Apparent Nitrogen Digestibility Data: AACC–ASTM Collaborative Study

1984 ◽  
Vol 67 (3) ◽  
pp. 621-622
Author(s):  
Muriel L Happich ◽  
C E Bodwell ◽  
L Ross Hackler ◽  
John G Phillips ◽  
Philip H Derse ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Adaptation Period ◽  
Efficiency Ratio ◽  
Protein Ratio ◽  
Protein Sources ◽  
Protein Levels ◽  
Collaborative Studies ◽  
Laboratory Group ◽  
Protein Diets ◽  
Net Protein

Abstract Apparent nitrogen digestibility data were obtained from 4 laboratories for 6 protein sources and 2 diet levels, 6 and 10% protein, after a 2-day adaptation period during the AACC–ASTM protein efficiency ratio (PER) and net protein ratio (NPR) collaborative studies. For 5 protein sources fed as 10% of the diet, the interlaboratory variation as measured by coefficient of variation (CV) values was low (1.5–3.5%), indicating high precision of the method. Wheat flour (6% protein diet) had the highest variation and, therefore, the lowest precision (CV of 7.10%). The interlaboratory variation (CV value) for 3 of the 4 laboratories was considerably lower, less than half that for the 4 laboratories. An analysis of variance of apparent nitrogen digestibility data indicated significant (P <0.05) effects for the 4-Iaboratory group due to laboratories and protein diets at both 10 and 6% protein levels, and for the 3-laboratory group at the 10% protein level. The 3-laboratory ANOVA for the 6% diets indicated a significant effect (P <0.05) due to diet only.

Net Protein Ratio Data: AACC-ASTM Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 255-262
Author(s):  
Muriel L Happich ◽  
C E Bodwell ◽  
L Ross Hackler ◽  
John G Phillips ◽  
Philip H Derse ◽  
...  
Keyword(s):  
Vegetable Protein ◽  
Corn Oil ◽  
Collaborative Study ◽  
Feed Consumption ◽  
Peanut Flour ◽  
Test Diet ◽  
Protein Ratio ◽  
Protein Sources ◽  
Textured Vegetable Protein ◽  
Net Protein

Abstract Seven- and 14-day net protein ratio (NPR) data were obtained from 7 laboratories for 6 protein sources: ANRC casein, lean beef, Iactalbumin, textured vegetable protein, and peanut flour were fed as 10% protein (N × 6.25) in the test diet. Wheat flour, casein, and textured vegetable protein were fed as 6% protein (N × 6.25) in the test diet. Weighed dry ingredients for each diet were sent to each collaborator, who mixed the dry ingredients, then added specified amounts of corn oil and water and mixed each complete diet thoroughly. Rats were adapted for 0, 2, or 4 days, and then were fed the test diets for 28 days for protein efficiency ratio (PER) diets. The animal weight gain and feed consumption data obtained after 7 or 14 days of feeding were used to calculate NPR values. Analyses of data were done before [net protein ratio (NPR)] and after (R-NPR [relative-NPR]) adjustment of the data from each laboratory by its results for the reference protein casein. From the analysis of variance for NPR, significant (P <0.05) interactions were observed among laboratories, protein sources, and adaptation times of the animals (0,2, or 4 days). Inter- and intralaboratory variability were decreased by use of 14-day values compared with 7- day values. Adjustment of the NPR data to R-NPR did not lower the intralaboratory variability but did lower the interlaboratory variability of the data. Increasing adaptation time did not consistently decrease interlaboratory or intralaboratory variability or decrease coefficients of variation (CV) of R-NPR values. The 14-day NPR inter- and intralaboratory variations for the 10 % protein diet over all factors (5 protein diets, 3 adaptation periods, and 7 laboratories), as measured by CV values, were 13.2 and 7.7%, respectively. The corresponding R-NPR values were 9.2 and 8.0%, respectively.

NUTRITIONAL EVALUATION OF AN ENSILED PRODUCT FROM FISH

1965 ◽  
Vol 43 (11) ◽  
pp. 1879-1883 ◽  
Author(s):  
M. A. Krishnaswamy ◽  
S. B. Kadkol ◽  
G. D. Revankar
Keyword(s):  
Protein Efficiency Ratio ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Efficiency Ratio ◽  
Protein Ratio ◽  
Protein Utilization ◽  
Streptococcus Lactis ◽  
Available Lysine ◽  
Net Protein

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.

Protein Efficiency Ratio: AACC/ASTM Collaborative Study

1984 ◽  
Vol 67 (1) ◽  
pp. 66-77
Author(s):  
L Ross Hackler ◽  
Clarence E Bodwell ◽  
Muriel L Happich ◽  
John G Phillips ◽  
Phillip H Derse ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Vegetable Protein ◽  
Protein Efficiency Ratio ◽  
Collaborative Study ◽  
Animal Experiments ◽  
Peanut Flour ◽  
Efficiency Ratio ◽  
Protein Sources ◽  
Lean Beef ◽  
Textured Vegetable Protein

Abstract Eight laboratories (7 of the laboratories conducted animal experiments) participated in a collaborative study to standardize some of the methodology associated with animal bioassays for determining protein efficiency ratios and to suggest improvements which would reduce the variation among laboratories. One-, 2-, 3-, and 4-week protein efficiency ratios (PER) with 0-, 2-, or 4-day adaptation periods were obtained from each laboratory, respectively, for 6 protein sources: casein, lean beef, lactalbumin, textured vegetable protein, peanut flour, and wheat flour. Analyses were computed for PER and adjusted PER (APER). From the analysis of variance for PER and APER, significant (P < 0.05) effects were observed due to laboratories, adaptation length, protein sources, and/or interactions among these variables. In general, APER values show much less variation among laboratories than PER values. The reproducibility and repeatability variances were significantly (P < 0.05) greater for an assay length of 2 weeks than they were for 3- or 4-week assays. Two protein sources, casein and textured vegetable protein, were fed at both high (10%) and low (6%) levels of protein. Analysis of variance of PER values shows a significant (P < 0.05) laboratory by protein level by assay length interaction.

Assessment of Rat Growth Methods for Estimating Protein Quality: Interlaboratory Study

1980 ◽  
Vol 63 (3) ◽  
pp. 462-467 ◽  
Author(s):  
J Murray Mclaughlan ◽  
G Harvey Anderson ◽  
L Ross Hackler ◽  
Douglas C Hill ◽  
G Richard Jansen ◽  
...  
Keyword(s):  
Protein Efficiency Ratio ◽  
Protein Quality ◽  
Interlaboratory Study ◽  
Official Method ◽  
Efficiency Ratio ◽  
Protein Ratio ◽  
Reference Protein ◽  
Rat Growth ◽  
Growth Methods ◽  
Net Protein

Abstract An interlaboratory study involving protein efficiency ratio (PER), net protein ratio (NPR), relative NPR (RNPR) and relative nitrogen utilization (RNU) was carried out. Six collaborators assayed 6 samples, including casein plus methionine which was used as a reference protein. Collaborators prepared their own diets and analyzed the diets for nitrogen. Test proteins were added at the 8% level (N × 6.25). PER values varied more than NPR values which varied more than either RNPR or RNU. RNU and RNPR produced almost identical values, but RNPR remains the official method of choice, because it is a well established method.

Influence of Salinity on Protein Requirements of Rainbow Trout (Salmo gairdneri) Fingerlings

1973 ◽  
Vol 30 (12) ◽  
pp. 1867-1873 ◽  
Author(s):  
I. H. Zeitoun ◽  
J. E. Halver ◽  
D. E. Ullrey ◽  
P. I. Tack
Keyword(s):  
Rainbow Trout ◽  
Protein Efficiency Ratio ◽  
Salmo Gairdneri ◽  
Efficiency Ratio ◽  
Protein Requirements ◽  
Protein Levels ◽  
Major Consequence ◽  
Percentage Weight ◽  
Net Protein ◽  
Representative Samples

Rainbow trout (Salmo gairdneri) juveniles maintained at 10 and 20 ppt salinity were fed seven diet treatments from 30 to 60% protein in 5% increments for 10 weeks. The fish were stocked in cones, initially 50 fish per cone. Biweekly weights of diets and fish were determined and mortality was recorded daily. Percentage weight gain, gross diet efficiency, and protein efficiency ratio (P.E.R.) were computed. The minimum protein levels required for fish to achieve highest performance using these criteria were 40 and 45% for those maintained at 10 and 20 ppt, respectively. Mortality was significantly (P < 0.05) higher for fish maintained at the higher salinity. Analyses of the fish carcasses were conducted at the beginning and end of the experiment on representative samples to estimate the grams protein retained and apparent net protein utilization (N.P.U.) to verify the above findings. All the available data showed that dietary protein was of major consequence on all measurements until the minimum required level of protein in the diet was reached, while salinity was of minor consequence. P.E.R. and apparent N.P.U. were 2.10 and 34.4, respectively, for casein diets at the 40% protein level.

Evaluation of Infant Formula Protein Quality: Comparison of In Vitro with In Vivo Methods

1988 ◽  
Vol 71 (2) ◽  
pp. 353-357
Author(s):  
David A Harris ◽  
Robert A Burns ◽  
Rida Ali
Keyword(s):  
Infant Formula ◽  
Protein Efficiency Ratio ◽  
Protein Quality ◽  
Infant Formulas ◽  
Efficiency Ratio ◽  
Protein Ratio ◽  
In Vitro Methods ◽  
Net Protein

Abstract Two-week protein efficiency ratio (2-wk PER), net protein ratio (NPR), calculated-protein efficiency ratio (C-PER), and discriminant computed- protein efficiency ratio (DC-PER) of milk- and soy-based infant formulas were compared to a 4-week protein efficiency ratio (PER). Expressed relative to ANRC casein, 2-week PER and NPR correlated significantly (P &lt; 0.01, r = 0.90) with PER. Although C-PER and DC-PER also correlated significantly (P &lt; 0.01) with PER, r = 0.71 and r = 0.87, respectively, these in vitro methods did not distinguish differences in protein quality among soy-based infant formulas. C-PER and DC-PER, as currently designed, are not applicable to the measurement of protein quality for all types of infant formulas.

Corrected Relative Net Protein Ratio (CRNPR) Method Based on Differences in Rat and Human Requirements for Sulfur Amino Acids

1985 ◽  
Vol 68 (4) ◽  
pp. 689-693 ◽  
Author(s):  
Ghulam Sarwar ◽  
Robert W Peace, ◽  
Herbert G Botting
Keyword(s):  
Amino Acids ◽  
Correction Factor ◽  
Protein Quality ◽  
Soybean Protein ◽  
Peanut Meal ◽  
Sulfur Amino Acids ◽  
Protein Ratio ◽  
Growing Rats ◽  
Protein Diets ◽  
Net Protein

Abstract The requirement for sulfur amino acids was calculated for growing rats fed 8% protein diets. The r a t and human requirements for sulfur amino acids were compared and a correction factor was developed to reflect the differences. This correction factor was used to determine corrected relative net protein ratio (CRNPR) values for a number of potential meat extenders and their mixtures with beef. The methionine + cystine requirement of growing rats was estimated to be 4% of protein for 8% protein diets. The methionine + cystine requirement of rats was about 50% higher than that of humans (2.65% of protein). Based on this comparison (rat/human), a correction factor of 1.5 was developed to correct RNPR values of those protein products that were deficient in sulfur amino acids for r a t growth. The CRNPR values of beef, casein, soybean protein products, pea concentrate, and peanut meal were 100,100, 91-97, 75, and 73, respectively. Mixtures (50:50 protein basis) of beef with casein, soybean concentrate, soybean isolate, pea concentrate, peanut meal, rapeseed concentrate, rapeseed isolate, sunflower isolate, or wheat gluten were equal to beef in CRNPR values. The CRNPR method is a good predictor of protein quality for humans of those protein products that are deficient in sulfur amino acids.

The Relative Nitrogen Utilization Method for Evaluating Protein Quality

1976 ◽  
Vol 59 (1) ◽  
pp. 42-45 ◽  
Author(s):  
J Murray McLaughlan
Keyword(s):  
Protein Quality ◽  
Poor Quality ◽  
Nitrogen Utilization ◽  
The Other ◽  
Efficiency Ratio ◽  
Protein Ratio ◽  
Test Protein ◽  
Reference Protein ◽  
Net Protein

Abstract A single-dose rat assay for protein quality called relative nitrogen utilization (RNU) is described. The method includes a factor for the protein utilized for maintenance. The protein quality of the test protein is expressed as a per cent of the value for Iactalbumin, the reference protein. For good quality proteins RNU gives results that are similar to those obtained by net protein ratio and relative protein value; for poor quality proteins RNU results fall between values by the other 2 methods. The protein efficiency ratio (PER) gives much lower values for poor quality proteins than any of the other 3 aforementioned methods and is influenced more by both level of protein and lipid in the diet. RNU is a more precise assay than PER as judged by the coefficient of variation.

scholarly journals Optimal Dietary Protein Requirement for Juvenile Sesarmid Crab (Episesarma singaporense)

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 998
Author(s):  
Chanyut Sudtongkong ◽  
Karun Thongprajukaew ◽  
Suktianchai Saekhow
Keyword(s):  
Dietary Protein ◽  
Sea Water ◽  
Protein Diet ◽  
Efficiency Ratio ◽  
Protein Requirement ◽  
Protein Levels ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Improvement In Survival ◽  
Protein Diets

The optimal dietary protein requirement for sesarmid crabs (Episesarma singaporense) was investigated. Juvenile E. singaporense, individually reared in plastic glasses containing 250 mL sea water, were fed five fish meal-soybean meal-microbound diets variously containing dietary protein levels of 30%, 35%, 40%, 45% and 50% for six weeks. A completely randomized design was used in the experiment, comprising five treatments with 60 crabs in each. At the end of the experiment, a significant improvement in survival was observed in all treatments relative to the diet containing 30% dietary protein (p < 0.05) while the growth performance parameters did not differ across the five dietary groups. A significantly higher protein efficiency ratio was observed in the E. singaporense crabs receiving 45% dietary protein relative to the remaining treatments. The specific activities of the digestive enzymes, pepsin-like, trypsin, amylase, and lipase, and the amylase to trypsin ratio fluctuated across the five treatments, but that of chymotrypsin remained consistent, suggesting different nutritional responses to the various dietary protein levels. The crabs receiving the 45% protein diet had significantly higher in essential amino acid (EAA) profiles followed by the 40% protein diet, although some EAA values were only moderate. The pattern for the non-EAA (NEAA) was reversed, and the ΣEAA/ΣNEAA ratio was higher in the crabs receiving the 45% protein diets relative to the other treatments. Based on our investigations, the optimal dietary protein requirement achieving desirable characteristics of juvenile E. singaporense crabs was 45%. This finding would be a useful guideline in preparing artificial diets for the mariculture of this species.

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