Limitations of the comparative slaughter technique in determining protein requirements for growth

Author(s):  
L.O. Tedeschi ◽  
G.E. Carstens
2021 ◽  
Vol 8 ◽  
Author(s):  
Anaiane P. Souza ◽  
Julián A. C. Vargas ◽  
Marcia H. M. R. Fernandes ◽  
Amélia K. Almeida ◽  
Kleber T. Resende ◽  
...  

This study aimed to estimate the protein requirements for the maintenance of growing Saanen goats of different sexes from 5 to 45 kg of body weight (BW) using two methods and applying a meta-analysis. For this purpose, two datasets were used. One dataset was used to evaluate the effects of sex on the protein requirements for maintenance using the comparative slaughter technique. This dataset was composed of 185 individual records (80 intact males, 62 castrated males, and 43 females) from six studies. The other dataset was used to evaluate the effects of sex on the protein requirements for maintenance using the N balance method. This dataset was composed of 136 individual records (59 intact males, 43 castrated males, and 34 females) from six studies. All studies applied an experimental design that provided different levels of N intake and different levels of N retention, allowing the development of regression equations to predict the net protein requirement for maintenance (NPM) and the metabolizable protein (MP) requirements for maintenance (MPM) in Saanen goats. The efficiency of MP use for maintenance (kPM) was computed as NPM/MPM. The efficiency of MP use for gain (kPG) was calculated using the equation of daily protein retained against daily MP intake above maintenance. A meta-analysis was applied using the MIXED procedure of SAS, in which sex was considered a fixed effect, and blocks nested in the studies and goat sex were considered as random effects. The NPM did not differ between sexes, irrespective of the approach used. The daily NPM estimated was 1.23 g/kg0.75 BW when using the comparative slaughter technique, while it was 3.18 g/kg0.75 BW when using the N balance technique for growing Saanen goats. The MPM estimated was 3.8 g/kg0.75 BW, the kPM was 0.33, and the kPG was 0.52. We observed that the NPM when using the comparative slaughter technique in growing Saanen goats is lower than that recommended by the current small ruminant feeding systems; on the other hand, the MPM was similar to previous reports by the feeding systems. Sex did not affect the protein requirements for maintenance and the efficiencies of use of metabolizable protein.


1952 ◽  
Vol 11 (2) ◽  
pp. 221-232 ◽  
Author(s):  
D. V. Catron ◽  
A. H. Jensen ◽  
P. G. Homeyer ◽  
H. M. Maddock ◽  
G. C. Ashton
Keyword(s):  

2021 ◽  
pp. 1-6
Author(s):  
Namrata S. Rao ◽  
Abhilash Chandra ◽  
Sai Saran ◽  
Manish Raj Kulshreshta ◽  
Prabhakar Mishra ◽  
...  

<b><i>Background:</i></b> Provision of oral protein in hemodialysis (HD) is desirable due to improved compliance to protein requirements and better nutritional status, but the risks of hypotension and underdialysis need to be considered. This study compared 2 different timings for administering oral nutritional supplements (ONS), predialysis and mid-dialysis, with respect to hemodynamics, dialysis adequacy, urea removal, and tolerability. <b><i>Methods:</i></b> This single-center, prospective crossover study analyzed 72 stable patients with ESRD on twice a week maintenance HD with a mean age of 38.7 (±11.2) years and a dialysis vintage of 28.2 (±13.1) months. In the first week, all the patients received ONS (450 kcal energy, 20 g protein) 1 h prior to start of dialysis (group 1) and in the next week, the supplement was administered after 2 h of start of dialysis (group 2), with a predialysis fasting period of at least 3 h in both groups. Blood pressures, serum, and spent dialysate samples were collected and nausea occurrence was noted by severity. <b><i>Results:</i></b> Predialytic intake (group 1) was associated with higher predialysis and 1st hour blood urea, dialysis adequacy, and urea removal than group 2. Both groups achieved mean Kt/V &#x3e; 1.2, and the occurrence of symptomatic hypotensive episodes and nausea was not significantly different between the groups. On repeated measures ANOVA, changes in blood urea over time showed significant group effect. <b><i>Conclusions:</i></b> Predialytic supplementation was associated with better dialysis adequacy and urea removal than intradialytic supplementation. However, both timings were equally tolerated and not associated with underdialysis.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1227
Author(s):  
Ian Chapman ◽  
Avneet Oberoi ◽  
Caroline Giezenaar ◽  
Stijn Soenen

Protein supplements are increasingly used by older people to maintain nutrition and prevent or treat loss of muscle function. Daily protein requirements in older people are in the range of 1.2 gm/kg/day or higher. Many older adults do not consume this much protein and are likely to benefit from higher consumption. Protein supplements are probably best taken twice daily, if possible soon after exercise, in doses that achieve protein intakes of 30 gm or more per episode. It is probably not important to give these supplements between meals, as we have shown no suppressive effects of 30 gm whey drinks, and little if any suppression of 70 gm given to older subjects at varying time intervals from meals. Many gastrointestinal mechanisms controlling food intake change with age, but their contributions to changes in responses to protein are not yet well understood. There may be benefits in giving the supplement with rather than between meals, to achieve protein intakes above the effective anabolic threshold with lower supplement doses, and have favourable effects on food-induced blood glucose increases in older people with, or at risk of developing, type 2 diabetes mellitus; combined protein and glucose drinks lower blood glucose compared with glucose alone in older people.


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