scholarly journals The effect of provision of the first-limiting amino acid, gastrointestinal microbial activity and the level of nitrogen intake on protein utilization and energy digestibility in rats

1985 ◽  
Vol 54 (3) ◽  
pp. 727-739 ◽  
Author(s):  
B. O. Eggum ◽  
R. M. Beames ◽  
K. E. Bach Knudsen

1. The present work with growing rats was undertaken to study the effect of protein quality, gastrointestinal microbial activity and the level of nitrogen intake on protein utilization and energy digestibiiity. The experiment involved a total of thirty-six dietary treatments in a 9 x 4 factorial design, with five rats per treatment. The thirty-six diets resulted from nine protein sources. Each diet was composed of a basal N-free mixture plus minerals and vitamins, with N sources added at the expense of the N-free mixture to provide 15.0 gN/kg dry matter (DM) in the first three protein-addition treatments and 30.0 gN/kg DM in the fourth protein-addition treatment. The nine protein sources were soya-bean meal, casein, wheat gluten, skim-milk powder, meat-and-bone meal, wheat bran, barley, wheat and cooked brown beans (Phaseolus vulgaris). The four formulations for each protein source incorporated the protein unsupplemented at 15.0 gN/kg DM, unsupplemented at 30.0 gN/kg DM, or supplemented at 15.0 gN/kg DM with the estimated first-limiting amino acid or the antibiotic Nebacitin.2. With all protein sources, the inclusion of the first-limiting amino acid had no effect on either protein or energy digestibility.3. The microbial activity in the digestive tract affected protein utilization and energy digestibility to a different degree depending primarily on the level and type of dietary fibre. True protein digestibility (TD) of skim-milk powder and brown beans, both rich in easily-fermentable energy, increased from 0.959 to 1.000 and from 0.680 to 0.777 respectively by the addition of Nebacitin. TD of the other protein sources was only marginally affected by the antibiotic treatment. Only with brown beans was the biological value (BV) markedly affected by Nebacitin with an increase from 0.482 to 0.557 by the treatment. Energy digestibility was significantly lower in rats given antibiotic with soya-bean meal, wheat bran, barley, wheat and brown beans.4. The effect of level of N intake on protein utilization was dependent on both protein quality and the fibre concentration of the diet. Protein sources with high BV were more affected than proteins of lower BV. It was concluded that TD is not always independent of dietary protein concentration.

1965 ◽  
Vol 43 (11) ◽  
pp. 1879-1883 ◽  
Author(s):  
M. A. Krishnaswamy ◽  
S. B. Kadkol ◽  
G. D. Revankar

Ensiled fish was prepared from a local variety of freshwater fish (Barbus carnaticus) by fermentation with a pure culture of Streptococcus lactis, commercial lactose being used as a source of fermentable carbohydrate. The fermented material (pH 4.7) was roller dried. The finished product was cream colored and had a somewhat aromatic odor. It had a protein content of about 72%. Total lysine, available lysine, methionine, cystine, and tryptophan of the ensiled fish (expressed as g/16 g N) were 10.1, 8.1, 3.6, 1.1, and 1.2%, respectively. Hygienically, the product, being free from coliforms, enterococci, Salmonella, coagulase-positive staphylococci, and pathogenic anaerobes, was satisfactory. The biological value of the product as determined by protein efficiency ratio (3.3), net protein utilization (82.3%), and net protein ratio (4.2) was not significantly different from that of skim milk powder, which has a protein efficiency ratio of 3.2, net protein utilization of 82.8%, and net protein ratio of 4.9.


2020 ◽  
Vol 98 (6) ◽  
Author(s):  
Lauren M Reilly ◽  
Patrick C von Schaumburg ◽  
Jolene M Hoke ◽  
Gary M Davenport ◽  
Pamela L Utterback ◽  
...  

Abstract The rising consumer demand for alternative and sustainable protein sources drives the popularity of the use of plant-based proteins in the pet food industry. Pulse crops, which include beans, peas, lentils, and chickpeas, have become an important addition to both human and animal diets due to their protein content and functional properties. However, knowledge of their nutrient composition and protein quality is necessary for the proper formulation of these ingredients in pet foods. The objective of this study was to determine the macronutrient composition and standardized amino acid digestibility and to describe the protein quality through the use of digestible indispensable amino acid scores (DIAAS-like) of five pulse ingredients. Black bean (BB) grits, garbanzo beans (GB), green lentils (GL), navy bean (NB) powder, and yellow peas (YP) were analyzed for dry matter (DM), ash and organic matter (OM), crude protein (CP), gross energy (GE), acid hydrolyzed fat (AHF), and total dietary fiber (TDF) to determine the macronutrient composition. Precision-fed rooster assays were conducted using cecectomized roosters to calculate standardized amino acid digestibility and true metabolizable energy corrected for nitrogen (TMEn). The essential amino acids, with the exception of methionine, were highly digestible with digestibility values of 80% to 90% (dry matter basis) for all selected pulse ingredients. BB grits had the lowest (P < 0.05) digestibility of arginine (86.5%) and histidine (80.6%) in contrast to GB (94.9% and 89.9%, respectively). The TMEn of GB was highest (P < 0.05) at 3.56 kcal/g compared with the other pulses. The DIAAS-like values for adult dogs were consistently the lowest for methionine for all pulses, making it the first-limiting amino acid in these ingredients. The DIAAS-like values for adult cats showed GL had lowest (P < 0.05) score in tryptophan compared with other pulses when using both AAFCO values and NRC recommended allowances as reference proteins. Methionine was the first-limiting amino acid for YP and tryptophan for GL. Based on macronutrient composition, protein quality, and amino acid digestibility, it can be concluded that pulse ingredients have the required nutritional characteristics to be viable protein sources in canine and feline foods. However, the use of complementary protein sources is recommended to counterbalance any potential limiting amino acids in pulse ingredients.


1964 ◽  
Vol 42 (3) ◽  
pp. 377-384 ◽  
Author(s):  
H. N. Parthasarathy ◽  
T. R. Doraiswamy ◽  
Myna Panemangalore ◽  
M. Narayana Rao ◽  
B. S. Chandrasekhar ◽  
...  

The true digestibility coefficient, biological value, and net available protein of diets based on processed soya flour supplemented with dl-methionine hydroxy analogue (MHA) or dl-methionine (at a level of 1.2 g/16 g N) have been determined in children aged 8–9 years. The mean daily intake of protein by the children on the different diets was maintained at a level of about 1.2 g/kg body weight. Supplementation of soya flour with dl-methionine brought about a marked increase in the biological value and net protein utilization of the proteins. MHA was, however, slightly less effective than dl-methionine in this respect. The biological value and net protein utilization of the different proteins were as follows: soya flour, 63.5 and 53.3; soya flour + MHA, 71.5 and 61.4; soya flour + methionine, 74.9 and 64.7; and skim milk powder, 82.6 and 72.0.


1976 ◽  
Vol 36 (3) ◽  
pp. 317-335 ◽  
Author(s):  
V. J. Williams ◽  
J. H. B. Roy ◽  
Catherine M. Gillies

1. The effect of different protein sources in milk-substitute diets on abomasal acidity and proteolytic activity was studied in Friesian calves, aged 20–58 d (Expt 1). The diets contained ‘mildly’ preheated, spray-dried skim-milk powder (MHM), ‘severely’ preheated, spray-dried skim-milk powder (SHM), fish-protein concentrate (FPC) or solvent-extracted soya-bean flour (SF) as the main protein source.2. Gastric juice was collected from abomasal pouches before feeding and at 15 min intervals for 8 h after the morning feed. Samples of digesta were obtained from the abomasum at 1 h intervals during the same period.3. Digesta pH was lower and titratable acidity higher 0-3 h after giving the diet containing MHM than when any of the other three diets was given.4. Acid secretion from the pouches for the different diets was in the order: FPC > MHM > SHM ≥ SF.5. Protease secretion from the pouches, assayed at pH 2.1, was in the order: MHM > SHM = FPC > SF.6. The effect of dry matter (dm) intake and concentration on abomasal acidity was also studied in calves given diets which contained MHM (Expt 2). This diet was reconstituted at either 100 or 149 g dm/kg liquid diet and fed at either 32.5 or 49.0 g DM/kg live weight 0.75 per d. Samples of abomasal digesta were collected as in Expt 1.7. A high intake of dm at a low dm concentration resulted in low acidity of the digesta in the first 3 h after feeding, which suggested a dilution effect. Comparison of two diets of different dm concentration, which were fed in the same volume of liquid, indicated that the greater the dm intake, the greater was the amount of acid secreted.8. It is concluded that the protein sources varied in their ability to stimulate abomasal acid and protease secretion and it is suggested that this may relate to calf performance.


1964 ◽  
Vol 42 (3) ◽  
pp. 385-393 ◽  
Author(s):  
H. N. Parthasarathy ◽  
Kantha Joseph ◽  
V. A. Daniel ◽  
T. R. Doraiswamy ◽  
A. N. Sankaran ◽  
...  

The effect of supplementing a rice diet providing about 1.3–1.4 g protein per kg body weight with lysine, methionine, and threonine individually or together on true digestibility coefficient (DC), biological value (BV), and net protein utilization (NPU) of the proteins has been studied in girls aged 8–9 years. The retention of nitrogen on the rice diet was very low (9.5% of intake in the first series and 8.5% in the second series). The BV and NPU of the proteins of rice diet were 64.1 and 52.9 in the first series and 66.6 and 54.9 in the second series. Supplementation of the rice diet with lysine or methionine or lysine + methionine brought about a significant improvement in N retention (12.6, 12.0, 13.5% of intake) and in the BV (68.3, 66.3, 69.3) and NPU (54.8, 55.7, 55.8). When the rice diet was supplemented with lysine and threonine, a highly significant improvement in the N retention (18.9% of intake) and in the BV (77.4) and NPU (63.4) was observed. Addition of methionine to rice diet containing lysine and threonine resulted in a further improvement in N retention, BV, and NPU of the diets. The net available protein (g/kg body weight) from the different diets were as follows: rice diet, 0.71; rice diet + lysine, 0.76; rice diet + methionine, 0.74; rice diet + lysine + methionine, 0.77; rice diet + lysine + threonine, 0.85; rice diet + lysine + threonine + methionine, 0.91; and skim milk powder diet, 0.96–0.98.


1964 ◽  
Vol 42 (5) ◽  
pp. 641-650 ◽  
Author(s):  
Myna Panemangalore ◽  
H. N. Parthasarathy ◽  
Kantha Joseph ◽  
A. N. Sankaran ◽  
M. Narayana Rao ◽  
...  

The effect of supplementing a poor rice diet commonly used in India with methionine-fortified soya flour or skim milk powder was studied in seven girls aged 8–9 years, using as criteria: the retention of nitrogen, digestibility coefficient, biological value, and net protein utilization of the proteins. The retention of nitrogen on the rice diet was very low (20.3 mg/kg day). Supplementation of the rice diet with soya flour, methionine-fortified soya flour or skim milk powder, so as to provide about 1 g/kg extra protein, made up the protein deficiency in the rice diet and resulted in a significant increase in nitrogen retention (95.6, 112.1, and 113.6 mg/kg day). The retention of nitrogen on the rice diet supplemented with methionine-fortified soya flour (112.1 mg/kg day) or skim milk powder (113.6 mg/kg day) was nearly the same and significantly higher than that (95.6 mg/kg day) observed with a diet supplemented with soya flour. The biological value and net protein utilization of the mixed proteins of rice – skim milk powder diet and rice–methionine-fortified soya flour diet (62.4 and 62.2 and 53.3 and 54.0 respectively) were nearly the same and significantly higher than those (58.3 and 49.9) of rice – soya flour diet. The results show that methionine-fortified soya flour is almost as good as skim milk powder and significantly superior to soya flour as a protein supplement to rice diet.


1971 ◽  
Vol 26 (2) ◽  
pp. 311-322 ◽  
Author(s):  
J. E. Ford ◽  
C. Shorrock

1. Freeze-dried cod muscle and casein were subjected to various conditions of heat treat-ment. Diets containing the different products, or the unheated materials, were given to a group of four adult male rats during successive 48 h periods, and urine was collected during the second 24 h of each 48 h period. A further collection of urine was made from the rats after they had been given protein isolated from heated skim-milk powder. The content and amino acid composition of the ‘peptide’ and ‘free amino acids’ in the urines were determined.2. Heat damage to the cod-fillet protein increased the total urinary excretion of peptide-bound amino acids, from 18·6 to 48·8 µmol/rat.d. The composition of the peptide also changed, and in particular there was a marked increase in lysine, from 2·98 to 20·30 µmol %. Three amino acids - lysine, aspartic acid and glutamic acid - together comprised nearly 70 % of the total amino acid residues. There was a corresponding increase in urinary excretion of free amino acids, from 53·7 to I 14·4 µmol/rat.d. The combined losses of lysine in urinary peptide and free amino acids were 1·5 % of the total lysine ingested, as against 0·3 % for the unheated cod fillet.3. The effects of similar heat treatment of casein on the composition of the urinary peptide and free amino acids were less marked. There was no increase in total urinary peptide excretion and there was a smaller increase in the lysine content of the peptide.4. In urine of rats given protein isolated from heated skim-milk powder, the peptide hydro-lysate was rich in lysine and in furosine, which together comprised 41 mol % of the total amino acid composition. These compounds were presumably formed, together with a smaller quantity of pyridosine, from lysine-carbohydrate complex in the urine. It is probable that, as compared with free lysine, the lysine-carbohydrate complex was absorbed relatively in-efficiently from the rat intestine.5. The findings are discussed in relation to the wider question of the metabolism of the ‚unavailable peptide’ that is released in the course of digestion of heat-damaged protein.


2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Lauren M Reilly ◽  
Patrick C von Schaumburg ◽  
Jolene M Hoke ◽  
Gary M Davenport ◽  
Pamela L Utterback ◽  
...  

Abstract Increased consumer interest in high-quality and novel protein sources has driven the demand for the inclusion of protein-rich ingredients in companion animal diets. Novel protein concentrates, with protein contents of at least 50%, have been used to satisfy these consumer demands. However, minimal information is available regarding the macronutrient composition and protein quality of these ingredients that is needed for proper formulation of pet foods. Therefore, the objectives of this study were to determine the macronutrient and amino acid compositions, standardized amino acid digestibility according to the precision-fed rooster assay, and protein quality using digestible indispensable amino acid score (DIAAS like) of pea protein (PP), potato protein (POP), faba bean protein (FBP), soy protein concentrate (SPC), and dried yeast (DY). Precision-fed rooster assays were conducted using cecectomized roosters to calculate standardized amino acid digestibility and true metabolizable energy corrected for nitrogen (TMEn). For all five protein concentrates, all essential amino acids were highly digestible (88.0% to 96.3%, dry matter basis) with differences (P < 0.05) in only lysine, methionine, and tryptophan digestibilities. The TMEn values were highest for POP (4.22 kcal/g) and DY (3.61 kcal/g). The DIAAS-like values for adult dogs indicated that methionine was the first-limiting amino acid in all protein concentrates except POP, where the first-limiting amino acid was tryptophan. Using Association of American Feed Control Officials (AAFCO)-recommended values for adult cats, DIAAS-like values for methionine were lowest (P < 0.05) for FBP at 81.5%, with all other amino acids for all protein concentrates over 100%. The National Research Council (NRC)-recommended allowances for adult cats indicated that DIAAS-like methionine values for PP (92.7%) and FBP (73.8%) were significantly lower (P < 0.05) with these being the first-limiting amino acids, with the remaining amino acids above 100% for the other protein concentrates. The protein quality and high essential amino acid digestibility of these protein concentrates indicate that they would be viable protein sources in canine and feline diets. However, additional complementary protein sources should be included to meet the requirements of all essential amino acids.


Metabolites ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 305 ◽  
Author(s):  
Jonathan B. Magan ◽  
Tom F. O’Callaghan ◽  
Jiamin Zheng ◽  
Lun Zhang ◽  
Rupasri Mandal ◽  
...  

The influence of bovine diet on the metabolome of reconstituted skim milk powder (SMP) and protein ingredients produced from the milk of cows fed on pasture or concentrate-based diets was investigated. Cows were randomly assigned to diets consisting of perennial ryegrass only (GRS), perennial ryegrass/white clover sward (CLV), or indoor total mixed ration (TMR) for an entire lactation. Raw milk obtained from each group was processed at pilot scale, to produce SMP and sweet whey, and SMP was further processed at laboratory scale, to yield ideal whey and acid whey. The total amino acid composition and metabolome of each sample were analyzed, using high-performance cation exchange and a targeted combination of direct-injection mass spectrometry and reverse-phase liquid chromatography–tandem mass spectrometry (LC–MS/MS), respectively. The nitrogen composition of the products from each of the diets was similar, with one exception being the significantly higher nonprotein nitrogen content in TMR-derived skim milk powder than that from the GRS system. Total amino acid analysis showed significantly higher concentrations of glycine in GRS- and CLV-derived sweet whey and acid whey than in those from TMR. The cysteine contents of CLV-derived ideal whey and acid whey were significantly higher than for TMR, while the valine content of GRS-derived acid whey was significantly higher than TMR. The phenylalanine content of GRS-derived ideal whey was significantly higher than that from CLV. Metabolomic analysis showed significantly higher concentrations of the metabolites glutamine, valine, and phosphocreatine in each ingredient type derived from TMR than those from GRS or CLV, while the serine content of each GRS-derived ingredient type was significantly higher than that in TMR-derived ingredients. These results demonstrate that the type of bovine feeding system used can have a significant effect on the amino acid composition and metabolome of skim milk and whey powders and may aid in the selection of raw materials for product manufacture, while the clear separation between the samples gives further evidence for distinguishing milk products produced from different feeding systems based on LC–MS/MS.


1981 ◽  
Vol 32 (1) ◽  
pp. 67-73 ◽  
Author(s):  
I. G. Partridge

ABSTRACTThirty-six pigs were weaned at 21 days of age and were given diets supplemented with either dicalcium phosphate (DCP) or defluorinated rock phosphate (DFP) from 4 weeks of age until slaughter at 50 kg live weight. From 4 to 9 weeks of age the diets contained either skim milk powder (SKIM) or soya bean meal (SOY) as the main protein supplement. The dietary treatments were arranged in a 2 × 2 factorial design. From 9 weeks of age until slaughter, SOY was the only protein supplement used. Four 7-day measurements of phosphorus, calcium and nitrogen balance were made on each pig. Faecal endogenous P was estimated in two pigs per treatment by the 32P dilution method.There were no significant effects of P supplement on performance or on apparent absorption, true absorption or retention of P. The apparent absorption and retention of Ca were both 0·07 lower with DFP than with DCP in the period from 9 weeks of age to slaughter (P< 0·001).From 4 to 9 weeks of age there was no effect of protein supplement on performance. From 9 weeks of age to slaughter, when all pigs were given SOY, those which had received SKIM in the previous period grew slightly faster (P<0·05); their growth-rate overall, from 4 weeks of age to slaughter, was also significantly better (P <0·05).Pigs given SKIM showed a higher apparent absorption of P (P < 0·001) and higher apparent absorption (P<0·01) and retention (P<0·001) of both Ca and N from 4 to 9 weeks of age. Again, there were carry-over effects in the period from 9 weeks of age to slaughter, although the trends observed in the first period were reversed; pigs previously given SKIM showed significantly lower apparent absorption and retention of both P and Ca, and apparent absorption of N, than those previously given SOY.There were no significant effects of dietary treatments on the ash, Ca or P content of the fourth metacarpal.


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