The effect of level of protein on protein quality of lysine-deficient foods

1970 ◽  
Vol 48 (3) ◽  
pp. 188-192 ◽  
Author(s):  
E. Yanez ◽  
J. M. McLaughlan
Keyword(s):  
Dietary Protein ◽  
Multiple Dose ◽  
Wistar Rats ◽  
Protein Quality ◽  
Poor Quality ◽  
Relative Order ◽  
Slope Ratio ◽  
Weight Changes ◽  
Per Se

Nitrogen intakes and weight changes of male weanling Wistar rats fed two or more levels of test proteins or a non-protein diet for 2 weeks were determined. The slope-ratio plot for multiple-dose assays showed clearly that proteins markedly deficient in lysine yielded invalid assays. NPR values for lysine-deficient protein were markedly higher when determined at the 5% than at the 10% level of protein but foods limiting in methionine, threonine, or lysine and threonine yielded similar values at the two levels of dietary protein. It was concluded that protein quality per se is not a fixed value and depends on the level of protein fed even at low and moderate concentrations. When PER, NPR, and slope-ratio values for several samples were expressed as a percentage of the values for casein, NPR and slope-ratio methods gave almost identical results but PER yielded low values for poor quality proteins. However, the three methods rated the eight test proteins in the same relative order.

scholarly journals The effect of dietary protein on reproduction in the mare. VI. Serum progestagen concentrations during pregnancy

1998 ◽  
Vol 69 (4) ◽  
Author(s):  
F.E. Van Niekerk ◽  
C.H. Van Niekerk
Keyword(s):  
Dietary Protein ◽  
Protein Quality ◽  
Amino Acid Content ◽  
Protein Supplementation ◽  
The Other ◽  
Protein Diet ◽  
Sharp Decline ◽  
High Quality Protein ◽  
Essential Amino Acid Content

Sixty-four Thoroughbred and Anglo-Arab mares aged 6-12 years were used, of which 40 were non-lactating and 24 lactating. Foals from these 24 mares were weaned at the age of 6 months. Non-lactating and lactating mares were divided into 4 dietary groups each. The total daily protein intake and the protein quality (essential amino-acid content) differed in the 4 groups of non-lactating and 4 groups of lactating mares. The mares were covered and the effect of the quantity and quality of dietary protein on serum progestagen concentrations during pregnancy was studied. A sharp decline in serum progestagen concentrations was recorded in all dietary groups from Days 18 to 40 of pregnancy, with some individual mares reaching values of less than 4 ng/mℓ. Serum progestagen concentrations recorded in some of the non-lactating mares on the low-quality protein diet increased to higher values (p<0.05) than those of mares in the other 3 dietary groups at 35-140 days of pregnancy. A similar trend was observed for the lactating mares on a low-quality protein diet at 30-84 days of pregnancy. No such trends were observed in any of the other dietary groups. High-quality protein supplementation increased serum progestagen concentrations during the 1st 30 days of pregnancy. Lactation depressed serum progestagen concentrations until after the foals were weaned.

Protein Quality of Four Peanut Cultivars Grown at Two Locations

1981 ◽  
Vol 8 (1) ◽  
pp. 61-65
Author(s):  
Josephine Miller ◽  
Timothy H. Sanders
Keyword(s):  
North Carolina ◽  
Dietary Protein ◽  
Nutritional Quality ◽  
Room Temperature ◽  
Protein Quality ◽  
Control Diet ◽  
Peanut Meal ◽  
A Value ◽  
Peanut Cultivars

Abstract Four cultivars of peanuts (Florigiant, Florunner, Starr and Tamnut) grown at two locations (Lewiston, North Carolina (NC) and Stephenville, Texas (TX)) in the National Regional Variety Trials were evaluated for protein nutritional quality. Peanuts, blanched with a minimum of heat treatment and partially defatted on a Carver press, were extracted with hexane at room temperature. Rats were fed these peanut meals to provide 10% of dietary protein (N × 6.25). PER was calculated as the ratio of weight gained to protein consumed for the 28-day feeding period. Adjusted PER values of the 8 peanut meals ranged from 1.3 to 1.7 compared to a value of 2.5 for the casein control diet. No statistically significant differences existed in PER among the 4 cultivars grown in NC. Florunner and Tamnut produced in TX had lower PER values than Florigiant and Starr grown at the same location. Florigiant, Florunner, and Tamnut grown in NC had lower PER values than the same varieties from TX. Rats were fed diets with Florunner peanut meal supplemented with methionine, lysine, and threonine, singly and in all combinations, for 7-day periods. Differences in protein quality between NC and TX-produced peanuts were overcome by addition of methionine to the diets. When all three amino acids were added, peanut meal from both locations supported growth of young rats equal to that of casein.

Protein quality of Altex canola meal for juvenile chinook salmon (Oncorhynchus tshawytscha) considering dietary protein and 3,5,3′-triiodo-L-thyronine content

Aquaculture ◽  
1983 ◽  
Vol 34 (3-4) ◽  
pp. 213-238 ◽  
Author(s):  
David A. Higgs ◽  
Ulf H.M. Fagerlund ◽  
Jack R. McBride ◽  
M.Dianne Plotnikoff ◽  
Bakhshish S. Dosanjh ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Dietary Protein ◽  
Oncorhynchus Tshawytscha ◽  
Protein Quality ◽  
Canola Meal ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

The Quality of Fish Flour, Liver Meal, and Visceral Meal as Sources of Dietary Protein

1961 ◽  
Vol 18 (1) ◽  
pp. 85-91
Author(s):  
B. A. Larsen ◽  
W. W. Hawkins
Keyword(s):  
Dietary Protein ◽  
Protein Quality ◽  
Muscle Preparation ◽  
Better Than

Rats were used to test the digestibility and protein quality of dried preparations of muscle and viscera from cod and haddock, and of liver from cod.The digestibility of the preparations from muscle and viscera was good, and better than that of the preparation from liver.The metabolic utilization of nitrogen and the support of growth were good in the case of the muscle preparation, and poor in the case of the visceral and liver preparations.

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 Food safety, hypolipidemic and hypoglycemic activities, and in vivo protein quality of microalga Scenedesmus obliquus in Wistar rats

2020 ◽  
Vol 65 ◽  
pp. 103711 ◽  
Author(s):  
Monique Ellen Torres da Silva ◽  
Kely de Paula Correa ◽  
Marcio Arêdes Martins ◽  
Sérgio Luis Pinto da Matta ◽  
Hércia Stampini Duarte Martino ◽  
...  
Keyword(s):  
Food Safety ◽  
Wistar Rats ◽  
Protein Quality ◽  
Scenedesmus Obliquus

scholarly journals Effects of the amount and quality of dietary protein on nitrogen metabolism and heat production in growing pigs

1987 ◽  
Vol 58 (2) ◽  
pp. 277-285 ◽  
Author(s):  
M. F. Fuller ◽  
A. Cadenhead ◽  
G. Mollison ◽  
B. Seve
Keyword(s):  
Heat Production ◽  
Dietary Protein ◽  
Protein Quality ◽  
Latin Square ◽  
Fat Deposition ◽  
Growing Pigs ◽  
Daily Rate ◽  
Additional Protein ◽  
Made In

1. Eight pigs with a mean weight of 48 kg were given, at a constant daily rate, diets of low (0.15) or high (0.30) protein content, very deficient in lysine, with or without a supplement of L-lysine (3.7 g/kg).2. Measurements of nitrogen and energy metabolism were made in four successive 14 d periods in a Latin-square design.3. The rate of protein accretion was substantially increased by increases in both protein and lysine supply, but the rate of heat production was not significantly changed.4. The rate of fat deposition varied inversely with the rate of protein accretion, being reduced by both protein and lysine supplements.5. The relation between heat production and protein accretion (allowing for a constant energy cost of fat deposition) suggested that heat production increased with additional protein accretion less when protein quality was improved than when more protein was given.

scholarly journals Protein quality of feeding-stuffs

1972 ◽  
Vol 27 (1) ◽  
pp. 7-17 ◽  
Author(s):  
K. J. Carpenter ◽  
I. McDonald ◽  
W. S. Miller
Keyword(s):  
Weight Gain ◽  
Standard Error ◽  
Protein Quality ◽  
Collaborative Study ◽  
Live Weight ◽  
Slope Ratio ◽  
Weight Gains ◽  
The Mean

1. The reproducibility of an assay for methionine based on live-weight gains in young chicks has been tested in a collaborative study in six laboratories.2. Results were analysed by the slope-ratio procedure and, in general, the assays were statistically valid. The variability between laboratories was similar to that found in previous studies of variablity within a single assay in one laboratory.3. With the combined estimates from five or six laboratories the standard error of the estimates was apporoximately 10% of the mean. Expressing response as‘g gain/g food eaten’ gave no more precision than using ‘weight gain’ alone, but is nevertheless thought to be less open to error due to apetite effects.4. The experiments have shown that materials can be ranked consistently, but that the absolute estimates of potency varied between assays and further improvements are desirable if potency estimates are to be used for the calibration of in vitro procedures of protein evaluation.

scholarly journals The influence of dietary protein quality on midgut and brain proteins in Morimus funereus larvae

2004 ◽  
Vol 56 (1-2) ◽  
pp. 9-13 ◽  
Author(s):  
Larisa Ilijin ◽  
Milena Jankovic-Tomanic ◽  
Marija Mrdakovic-Mitic ◽  
Milena Vlahovic ◽  
Vesna Peric-Mataruga ◽  
...  
Keyword(s):  
Body Mass ◽  
Dietary Protein ◽  
Artificial Diet ◽  
Protein Quality ◽  
Soya Protein ◽  
Brain Proteins ◽  
Morimus Funereus

The response of starved Morimus funereus larvae refed with an artificial diet (Galford, 1967) was examined in the present paper. Larvae were offered diets varying in protein quality (soya protein, casein, and gelatin). Refeeding with the Galford diet (G I) and two modifications of it in which soya protein was supplemented with casein (G II) or gelatin (G III) led to an increase of body mass. Different protein quality in the nutritive substrate influenced both the quantity and quality of midgut and brain proteins.

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