The relationship between protein, essential amino acids and energy requirements of broiler chickens fed practical diets

1977 ◽  
Vol 17 (89) ◽  
pp. 920 ◽  
Author(s):  
N Guirguis

The relationship between dietary protein, essential amino acids (EM) and energy was examined in two experiments using male broiler chicks fed practical diets to eight weeks of age. All diets contained a balanced proportion of ten EAA which was maintained over various treatments. Growth of birds was closely related to the EAA content of the diet and poorly related to dietary protein content. When the dietary concentration of ten EAA was treated as a combined unit and expressed as proportion of diet, 7.6 per cent EAA in an 18 per cent protein starter diet and 5.8 per cent EAA in a 16 per cent protein finisher diet were adequate to support maximal growth of male birds to eight weeks of age. Feed intakes were reduced as energy concentrations increased in diets regardless of protein content of diets.

1981 ◽  
Vol 61 (3) ◽  
pp. 769-773 ◽  
Author(s):  
MARY-LOU FISHER ◽  
S. LEESON ◽  
W. D. MORRISON ◽  
J. D. SUMMERS

Feather-sexed broiler chicks were reared in litter floor pens in a controlled environment building and offered mash diets meeting National Academy of Science-National Research Council specifications. Ten birds of each sex were killed at weekly intervals and individual feather weight recorded. These feathers were analyzed for crude protein and essential amino acids. From within five replicate pens of each sex, litter was removed weekly from 28 to 49 days, and molted feathers removed, cleaned and weighed. Feather weight was consistently correlated (P < 0.05) with body weight only from 5–7 wk of age. Females lost consistently more feathers than male birds, with this differential being a factor of 3.5. The methionine content of feathers decreased with age, while that of threonine, isoleucine and valine increased with age. The data are presented for use in model prediction of broiler amino acid requirements.


Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2024 ◽  
Author(s):  
Kiran Javed ◽  
Stefan Bröer

Dietary protein restriction has beneficial impacts on metabolic health. B0AT1 (SLC6A19) is the major transporter of neutral amino acids at the intestinal epithelia and absorbs the bulk of the diet-derived neutral amino acids from the intestinal lumen. It also reabsorbs neutral amino acids in the renal proximal tubules. Mice lacking B0AT1 show cellular outcomes of protein restriction, such as high FGF21 levels and low mTORC1 activity. Moreover, they have improved glucose homeostasis and resist diet-induced obesity. In this study, we investigated the relationship between protein restriction and dietary protein intake in C57Bl6/J wild-type (wt) and SLC6A19-knockout (SLC6A19ko) mice. When SLC6A19ko mice were fed diets containing 5%, 25%, or 52% of their total calories derived from protein, no differences in food intake or weight gain were observed. All essential amino acids significantly positively correlated with increasing dietary casein content in the wt mice. The SLC6A19ko mice showed reduced postprandial levels of essential amino acids in plasma, particularly following high-protein diets. Upon fasting, essential amino acids were the same in the wt and SLC6A19ko mice due to reduced amino acid catabolism. Bacterial metabolites originating from amino acid fermentation correlated with the dietary protein content, but showed a complex profile in the blood of the SLC6A19ko mice. This study highlights the potential of SLC6A19 as a knock-out or inhibition target to induce protein restriction for the treatment of metabolic disorders.


2021 ◽  
Vol 7 (2) ◽  
pp. 97-105
Author(s):  
M. C. Njike ◽  
L. I. Ndife

An experimental design consisting of four or three protein levels and three energy levels were used to determine the optimum protein and energy requirements for starting broilers (0-6) weeks of age and finishing broilers (6-10) weeks of age. For the starting phase, four protein levels (20, 23, 24 and 26%) and three energy levels (2800, 3000 and 3200 Kcal ME/kg) were employed, while in the finishing phase three protein levels (18, 20 and 22%) and the same three energy levels as in the starting phase were used. In the two experiments growth rate and feed efficiency improved as protein level increased. The 3000 Keal ME/kg energy level appeared to be the best for maximal growth. Of the four protein levels used for the starting phase, the minimum required for growth was clearly shown to be 23% while 20% was minimum required for the finishing phase. The results of the present studies indicate that the following minimal protein and metabolizable energy levels were required for broiler chicks in the tropics: 23–24% protein with energy level of 2800-3000 Kcal ME/kg for the starting phrase and 20% protein and energy level of 2800 - 3000 Kcal ME/kg for the finishing phase.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sonia Yun Liu ◽  
Shemil P. Macelline ◽  
Peter V. Chrystal ◽  
Peter H. Selle

AbstractThe prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein (CP) diets and sustainable chicken-meat production may be best achieved. Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions; moreover, they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents. The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed. The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids. Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine, this emphasises the value of so-called “non-essential” amino acids. Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed, although the functions of insulin in avian species require clarification. Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets; if so, the identification of the underlying reasons for this difference should be instructive. Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance. Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance. If progress in these directions can be realised, then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.


2014 ◽  
Vol 43 (6) ◽  
pp. 301-309 ◽  
Author(s):  
Juliana Beatriz Toledo ◽  
Antonio Claudio Furlan ◽  
Paulo Cesar Pozza ◽  
Jocasta Carraro ◽  
Gabriel Moresco ◽  
...  

2020 ◽  
Vol 2 (2) ◽  
pp. 77-85
Author(s):  
Slamet Hadi Kusumah ◽  
Robi Andoyo ◽  
Tita Rialita

Stunting children need food intake with higher protein and essential amino acids such as lysine and leucine than normal children. Red Beans (Phaseolus Vulgaris L.) and Green Beans (Phaseolus Radiatus L.) have protein content, respectively 22.07 ± 0.13% and 19.99 ± 0.07%, and are rich in essential amino acids lysine and leucine needed by a stunting child. The Development of food products with high protein concentrations (high protein food) such as isolates/protein concentrates is an important subject that must be done. This study aims to determine the technique of isolating red bean and green bean protein through extraction and deposition methods at isoelectric pH. The research method used is an experimental method with descriptive data analysis. Identification of isoelectric pH of red bean and green bean protein is done through electrophoretic mobility (cm2/Vs) testing on samples that have been conditioned at 3 different depositional pHs namely pH 3.00, 4.00, and 5.00. The results showed the isoelectric pH value of red bean and green bean protein, namely pH 4.56 and pH 4.81 respectively, where the pH had electrophoretic mobility values equal to zero. The process of isolating red bean and green bean protein produces protein powder with a protein content of 79.22 ± 0.06% and 80.69 ± 0.06%, respectively. Based on the weight yield, red bean and green bean protein concentrate powder had a yield of 14.88% and 16.75%, respectively.


1963 ◽  
Vol 43 (1) ◽  
pp. 65-67 ◽  
Author(s):  
D. R. Clandinin ◽  
Louise Bayly

The protein content and the distribution of essential amino acids in the protein of six varieties or strains of rapeseed grown at three widely separated locations in Alberta, Beaverlodge, Edmonton and Lethbridge, were studied. Differences in protein content and amino acid distribution in the protein of the seed attributable to varietal or strain effects were noted. Turkish and Polish rapeseed were significantly lower in protein content than rapeseed of the Argentine variety. The Argentine variety and the two strains of Argentine-type studied were significantly lower in lysine than the Polish variety. Station differences in protein content approached significance at the 5 per cent level while location had a highly significant effect on the lysine content of the protein of the seed and significant effects on the histidine, arginine, phenylalanine and leucine content.


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