Levels Of Non-essential Amino Acids Research Articles

208 Effect of SID LYS Level with Constant Non-Essential Amino Acids

Abstract Many investigations on the effect of low protein diets reduce crude protein (CP) and have a constant standardized ileal digestible (SID) LYS resulting in reductions in ADG, ADFI, and gain:feed is some cases. This experiment was conducted to determine the impact of maintaining constant non-essential amino acids and changing SID LYS and other essential amino acids. For the experiment, 288 pigs (~22 d of age, 6.61 ± 0.95 kg, 8 replicates/treatment, 6 pigs/pen) were stratified by body (BW) and randomly allotted to one of 6 treatments in a randomized complete block design. Non-essential amino acids were fixed in all diets and synthetic amino acids were added to increase SID LYS from 1.15% to 1.4% while maintaining constant ratios of MET+CYS, THR, TRP, VAL, and ILE to LYS. Diets were corn, wheat, barley, and soy based with 1.1% corn starch in the least SID LYS diet. Synthetic amino acids were added to the diet at the expense of corn starch to maintain non-essential amino acid levels. The CP ranged from 17.8% when SID LYS was 1.15% and 18.6% when SID LYS was 1.4%. Experimental diets were fed for 21 d. Body weight, feed disappearance, visual fecal scores, and visual piglet scores were measured. Visual fecal scores (1 = normal to 4 = watery) and visual pig appearance scores (1 = pale and hairy to 4 = normal color and well-rounded muscle) were assessed on ordered likert scales to determine the probabilities of observing a more normal stool quality and a worse visual appearance, respectively. Performance data were analyzed as a general linear model. Stool quality and visual appearance were analyzed as a generalized linear mixed model. Contrasts were used to test linear and quadratic effects of dietary SID LYS. Results of the experiment are presented in Table 1. Increasing SID LYS with constant non-essential amino acids did not affect ADG or BW. The ADFI was linearly decreased (P < 0.1) and gain:feed was linearly increased (P < 0.0001) with increasing SID LYS (Table 1). Stool quality was not affected. Visual appearance of the pigs was quadratically affected (P < 0.05) by changing SID LYS. Pigs that had consumed diets with the lowest or highest SID LYS had the best visual appearance (lowest probability). The results of the current experiment differ suggest SID LYS may regulate feed intake and nutrient efficiency, but BW gain is not affected when non-essential amino acids are held constant. This differs from cases where CP is reduced, which results are decreased growth in many cases.

Involvement of insulin-like growth factor binding proteins (IGFBPs) and activation of insulin/IGF-like signaling (IIS)-target of rapamycin (TOR) signaling cascade in pacific white shrimp, Litopenaeus vannamei exposed to acute low-salinity

Acute low-salinity induces multiple stress responses and significantly impact the health of aquatic animals. However, the molecular regulation network and metabolic adaptation of low salinity stress in aquatic organisms remain unclear. The insulin-like growth factor binding proteins (IGFBPs) and insulin/IGF-like signaling (IIS)-target of rapamycin (TOR) signaling cascade are evolutionarily conserved regulators known to play crucial roles in response to various stressors. In this study, we used the euryhaline Pacific white shrimp (Litopenaeus vannamei) as a model organism to investigate the involvement of IGFBP and IIS-TOR signaling cascade in acute low-salinity response. We found seven LvIGFBPs and evaluated 18s as one of most stable internal reference genes under acute low salinity stress. The expression of LvIGFBP4, LvSIBD1, and LvSIBD2 was significantly increased after 6-hours 5‰ salinity treatment. LvSIBD2 was specifically expressed on the surface of gill branch axis. Acute low-salinity significantly induced the phosphorylation of Akt and S6K in the gill but not in the muscle. We found acute low-salinity increased the levels of total essential amino acids, including leucine and arginine, while decreasing the total non-essential amino acid levels in the gill. Furthermore, glucose and key metabolites in glycolysis and tricarboxylic acid cycle (TCA cycle) were increased, indicating remodeling of energy metabolism occurred. These results demonstrate the involvement of IGFBP and IIS-TOR signaling cascade in acute low-salinity response and provide new insights into understanding the mechanism of osmoregulation in euryhaline crustacean species.

Modulation of Mucin Secretion in the Gut of Young Pigs by Dietary Threonine and Non-Essential Amino Acid Levels.

Simple SummaryThe mucus layer is an important part of the system protecting the gut against injuries and bacterial infections. The main components of mucus responsible for its properties are mucins. They are large glycoproteins with a protein core rich in threonine (Thr) and many sugar side chains that differ in structure and affect mucin functions. Diet composition affects the amount of secreted mucins and their quality. Therefore, the aim of the study was to determine the effect of Thr and wheat gluten (WG) protein, added as a source of non-essential amino acids, on the content of tissue and luminal mucins in different parts of the intestine of young pigs. Results showed that tissue and luminal mucin content was only affected by WG levels in the duodenum and middle jejunum, and in the proximal colon, respectively. The effect of WG on luminal mucin content in the proximal colon depended on the analytical method applied.The aim of the study was to determine the effect of threonine (Thr) and non-essential amino acid (NEAA) levels on mucin secretion and sugar composition of digesta and crude mucin preparations analyzed in different segments of the gut in young pigs. A two-factorial experiment was conducted on 72 pigs using the following factors: Thr level (5.1, 5.7, 6.3 and 6.9 g standardized ileal digestible(SID) Thr/kg) and wheat gluten (WG) level used as a source of NEAA (20.4, 40.4 and 60.4 g WG protein in WG20, WG40 and WG60 diets, respectively). Mucin content was affected only by WG level. Tissue mucin content in the duodenum was higher in WG60 pigs than in WG20 and WG40 pigs, whereas in the middle jejunum was higher in WG40 and WG60 pigs than in WG20 pigs. In contrast, luminal crude mucin content in the proximal colon was lower in WG60 pigs compared to WG40 pigs. The lowest and highest Thr levels reduced arabinose and xylose contents and increased glucose content in ileal digesta. The highest WG level reduced arabinose and xylose contents and increased glucose content in ileal digesta. The lowest WG level increased mannose content in ileal digesta. WG60 level decreased the content of arabinose and galactose compared to lower WG levels in colonic digesta. Arabinose content was higher, while glucose and galactose contents were lower in crude mucin preparations isolated from colonic digesta in pigs fed diets containing the highest Thr level. The content of tissue mucin was higher in the ileum and proximal colon and lower in the duodenum than in the middle jejunum, whereas luminal mucin content was lower in the proximal colon than in the ileum. Ileal digesta contained less arabinose and glucose and more galactose as compared to colonic digesta. In conclusion, no effect of dietary Thr levels on mucin secretion in the gut of young pigs was found. Wheat gluten added to the diet with adequate Thr content positively affected mucin secretion only in the duodenum and middle jejunum.

Influence of the extracorporeal detoxication methods on the levels of nonessential amino acids in the blood plasma of patients with sepsis (Communicated by Corresponding Member Nikolay S. Serduchenko)

Some disadvantages of the extracorporeal blood purification (EBP) methods as reducing plasma levels of different important metabolites are described. Disorders of amino acid metabolism in sepsis are manifested into microcirculation interruptions, a decreased immune response and an increased mortality. The aim of the study is to investigate the EBP influence on the levels of nonessential amino acids in the blood plasma of patients with sepsis. 28 patients diagnosed with “sepsis” were selected. Standard treatment protocols of plasma filtration, hemofiltration and hemadsorption with various sorbents were used. A significant decrease in the levels of asparagine, phosphoethanolamine, proline; α -aminobutyric acid showed a significant increase in these levels in patients who underwent “Proteasosorb” sorbent hemadsorption. A significant decrease in the levels of ornithine, aspartic acid, 3-methylhistidine, 1-methylhistidine in patients treated with hemofiltration was found. The EBP methods significantly influence the amino acid metabolism.

Dietary Protein and Amino Acid Deficiency Inhibit Pancreatic Digestive Enzyme mRNA Translation by Multiple Mechanisms.

Background & AimsChronic amino acid (AA) deficiency, as in kwashiorkor, reduces the size of the pancreas through an effect on mammalian target of rapamycin complex 1 (mTORC1). Because of the physiological importance of AAs and their role as a substrate, a stimulant of mTORC1, and protein synthesis, we studied the effect of acute protein and AA deficiency on the response to feeding.MethodsICR/CD-1 mice were fasted overnight and refed for 2 hours with 4 different isocaloric diets: control (20% Prot); Protein-free (0% Prot); control (AA-based diet), and a leucine-free (No Leu). Protein synthesis, polysomal profiling, and the activation of several protein translation factors were analyzed in pancreas samples.ResultsAll diets stimulated the Protein Kinase-B (Akt)/mTORC1 pathway, increasing the phosphorylation of the kinase Akt, the ribosomal protein S6 (S6) and the formation of the eukaryotic initiation factor 4F (eIF4F) complex. Total protein synthesis and polysome formation were inhibited in the 0% Prot and No Leu groups to a similar extent, compared with the 20% Prot group. The 0% Prot diet partially reduced the Akt/mTORC1 pathway and the activity of the guanine nucleotide exchange factor eIF2B, without affecting eIF2α phosphorylation. The No Leu diet increased the phosphorylation of eIF2α and general control nonderepressible 2, and also inhibited eIF2B activity, without affecting mTORC1. Essential and nonessential AA levels in plasma and pancreas indicated a complex regulation of their cellular transport mechanisms and their specific effect on the synthesis of digestive enzymes.ConclusionsThese studies show that dietary AAs are important regulators of postprandial digestive enzyme synthesis, and their deficiency could induce pancreatic insufficiency and malnutrition.

Autophagy flux in critical illness, a translational approach

Recent clinical trials suggest that early nutritional support might block the induction of autophagy in critically ill patients leading to the development of organ failure. However, the regulation of autophagy, especially by nutrients, in critical illness is largely unclear. The autophagy flux (AF) in relation to critical illness and nutrition was investigated by using an in vitro model of human primary myotubes incubated with serum from critically ill patients (ICU). AF was calculated as the difference of p62 expression in the presence and absence of chloroquine (50 µM, 6 h), in primary myotubes incubated for 24 h with serum from healthy volunteers (n = 10) and ICU patients (n = 93). We observed 3 different phenotypes in AF, non-altered (ICU non-responder group), increased (ICU inducer group) or blocked (ICU blocker group). This block was not associate with a change in amino acids serum levels and was located at the accumulation of autophagosomes. The increase in the AF was associated with lower serum levels of non-essential amino acids. Thus, early nutrition during critical illness might not block autophagy but could attenuate the beneficial effect of starvation on reactivation of the autophagy process. This could be of clinical importance in the individual patients in whom this process is inhibited by the critical illness insult.

Use of isotopic enrichment to assess the relationship among dietary protein levels, growth and nitrogen retention in juvenile Totoaba macdonaldi

Stable isotope analysis was used to investigate the relationships among dietary protein levels, growth, protein utilization efficiency, and isotopic enrichment per amino acid for juvenile Totoaba macdonaldi. Four isocaloric diets were formulated to contain different protein levels (400, 430, 460 and 490 g kg−1 DM). After 60 days, growth increased proportionally as dietary protein content increased. The isotopic discrimination factor in bulk samples, revealed increases of 0.83 to 1.24‰ and 3.31 to 3.55‰ for ∆δ15N values of liver and muscle tissues, respectively, of fish fed diets containing 40% to 49% dietary protein. Compound-specific isotope analysis (CSIA) revealed that Δδ15N for Glu in the liver and Ala in the muscle tissues were enriched by up to 9.37% and 9.0%, respectively, for fish in the 49% dietary treatment, possibly due to transamination processes. Using the traditional parameters such as protein efficiency ratio (PER) failed to show significant differences. Growth of totoaba increased in conjunction with a lower retention of nitrogen according to bulk isotopic values, suggesting that proportionately more protein was being used as an energy source. Relationships among protein productivity values (PPV) corresponded well to those among bulk isotopic values. Considering the low isotopic enrichment in bulk from treatment D40, a diet containing 400 g kg−1 crude protein is recommended for use in future investigations, through the addition of each particular essential amino acids to reach the amount found in a diet contained with 49% protein. And thereafter to determine whether dietary levels of non-essential amino acids might be limiting using the CSIA for amino acids.

Modulation of nonessential amino acid biosynthetic pathways in virulent Hessian fly larvae (Mayetiola destructor), feeding on susceptible host wheat (Triticum aestivum)

Compatible interactions between wheat (Triticum aestivum), and its dipteran pest Hessian fly (Hf, Mayetiola destructor) result in successful establishment of larval feeding sites rendering the host plant susceptible. Virulent larvae employ an effector-based feeding strategy to reprogram the host physiology resulting in formation of a protein- and sugar-rich nutritive tissue beneficial to developing larvae. Previous studies documented increased levels of nonessential amino acids (NAA; that need not be received through insect diet) in the susceptible wheat in response to larval feeding, suggesting importance of plant-derived NAA in larval nutrition. Here, we investigated the modulation of genes from NAA biosynthetic pathways (NAABP) in virulent Hf larvae. Transcript profiling for 16 NAABP genes, annotated from the recently assembled Hf genome, was carried out in the feeding first-, and second-instars and compared with that of the first-instar neonate (newly hatched, migrating, assumed to be non-feeding) larvae. While Tyr, Gln, Glu, and Pro NAABP genes transcript abundance declined in the feeding instars as compared to the neonates, those for Ala, and Ser increased in the feeding larval instars, despite higher levels of these NAA in the susceptible host plant. Asp, Asn, Gly and Cys NAABP genes exhibited variable expression profiles in the feeding first- and second-instars. Our results indicate that while Hf larvae utilize the plant-derived NAA, de novo synthesis of several NAA may be necessary to: (i) provide larvae with the requisite amount for sustaining growth before nutritive tissue formation and, (ii) overcome any inadequate amounts in the host plant, post-nutritive tissue formation.

Construing temporal metabolomes for acetous fermentative production of Rubus coreanus vinegar and its in vivo nutraceutical effects

The temporal metabolomes associated with Rubus coreanus (RC) vinegar production were delineated using mass spectrometry-based metabolomic analyses with multivariate studies. We observed a clustered pattern of 27 discriminant metabolites: 4 organic acids, 9 sugars and sugar derivatives, 2 alcohol and carboxylic acid, 6 esters, and 6 terpenes. The levels of organic acids and alcohols were steadily decreased throughout fermentation, whereas those of sugars and sugar derivatives, carboxylic acids, esters, and terpenes peaked at 6days. Further, the in vivo nutraceutical potentials of RC vinegar were examined with its metabolomic implications for bone health in growing rat model. Intriguingly, the plasmatic metabolomes among treated rat groups were observed with lower levels of non-essential amino acids and lysophosphatidylcholines (LysoPCs) coupled with higher levels of fatty acids and bile acids. The plasmatic metabolomes complemented with bone morphometric and clinical parameters suggest the bone health ameliorating effects of RC vinegar.

Protein Supplementation of a High-Carbohydrate Diet during Resistance Training Enhances Muscle Mass and Function by Increasing Essential Amino Acids

Objective: Previous studies have presented the effects of carbohydrate and protein intake using a single food or supplement. However, little knowledge is available regarding the long-term effects of protein diet supplementation on muscle mass and function. This study was conducted to investigate the effects of a 12-week high-intensity resistance exercise program combined with a high-carbohydrate (HCHO), high-protein (HPRO) diet on body composition, muscle function, anabolic/catabolic hormones, and blood amino acid levels. Methods: This study included 27 male college students, who were divided into an HPRO group (n=12) and an HCHO group (n=15). Three to five sets of resistance exercises were performed four times a week at 75% of 1- repetition maximum for 12 weeks. Results: The weight and body fat percentage decreased in both groups after the 12-week resistance exercise, and muscle mass increased in the HPRO group. The peak torque increased in the HPRO group, and the average power increased in both the HCHO and HPRO groups, although there was no significant difference between the changes in both groups. However, the testosterone level and the ratio of testosterone to cortisol increased in the HCHO group, and the changes were significantly different between the groups. The blood essential amino acid (EAA) and non-essential amino acid levels showed a time × group effect. Conclusion: Protein supplementation of a high-carbohydrate diet during resistance training may enhance body composition and muscle mass and function by increasing the blood EAA levels. Therefore, considering that Asians tend to consume high-carbohydrate diets, a diet with slightly less carbohydrate and increased protein may be more effective for increased muscle strength and mass during training.

Amino Acid Levels in Muscle Tissue of Six Wild Feathered Species

The objective of this study was to determine and compare the levels of amino acids (AAs) in breast and thigh muscles of six species of feathered game of the same age. The experiment involved the following species: wild turkey (Meleagris gallopavo), guinea fowl (Numida meleagris), chukar partridge (Alectoris chucar), Japanese quail (Coturnix coturnix japonica), common pheasant (Phasianus colchicus) and grey partridge (Perdix perdix). The highest content of AAs was found in the chukar partridge (breast: 815.7 ± 47.71 g/kg; thigh: 771.4 ± 107.0 g/kg, on a dry matter basis), the lowest levels of AAs were found in Japanese quail (breast: 734.2 ± 45.07 g/kg) and grey partridge (thigh: 614.9 ± 49.66 g/kg). In all examined species, the level of histidine in breast muscles differed (P ≤ 0.01) from that in thigh muscles. In all investigated species, the levels of essential AAs in breast muscles were higher (P ≤ 0.01) than those in thigh muscles, whereas the levels of non-essential AAs in breast muscles were lower (P ≤ 0.01) than those in thigh muscles. Breast muscles are therefore more valuable than thigh muscles because of the content of essential AAs.

Study of plasma amino acid levels in children with autism: An Egyptian sample

BackgroundThe aetiology of autism is unclear and autistic symptoms had been attributed to an abnormal functional imbalance in neurotransmitter amines such as dopamine, noradrenaline and serotonin. ObjectiveTo study plasma essential and non-essential amino acid levels, protein electrophoresis, serum ammonia, and urea in autistic children in comparison with controls. MethodsTwenty autistic children were compared to twenty healthy age and sex matched normal children serving as control, where serum amino acids, urea, ammonia and protein electrophoresis were estimated. ResultsAs regards essential amino acid levels, autistic children had significant lower plasma levels of leucine, isoleucine, phenylalanine, methionine and cystine than controls (P<0.05),while there was no statistical difference in the level of tryptophan, valine, threonine, arginine, lysine and histidine (P>0.05). In non-essential amino acid levels, phosphoserine was significantly raised in autistic children than in controls (P<0.05). Autistic children had lower level of hydroxyproline, serine and tyrosine than controls (P<0.05). On the other hand there was no significant difference in levels of taurin, asparagine, alanine, citrulline, GABA, glycine, glutamic acid, and ornithine (P>0.05).There was no significant difference between cases and controls as regards the levels of urea, ammonia, total proteins, albumin and globulins (alpha 1, alpha 2, beta and gamma) (P>0.05). ConclusionsAutistic children had lower levels of some plasma amino acids except for glycine and glutamic acids and phosphoserine were increased with normal serum levels of urea, ammonia, total proteins, albumin and globulins (alpha 1, alpha 2, beta and gamma).

Proximate Composition, Cholesterol, and Fatty Acid Content of Brown Shrimp (Crangon crangon L. 1758) from Sinop Region, Black Sea

Proximate composition, cholesterol, and fatty acid content of brown shrimp (Crangon crangon L. 1758) harvested from the Sinop region of the Black Sea in Turkey was determined. Crude protein, lipid, moisture, and ash contents were 18.47 ± 0.09 g/100 g, 0.95 ± 0.05 g/100 g, 79.21 ± 0.01 g/100 g, and 1.39 ± 0.01 g/100 g, respectively. Cholesterol content was 173.56 ± 0.24 mg/100 g. Fatty acid composition was 33.04% saturated (SFAs), 22.17% monounsaturated (MUFAs), and 29% polyunsaturated (PUFAs). Among the SFAs, palmitic acid (C16:0) was predominant at 20.69% of the total fatty acid composition. Oleic acid (C18:1) was the predominant MUFA (14.25%), and the highest PUFAs were eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3), contributing 41% and 32% to the total PUFA content of the lipids, respectively. Thrombogenicity (TI) and atherogenicity (AI) index values were 0.31 and 1.34, respectively. The highest essential amino acids were leucine, lysine, valine, and isoleucine; while the highest levels of non-essential amino acids were aspartic acid, glutamic acid, glycine, and alanine, respectively.

Growth, food efficiency, and biochemical composition of juvenile spotted babylon Babylonia areolata (Link) fed on conventional trash fish and a formulated moist diet

A 120-day feeding trial was conducted to determine growth, feeding efficiency, and biochemical composition of juvenile spotted babylon Babylonia areolata (initial mean weight of 1.48 ± 0.06 g) fed on conventional trash fish and a formulated moist diet in a flow-through grow-out system. The snails readily accepted the formulated moist diet and showed good growth and survival during the trial. There were no significant differences in specific growth rate, feeding efficiency, and survival between the snails fed on trash fish or the formulated moist diet. At the end of the experiment, biochemical analysis of the snail flesh showed significant differences in flesh quality, with the snails fed on trash fish having a significantly higher crude protein compared to those fed on the formulated diet, but there was little difference in crude lipid content. Whole body tissue of snails fed on trash fish had significantly higher total amino acid, essential amino acid, and non-essential amino acid levels compared to those fed the formulated diet. This study showed that the formulated moist diet can be readily used for B. areolata growout for maximizing growth, survival, and feeding efficiency; however, further research is needed to improve the flesh quality particularly amino acid and fatty acid levels before its suitability for B. areolata is assured.

Free amino acid distribution in plasma and liver of juvenile cobia (Rachycentron canadum) fed increased levels of lizardfish silage

Juvenile cobia (Rachycentron canadum) (100 g) were fed four moist diets (447–476 g kg−1 dry wt) where 0, 130, 260 or 390 g kg−1 of concentrated lizardfish (Saurida undosquamis) silage replaced fresh lizardfish, respectively. Blood and livers were sampled at 0, 6, 12, 24 and 48 h postfeeding at the end of the 3-week experiment. At 6 h postfeeding in all groups, maximum concentrations of most plasma essential amino acids were observed, while significantly lower levels of most non-essential amino acid levels were recorded compared to the other sampled times. At 6 and 12 h after feeding, the concentration of most plasma free amino acid (FAA) increased with an increase in dietary fish silage levels. Most FAA in livers of all groups peaked at 12 and 24 h postfeeding. However, at 48 h postfeeding, concentrations of most plasma FAA were significantly higher in fish fed 0% silage-based diet than in fish fed the other diets (4999 versus 3390–4339 nmol AA mL−1 plasma). Growth rates and feed utilization were significantly lower in cobia fed 26% or 39% silage-based diets than in fish fed 0% or 13% silage-based diets. Different levels of silage protein thus seemed to have effects on growth and feed utilization efficiency of juvenile cobia. Results from this study support the premise that fish silage can be included until 130 g kg−1 in cobia diets.

Effects of Water Pollution in Lake Mariut on Gonadal Free Amino Acid Compositions in Oreochromis niloticus Fish

In the present report, we have determined the gonadal free amino acid compositions in Oreochromis niloticus collected from three sites in Lake Mariut: SE basin (less polluted), main basin (moderately polluted) and SW basin (highly polluted), in an attempt to develop sensitive biomarker to evaluate pollution effects from multiple sources. Variations of free amino acids (FAAs) were apparent in the polluted sites; total FAAs in testes and ovaries exhibited significant increases as compared to the less polluted site. This increase was attributed to increases in all individual amino acids including essential and non-essential ones. ANOVA indicated significant changes in all testicular FAAs, excluding phenylalanine. Levels of non-essential amino acids showed obvious alterations in ovaries. However, the increase in most essential amino acids, although insignificant, yet it was quite observable. In addition, the ratio of essential to non-essential amino acids was insignificantly decreased in gonads. This may be indicative of changes in protein metabolism.

Use of Samh Seeds (Mesembryanthemum forsskalei Hochst) in the Laying Hen Diets

Samh plant is grown wildly in the northern part of Saudi Arabia. This study was conducted to determine the chemical analysis and the True Metabolizable energy of the Samh seeds and the possibilities of using this feed ingredient in the diets of layers. The chemical analysis of the Samh showed that it contained 22.16% protein, 3.09% fat, 10.62% fiber, 6.93% moisture, 0.05% Ca, 0.17% P and 2.49% Ash. The amino acid profile showed higher levels of non-essential amino acids and lower essential amino acids than SBM. The AME of the seeds, calculated from the TME, was found to be 2976 Kcal/Kg. A trial was conducted for 24 weeks using 0, 5, 10, 20 and 30% Samh seeds in layer diets, showed that including up to 10% Samh seeds in the layer diet improved egg weight, production rate and egg mass of the layer. However, feed consumption and conversion were deteriorated as level of Samh seeds increased beyond 5% level. Birds, fed Samh seeds produced lighter color yolk than the control birds. Yolk index was better in the control birds comparing to those fed the Samh seeds. It was concluded that until more research is conducted in this area, no recommendations can be drawn in favor of the Samh seeds, however, there was some indications that Samh seeds can replace part of corn, but in this case the diet should be fortified with yolk coloring agent.

Influence of feeding diets with and without fish meal by hand and by self-feeders on feed intake, growth and nutrient utilization of juvenile rainbow trout ( Oncorhynchus mykiss)

Feed intake, growth performance and nutrient utilization by juvenile rainbow trout fed diets with and without fish meal were compared between two feeding regimes: manual feeding and self-feeding. A fish meal-based diet and two non-fish meal diets, fortified with and without essential amino acids (EAA) to simulate the EAA composition of the fish meal diet, were prepared. The two non-fish meal diets were composed mainly of extruded defatted soybean meal (ExSBM), meat and bone meal (MBM) and corn gluten meal (CGM). Each diet was fed to four replicate groups (initial BW; 19.0±2.3 g, 700 g/60 l tank) either by hand to apparent satiation twice daily (0800 and 1730 h) or by self-feeders (feeds were dispensed by fish demands during the light phase) for 60 days at 17 °C under a 14 h light and 10 h dark cycle. Feeding regime did not significantly affect feed intake, weight gain, protein and energy retention, or whole body proximate composition ( P>0.05). Fish fed with the non-fish meal diet with EAA supplementation attained equivalent weight gain and retention of protein as the fish fed with the fish meal diet. However, these parameters for fish fed with the non-fish meal diet without EAA supplementation were significantly inferior ( P<0.05). The whole body fat content of fish fed with this diet was significantly higher than that of fish fed with the other diets. Free EAA levels in the plasma of fish fed with the EAA supplemented non-fish meal diet were similar to those fed with the fish meal diet except for threonine, which was lower in the EAA supplemented non-fish meal diet group. The branched-chain amino acid levels in the plasma of the two non-fish meal diet groups fed by hand increased more sharply and reached higher levels after feeding compared with fish fed with the same diets by self-feeders. The low levels of free threonine, methionine and lysine in the dorsal white muscle of fish fed with the EAA-unsupplemented non-fish meal diet increased in fish fed with the EAA supplemented non-fish meal diet, this increase was especially notable in the manually fed fish. Free non-essential amino acid levels in muscle of fish fed with the non-fish meal diet without EAA were generally the highest among the treatments. The feeding regime affected the levels of serine, glycine and hydroxyproline levels in the muscle (manual feeding<self-feeding). The results of this study indicate that a combination of ExSBM, MBM and CGM, when EAA are supplemented, has the potential to totally replace fish meal in juvenile rainbow trout diets. Feeding diets by self-feeders proved to attain growth and feed performance comparable to those fed by hand. Self-feeding non-fish meal diets affected certain amino acid levels in the plasma and muscle but the effects were not reflected in their growth and protein utilization in this 60-day feeding period.

Lactation during hibernation in wild black bears: effects on plasma amino acids and nitrogen metabolites.

This study examined the seasonal and reproductive influences on individual plasma amino acid concentrations and nitrogen metabolites in a black bear population (Ontario, Canada). During hibernation, 11 of 23 plasma amino acids were significantly higher (13%-108%) in lactating than in nonlactating females, without an alteration in plasma total protein or total essential or nonessential amino acid levels. The greatest changes were observed in glutamine, arginine, and glycine levels. Plasma urea, urea/creatinine, and ammonia levels were significantly lower in hibernating compared with active female bears, but lactation had no effect on these parameters. Taken together these results show that lactation during hibernation is an additional metabolic challenge that results in increased mobilization of individual plasma amino acids and no accumulation of nitrogen end products, underlining the remarkable efficiency of amino acid and urea recycling in denning female black bears.

Combined impairment of nutritional parameters and thyroid homeostasis in mildly iodine-deficient children.

The relation between thyroid homeostasis and the biochemical parameters of subclinical protein malnutrition has been analyzed in schoolchildren in a rural area in the south of Italy, known to be moderately iodine-deficient. The sera of 32 children (15 males and 17 females aged 6 to 11 years) have been analyzed. These children were divided into two groups, according to thyroid function: (1) 16 euthyroid children (mean thyrotropin [TSH] 2.38 +/- .35 mU/L; 6 with goiter) and (2) 16 subclinical hypothyroid children (mean TSH 7.32 +/- 1.68 mU/L; 6 with goiter). Retinol circulating complex (RCC) components were determined in serum by high-performance liquid chromatography (HPLC) and radial immunodiffusion and the essential and nonessential amino acid levels by ion exchange chromatography. Reduced retinol binding protein (RBP) and transthyretin (TTR) levels were recorded in the sera of 11 of 32 (34%) and in 5 of 32 (16%) patients, respectively. The linear regression analysis revealed that RBP and TSH levels were inversely correlated (r = -0.514; p < 0.0026). The RBP levels were subnormal in 2 of 16 euthyroid and in 9 of 16 hypothyroid patients (Fisher test p < 0.023), and the mean RBP levels were significantly reduced in the hypothyroid patients when compared with those of the euthyroid group (p < 0.0026). The retinol/RBP ratio was also significantly different between euthyroid and hypothyroid children (0.75 vs. 0.95; p < 0.0002). The mean essential amino acid levels, with the exception of methionine, were all in the normal range. The selected amino acid ratios confirmed that the patients were exposed to mild protein malnutrition. These results provide evidence that even mild protein-energy malnutrition may have detrimental effects on thyroid homeostasis in iodine-deficient areas.