Amino Acid Fortification Research Articles

Branched-Chain Amino Acid Fortification Does Not Restore Muscle Protein Synthesis Rates following Ingestion of Lower- Compared with Higher-Dose Mycoprotein

We have shown that ingesting a large bolus (70g) of the fungal-derived, whole food mycoprotein robustly stimulates muscle protein synthesis (MPS) rates. The aim of this study was to determine if a lower dose (35g) of mycoprotein enriched with branched-chain amino acids (BCAAs) stimulates MPS to the same extent as 70g of mycoprotein in resistance-trained young men. Nineteen men [aged 22±1y, BMI (kg/m2): 25±1] took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of l-[ring-2H5]phenylalanine and ingested either 70g mycoprotein (31.5g protein; MYCO; n=10) or 35g BCAA-enriched mycoprotein (18.7g protein: matched on BCAA content; ENR; n=9) following a bout of unilateral resistance exercise. Blood and bilateral quadriceps muscle samples were obtained before exercise and protein ingestion and during a 4-h postprandial period to assess MPS in rested and exercised muscle. Two- and 3-factor ANOVAs were used to detect differences in plasma amino acid kinetics and mixed muscle fractional synthetic rates, respectively. Postprandial plasma BCAA concentrations increased more rapidly and to a larger degree in ENR compared with MYCO. MPS increased with protein ingestion (P≤0.05) but to a greater extent following MYCO (from 0.025%±0.006% to 0.057%±0.004% · h-1 in rested muscle, and from 0.024%±0.007% to 0.072%±0.005% · h-1 in exercised muscle; P<0.0001) compared with ENR (from 0.031%±0.003% to 0.043%±0.005% · h-1 in rested muscle, and 0.027%±0.005% to 0.052%±0.005% · h-1in exercised muscle; P<0.01) ingestion. Postprandial MPS rates were greater in MYCO compared with ENR (P<0.01). The ingestion of lower-dose BCAA-enriched mycoprotein stimulates resting and postexercise MPS rates, but to a lesser extent compared with the ingestion of a BCAA-matched 70-g mycoprotein bolus in healthy young men. This trial was registered at clinicaltrials.gov as 660065600.

Effect of Essential Amino Acid Fortification on Growth Performance of Finishing Pigs at a High Ambient Temperature

Effect of Essential Amino Acid Fortification on Growth Performance of Finishing Pigs at a High Ambient Temperature

Influence of diet fortification on body composition and apparent digestion in mature horses consuming a low-quality forage.

Stock-type mares (498 ± 9 kg BW; 12 ± 7 yr) were used in a completely randomized design for 56 d to test the hypothesis that concentrate fortification improves apparent digestion and enhances lean mass over the topline. Horses were stratified by age, BW, and BCS and randomly assigned to either a custom pelleted concentrate (CON; n = 13), or an iso-caloric, iso-nitrogenous pellet that included amino acid fortification, complexed trace minerals, and fermentation metabolites (FORT; n = 10). Concentrate was offered at a total 0.75% BW/d (as-fed) twice daily, and diets were designed to meet or exceed maintenance requirements for mature horses. Horses had ad libitum access to Coastal bermudagrass hay (7.4% CP, 67% NDF, and 40% ADF). Every 14 d BW and BCS were recorded, and ultrasound images were captured every 28 d. longissimus dorsi area (LDA) and subcutaneous fat thickness (FT) were measured between the 12th and 13th ribs (12th/13th) and 17th and 18th ribs (17th/18th). Intramuscular fat at the 17th/18th ribs and rump fat-thickness were also obtained. Horses were dosed with 10 g/d of titanium dioxide (TiO2) for 14 d to estimate forage dry matter intake (DMI). To account for diurnal variation, fecal samples were collected twice daily at 12-h intervals during the last 4 days, advancing by 3 h each day to represent a 24-h period. Fecal samples were composited by horse and analyzed for TiO2 to estimate fecal output and acid detergent insoluble ash was used to calculate forage DMI. To evaluate body composition, horses were infused with a 0.12 g/kg BW deuterium oxide (D2O) on d 0 and 56. Body fat percentage (BF) was determined by quantifying D2O in plasma samples collected at pre- and 4-h postinfusion via mass spectrometry. All data were analyzed using PROC MIXED (SAS v9.4). The model contained a fixed effect of diet; horse (diet) was a random effect. Horses receiving FORT gained 17th/18th FT (P < 0.01) and increased 17th/18th LDA from d 0 to 56 (P < 0.01) while 17th/18th FT and LDA were unchanged in CON. Regardless of diet, BF estimated by D2O infusion increased in all horses from d 0 to 56 (P < 0.01). Average hay DMI was 2.1% BW, but did not differ between diets. In this study, concentrate fortification did not significantly (P ≥ 0.27) affect apparent digestion. In conclusion, concentrate fortification may promote greater muscle development along the posterior topline.

The Graded Inclusion of Algae (&amp;lt;i&amp;gt;Spirulina platensis&amp;lt;/i&amp;gt;) or Insect (&amp;lt;i&amp;gt;Hermetia illucens&amp;lt;/i&amp;gt;) Meal as a Soybean Meal Substitute in Meat Type Chicken Diets Impacts on Growth, Nutrient Deposition and Dietary Protein Quality Depending on the Extent of Amino Acid Supplementation

Three consecutive growth experiments were conducted to evaluate growth performance, whole body analyses and protein quality parameters from chicken diets with 50%, 75% and 100% substitution of soybean meal (SBM) by Spirulina meal (SM) or partly defatted Hermetia meal (HM). Each of the experiments was divided into a starter period (1 - 21 d) and a grower period (22 - 34 d). One-day-old male growing chickens (Ross 308) were randomly allotted to 48 floor pens making use of 6 birds/pen (Exp.1) or 7 birds/pen (Exp. 2, 3), and the experiments included a control diet (n = 12) and four experimental diets (n = 9). Experiment 1 examined a 50 % replacement of SBM by the alternative proteins under study, both on a basic and an advanced level of amino acid (AA) fortification to meet the recommended ideal amino acid ratio (IAAR). In experiment 2, 75% (starter diet) and 50% (grower diet) replacement of SBM was investigated. Experiment 3 investigated the effects of complete SBM substitution by SM or HM in starter and grower diets. In the second and third experiment diets with both of the alternative proteins and the control diet were AA supplemented to meet the current IAAR. In a further step, the calculated first limiting AA (LAA) was reduced to 80% of its requirement recommendation to allow for further evaluation of the individual AA efficiency according to the “Goettingen approach”. Different levels (50%, 75%, or 100%) of replacing SBM by HM or SM in chicken diets depressed dietary protein quality (p 0.001) and zoo-technical parameters (p 0.001) with only a basic level of AA supplementation. This effect was much more pronounced in diets with SM. However, with an extended level of dietary AA supplementation zoo-technical parameters (p 0.001), crude protein deposition (p 0.001) and protein quality parameters (p 0.001) were significantly improved. HM diets with an advanced level of AA tended to provide higher dietary protein quality and growth performance as compared to all SBM replacement levels through SM with different levels of AA supplementation and control diets.

Effects of 50 Percent Substitution of Soybean Meal by Alternative Proteins from &amp;lt;i&amp;gt;Hermetia illucens&amp;lt;/i&amp;gt; or Spirulina platensis in Meat-Type Chicken Diets with Graded Amino Acid Supply

Alternative protein sources, such as insects or algae meals are in special focus of animal nutrition in order to replace soybean meal (SBM). As part of the multidisciplinary project “sustainability transitions” this study evaluated effects of replacing SBM by partly defatted larvae meal from the black soldier fly, Hermetia illucens or meal from the micro algae Spirulina platensis in broiler diets. The aim of the current study was to investigate the chickens’ growth performance and the intestinal morphology as well as the health status. 288 one-day-old male growing chickens (Ross 308) from a commercial hatchery were randomly allotted to 48 pens (6 birds per pen) for the growth study with five diets and feed supply on free choice level. The control diet was based on wheat, corn and SBM. The experimental diets replaced 50% of SBM by the alternative proteins under study, both on a basic level of amino acid (AA) supplementation (Lys and Met added equal to the control diet) (diet HM and SM) and an extended level of AA fortification (Lys, Met, Thr, Arg, Val added) (diet HM+ and SM+). Response of chickens was evaluated by zoo-technical parameters, which were under weekly control (e.g. growth, feed intake, feed conversion ratio, mortality). After finishing the growth study birds from control and the experimental diets at the basic level of AA supplementation were slaughtered after 12 hour fastening and utilized for gut morphometric analysis and histological evaluation of the health status. Diets at a basic level of AA fortification led to significant depression of growth, feed intake, feed conversion ratio, and protein conversion ratio, respectively. In addition, the acceptance of the Spirulina diet was lower (p ≤ 0.001) as compared to the Hermetia based diet. However, the extended level of AA supplementation improved all parameters significantly. Diets without extended AA supply altered some morphological parameters of the intestinal wall, but the nutritional significance of this observation needs to be verified in AA balanced diets. The health state of chicken was not impaired by the diets under study.

Effects of the Partial Replacement of Soybean Meal by Insect or Algae Meal in Chicken Diets with Graded Amino Acid Supply on Parameters of Gut Microbiology and Dietary Protein Quality

Insects or algae are considered future solutions to substitute imported feed proteins like soybean meal (SBM) in animal nutrition. The objective of this research, as part of the multidisciplinary project “Sustainability transitions”, focused on replacing 50% SBM by partly defatted larvae meal from black soldier flies (Hermetia illucens) or the blue-green algae Spirulina platensis in meat type chicken diets. The current study aimed to evaluate the effects on body composition, protein quality, apparent precaecal digestibility (apcD) and parameters of intestinal microbiota. In total, 288 one-day-old male growing chickens (Ross 308) from a commercial hatchery were randomly allotted to 48 pens (6 birds per pen) across five diets, which were fed at a free choice level. The control diet utilized SBM, wheat and corn as main ingredients, and experimental diets replaced 50% of SBM by the alternative proteins under study. Amino acid (AA) supplementation of the final diets was conducted both at a basic level (diets HM, SM; Lys and Met added equal to the control diet) and an extended level of AA fortification (diets HM+, SM+; extended supplementation of Lys, Met, Thr, Arg). After finishing the growth study, 4 individual birds per diet were slaughtered for whole body analyses to derive nutrient utilization and dietary protein quality parameters. Additionally, pooled chyme samples from 16 birds per diet (control, HM and SM) were analyzed to assess apcD and microbial parameters. Diets HM and SM with a basic level of AA fortification led to significant depressions in nutrient deposition and dietary protein quality. However, HM+ and SM+ diets with an extended level of AA supplementation led to significantly improved responses; however these were still generally not on par with the control diet. The HM+ diet provided superior CP deposition and dietary protein quality, as compared to the SM+ diet, but equal to the control diet. Results of gut microbiology yielded no significant effects due to feeding the alternative protein sources under study.

Effects of increasing crystalline amino acids in sorghum- or corn-based diets on nursery pig growth performance (2014)

A total of 300 pigs (PIC 1050; initially 23.3 lb BW) were used in a 21-d study to compare the effects of increasing crystalline amino acids in sorghum- and corn-based diets on nursery pig growth performance. Treatments with 5 pigs per pen and 10 pens per treatment were arranged in a 2 × 3 factorial with main effects of grain source (sorghum vs. corn) and crystalline amino acid supplementation (low, medium, or high). Amino acid ratios to lysine as well as standardized ileal digestibility coefficients used were set by NRC (20123). Because replacing increasing amounts of soybean meal with crystalline amino acids changes the NE of the diet, all diets were formulated to the same Lys:NE ratio. The lysine concentration in the diets was formulated at 95% of the pig’s estimated requirement to ensure that the other amino acids, on a ratio to lysine, would not be underestimated. The grain sources and soybean meal were analyzed for amino acid profile and diets formulated from these concentrations. The low amino acid fortification contained L-lysine HCl and DL-methionine. The medium amino acid fortification contained L-lysine HCl, DL-methionine, and L-threonine, and the high amino acid fortification contained L-lysine HCl, DL-methionine, L-threonine, and L-valine. Overall, no main or interactive effects (P > 0.05) of grain source or added amino acids were detected for any response criteria. This suggests that balancing to the third, fourth, or fifth limiting amino acids is possible in both sorghum- and corn-based diets with the use of crystalline amino acids without detrimental effects on growth performance.; Swine Day, Manhattan, KS, November 20, 2014

Amino Acids Fortification of Low-Protein Diet for Broilers Under Tropical Climate: Ideal Essential Amino Acids Profile

A three-week trial was conducted to determine the effect of lowering dietary protein level (DPL) with optimal amino acid (AA) profile on growth performance, blood metabolites, and relative weights of abdominal fat and internal organs in broiler chickens raised under tropical hot and humid environment. Five isocaloric (3023 metabolisable energy/kg) starter (1-21 days) experimental diets were formulated in a gradual crude protein (CP) decline from 22.2 (control) to 16.2% by 1.5% interval. All diets were meeting or exceeding National Research Council recommendations except CP and metabolisable energy. The formulations were also adjusted to contain 1.1 digestible Lys to meet the ideal AA ratios concept. Body weights (BW), weight gains (WG), feed intake and feed conversion ratio of groups with 19.2, 20.7 and 22.2% DPL were not significantly different. However, BW and WG suppressed (P<0.05) with 16.2 and 17.7% DPL. Feeding the 16.2% CP diet significantly reduced serum total protein and uric acid, but increased serum triglyceride (P<0.05). Moreover, relative heart weights increased (P<0.05) but no changes occurred in liver and abdominal fat weights in chicks with 16.2% DPL. In summary, CP of broilers starter (1-21 days) diet can be reduced till 19.2% with essential AA fortification and without any adverse effect on growth performance under the hot, humid tropics.

Canine dietary protein influences glomerular filtration rate in adult dogs

Seventy normal adult dogs were randomly assigned to five dietary protein levels with and without amino acid fortification. This study was run to determine the effect of different protein and amino acid concentration on renal function as measured by glomerular filtration rate (GFR) and body composition in a six month study. The experimental protocol was reviewed and approved by the Institutional Animal Care and Use Committee. Dogs had daily socialization through interacting with other dogs and daily walks with people. Glomerular filtration rate was measured by iohexol clearance while body composition was determined via dual energy x‐ray absorptiometry (DXA). GFR and DXA were measured before and after six months on treatment. Foods were formulated to contain 15, 19, 22, 25, or 30% protein. All treatments had numeric increases in body lean but change in lean was not influence by diet. Dietary protein had a significant quadratic and linear effect (P&lt;0.05) on GFR. Increased GFR was attained through either increasing above or reducing below 21% protein. These data show that renal function as measured by GFR may be increased with increasing protein and through restricting excess protein.

Diet supplied with L‐lysine and L‐arginine during chronic stress of high stock density normalizes growth of broilers

ABSTRACTThe effects of fortifying a diet with L‐lysine HCl (Lys) and L‐arginine (Arg) in broilers housed under conditions of high stock density, were studied in an experiment that measured bodyweight, feed intake, feed conversion, body temperature, serum protein, immune parameters and neutrophils. A diet fortified with Lys and Arg increased bodyweight gain in broilers housed under high stock density conditions, but not in normally housed controls. The diet fortified with Lys and Arg decreased the feed conversion ratio and abdominal fat, as compared to the effects of a control diet, without regard to housing conditions. No effects of amino acid fortification or stock density on body temperature, serum protein or immune parameters were recorded. The results indicate that an increase in the dietary supply of Lys and Arg is beneficial to broilers during stressful conditions of high stock density, potentially contributing to an enhancement of animal welfare in broiler farms.

The effects of diets formulated on an ideal protein basis on growth performance, carcass characteristics, and thermal balance of finishing gilts housed in a hot, diurnal environment2

Forty-eight finishing gilts (initial BW = 70.6 +/- .95 kg) were randomly assigned to one of eight experimental treatments in a 2 x 2 x 2 factorial arrangement with main effects including dietary lysine (.60 vs 1.00%), source of amino acid fortification (intact protein vs synthetic amino acids formulated on an ideal protein basis), and environmental temperature (thermoneutral [TN]: 20 degrees C vs hot, diurnal [HD]: 27.7 to 35 degrees C). The ideal protein diets were formulated by using corn and soybean meal to meet the fifth-limiting amino acid; synthetic lysine, threonine, tryptophan, methionine, or isoleucine were added to meet the gilts' estimated requirements. The ratios of other total amino acids relative to lysine were as follows: threonine, 66%; tryptophan, 17%; methionine and cystine, 56%; and isoleucine, 63%. Average daily gain, ADFI, and feed efficiency (G/F) were similar for gilts fed the intact and those fed the ideal proteins diets (P > .10). Increasing dietary lysine improved d 0 to 14 ADG (P < .01), but no differences were observed for the overall experiment. Gilts in the HD environment ate less feed and had lower ADG than gilts in the TN environment (P < .01). A temperature x lysine interaction was observed (P < .02) for G/F. Increasing dietary lysine had no effect on G/F of gilts in the TN environment but improved G/F of gilts in the HD environment. Gilts fed the intact protein diets had higher (P < .01) N intake and plasma urea concentrations. Gilts fed the ideal protein diets had lower (P < .05) plasma essential amino acids, with the exception of lysine. Carcass protein and lipid contents were improved (P < .01) for gilts in the HD environment and for those fed 1.00% lysine. Backfat thickness and longissimus muscle area (P < .01) were improved and lipid accretion rate tended to decrease (P < .08) in gilts fed 1.00% lysine. The source of amino acid fortification did not influence carcass characteristics (P > .10). Rectal, skin, and ear temperatures were higher for gilts in the HD environment (P < .05). Metabolic heat production was elevated by feeding gilts the ideal protein diets (P < .03). In conclusion, increased dietary lysine improved G/F and carcass leanness in gilts to a greater extent in HD than in TN environments. However, no improvements in growth performance or carcass traits resulted from feeding ideal protein diets.

Amino Acid Fortification of a Low-Protein Corn and Soybean Meal Diet for Chicks

Seven experiments were conducted to investigate whether a 19% CP corn and soybean meal (CS) diet could be fortified properly with amino acids (AA) to produce performance in 1- to 3-wk-old chicks equal to that obtained with a 23% CP, CS diet supplemented with Met. In one experiment, the assay was carried out to 6 wk of age. During 4- to 6-wk posthatching, the positive control was a 20% CP, CS diet with added Met and the low-protein diet was a 16% CP, CS diet fortified with limiting AA.The two most limiting AA in the low-protein diet (19% CP) were found to be Met and Lys. Arginine, Val, and Thr were observed to be limiting as well. Weight gain and feed efficiency were substantially increased and body fat content decreased when the low-protein diet was supplemented with the five limiting AA and amino nitrogen in the form of Glu. Addition of potassium had no effect on performance of chicks fed the AA-fortified, low-protein diet. With all trials considered together, chicks fed the low-protein diet fortified with the five limiting AA and Glu gained at the same rate with similar feed efficiency and had estimated body fat levels comparable to birds fed the 23% CP, positive control diet. From 3 to 6 wk of age, chicks fed the AA-fortified, 16% CP diet had growth performance similar to chicks fed the 20% CP, positive control diet.

The effects of diets formulated on an ideal protein basis on growth performance and carcass characteristics of finishing gilts housed in a hot diurnal environment (1992)

Forty-eight finishing gilts (initial weight = 155 ± 2 lb) were randomly assigned to one of eight experimental treatments in a 2 x 2 x 2 factorial arrangement with main effects including dietary lysine (.60 vs 1.00%), source of amino acid fortification (intact protein vs synthetic amino acids formulated on an ideal protein basis) and environmental temperature (thermoneutral (TN): 68°F vs hot, diurnal (HS): 82 to 95 °F). The ideal protein diets were formulated by using corn and soybean meal to meet the 5th limiting amino acid with additions of synthetic lysine, threonine, tryptophan, methionine, or isoleucine to meet the pigs estimated requirement. The ratios of other total amino acids relative to lysine were: threonine 66%, tryptophan 17%, methionine and cystine 56%, and isoleucine 63%. Average daily gain (ADG), average daily feed intake (ADFn, and feed efficiency (FIG) were similar for gilts fed the intact and ideal proteins diets. Increasing dietary lysine improved d 0-14 ADG and resulted in a numerical improvement for the overall study. Gilts in the HS environment ate less feed and had lower ADG than gilts at TN. A temperature X lysine interaction was observed for FIG. Increasing dietary lysine had no effect on FIG of gilts in the TN environment, but improved FIG of gilts in the HS environment. Carcass protein and lipid contents were improved for gilts in the HS environment and by increased dietary lysine. Accretion rates for protein and lipid, backfat thickness, and longissimus muscle area were improved in gilts fed 1.00% lysine. The source of amino acid fortification did not influence carcass characteristics. In conclusion, increased dietary lysine improved FIG and carcass leanness in gilts to a greater extent in HS than TN environments. However, no improvements were observed in growth performance or carcass traits from feeding ideal protein diets.; Swine Day, Manhattan, KS, November 19, 1992

Evaluation of plant proteins to solve nutritional problems of the third world

In most countries of the third world, foods of plant origin are the primary sources of dietary protein; in many of these countries, dietary protein often is supplied solely from plant sources. Under these conditions, the nutritive value of the protein in the diets may be low due to amino acid deficiencies or imbalances. Alternately if the protein level is low in the plant sources, then the total amount of dietary protein may be inadequate. Various approaches have been used to increase the amount of utilizable protein. Those discussed include amino acid fortification, uses of protein mixtures (protein supplementation and complementation), and genetic alterations of food crops. The need for nutritional improvement of plant proteins is considered in relation to the current questions about protein requirements and the adequacy of plant foods in meeting protein requirements. The dependence for success of any protein-improvement upon non-nutritional, socio-economic factors is noted.

1117 INTRAUTERINE DIET FORTIFICATION AND OFFSPRING BRAIN DEVELOPMENT

Vegetable protein, providing 80% of protein requirements in Third World Countries, can be quantitatively adequate but qualitatively inadequate in protein content. Supplementation with limiting amino acids (AA's) is possible and might aid intrauterine offspring development. In the present experiments 21 Sprague Dawley rats were impregnated and groups of 7 begun on one of 3 diets: A) bread, B) bread + lysine and threonine, or C) lab chow. Weights of all offspring at birth were lower (p< .001) in group A (5.64 ± 0.52g) compared to groups B (6.39 ± 0.88g) or C (6.49 ± 0.34g). Two newborns from each of the 7 litters in each of the 3 groups were randomly selected for further brain studies. Total brain weights were lower for group A pups (.239 ± .019) compared to groups B (.279 ± .022, p<.05) or C (.258 ± .026, p<.001). Total DNA, representing total cell number, was higher in the cortices of AA supplemented (group B) offspring (.562 ± .019) compared to group A neonates (.537 ± .029, p<.01). DNA was also higher in the cerebellum-brain stem of group B animals (.169 ± .010) compared to group A animals (.158 ± .014, p<.05). There were no significant differences in DNA between the AA supplemented and the chow fed offspring. Total cortex protein was lower in group A animals compared to groups B (p<.001) or C (p<.02). These experiments demonstrate that amino acid fortification of a maternal vegetable protein diet results in improved intrauterine brain development.

Science—neglected ingredient of nutrition policy. 10th Martha F. Trulson Memorial Lecture

Programs to alleviate malnutrition in children in developing countries need revision. Intervention field trials in Thailand, Tunisia, and Guatemala, based on amino acid fortification and supplementary vitamins and minerals, have had little effect on children. In fact, it is often a misconception that frank deficiencies are common characteristics of malnutrition in developing countries.Rather, stunted growth--caused by caloric deficiency often in the presence of adequate food supplies--may be the most prevalent form of malnutrition. The situation occurs when the customary staple food--for instance, rice in Thailand--has such a high caloric density that children cannot eat enough food to meet their needs. Knowledge is not vet available on ways to solve this dilemma. Nevertheless nutritionists must come forward and be willing to contribute their knowledge and expertise in the shaping of national and international nutrition policies to improve the healthand well-being of populations.

Evaluation of Supplemental Protein Sources for Broiler Chicks

Two chick growth assays were completed to evaluate cottonseed meal, single-cell protein (torula yeast) and dehulled soybean meal in various combinations. In all cases, ground yellow corn supplied 4% of the total dietary crude protein (23%) with the balance coming from supplemental protein sources under study. To simulate conditions in those parts of the world where crystalline methionine and lysine are not readily available or economical, no amino acid fortification was carried out. As the sole source of supplemental protein, soybean meal was far superior to the rest, but equal protein contributions from soybean meal and cottonseed meal or from soybean meal, cottonseed meal and single-cell protein resulted in weight gains similar to those obtained with soybean meal alone. Equal protein contributions from cottonseed meal and single-cell protein resulted in gains and gain/feed ratios considerably greater than those occurring when either of these ingredients was fed alone. With soybean meal-cottonseed meal combinations, chicks gained similarly when fed soy-cottonseed protein ratios of 1:0, 5:1, 2:1, 1:1 or 1:2, but gain/feed declined linearly as cottonseed protein replaced soy protein in the diet.

Amino Acid Fortification of Bread Fed at Varying Levels during Gestation and Lactation in Rats

The effects of protein quality improvement of white bread fed to female rats during pregnancy and lactation, under varying degrees of adequacy in food energy, on growth and brain development of the offspring have been studied. Weaning weight and the weight, protein and DNA of whole brain and major regions of the brain at weaning were determined. Lysine addition significantly increased all parameters, and threonine addition gave additional significant increments. Restricting energy intake decreased most parameters independent of protein quality. Brain cellularity was significantly higher in offspring of dams fed lysine and threonine fortified bread than in offspring of dams fed casein. All parameters measured in the offspring of dams fed lysine and threonine fortified bread at 70% ad libitum consumption were significantly increased over the values obtained in the offspring of dams fed unfortified bread ad libitum even though they had consumed 13% less protein and dietary energy during the pregnancy and lactation period. The implications of these findings for practical problems in human nutrition are considered.

Amino Acid Fortification of Wheat Diets Fed at Varying Levels of Energy Intake to Rats

The effects on growth and nitrogen utilization of protein quality improvement of white bread fed under varying degrees of adequacy of food energy have been studied. Weanling rats were fed white bread bread plus lysine, and bread plus lysine plus threonine at energy levels ranging from 55% to 100% of ad libitum consumption. Weight gain, protein efficiency ratio (PER), net protein ratio (NPR), and net protein utilization (NPU) were measured and plotted against food consumption. The improvement in growth and nitrogen utilization resulting from amino acid fortification of bread, even when food intake was little more than half ad libitum consumption, was significant. For example, the NPR and NPU values obtained with lysine fortified bread fed at 70% of adlibitum consumption were 1.5 to 2 times those obtained with unfortified bread in spite of the fact that the latter rats consumed 25% more food energy. The implications of these findings for practical problems in human nutrition are discussed.

EFFECTS OF LYSINE AND THREONINE FORTIFICATION OF BREAD DURING GESTATION AND LACTATION ON OFFSPRING BRAIN LIPID DEVELOPMENT

Abstract– Offspring brain lipid development has been studied following the amino acid fortification of wheat diet fed to pregnant and lactating rats. Comparisons are made with a 13% casein diet which contains a similar quantity of protein of known high quality, with a 26% casein diet, and with a standard laboratory diet. Increased maternal energy intake was found, particularly during lactation, with protein quality improvement. Offspring of mothers receiving the unsupplemented bread diet had lower total brain cholesterol, phospholipid, cerebroside‐sulfatide, and (for 4 of the 5 other diets) ganglioside‐NANA levels in comparison to offspring whose mothers received the other diets. Brain cerebroside‐sulfatide and cholesterol concentrations were also lower in the offspring whose mothers received the unsupplemented bread, suggesting impaired myelin formation. Phospholipid and ganglioside‐NANA concentrations were not lower. Fortification of the bread diet with lysine resulted in increases in both the total levels and concentrations of cerebroside‐sulfatide and cholesterol. When both lysine and threonine were added, the cerebroside‐sulfatide and cholesterol levels and concentrations were similar to or greater than values for the two casein diets and the standard laboratory diet. The 26% casein diet did not result in higher lipid values than obtained with the 13% casein diet. This study demonstrates the adequacy of amino acid supplementation of a maternal cereal protein diet in allowing normal offspring brain lipid development.