adipose tissues of rats fed a low amino acid (low-AA) diet. In addition, dietary lysine restriction (low-Lys) induces lipid accumulation in muscle and adipose tissues. In adjusting the nitrogen content to that of the control diet, we found that glutamic acid supplementation to the low-AA diet blocked lipid accumulation, but supplementation with the low-Lys diet did not, suggesting that a shortage of nitrogen caused lipids to accumulate in the skeletal muscle in the rats fed a low-AA diet. Serum amino acid measurement revealed that, in rats fed a low-Lys diet, serum lysine levels were decreased, while serum threonine levels were significantly increased compared with the control rats. When the threonine content was restricted in the low-Lys diet, TAG accumulation induced by the low-Lys diet was completely abolished in skeletal muscle. Moreover, in L6 myotubes cultured in medium containing high threonine and low lysine, fatty acid uptake was enhanced compared with that in cells cultured in control medium. These findings suggest that the increased serum threonine in rats fed a low-Lys diet resulted in lipid incorporation into skeletal muscle, leading to the formation of fatty muscle tissue. Collectively, we propose conceptual hypothesis that “amino-acid signal” based on lysine and threonine regulates lipid metabolism.

Dietary lysine supplementation improves growth performance and skeletal muscle development in rabbits fed a low protein diet

The purpose of this study was to investigate the effects on growth of Lysine (Lys) supplementation in a low protein diet. We also investigated the gene or protein expression related to skeletal muscle development and intestinal amino acid transporters, and determined the major signalling associated with Lys-regulating skeletal muscle development. 1000healthy, weights averaging 938.6±6.54g weaned rabbits were randomly divided into five groups (five replicates in each group and 40 rabbits in each replicate). These groups consisted of the normal protein group (NP group, consuming a diet containing 16.27% protein), the low protein group (LP group, 14.15%-14.19% protein) and the LP group with an addition of 0.15%, 0.3% or 0.45% Lys. The trial included 7 d of pre-feeding and 28 d of exposure to the treatment. Compared with NP diet and LP diet, LP+0.3% Lys group improved growth performance (p<0.05), full-bore weight and half-bore weight of rabbits (p<0.05). The LP+0.3% Lys group also resulted in a decrease in the excretion of faecal nitrogen and urinary nitrogen (FN; UN; p<0.05), and an increase in nitrogen utilisation rate (NUR; p<0.05). LP diet increased the mRNA expression of MSTN and WWP1, and decreased the mRNA expression of IGF1 (p<0.05). LP diet decreased the protein expression of P-P70S6K1, P-4EBP1 and P-S6 (p<0.05). LP+0.3% Lys group attenuated the effects of LP diet on the expression of MSTN, WWP1, IGF1, P-P70S6K1, P-4EBP1 and P-S6 (p<0.05). LP+0.3% Lys group resulted in an increase in mRNA expression of MyoD and protein expression of P-mTOR relative to the NP and LP groups (p<0.05). In summary, the addition of Lys to a LP diet provides a theoretical basis for the popularisation and application of Lys in rabbit production.

Dietary lysine requirement of greater amberjack juvenile ( Seriola dumerili , Risso, 1810)

An 8-week feeding trial was conducted to determine the dietary lysine requirement of greater amberjack, Seriola dumerili. Six experimental diets resulting from a practical basal formulation were produced to containing mainly plant ingredients (25% fish meal) were supplied with graded levels of crystalline L-lysine-HCl and the analysed lysine concentration in each diet was found to be 1.93 (basal diet; CL1.93), 2.01 (CL2.01), 2.11 (CL2.11), 2.15 (CL2.15), 2.20 (CL2.20) and 2.29 (CL2.29) g/100 g diet respectively. Seriola dumerili of 32.8 g ± 3.0 (mean ± SD) were randomly assigned to 18 experimental small cages, and each was stocked with 25 fish per cage in triplicates. The fish were hand-fed with the experimental diets twice daily (09:00 h and 15:00 h) to apparent satiation, 6 days a week for 56 days. No significant differences were observed in weight gain (WG), daily growth index (DGI), specific growth rate (SGR) and protein efficiency ratio (PER) among the dietary groups. However, the pairwise linear regression of WG showed that the dietary lysine requirement of greater amberjack juvenile is 2.11% of the diet. The activity of catalase enzyme among the dietary treatments differed significantly (p < .05) in both the liver and intestine. Similar results were found for the heat shock proteins (HSP70 and HSP90) with a tissue-specific response. Based on the results obtained, the dietary lysine requirements that can support maximum WG and PER of greater amberjack juvenile were found to be between 2.03% and 2.11% of the diet (4.55%–4.73% of dietary protein).

사료 내 라이신 수준이 육성돈의 성장, 영양소소화율, 혈액성상 및 경제성에 미치는 영향

본 연구는 사료 내 라이신 수준이 육성돈의 성장, 영양소소화율, 혈액성상 및 경제성에 미치는 영향을 평가하기 위해 수행하였다. 총 108두의 3원 교잡 육성돈(Landrace×Yorkshire×Duroc; 24.86±1.84 kg)을 공시하였으며, 개시체중에 기반하여, 3처리 18반복, 반복당 2두씩 완전임의 배치하였다. 시험기간은 phaseⅠ(25-50 kg), phaseⅡ(50-75 kg)로 나누어 진행하였다. 시험구는 National Research Council 라이신 요구량에 기반된 대조구(CON)와 라이신을 대조구 대비 각각 5%(HL5), 10%(HL10) 증량된 처리구가 포함되었다. PhaseⅡ에서 HL10 처리구의 사료효율이 CON에 비해 유의적으로 높게 나타났다. Overall에서 HL10의 일당증체량과 사료효율이 유의적으로 개선되는 것으로 나타났다. PhaseⅠ에서 HL10의 건물과 에너지 소화율이 유의적으로 개선되는 것으로 나타났다. PhaseⅡ의 조단백질 소화율은 HL10 처리구가 CON에 비해 유의적으로 높게 나타났다. PhaseⅠ에서 HL5와 HL10 처리구가 CON에 비해 혈 중 총단백질 함량이 유의적으로 높게 나타났다. 사료 내 라이신 수준은 혈액성상에 영향을 미치지 않았다. Overall에서 HE10 처리구의 총증체량과 1 kg 증체당 사료비가 CON에 비해 유의적으로 개선되는 것으로 나타났다. 시험의 결과를 종합해보면, 육성돈 사료 내 10% 수준의 라이신 증량은 성장, 영양소소화율 및 경제성에 긍정적인 효과를 미친다.

Utilization of different lysine isomers: A case study on the growth, metabolic enzymes, antioxidant capacity and muscle amino acid composition in Macrobrachium rosenbergii

An 8-week feeding trial was conducted to compare the effects of different lysine isomers on growth performance, amino acid metabolism-related enzyme activities, antioxidant capacity and muscle amino acid composition of giant river prawn (Macrobrachium rosenbergii). The basal diet was formulated to be low in lysine and contained only 10.9 g/kg lysine. The other three experimental diets were supplemented with 12 g/kg D-lysine, L-lysine, and DL-lysine, respectively. Dietary lysine supplementation improved the growth rate and feed utilization of M. rosenbergii, but significant differences were only found between the prawn fed the control diet and the L-lysine diet. L-lysine supplementation significantly improved the intestinal and hepatic trypsin activities, but unaffected the lipase and amylase activities. The highest hepatic aspartate aminotransferase and alanine aminotransferase activities were observed in prawn fed the L-lysine diet, whereas the highest γ-glutamyl transferase activity was found in prawn fed the D-lysine diet. D-lysine supplementation significantly increased the intestinal and hepatic D-amino acid oxidase activities. However, L-lysine supplementation improved the hepatic lysozyme activity and total antioxidant capacity, depressed the hepatic lactate dehydrogenase and alkaline phosphatase activities. Conversely, D-lysine supplementation generally depressed the hepatic superoxide dismutase and peroxidase activities, and nitric oxide content. Furthermore, L-lysine supplementation increased the muscle aspartic acid, serine, glutamic acid, alanine, lysine, arginine, delicious amino (DAA), non-essential amino acids, total amino acids (TAA) contents and DAA/TAA ratio. These results indicate that M. rosenbergii can effectively utilize L-lysine for growth; D-lysine may partly be used but reveal specific toxic effects on antioxidant response.

The role of serum and dietary advanced glycation endproducts in relation to cardiac function and structure: The Hoorn Study

Background and aimsThis study aims to investigate the relationship of serum and dietary advanced glycation endproducts (AGEs) with cardiac function and structure after eight years of follow-up. Methods and resultsWe included 370 Hoorn Study participants (aged 66.4 ± 6.1, 47% women). Serum protein-bound AGEs [Nε-(carboxymethyl)lysine, Nε-(carboxyethyl)lysine, and pentosidine], as well as echocardiography to assess left atrium volume index (LAVI), left ventricle ejection fraction (LVEF), and left ventricle mass index (LVMI), were measured at baseline and after 8 years of follow-up. Dietary AGEs [Nε-(carboxymethyl)lysine and Nε-(carboxyethyl)lysine] were estimated at baseline with a validated food-frequency questionnaire and an AGEs database. Increased pentosidine [-1.4% (−2.6;-0.2)] and overall serum AGEs Z-scores over time [-2.1% (−3.8;-0.5)] were associated with decreased LVEF at follow-up, adjusted for confounders. Glucose metabolism status was an effect modifier (P-for-interaction = 0.04). In participants with impaired glucose metabolism, but not type 2 diabetes, increased pentosidine was associated with decreased LVEF [-4.2 (−8.0;-0.3)%]. Higher dietary Nε-(carboxyethyl)lysine [1.9 (0.1; 3.7)%] and overall dietary AGEs Z-scores [2.1 (0.1; 4.2)%] were associated with higher LVEF at follow-up. However, prior cardiovascular disease (CVD) was an effect modifier (P = 0.02). We found a stronger, non-significant, association of higher dietary (carboxyethyl)lysine with higher LVEF at follow-up in participants without CVD [2.3 (−0.1; 4.7)%] compared to participants with CVD [0.6 (−2.1; 3.4)%]. ConclusionOverall serum AGEs were longitudinally associated with impaired systolic function. Future research should focus on including changes in dietary AGEs intake over time and the relation of dietary AGEs with cardiac measures needs to be established in intervention studies using low AGEs diets.