scholarly journals Digestible protein requirements for maintenance, growth, and efficiency of protein utilization in pacu (Piaractus mesopotamicus) juveniles: an exponential nitrogen utilization model

2021 ◽  
Vol 49 (4) ◽  
pp. 608-619
Author(s):  
Cleber F.M. Mansano ◽  
Edney P. Da Silva ◽  
Kifayat U. Khan ◽  
Beatrice I. Macente ◽  
Thiago M.T. Nascimento ◽  
...  

The present study aimed to estimate digestible protein (DP) requirements for maintenance and growth and assess the efficiency of protein utilization in pacu (Piaractus mesopotamicus) juveniles. A complete randomized design consisted of seven treatments, and five replicates (tanks) per treatment was used. After a one-week acclimation period, 350 pacu juveniles of 27.48 ± 1.8 g (initial average body weight - BW) were equally distributed among 35 tanks (10 fish per tank) of 450 L. Fish were fed with seven graded digestible protein levels (64.5, 111.8, 164.6, 217.1, 264.4, 316.2 and 369.5 g kg-1) three times a day until apparent satiation for 120 days. The monomolecular model parameters including nitrogen maintenance requirement (NMR) (37.76 mg BW0.67 kg-1 d-1), daily nitrogen deposition (ND) (194.8 mg BW0.67 kg-1 d-1), and protein intakes (based on metabolic BW) of 1638, 1902, and 2241 mg kg-1BW0.67 d-1 for 75, 80 and 85% maximum theoretical nitrogen retention (NRmaxT), respectively and the efficiency of protein utilization (529×10-6) were estimated through the relationship between nitrogen intake (NI) and ND. The digestible protein requirements for 75, 80, and 85% of NRmaxT were estimated as 187, 217, and 256 g kg-1 respectively by the monomolecular model based on the daily feed intake of 2% of live BW of pacu juveniles.

1962 ◽  
Vol 40 (12) ◽  
pp. 1663-1670 ◽  
Author(s):  
A. B. Morrison ◽  
Z. I. Sabry ◽  
J. A. Campbell

The effects of deficiency of vitamins and minerals on net protein utilization (N.P.U.) values obtained with casein at various protein levels were studied in growing male rats. Animals given diets without added vitamins and minerals lost weight and had reduced N.P.U. values. Carcass analysis data indicated that nitrogen retention occurred in these animals concomitantly with loss of body water and fat. In further studies, a direct relationship was observed between N.P.U. values and the dietary lysine content, at lysine concentrations varying from 0.32 to 0.72%. The use of various control groups to estimate endogenous and metabolic nitrogen losses gave similar N.P.U. values.


1972 ◽  
Vol 14 (1) ◽  
pp. 57-67 ◽  
Author(s):  
G. M. Babatunde ◽  
M. J. Olomu ◽  
V. A. Oyenuga

SUMMARYFeeding trials were carried out at different times of the year to determine the optimum crude protein requirements of weaner and growing pigs, using principally the locally available ingredients. The animals used were 96 weaners and 113 growing pigs of the Large White and Landrace breeds of average initial weights of about 9 kg and 41 kg respectively. Test diets contained protein levels ranging from 12% to 24% on a dry-matter basis, and the pigs were mostly group-fed ad libitum except for one trial. Average daily gains, efficiency of feed utilization, apparent nitrogen retention and digestibility, and feed cost per kg of body gain were measured. In a humid tropical environment, such as Ibadan, the optimum crude protein requirement for weaner pigs from 9 kg to 34 kg live weight is between 22 % and 24 % of dry matter, while that for the fattening pigs from 41 kg to 82 kg live weight is between 18% and 21% of dry matter.


1957 ◽  
Vol 37 (2) ◽  
pp. 157-167 ◽  
Author(s):  
G. J. Brisson ◽  
H. M. Cunningham ◽  
S. R. Haskell

The protein and energy requirements of pre-weanling dairy calves were studied through the use of growth and balance trial techniques. Various levels of protein and energy were fed in both purified and semi-purified diets. The nitrogen retention of calves fed diets adequate in protein was 3.22 gm. per 100 gm. of gain in body weight. Energy requirement for maintenance was 44.7 digestible Calories per kg. of body weight per day and 268 digestible Calories were required per 100 gm. of gain in weight. These factors, along with previously determined values for endogenous nitrogen, were used to calculate the practical digestible energy and apparent digestible protein requirements of dairy calves.


1962 ◽  
Vol 40 (1) ◽  
pp. 1663-1670
Author(s):  
A. B. Morrison ◽  
Z. I. Sabry ◽  
J. A. Campbell

The effects of deficiency of vitamins and minerals on net protein utilization (N.P.U.) values obtained with casein at various protein levels were studied in growing male rats. Animals given diets without added vitamins and minerals lost weight and had reduced N.P.U. values. Carcass analysis data indicated that nitrogen retention occurred in these animals concomitantly with loss of body water and fat. In further studies, a direct relationship was observed between N.P.U. values and the dietary lysine content, at lysine concentrations varying from 0.32 to 0.72%. The use of various control groups to estimate endogenous and metabolic nitrogen losses gave similar N.P.U. values.


1977 ◽  
Vol 37 (2) ◽  
pp. 143-155 ◽  
Author(s):  
J. R. Carr ◽  
K. N. Boorman ◽  
D. J. A. Cole

1. Published results have been used to study the relationships between nitrogen retention (NR), body-weight (W) and N intake in the pig.2. The general decrease in maximal NR (g/d per kg W0.75) with increasing W (kg) was curvilinear for values of W from 1.5 to 45: NR = 3.324−0.098 W+0.001 W2; and rectilinear for values of W from 45 to 165: NR = 1.252−0.006 W. Values for protein requirements derived from these equations agreed closely with published estimates.3. The slopes of the curves for NR (g/d per kg W0.75) v. N intake (g/d) decreased as W (kg) increased from about 2.5 to 190. After extrapolation to a proposed common intercept on the NR axis of -150 mg N/d per kg W0.75, regression analysis of the intercepts of these curves on the N-intake axis v. W gave an estimate of N requirements for maintenance of 246±19 mg/d per kg W0.75.4. The results also indicated that at low N intakes net protein utilization (N retention+ total obligatory N losses ÷ N intake) was essentially independent of W, whereas the gross efficiency of N utilization (NR ÷ N intake) was influenced by both W and N intake.


Aquaculture ◽  
2018 ◽  
Vol 495 ◽  
pp. 794-802 ◽  
Author(s):  
Fernando Barreto-Curiel ◽  
Ulfert Focken ◽  
Louis R. D'Abramo ◽  
Jose A. Cuarón ◽  
María Teresa Viana

1989 ◽  
Vol 66 (3) ◽  
pp. 1280-1286 ◽  
Author(s):  
G. Brandenberger ◽  
M. Follenius ◽  
J. Di Nisi ◽  
J. P. Libert ◽  
C. Simon

To assess the effect of continuous heat exposure on the nocturnal patterns of renin, aldosterone, adrenocorticotropic hormone (ACTH), and cortisol, six young men were exposed to thermoneutral environment for 5 days, followed by a 5-day acclimation period in a hot dry environment (35 degrees C). Blood was collected at 10-min intervals during the second night at thermoneutrality (N0) and during the first (N1) and the last (N5) nights of heat exposure. Polygraphic recordings of sleep were scored according to established criteria. Continuous heat exposure led to progressive decreases in the 24-h urinary volume and in Na excretion, whereas urinary osmolality increased. After 5 days of uninterrupted heat, significant increases were found in plasma volume (P less than 0.05), osmolality (P less than 0.01), plasma Na (P less than 0.01), and protein levels (P less than 0.05). Sweat gland output increased during the first 3 days and then declined without any concomitant increases in body temperature. Compared with N0, there were no differences in plasma renin activity (PRA) and aldosterone (PA) profiles during N1 at 35 degrees C. However, during N5 the mean PRA and PA levels were significantly (P less than 0.05) enhanced, and their nocturnal oscillations were amplified (P less than 0.05). This amplification occurred mainly in the second part of the night when regular rapid-eye-movement and non-rapid-eye-movement sleep cycles were observed, leading to a general upward trend in the nocturnal profiles. The relationship between the nocturnal PRA oscillations and the sleep cycles was not modified. ACTH and cortisol patterns were not affected by continuous heat exposure.(ABSTRACT TRUNCATED AT 250 WORDS)


2020 ◽  
Vol 17 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Dan Wang ◽  
Zhifu Fei ◽  
Song Luo ◽  
Hai Wang

Objectives: Alzheimer's disease (AD), also known as senile dementia, is a common neurodegenerative disease characterized by progressive cognitive impairment and personality changes. Numerous evidences have suggested that microRNAs (miRNAs) are involved in the pathogenesis and development of AD. However, the exact role of miR-335-5p in the progression of AD is still not clearly clarified. Methods: The protein and mRNA levels were measured by western blot and RNA extraction and quantitative real-time PCR (qRT-PCR), respectively. The relationship between miR-335-5p and c-jun-N-terminal kinase 3 (JNK3) was confirmed by dual-luciferase reporter assay. SH-SY5Y cells were transfected with APP mutant gene to establish the in vitro AD cell model. Flow cytometry and western blot were performed to evaluate cell apoptosis. The APP/PS1 transgenic mice were used as an in vivo AD model. Morris water maze test was performed to assess the effect of miR- 335-5p on the cognitive deficits in APP/PS1 transgenic mice. Results: The JNK3 mRNA expression and protein levels of JNK3 and β-Amyloid (Aβ) were significantly up-regulated, and the mRNA expression of miR-335-5p was down-regulated in the brain tissues of AD patients. The expression levels of miR-335-5p and JNK3 were significantly inversely correlated. Further, the dual Luciferase assay verified the relationship between miR-335- 5p and JNK3. Overexpression of miR-335-5p significantly decreased the protein levels of JNK3 and Aβ and inhibited apoptosis in SH-SY5Y/APPswe cells, whereas the inhibition of miR-335-5p obtained the opposite results. Moreover, the overexpression of miR-335-5p remarkably improved the cognitive abilities of APP/PS1 mice. Conclusion: The results revealed that the increased JNK3 expression, negatively regulated by miR-335-5p, may be a potential mechanism that contributes to Aβ accumulation and AD progression, indicating a novel approach for AD treatment.


1991 ◽  
Vol 334 (1270) ◽  
pp. 161-170 ◽  

Many studies have examined the proportion of time that primates devote to feeding on various types of food, but relatively little is known about the intake rates associated with each food. However, the nutritional consequences of foraging can only be interpreted by comparing nutrient intakes with estimated nutrient requirements. The energy available to primates from ingested foods will depend both on the composition of the food and the extent to which various constituents, including fibre fractions, are digested. Both human and non-human primates have relatively low requirements for protein as a consequence of slow growth rates, small milk yields and relatively dilute milk. Because the nutrient demands of growth and reproduction are spread out over time, it appears that primates do not need to seek out foods of particularly high nutrient density, except perhaps during weaning. Although food selection in some species of primates appears to be correlated with the protein concentration of foods, it is unlikely that high dietary protein levels are required, at least when foods of balanced amino acid composition (such as leaves) are included in the diet.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satoshi Miyamoto ◽  
Zu Soh ◽  
Shigeyuki Okahara ◽  
Akira Furui ◽  
Taiichi Takasaki ◽  
...  

AbstractThe need for the estimation of the number of microbubbles (MBs) in cardiopulmonary bypass surgery has been recognized among surgeons to avoid postoperative neurological complications. MBs that exceed the diameter of human capillaries may cause endothelial disruption as well as microvascular obstructions that block posterior capillary blood flow. In this paper, we analyzed the relationship between the number of microbubbles generated and four circulation factors, i.e., intraoperative suction flow rate, venous reservoir level, continuous blood viscosity and perfusion flow rate in cardiopulmonary bypass, and proposed a neural-networked model to estimate the number of microbubbles with the factors. Model parameters were determined in a machine-learning manner using experimental data with bovine blood as the perfusate. The estimation accuracy of the model, assessed by tenfold cross-validation, demonstrated that the number of MBs can be estimated with a determinant coefficient R2 = 0.9328 (p < 0.001). A significant increase in the residual error was found when each of four factors was excluded from the contributory variables. The study demonstrated the importance of four circulation factors in the prediction of the number of MBs and its capacity to eliminate potential postsurgical complication risks.


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