Net Protein Research Articles

EFFECT OF RESTRICTED FEEDING ON GROWTH PERFORMANCE AND FEED UTILIZATION OF FRESHWATER PRAWN (Macrobrachium rosenbergii) IN POND AQUACULTURE SYSTEM

The present study aimed to evaluate the effect of rate restricted feeding on the growth performance and feed utilization efficiency of prawn (Macrobrachium rosenbergii) in improved traditional pond culture system. There was a control group (T2,) ad libitum of prawn) and two treatments which were 25% reduction(T2) and 50% reduction (T3) of artificial feed than control and each treatment were 25% reduction(T2) and 50% reduction (T3) of artificial feed than control and each treatment was triplicated. After nine experimental ponds (each was 120 m2) preparation, prawn PL was reared in the nursery pond for 45 days to become juvenile and the juvenile was then stocked in grow out at density of 2/m2. After 100 days of culture, the final mean weight was 16.14±8.2, 16.56±1.57 and 19.33±7.75 g for T1, T2 and T3 respectively. Higher SGR (2.89 % BW/d) was found in T3 which was significantly (p<0.05) higher than T1 (2.67 % BW/d) and T2 (2.72 %BW/d). Significantly (p<0.05) lowest survival rate (71%) was observed for T3 and highest survival rate (93%) was found forT1. The feed conversion efficiency (FCR) decreased significantly (p<0.05) with increasing feed restriction and lowest value (0.81) was observed for T3. The protein efficiency ratio (PER) and net apparent protein utilization (NPUa) found to increase with increasing feed restriction which indicates the better utilization of feed. The present study indicates that prawns are subjected to rate restriction of feeding condition was able to maintain the same and even high growth rate as control.

Branched-chain amino acids regulate intracellular protein turnover in porcine mammary epithelial cells.

Dietary supplementation with branched-chain amino acids (BCAAs) to lactating sows has been reported to enhance their milk production, but the underlying mechanisms remain largely unknown. This study was conducted with porcine mammary epithelial cells (PMECs) to test the hypothesis that individual BCAAs or their mixture stimulates protein synthesis and inhibit proteolysis in PMECs. Cells were cultured at 37°C in customizedDulbecco's modified Eagle medium containing 5mmol/L D-glucose, 1mmol/L L-phenylalanine, L-[ring-2,4-3H]phenylalanine, 0.1 (control), 0.25, 0.5, 1, or 2mmol/L L-leucine, L-isoleucine or L-valine or an equimolar mixture of the three BCAAs. The culture medium also contained physiological concentrations of other amino acids found in the plasma of lactating sows. Proliferation, protein synthesis, proteolysis, β-casein production, the mechanistic target of rapamycin (mTOR) signaling, and the ubiquitin-proteasome pathway were determined for PMECs. Cell proliferation and abundances of phosphorylated mTOR, eukaryotic translation initiation factor 4E-binding protein 1, and ribosomal protein S6 kinase β-1 proteins increased (P < 0.05), but abundances of ubiquitinated protein and 20S proteasome decreased (P < 0.05) when extracellular concentrations of L-leucine, L-isoleucine, L-valine, or an equimolar mixture of BCAAs were increased from 0.1 to 2mmol/L. Compared with the control, 0.25, 0.5, 1 or 2mmol/L BCAAs enhanced (P < 0.01) protein (including β-casein) synthesis, while decreasing (P < 0.05) proteolysis in PMECs in a dose-dependent manner. Collectively, our results indicate that physiological concentrations of BCAAs regulate protein turnover in mammary epithelial cells to favor net protein synthesis through stimulating the mTOR signaling pathway and inhibiting the ubiquitin-proteasome pathway.

Efficacy of crystalline amino acids supplementation in reduction of intact protein level in channel catfish Ictalurus punctatus diets

A 9-week growth trial was performed to assess the role of indispensable (IAA) and dispensable amino acids (DAA) supplementation in diets designed for juvenile (10.6 g) channel catfish (Ictalurus punctatus). The effects on fish growth, feed utilization, proximate, amino acids (AA) composition, and morphometric indicators were followed. Nine iso-lipidic (8 %) experimental diets were formulated with different levels of intact protein (32, 30, 28, 26, and 24 IP) supplemented with IAA (Lysine and Histidine) to restore IAA balance to those stated in NRC (2011). Additionally, DAA (Glutamic acid and Glycine) were added to the 24IP at different rates (2 %, 4 %, 6 %, and 8 %). At the conclusion of the growth trial, however, there was a linear decrease in fish growth as IP was lowered from 32% to 24%. But, based on mean separation; final mean weight (g), thermal growth coefficient (TGC), and feed conversion ratio (FCR) of channel catfish were not significantly different (P > 0.05) among fish groups fed diets containing 32 %, 30 %, 28 % and 26 % IP supplemented with IAA. Fish growth was significantly reduced, while apparent net protein retention (ANPR) and FCR significantly increased as IP was lowered to 24%. While growth and FCR of catfish fed 24IP with DAA (2–6 %) were not significantly different compared to catfish fed 32 % and 30 %IP diets. In conclusion, IAA (lysine and histidine) could be used as a supplement to reduce intact protein from 32 % to 26 % in channel catfish diets with maintaining IAA balance as recommended by NRC (2011). Catfish growth was improved by fortification of the 24IP diet with DAA (2–6 %), so the dietary IP level could be further lowered to 24 % with supplementation of IAA and DAA.

Impact of divalent cations on lysozyme-induced solubilisation of waste-activated sludge: Perspectives of extracellular polymeric substances and surface electronegativity

Lysozyme hydrolysis can accelerate waste-activated sludge (WAS) solubilisation, which can significantly shorten the process and promote the efficiency of anaerobic digestion. This study investigated the impact of divalent cations on lysozyme-induced solubilisation of WAS. The performance of lysozyme pretreatment was dramatically inhibited by Mg2+ and Ca2+. Compared to the control group, the amount of net SCOD, protein, and polysaccharides released to the supernatant were reduced by 36.6%, 44.7%, and 35.8%, respectively, in the presence of divalent cations. The extracellular polymeric substance (EPS) matrix became tightly bound, resulting in fewer proteins and polysaccharides being extracted from loosely-bound EPS (LB-EPS) with divalent cations, which was detrimental to the solubilisation of WAS. Divalent cations decreased the surface electronegativity of sludge particles and prolonged the adsorption of lysozymes by sludge flocs. More than 16.6% of total lysozymes remained in the liquid phase of WAS after 240min Mg2+ and Ca2+ strengthened the binding among proteins and polysaccharides and promoted the intermolecular cross-linking of polysaccharides. The EPS matrix formed a dense spatial reticular structure that blocked the transfer of lysozymes from the EPS matrix to the pellet. As a result, the lysozymes accumulated in LB-EPS rather than hydrolysing the microorganism's cell wall. This study provides a new perspective on the restriction of WAS pretreatment with lysozymes and optimises the method of lysozyme-induced solubilisation of WAS.

Functional reorganization of monoamine transport systems during villous trophoblast differentiation: evidence of distinct differences between primary human trophoblasts and BeWo cells

BackgroundThree primary monoamines—serotonin, norepinephrine, and dopamine—play major roles in the placenta-fetal brain axis. Analogously to the brain, the placenta has transport mechanisms that actively take up these monoamines into trophoblast cells. These transporters are known to play important roles in the differentiated syncytiotrophoblast layer, but their status and activities in the undifferentiated, progenitor cytotrophoblast cells are not well understood. Thus, we have explored the cellular handling and regulation of monoamine transporters during the phenotypic transitioning of cytotrophoblasts along the villous pathway.MethodsExperiments were conducted with two cellular models of syncytium development: primary trophoblast cells isolated from the human term placenta (PHT), and the choriocarcinoma-derived BeWo cell line. The gene and protein expression of membrane transporters for serotonin (SERT), norepinephrine (NET), dopamine (DAT), and organic cation transporter 3 (OCT3) was determined by quantitative PCR and Western blot analysis, respectively. Subsequently, the effect of trophoblast differentiation on transporter activity was analyzed by monoamine uptake into cells.ResultsWe present multiple lines of evidence of changes in the transcriptional and functional regulation of monoamine transporters associated with trophoblast differentiation. These include enhancement of SERT and DAT gene and protein expression in BeWo cells. On the other hand, in PHT cells we report negative modulation of SERT, NET, and OCT3 protein expression. We show that OCT3 is the dominant monoamine transporter in PHT cells, and its main functional impact is on serotonin uptake, while passive transport strongly contributes to norepinephrine and dopamine uptake. Further, we show that a wide range of selective serotonin reuptake inhibitors affect serotonin cellular accumulation, at pharmacologically relevant drug concentrations, via their action on both OCT3 and SERT. Finally, we demonstrate that BeWo cells do not well reflect the molecular mechanisms and properties of healthy human trophoblast cells.ConclusionsCollectively, our findings provide insights into the regulation of monoamine transport during trophoblast differentiation and present important considerations regarding appropriate in vitro models for studying monoamine regulation in the placenta.

Biotechnological Effect of Fermented Mung Beans (Vigna Radiata) Flour and Its Protein Quality in Wistar Rats

Fermentation with inclusion of organisms has been shown to improve the nutritional quality of food. This work was designed to investigate the effect of fermented mung beans (Vigina radiata) flour and protein quality in Wistar rats. The seed of V. radiata was sorted, washed, sun-dried, and later aseptically pulverized. The flour was then divided into seven portions of 500 g each and put in sterile containers. The six portions of flour were subjected to natural and induced fermentation for 4 days, using naturally occurring bacteria singly as a starter culture at 28 ±2oC, while the unfermented portion served as a control. The product of fermentation was used to determine the nutritional quality of the unfermented and fermented mung beans flour by studying the growth weight of visceral organs and body weight of rats and nitrogen retention of animals in various tissues of the internal organs, faeces and urine and protein quality of experimental animals fed. The growth weight of visceral organs and body weight of rats in the kidney (g) ranged from 17.52 ±0.62 to 23.07 ±0.78, liver (g) from 85.77 ±0.30 to 117.52 ±0.50 while muscle (g) ranged from 68.99 ±0.10 to 134.56 ±0.47. Nitrogen retention of animals fed with unfermented and fermented mung beans flour in kidney (g) 13.45 ±0.02 to 50.34 ±0.01, liver (g) 12.44 ±0.01 to 50.38 ±0.02, muscle (g) 12.89 ±0.01 to 50.55 ±0.01, faeces (g) 0.36 ±0.01 to 0.89 ±0.01 while urine 0.35 ±0.01 to 0.84 ±0.02. The protein quality of experimental animals fed in Biological Value (BV) ranged from 0.00 to 70.67 ±1.15, Net Protein Utilization (NPU) 0.00 to 76.33 ±1.53, Protein Efficiency Ratio (PER) 0.00 to 2.27 ±0.15, Net Protein Ratio (NPR) 0.00 to 3.47 ±0.11 while gained/loss ranged from -10.59 ±0.01 to 30.88 ±5.76. The fermentation increase quality of nutrient present in mung beans and fermented mung beans flour may promote the weight of internal organs of Wistar rats.

Health Functions of Egg Protein.

Egg protein is a remarkably abundant source of protein, with an amino acid score of 100 and the highest net protein utilization rate. However, there have been relatively fewer studies investigating the health benefits of egg protein. In this review, we have summarized the available information regarding the health benefits of egg proteins based on human studies. In particular, studies conducted on the characteristics of egg whites, as they are high in pure protein, have reported their various health functions, such as increases in muscle mass and strength enhancement, lowering of cholesterol, and visceral fat reduction. Moreover, to facilitate and encourage the use of egg white protein in future, we also discuss its health functions. These benefits were determined by developing an egg white hydrolysate and lactic-fermented egg whites, with the latter treatment simultaneously improving the egg flavor. The health benefits of the protein hydrolysates from the egg yolk (bone growth effect) and eggshell membrane (knee join pain-lowering effect) have been limited in animal studies. Therefore, the consumption of egg protein may contribute to the prevention of physical frailty and metabolic syndromes.

The Effect of Glucagon on Protein Catabolism During Insulin Deficiency: Exchange of Amino Acids Across Skeletal Muscle and the Splanchnic Bed.

Transient insulin deprivation with concurrent hyperglucagonemia is a catabolic state that can occur in type 1 diabetes. To evaluate glucagon's catabolic effect in the setting of its glucogenic effect, we measured the regional exchanges of amino acid metabolites (amino-metabolites) across muscle and splanchnic beds in 16 healthy humans during either somatostatin followed by glucagon or saline infusion alone. Despite a twofold or greater increase in the regional exchange of amino-metabolites by glucagon, whole-body kinetics and concentrations of amino acids (AA) remained stable. Glucagon increased the splanchnic uptake of not only gluconeogenic but also essential (EAA) AA while increasing their release from the muscle bed. Regional tracer-based kinetics and 3-methylhistidine release indicate that EAA release from muscle is likely caused by reduced protein synthesis rather than increased protein degradation. Furthermore, many metabolites known to affect insulin action and metabolism were altered by hyperglucagonemia including increase in branched-chain AA and keto acids of leucine and isoleucine in arterial plasma. Further, an increase in arterial concentrations of α-aminoadipic acid arising from increased conversion from lysine in the splanchnic bed was noted. These results demonstrate that hyperglucagonemia during hypoinsulinemia increases net muscle protein catabolism and substantially increases the exchange of amino metabolites across splanchnic and muscle beds.

A Comparative Study on the Proximate Composition and Protein Quality of Soya Bean Flour and Smoked Crayfish Sold in Dschang, Cameroon

A study was carried outto compare the proximate composition and protein quality of soya beans flour and smoked crayfish. Proximate compositions of soya beans flour and smoked crayfish were determined and diets composed for rat growth and balance experimentation. Eighteen (18) weanling male wistar rats were distributed in three groups of sixelements.Test groups received respectively soya beans-based and smoked crayfish-based diets. Eachprotein product was fed as the sole source of 10% dietary protein. The evaluated biological parameters were protein efficiency ratio (PER) and net protein ratio (NPR).Smoked crayfish had significantly (p &lt;0.05)higher values of crude protein (77.31±0.63% DM) and ash (5.89±0.08%) while soya beans flour containedhigher values ofcrude lipid (18.03±0.11%DM), carbohydrates (37.2±0.01% DM) and crude fibre (5.50±0.15% DM).Smoked crayfish showed significantly (p &lt; 0.05) higher PER (3.83) and NPR (3.96) values compared to soya bean (3.20) and (3.39) respectively. Smoked crayfish could be a better source of dietary protein especially in weaning diet.

Carbohydrate and Protein Fractionations of commonly used forages and agro-industrial byproducts as per Cornell Net Carbohydrate and Protein system (CNCPS)

Carbohydrate and Protein Fractionations of commonly used forages and agro-industrial byproducts as per Cornell Net Carbohydrate and Protein system (CNCPS)

Protein and carbohydrate profiles of a diploid and a tetraploid red clover cultivar

Red clover (Trifolium pratense L.) is characterized by high dry matter (DM) yield and a high nutritive value. It has a higher concentration of soluble carbohydrate than lucerne and its protein is less degradable in the rumen than lucerne protein. The aim of this study was to quantify the main crude protein (CP) and carbohydrate (CHO) fractions of a tetraploid (4n, cv K-32) and a diploid (2n, cv K-39) red clover cultivar harvested at three stages of development in the spring growth. Results showed that the cultivar and stage of development had a large impact on chemical composition and the protein and carbohydrate fractions determined by the Cornell Net Carbohydrate and Protein System (CNCPS). The rapidly degradable protein fraction (PA) was significantly higher in the tetraploid (272 to 287 g kg-1 CP with advancing plant development) than in the diploid red clover cultivar (214 to 268 g kg-1 CP). Rumen degradable carbohydrate concentration was not affected by cultivar but it was significantly influenced by the stage of development. The concentration of rumen degradable protein decreased from 726 to 655 g kg-1 CP with advancing plant development in the diploid red clover cultivar. In conclusion, the tetraploid red clover cultivar was higher in CP, its protein was more rapidly degradable, and it was characterized by lower concentrations of lignin and unavailable carbohydrate fractions than the diploid cultivar.

Ribo-DT: An automated pipeline for inferring codon dwell times from ribosome profiling data.

Protein synthesis is an energy consuming process characterised as a pivotal and highly regulated step in gene expression. The net protein output is dictated by a combination of translation initiation, elongation and termination rates that have remained difficult to measure. Recently, the development of ribosome profiling has enabled the inference of translation parameters through modelling, as this method informs on the ribosome position along the mRNA. Here, we present an automated, reproducible and portable computational pipeline to infer relative single-codon and codon-pair dwell times as well as gene flux from raw ribosome profiling sequencing data. As a case study, we applied our workflow to a publicly available yeast ribosome profiling dataset consisting of 57 independent gene knockouts related to RNA and tRNA modifications. We uncovered the effects of those modifications on translation elongation and codon selection during decoding. In particular, knocking out mod5 and trm7 increases codon-specific dwell times which indicates their potential tRNA targets, and highlights effects of nucleotide modifications on ribosome decoding rate.

Quantitation of relationship and development of nutrient prediction with vibrational molecular structure spectral profiles of feedstocks and co-products from canola bio-oil processing.

This program aimed to reveal the association of feed intrinsic molecular structure with nutrient supply to animals from canola feedstocks and co-products from bio-oil processing. The special objective of this study was to quantify the relationship between molecular spectral feature and nutrient availability and develop nutrient prediction equation with vibrational molecular structure spectral profiles. The samples of feedstock (canola oil seeds) and co-products (meals and pellets) from different bio-oil processing plants in Canada (CA) and China (CH) were submitted to this molecular spectroscopic technique and their protein and carbohydrate related molecular spectral features were associated with the nutritional results obtained through the conventional methods of analyses for chemical and nutrient profiles, rumen degradable and intestinal digestible parameters. The results showed that the spectral structural carbohydrates spectral peak area (ca. 1,487.8 to 1,190.8 cm-1) was the carbohydrate structure that was most significant when related to various carbohydrate parameters of canola meals (p<0.05, r>0.50). And spectral total carbohydrate area (ca. 1,198.5 to 934.3 cm-1) was most significant when studying the various carbohydrate parameters of canola seeds (p<0.05, r>0.50). The spectral amide structures (ca. 1,721.2 to 1,480.1 cm-1) were related to a few chemical and nutrient profiles, Cornell Net Carbohydrate and Protein System (CNCPS) fractions, truly absorbable nutrient supply based on the Dutch protein system (DVE/OEB), and NRC systems, and intestinal in vitro protein-related parameters in co-products (canola meals). Besides the spectral amide structures, α-helix height (ca. 1,650.8 to 1,643.1 cm-1) and β-sheet height (ca. 1,633.4 to 1,625.7 cm-1), and the ratio between them have shown to be related to many protein-related parameters in feedstock (canola oil seeds). Multiregression analysis resulted in moderate to high R2 values for some protein related equations for feedstock (canola seeds). Protein related equations for canola meals and carbohydrate related equations for canola meals and seeds resulted in weak R2 and low p values (p<0.05). In conclusion, the attenuated total reflectance Fourier transform infrared spectroscopy vibrational molecular spectroscopy can be a useful resource to predict carbohydrate and protein-relates nutritional aspects of canola seeds and meals.

The Combination of Plant Extracts and Probiotics Improved Jejunal Barrier and Absorption Capacity of Weaned Piglets

Plant extracts and probiotics play a vital role in maintaining animal intestinal health. However, their joint compatibility program still needs to be further explored. In our study, thirty two piglets (Duroc × Landrace × Yorkshire) were selected to divided into four treatments, which included basal diet, basal diet + 1000 mg/kg probiotics with added glucose oxidase (PGO), basal diet + 500 mg/kg Illicium verum extracts (IVE), and basal diet + 500 mg/kg IVE + 1000 mg/kg PGO. All the piglets were housed individually for the 42-d trial period after 7-d adaptation. Results showed that dietary supplementation of PGO and IVE increased the digestibility of ether extract (EE), crude protein (CP), and lysine (p &lt; 0.05). Likewise, the net protein utilization (NPU) was also improved (p &lt; 0.05). What is more, adding PGO and IVE reduced crypt depth, increased villus length, and chrionic gland ratio of piglets (p &lt; 0.05). Additionally, IVE or PGO that was applied alone can increase the expression of Occludin, Zona occludens 1 (ZO-1), and Sodium-dependent glucose transporters 1 (SGLT1) in jejunum (p &lt; 0.05). Our results strongly suggest that the combination of IVE and PGO can improve the nutrient digestibility of weaned piglets by increasing the expression of nutrient transport vectors (SGLT1 and CAT1) and tight junction proteins (Occludin and ZO-1) in the jejunum. In conclusion, the combination of plant extracts and probiotics is a vital strategy to improve animal health before the advent of antibiotic substitutes with absolute advantages.

Apparent nutrient utilization and metabolic growth rate of Nile tilapia, Oreochromis niloticus, cultured in recirculating aquaculture and biofloc systems

Abstract Introduction Recirculating aquaculture systems (RAS) and biofloc systems (BFS) have been considered eco-friendly aquaculture technologies in the last few decades. However, which system performs better has become a common question for fish farmers. Thus, this study aimed to compare the performances of the two aquaculture systems in culturing Nile tilapia, Oreochromis niloticus, larvae. Materials and methods The experiment was conducted by culturing 3-day post-hatching (dph) tilapia larvae in either the RAS or BFS for 43 days. At the end of the culture period, apparent net protein utilization (NPUa), apparent fat utilization (NFUa) and apparent net energy utilization (NEUa), metabolic growth rate (GRmet) of Nile tilapia, and water quality were compared using analysis of variance. Results The result showed, in general, that RAS performed better than BFS. NPUa and NEUa were significantly higher in Nile tilapia cultured in RAS than that of BFS, p &lt; 0.05. While NFUa was not significantly different, p &gt; 0.05. GRmet of tilapia cultured in BFS was higher in the first week but showed to be the same during the second week to the fourth week. At the end of the culture period (43 days), the GRmet of tilapia cultured in RAS was significantly higher than those of fish raised in the BFS. Other results showed that water quality parameters, including total ammonia nitrogen (TAN-N) and nitrite nitrogen (NO2–N), were lower in RAS than in BFS during the culture periods. While urea and CO2 were significantly higher in the rearing water of BFS than that of RAS, p &lt; 0.05. Conclusion The RAS had better performance than the BFS in culturing tilapia larvae.

Addition of turmeric (Curcuma longo LINN) extract on artificial feed to increase feed eficiency and the growth of gouramy fry (Osphronemus goramy

Artificial feed consisting of anting spinach flour (Acalypha indica L) and mung bean sprout waste (Vigna radiata) with the addition of turmeric extract is a fish feed that has not been widely used as a source of vegetable protein raw materials. This study aims to determine the effect of adding turmeric extract (Curcuma longa LINN) to the feed formula on increasing feed efficiency and growth of Osphronemus gourami. Materials and methods, the test fish used was gourami with an average individual weight of 5.04±0.5 g/head. Feeding at 08.00, 12.00 and 16.00 with feeding at satition. The test fish were reared with a stocking density of 13 fish/20 L, using a 30 liter bucket container with a maintenance period of 42 days. This research was conducted by experimental method using Completely Randomized Design (CRD) with 4 treatments and 3 replications. Each treatment contains 31.5-32.33% crude protein. The treatment is A: without spinach anting flour and bean spout flour, B: 100% spinach anting flour and 0% bean sprout flour, C: 50% spinach anting flour and 50% bean sprout pulp flour, D : 100% test feed of bean sprout pulp flour and each treatment was repeated three times. The treatment tested was the same dose of turmeric extract added to the feed with treatments A, B, C and D, each dose was given the same (15 ml/kg feed). The observed data included feed consumption rate (TKP), feed utilization efficiency (FUE), protein efficiency ratio (PER), feed conversion ratio (FCR), protein eficiency ratio (PER), net protein utilization (NPU), relative growth rate (RGR), survival rate ( SR) and water quality. The best EPP treatment was C 95.92±2.49%, and FCR value 1.67±0.03. PER value 3.00±0.077%. NPU value... The treatment with the best growth was treatment C, which was RGR 6.11±0.07%/day. The water quality in the rearing media was in the appropriate range for rearing the test fish.

Increased Amino Acid Turnover and Net Protein Breakdown but Preserved Muscle and Cognitive Function in Obese Middle-Age Adults

ObjectivesSkeletal muscle weakness has been observed in obese patients despite preserved or even greater lean body mass. Additionally, the presence of obesity-related comorbidities is a recognized risk factor for cognitive dysfunction and mood disturbances. Metabolism of several amino acids (AAs) including the Branched-chain Amino Acids (BCAAs) is altered in obesity but whether these disturbances are associated with muscle and cognitive dysfunction remain underexplored.Methods159 subjects were divided, using the BMI cut-off of 30 kg/m2, into two groups: 79 non-obese (32 males/47 females, age 48.5 [43.3, 53.7], BMI 25.2 [24.6, 25.7] kg/m2) and 80 obese (31 males/49 females, age 54.3 [51.0, 57.6], BMI 38.3 [36.9, 39.6] kg/m2). Postabsorptive whole-body production (WBP) rates of several AAs were measured by IV pulse of stable isotopes including BCAAs, Phenylalanine (Phe), Tyrosine (Tyr), Glutamate (Glu), and Tryptophan (Trp). Plasma amino acid enrichments and concentrations were analyzed by LC-MS/MS. Large Neutral Amino Acids (LNAA) was calculated as the sum of BCAAs, Phe, and Tyr. Body composition (DXA), hand and leg peak strength and endurance (isokinetic dynamometer), cognitive function (Stroop, TMT), and mood (POMS, HADS) were assessed. Statistics performed by ANCOVA with age, gender, and lean body mass as covariates. Significance at P < 0.05. Results expressed as means [95% CI].ResultsObese subjects had higher concentrations of plasma Leu (12%, P = 0.0097), Ile (7%, P = 0.0310), Tyr (23%, P < 0.0001), and Glu (40%, P = 0.0001). The obese group was also characterized by elevated WBP of BCAAs (8%, P = 0.0343), Phe (12%, P = 0.0003), Tyr (18%, P = 0.0005) and increased whole-body net protein breakdown (Phe to Tyr conversion, 11%, P = 0.0212). Both groups had similar muscle and cognitive functions but obese individuals had greater scores for self-reported depressive symptoms (P = 0.0273), anger (P = 0.0234), fatigue (P = 0.0098), and tension (P = 0.0158). No changes in Trp metabolism were found but obese subjects had elevated LNAA (7%, P = 0.0170) resulting in increased systemic Trp availability to the brain (P = 0.0014).ConclusionsObese subjects have preserved muscle and cognitive function despite greater whole-body net protein breakdown and increased turnover of several AAs involved in muscle metabolism and serotonin synthesis.Funding SourcesNone.

Continuous oral stable isotope ingestion to measure whole-body protein turnover.

Protein kinetic responses to nutrition and exercise interventions are commonly evaluated using a primed-constant infusion of stable isotope tracers. While this methodology is state-of-the-art, the required preparation at a certified pharmacy makes the utilization of isotope infusion both expensive and logistically cumbersome. Oral tracer ingestion has been used to quantify 24-hwhole-body protein status; however, this does not permit examination of acute interventional effects. Ingestion of a priming bolus, followed by continuous ingestion of stable isotope tracer in a 'sip feeding' fashion may provide a more feasible alternative for quantifying acute kinetic responses. Therefore, the purpose of this study was to evaluate the viability of a primed continuous oral sip-ingestion method of stable isotope tracers for the evaluation of whole-body protein kinetics. In a randomized, crossover design, eight healthy adults (63% female; Age: 29.4±5.8yrs; BMI: 24.3±2.7kg/m2) completed two, two-period stable isotope oral ingestion studies, consisting of a 3hbasal fasted period, followed by a 4-hpost-ingestion period. After the basal period, subjects ingested either 6.3g (Low) or 12.6g (High) of an essential amino acid (EAA) enriched whey protein supplement. The continuous oral sip-feed method was initiated with a primed oral bolus dose of L-[ring-2H5]phenylalanine, L-[ring-2H2]tyrosine, and L-[ring-2H4]tyrosine, followed by oral sip doses of L-[ring-2H5]phenylalanine, L-[ring-2H2]tyrosine every 10min to approximate steady state tracer enrichment. Blood samples were taken throughout the basal and post-meal periods to determine tracer enrichment. Whole-body net protein balance (NB), synthesis (PS), breakdown (PB), and exogenous hydroxylation were calculated for each period. Repeated measure ANOVAs (treatment×time) were used to assess differences in protein kinetics. Using the sip feed method, NB, PS, and hydroxylation were significantly increased with ingestion of protein (p<0.05) during the postprandial period, regardless of amount of protein ingested; ΔNB from the postabsorptive to postprandial period was significantly greater for high compared to low protein (p=0.026; low=6.2±5.1g protein·240min-1; high=11.8±3.9g protein·240min-1). The current study provides preliminary evidence that continuous oral sip-feeding of stable isotope tracer is a feasible method that provides physiologically relevant measures of protein metabolism. Assessments of variance and individual responses revealed high measurement variability with the sip-feed method compared to previously published constant infusion responses, but ΔNB, ΔPS, and ΔPB were comparable. In situations where constant infusion is not feasible, oral sip-feeding could be used as an alternative method for measurement of acute, postprandial protein metabolism.

Alterations in meat nutrient composition in response to a partial replacement of corn with triticale in the broiler diet

Abstract The study evaluated the effect of feeding triticale on proximate composition, amino acids (AA) profile and nutritional value of meat (breast and thigh) of broiler chickens. A 5-weeks trial (1-35d) was conducted on Cobb 500 broilers (n=400), allotted into two dietary groups with five replicates (40 birds/replicate) and fed control (C, corn-soybean meal) and triticale (T, corn-triticale-soybean meal) diets. Broilers meat’s proximate composition and energy value showed no significant differences between treatments. Feeding triticale significantly increased (P&lt;0.05) breast muscle concentrations of arginine, valine and phenylalanine, while the methionine and alanine decreased (P&lt;0.05) and did not affect the total AA, essential, non-essential or flavor AA. Concerning the thigh muscle AA profile, partial corn replacing with triticale decreased (P&lt;0.05) the content of isoleucine, leucine, serine and alanine, without altering the total AA, EAA, NEAA, flavor AA or their ratio. The limiting AA in both muscle types was leucine, irrespective of diet. The EAA index and net protein value revealed no significant differences between diets or muscle types. In conclusion, partial corn replacement in broilers’ diets with triticale did not adversely affect the proximate meat composition and positively impacted broilers’ nutritional meat protein quality.

Estimation of Nutritive Value and Protein Degradability of Trifolium Repens and Poa Pratensis as the Dominant Pasture Species, Under Simulated Rotational Grazing

Summary A cutting trial was conducted to determine the nutritional value, crude protein (CP) fractions distribution and CP ruminal degradability of white clover (Trifolium repens L.) and Kentucky bluegrass (Poa pratensis L.) as the dominant species of permanent grassland. The legume and grass herbage was obtained in the field experiment carried out on pasture throughout a spring growth season where rotational grazing was simulated using three consecutive cuts, which were compared. The fractionation of CP, according to Cornell Net Carbohydrate and Protein System (CNCPS v6.5), was used to predict protein degradability of the legume and grass forage. A significant (p &lt;0.05) lowering of the CP content in the legume and grass herbage was found, while NDF (neutral detergent fiber) and ADF (acid detergent fiber) significantly increased (p &lt;0.05) as the spring growth season progressed. A significant decrease (p &lt;0.05) of fractions A1 and A2 was noted in the legume and grass herbage, with a significant (p &lt;0.05) increase of CP fractions B2 and C as the vegetation season progressed. A higher rumen degradable protein (RDP) content (p &lt;0.05) of white clover and Kentucky bluegrass herbage was obtained in the first harvest, compared with the second and third one. Significantly larger values (p &lt;0.05) of net energy were observed in the white clover and Kentucky bluegrass forage obtained from the first cut, compared with later regrowths, and white clover was characterized by a higher energy content of 12.4–33.1% (dry matter basis), relative to Kentucky bluegrass.