Amino Acid Requirements For Growth Research Articles

COMPARATIVE RESPONSES OF LARGE WHITE X LANDRACE AND THE INDIGENOUS NIGERIAN PIGS TO DIETS OF VARYING PROTEIN CONCENTRATION

A total of 60 pigs made up of 30 Large White x Landrace pigs (LW X LD) and 30 indigenous Nigerian pigs were allocated to five groups of 12 pigs each, such that there were 3 barrows and 3 gilts of each breed within the group. These were individually fed one of 5 dietary protein levels (12%, 14%, 16%, 18% and 20% CP), from an approximate initial weight of 9 kg to a terminal weight of approximately 68 kg, at which weight all pigs were slaughtered for carcass appraisal. Protein level increments significantly improved both rate and efficiency of gain of the LW X LD pigs, being best on the 20% protein diet. For the IND pigs, best rate of gain was obtained on the lowest protein level, while at levels of protein above 16%, an obvious decline in rate of gain resulting from further increases in protein levels were observed. Feed efficiency in the IND pigs was improved when protein levels in diets were increased from 12% to either 14% or 16%. This improvement was more obvious at lower weight class intervals, than when pigs were reared to heavy weights. Carcass traits were improved in both breeds as protein levels were increased, the improvements being more marked for the LW X LD pigs. There were highly significant breed differences for growth, feed efficiency and all carcass measurements. Significant breed x ration interaction was obtained for growth rate, feed efficiency and most carcass traits, except percentages bone, skin and shoulder, carcass length and dressing percentage. The results indicate obvious differences in protein and amino acid requirements for growth and best carcass quality, which are discussed in relation to inherently different capacities for proteinaceous and fatty tissue growth.

Total versus digestible amino acid requirements for growth and nutrient utilization of naked neck broilers during finishing phase

Total versus digestible amino acid requirements for growth and nutrient utilization of naked neck broilers during finishing phase

Control of the release of digestive enzymes in the larvae of the fall armyworm, Spodoptera frugiperda

There is a basal level of enzyme activity for trypsin, aminopeptidase, amylase, and lipase in the gut of unfed larval (L6) Spodoptera frugiperda. Trypsin activity does not decrease with non-feeding, possibly because of the low protein levels in plants along with high amino acid requirements for growth and storage (for later reproduction in adults). Therefore, trypsin must always be present so that only a minimal protein loss via egestion occurs. Larvae, however, adjust amylase activity to carbohydrate ingestion, and indeed amylase activity is five-fold higher in fed larvae compared to unfed larvae. Gut lipase activity is low, typical of insects with a high carbohydrate diet. A flat-sheet preparation of the ventriculus was used to measure the release of enzymes in response to specific nutrients and known brain/gut hormones in S. frugiperda. Sugars greatly increase (>300%) amylase release, but starch has no effect. Proteins and amino acids have little or no effect on trypsin or aminopeptidase release. The control of enzyme release in response to food is likely mediated through neurohormones. Indeed, an allatostatin (Spofr-AS A5) inhibits amylase and trypsin, and allatotropin (Manse- AT) stimulates amylase and trypsin release. Spofr-AS A5 also inhibits ileum myoactivity and Manse-AT stimulates myoactivity. The epithelial secretion rate of amylase and trypsin was about 20% of the amount of enzyme present in the ventricular lumen, which, considering the efficient counter-current recycling of enzymes, suggests that the secretion rate is adequate to replace egested enzymes.

Digestible Lysine Requirements for Maintenance in the Starting Turkey

The objective of these studies was to determine the digestible threonine requirement for maintenance in turkeys during the starter period. Amino acid requirement data can be determined in multiple fashions. One method for determining amino acid requirements is through modeling. A portion of the data required for a comprehensive model is the maintenance requirement. Two studies were conducted to determine the maintenance requirement for threonine during the starter period for turkeys. Day-old poults (192 birds) were randomly assigned to pens to provide for six replications of eight treatments in each trial and a low protein diet was formulated so that different levels of threonine could be fed to young turkeys. The maintenance requirements of threonine were 25.94 and 29.51 mg/bird/day in experiment 1 and experiment 2, respectively. This information, coupled with the amino acid requirements for growth, will allow for the construction of an effective model to predict amino acid requirements over a wide range of environment and physiological conditions.

Digestible Sulfur Amino Acid Requirements for Maintenance in the Starting Turkey

Amino acid requirement data can be determined in multiple fashions. One method for determining amino acid requirement is through modeling. A portion of the data required for a comprehensive model is the maintenance requirement. Two studies were conducted to determine the maintenance requirement for the sulfur amino acids during the starter period for turkeys. A low protein diet was formulated so that different levels of total sulfur amino acids could be fed to young turkeys. A maintenance requirement of approximately 26 mg/bird/day was found in both experiments. This information, coupled with the amino acid requirements for growth, will allow for the construction of an effective model to predict amino acid requirements over a wide range of environment and physiological conditions.

Dietary Protein Quality in Humans—An Overview

The first objective in evaluating protein quality is to permit a ranking of proteins according to their potential nutritive value and to permit detection of changes in nutritive value due to processing and/or storage. The second objective is to permit prediction of the contribution a food protein, or mixture of food proteins, makes toward meeting nitrogen and amino acid requirements for growth or maintenance. Different approaches are used in meeting these distinct aims. The preferred current method to meet the second aim is the protein digestibility corrected amino acid score (PDCAAS). This article introduces the concept of PDCAAS and places it in the context of the series of papers published in this Special Guest Editor Section addressing aspects of dietary amino acid utilization.

Effect of dipeptides on the growth of Oenococcus oeni in synthetic medium deprived of amino acids.

Oenococcus oeni has numerous amino acid requirements for growth and dipeptides could be important for its nutrition. In this paper the individual or combined effect of dipeptides on growth of O. oeni X2L in synthetic media deficient in one or more amino acids with L-malic acid was investigated. Utilization of dipeptides, glucose, and L-malic acid was also analyzed. Dipeptides were constituted by at least one essential amino acid for growth. Dipeptides containing two essential amino acids, except leucine, had a more favorable effect than free amino acids on the growth rate. Gly-Gly was consumed to a greater extent than Leu-Leu and a rapid exodus of glycine to the extracellular medium accompanied it. The microorganism could use glycine in exchange for other essential amino acids outside the cell, favoring growth. In the presence of Leu-Leu, the increase in glucose consumption rate could be related to the additional energy required for dipeptide uptake.

Effects of a dietary mixture of meat and bone meal, feather meal, blood meal, and fish meal on nitrogen utilization in finishing Holstein steers.

Our objective was to determine to what extent rate and efficiency of protein gain in finishing cattle can be enhanced by feeding an amino acid-balanced mixture of undegraded intake proteins. The Cornell Net Carbohydrate and Protein System (CNCPS) model was used to formulate a corn-based diet that would meet the rumen requirements for 410-kg large-framed steers with an estrogen implant and fed an ionophore. The CNCPS model was also used to formulate a highly undegradable intake protein (UIP) mixture from meat and bone meal, blood meal, fish meal, and hydrolyzed feather meal to provide the amino acids needed to supplement those derived from microbial protein to better meet amino acid requirements for growth. Four Holstein steers weighing 407 kg were offered a 90:10 concentrate-forage diet at hourly intervals at 95% of ad libitum intake. The steers were injected with 500 microg of estradiol-17beta at 12-h intervals to mimic the effects of an estrogenic implant. Treatments planned consisted of inclusion of the UIP mixture at 0, 2.5, 5, and 7.5% of the diet DM. Dry matter intake was fixed at 6.4 kg/d, and DM digestibility was not significantly affected by varying the amount of UIP addition. Apparent digestibility of N increased (P = .011) from 63.8 to 65.8, 70.7, and 71.5%, the amount of N absorbed increased (P = .001) from 73 to 84, 100, and 106 g/d, and N balance increased (P = .003) from 20 to 30, 33, and 39 g/d when UIP was fed at 0, 2.6, 5.2, and 7.8% of diet DM, respectively. The efficiency of N use increased 39.7%, and biological value increased 31.6% when the UIP mixture was added to the diet. Circulating concentrations of plasma urea N (PUN) were increased (P = .017) from 4.5 for the control diet to 5.7, 6.2, and 6.1 mg/dL when the UIP mixture was added at 2.6, 5.2, and 7.8%, respectively. Corresponding IGF-I concentrations were also increased from 491 to 558 and 624 ng/mL with 2.6 and 5.2% levels of UIP addition. Plasma glucose, NEFA, and insulin concentrations were not affected by feeding the UIP mix. The rate and efficiency of N use for growth improved with addition of an amino acid-balanced UIP mixture to the diet.

Protein and Amino Acid Requirements for Maintenance and Amino Acid Requirements for Growth of Laboratory Rats

Protein and Amino Acid Requirements for Maintenance and Amino Acid Requirements for Growth of Laboratory Rats

Quantitative essential amino acid requirements for growth of catla, Catla catla (Hamilton)

The quantitative dietary essential amino acid requirements by the fry of catla, Catla catla, were determined using a test diet containing purified ingredients. The test diets did not contain any intact protein and the only source of nitrogen was from crystalline amino acids. The quantitative requirements were elucidated by feeding a graded level of one amino acid at a time by replacement with L-alanine, isonitrogenously maintaining dietary crude protein at 40%. The feeding trials were carried out for 8 weeks under static rearing conditions. Weight gain is taken as a criterion for estimating the requirement. The break point for each requirement value was then calculated using broken line regression method. When expressed as a percentage of dietary protein, the fry of catla were found to require 4.80% arginine, 2.45% histidine, 2.35% isoleucine, 3.70% leucine, 6.23% lysine, 3.55% methionine (in the absence of cystine), 3.70% phenylalanine (with 1.0% tyrosine), 4.95% threonine, 0.95% tryptophan and 3.55% valine.

Amino acid requirements for growth of Chlamydia pneumoniae in cell cultures: growth enhancement by lysine or methionine depletion

Amino acid requirements for growth of two isolates of Chlamydia pneumoniae were studied and compared with those for one strain of Chlamydia trachomatis in a HeLa 229 cell culture. It was shown that among 13 amino acids in Eagle minimum essential medium, C. pneumoniae required all amino acids except lysine. A true requirement for arginine, isoleucine, leucine, threonine, and valine could not be determined because depletion of 100% of these amino acids caused cell detachment. Consequently, a requirement for these amino acids was based on 90% depletion. C. trachomatis biovar trachoma required all amino acids except threonine, which was indeterminable. Depletion of 100 and 90% of the lysine and 90 to 70% of the methionine was shown to enhance the growth of C. pneumoniae. This phenomenon was shown to be a property of C. pneumoniae because the effect of lysine and methionine reduction was also demonstrated in another human line, HL cells, and a mouse line, McCoy cells.

Amino acid requirements of the growing meat rabbit 1. The amino acid composition of rabbit whole-body tissue — a theoretical estimate of ideal amino acid balance

ABSTRACTWhole-body amino acid composition was determined in six male and six female 53-day-old New Zealand White rabbits. There were no significant sex differences in whole-body amino acid compositition except for arginine and glycine where whole-body concentrations (g/16 g N) were significantly lower in the females (P< 0·05). Overall mean whole-body essential amino acid levels (relative to lysine = 100 units) were methionine = 20; cystine = 41; histidine = 50; phenylalanine = 65; tyrosine = 50; threonine = 64; leucine = 112; isoleucine = 51; valine = 62; arginine = 109. The lysine concentration of rabbit whole-body tissue was 6·12 g/16 g N. There was close agreement between rabbit whole-body amino acid composition and corresponding published values for the rat and pig, although the rabbit whole-body cystine was high and methionine concentration low compared with the rat or pig. The rabbit whole-body amino acid pattern can be regarded as approximating an ideal balance of dietary amino acids and as such indicates discrepancies in current recommendations on the essential amino acid requirements for growth in the meat rabbit.

Regulation of Chlamydia psittaci (strain guinea pig inclusion conjunctivitis) growth in McCoy cells by amino acid antagonism.

Chlamydiae have amino acid requirements for growth in tissue culture as defined by those amino acids whose individual omission from the growth medium prevents chlamydial multiplication. We have tested the hypothesis that this inhibition of growth arises as a result of antagonism between particular amino acids such that inhibition occurs when the concentration of one amino acid is reduced in the presence of the antagonist amino acid at high concentration. Using the Chlamydia psittaci strain guinea pig inclusion conjunctivitis (GPIC), in the presence of cycloheximide, the requirement for valine was abrogated by the simultaneous omission of isoleucine, that for phenylalanine by simultaneous omission of tryptophan and that for leucine by simultaneous omission of isoleucine plus valine. The antagonism shown between leucine and isoleucine plus valine appears to be unique among bacteria. In the absence of cycloheximide, GPIC had an additional need for tryptophan, tyrosine and isoleucine; these amino acid requirements were shown for both infected McCoy, HeLa and BHK cells. The results are consistent with a mechanism for regulation of parasite growth which depends on the balance of amino acid concentrations in the extracellular environment.

Amino acid requirements for growth and development of the tachinid Eucelatoria bryani

1. 1. Deletion of free amino acids from an oligidic diet containing 1.4% soy protein resulted in the failure of E. bryani to develop beyond the third instar. 2. 2. Deletion of single amino acids from diet containing 1.83% free amino acids and 1.4% soy protein demonstrated that arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine were essential. 3. 3. Proline was required because its deletion allowed only 3% of E. bryani to survive to the adult stage. Proline was the only “non-essential” amino acid deleted that significantly affected development from the puparium to the adult. 4. 4. Tyrosine and glycine are beneficial because deletion somewhat reduced puparial and adult survival.

Significance of Extracellular Protease for Growth of a Heterotrophic Bacterium, Aeromonas salmonicida

The role of protease produced by a heterotrophic bacterium during growth was investigated with Aeromonas salmonicida, the pathogen of fish furunculosis, strain A-7301 and its protease-deficient mutant NTG-1 induced by mutagenesis. Strain A-7301 produced extracellular protease in a mixed amino acid medium (composed of Gly, Ala, Val, Ile, Leu, Thr, Ser, Cys, Met, Phe, Tyr, Lys, Arg, Pro, His, Try, Asp, Asn, Glu, and Gln at equal concentrations of 0.1 g/liter). Its multiplication rate was limited by the amounts of amino acids present, whereas strain NTG-1 showed no protease production despite considerable growth similar to that of A-7301. There was no difference between A-7301 and NTG-1 in amino acid requirements for growth, and seven amino acids (Gly, Ala, Val, Thr, Cys, Met, and His) were found to be indispensable. A defined level of the mixed amino acids (0.4 to 0.5 g/liter) was needed for A-7301 to initiate a large production of protease. Neither of the strains grew well in a casein medium, to which no amino acids were added. However, when a protease fraction obtained from extracellular products of A-7301 by DEAE-cellulose column chromatography was added, NTG-1 successfully reproduced in the casein medium. These results indicate that the extracellular protease plays an important role in supplying A. salmonicida cells with available amino acids as nutrients and that higher growth is closely associated with protease production which stimulates further reproduction.

The uptake of amino acids by mouse cells (strain LS) during growth in batch culture and chemostat culture: the influence of cell growth rate.

The uptake of thirteen essential amino acids by mouse LS cells in suspension culture was determined by bacteriological assay methods. Chemostat continuous-flow cultures were used to determine the effect of different cell growth rates on the quantitative amino acid requirements for growth. The growth yields of the cells ( Y = g cell dry weight produced/g amino acid utilized) were calculated for each of the essential amino acids. A mixture of the non-essential amino acids, serine, alanine and glycine increased the cell yield from the essential amino acids. The growth yields from nearly all the essential amino acids in batch culture were increased when glutamic acid was substituted for the glutamine in the medium. The growth yields from the amino acids in batch culture were much less at the beginning than at the end of the culture. The highest efficiencies of conversion of amino acids to cell material were obtained by chemostat culture. When glutamic acid largely replaced the glutamine in the medium the conversion of amino acid nitrogen to cell nitrogen was 100 % efficient (that is, the theoretical yield was obtained) at the optimum growth rate (cell doubling time, 43 h). The maximum population density a given amino acid mixture will support can be calculated from the data. It is concluded that in several routinely used tissue culture media the cell growth is limited by the amino acid supply. In batch culture glutamine was wasted by (1) its spontaneous decomposition to pyrrolidone carboxylic acid and ammonia, and (2) its enzymic breakdown to glutamic acid and ammonia, but also glutamine was used less efficiently than glutamic acid. Study of the influence of cell growth rate on amino acid uptake rates per unit mass of cells indicated that a marked change in amino acid metabolism occurred at a specific growth rate of 0.4 day -1 (cell doubling time, 43 h). With decrease in specific growth rate below 0.4 day -1 there was a marked stimulation of amino acid uptake rate per cell and essential amino acids were consumed increasingly for functions other than synthesis of cell material.

Amino acid requirements for growth of the rabbit blastocyst in vitro.

AbstractTen amino acids, namely, arginine, histidine, lysine, tryptophane, methionine, phenylalanine, leucine, valine, threonine and serine were indispensable for growth of rabbit blastocysts in vitro; others were nonessential. Of all the essential amino acids, arginine and lysine were required in relatively high concentrations, 10−2 M and 10−3 M, respectively, for optimum growth. Complete omission of the non‐essential amino acids from the medium markedly reduced blastocyst growth. Interaction between serine and glycine demonstrated a partial sparing action on serine by glycine, similar to that observed between methionine and cysteine. The amino acid composition of a culture medium capable of providing continuous and consistent growth of rabbit blastocysts in vitro is described.

The Effects of Breed, Sex, an Arsenical and Nutrient Density on the Utilization of Dietary Energy

DIFFERENCES in dietary requirements between breeds, strains and sexes of birds have been demonstrated on many occasions. Serfontein and Payne (1934) reported that susceptibility to perosis was at least partially governed by inheritance; this suggested a genetic difference in manganese requirements. Lamoreux and Hutt (1939) found Rhode Island Reds to be more susceptible to a thiamine deficiency than White Leghorns while Thornton (1960) and Thornton and Shutze (1960) found that the thiamine requirements were greater for light than for heavy breed chicks. A genetic difference in roboflavin requirements was demonstrated by Lamoreux and Hutt (1948) while a sex difference in vitamin A requirements was reported by Thornton and Whittet (1962). Breed differences in amino acid requirements for growth have been reported by Almquist (1957) and McDonald (1957) while Cooper et al. (1960) have observed genetic variations in amino acid requirements for egg production. Working with turkeys, Wilcox et al. (1961)…

Sulfur Amino Acid Requirements for Growth of Mice Fed Two Levels of Nitrogen

Sulfur Amino Acid Requirements for Growth of Mice Fed Two Levels of Nitrogen

The formation of higher aliphatic alcohols by mutant strains of Saccharomyces cerevisiae

The ratio of isobutyl to the amyl alcohols formed was shown to remain constant throughout the course of alcoholic fermentation by resting and growing cells of Saccharomyces cerevisiae. But the composition of the higher alcohols formed is changed both qualitatively and quantitatively by employing yeasts with certain amino acid requirements for growth. An isoleucine-requiring mutant produces no active amyl alcohol. A leucine-requiring mutant produces only a trace of isoamyl alcohol. And a valine-requiring mutant produces markedly less isobutyl alcohol than does the parent strain. These results are consistent with and support the hypothesis that resting yeast cells synthesize higher alcohols by pathways common in certain reactions with the synthesis of the homologous amino acids (those with one more carbon atom). The formation of large amounts of n-propyl alcohol is reported and discussed.