scholarly journals The protein requirement of infants at the age of about 1 year

1966 ◽  
Vol 20 (4) ◽  
pp. 775-782 ◽  
Author(s):  
H. Chan ◽  
J. C. Waterlow

1. A study has been made of the protein requirements for maintenance and for growth of children about 1 year old who had recovered from malnutrition. 2. The diets used supplied 120kcal/kg daily; the sole source of protein was dried skim milk. 3. The average maintenance requirement, measured by nitrogen balance, was found to be 100 mg N/kg day. At this level of intake the net protein utilization (NPU) of cow's milk protein approached 100. 4. An intake of 200 mg N/kg day was enough to produce normal growth and N retention. 5. The amount of N retained was 2.9 g/100 g weight gain, indicating that no excess of fat was being laid down. 6. These results are in close agreement with theoretical studies of the protein requirement of children at this age.

1964 ◽  
Vol 42 (3) ◽  
pp. 385-393 ◽  
Author(s):  
H. N. Parthasarathy ◽  
Kantha Joseph ◽  
V. A. Daniel ◽  
T. R. Doraiswamy ◽  
A. N. Sankaran ◽  
...  

The effect of supplementing a rice diet providing about 1.3–1.4 g protein per kg body weight with lysine, methionine, and threonine individually or together on true digestibility coefficient (DC), biological value (BV), and net protein utilization (NPU) of the proteins has been studied in girls aged 8–9 years. The retention of nitrogen on the rice diet was very low (9.5% of intake in the first series and 8.5% in the second series). The BV and NPU of the proteins of rice diet were 64.1 and 52.9 in the first series and 66.6 and 54.9 in the second series. Supplementation of the rice diet with lysine or methionine or lysine + methionine brought about a significant improvement in N retention (12.6, 12.0, 13.5% of intake) and in the BV (68.3, 66.3, 69.3) and NPU (54.8, 55.7, 55.8). When the rice diet was supplemented with lysine and threonine, a highly significant improvement in the N retention (18.9% of intake) and in the BV (77.4) and NPU (63.4) was observed. Addition of methionine to rice diet containing lysine and threonine resulted in a further improvement in N retention, BV, and NPU of the diets. The net available protein (g/kg body weight) from the different diets were as follows: rice diet, 0.71; rice diet + lysine, 0.76; rice diet + methionine, 0.74; rice diet + lysine + methionine, 0.77; rice diet + lysine + threonine, 0.85; rice diet + lysine + threonine + methionine, 0.91; and skim milk powder diet, 0.96–0.98.


1918 ◽  
Author(s):  
◽  
Solomon Fine

Text from page 1: "By minimum protein requirements of growing dairy heifers is meant the least quantity of protein in the ration which will allow normal growth to proceed. A study or investigation leading to a knowledge of the minimum amount of protein to be fed growing dairy heifers, to solve the fundamental problems should be conducted with animals receiving purified food substances, and every nutritional factor should be under complete control. It is obvious that this is entirely impractical with such large farm animals as dairy heifers. Consequently the results cannot be entirely satisfactory from a scientific standpoint. Yet if such experiments are properly controlled they should give results of value both scientifically and practically."


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.


Author(s):  
F.A.S. Silva ◽  
P. Del Bianco Benedeti ◽  
B.C. Silva ◽  
M.V.C. Pacheco ◽  
L.A. Godoi ◽  
...  

1965 ◽  
Vol 43 (11) ◽  
pp. 1879-1883 ◽  
Author(s):  
M. A. Krishnaswamy ◽  
S. B. Kadkol ◽  
G. D. Revankar

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.


2015 ◽  
Vol 82 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Sema Demirci Çekiç ◽  
Aslı Demir ◽  
Kevser Sözgen Başkan ◽  
Esma Tütem ◽  
Reşat Apak

Most milk-applied antioxidant assays in literature are based on the isolation and quantification of individual antioxidative compounds, whereas total antioxidant capacity (TAC) gives a more holistic picture due to cooperative action of antioxidants. Recently, the cupric reducing antioxidant capacity (CUPRAC) method has been modified to measure the antioxidant capacities of thiol-containing proteins, where the classical ammonium acetate buffer – that may otherwise precipitate proteins– was replaced with concentrated urea buffer (able to expose embedded thiol groups of proteins to oxidative attack) adjusted to pH 7.0. Thus, antioxidant capacity of milk was investigated with two competing TAC assays, namely CUPRAC and ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid))/persulphate, because only these assays were capable of evaluating protein contribution to the observed TAC value. As milk fat caused turbidity, experiments were carried out with skim milk or defatted milk samples. To determine TAC, modified CUPRAC method was applied to whole milk, separated and redissolved protein fractions, and the remaining liquid phase after necessary operations. Both TAC methods were investigated for their dilution sensitivity and antioxidant power assessment of separate milk fractions such as casein and whey. Proteins like β-lactoglobulin and casein (but not simple thiols) exhibited enhanced CUPRAC reactivity with surfactant (SDS) addition. Addition of milk protein fractions to whole skim milk produced significant ‘negative-biased’ deviations (up to −26% relative standard error) from TAC absorbance additivity in the application of the ABTS method, as opposed to that of the CUPRAC method less affected by chemical deviations from Beer's law thereby producing much smaller deviations from additivity (i.e. the property of additivity is valid when the measured TAC of a mixture is equal to the sum of individual antioxidant capacities of its constituents).


Author(s):  
C. J. Härter ◽  
D. S. Castagnino ◽  
L. D. Lima ◽  
A. R. Rivera ◽  
H. G. O. Silva ◽  
...  

2019 ◽  
Vol 3 (4) ◽  
pp. 1575-1584 ◽  
Author(s):  
Jessica R Baber ◽  
Jason E Sawyer ◽  
Ben P Holland ◽  
Kendall J Karr ◽  
Alyssa B Word ◽  
...  

Abstract: Feedlot efficiency increases as technologies are adopted and new feed ingredients, especially byproducts, become available and incorporated into diets. Byproduct availability increased in response to the renewable fuels standard of 2005, creating substantial amounts of feedstuffs best used by ruminants. Cereal grains have been partially replaced with human-inedible byproducts, as they provide comparable levels of energy in cattle diets. To evaluate the effects of changes in diet and feedlot production practices on net protein contribution (NPC) and human-edible protein conversion efficiency (HePCE) across time, a deterministic NPC model was used. NPC was assessed for the feedlot industry using lot level production data from 2006 to 2017 for eight commercial feedlots. Ingredient and nutrient composition was collected for a representative starter and finisher diet fed for each year from each feedlot. NPC was calculated by multiplying human-edible protein (HeP) in beef produced per unit of HeP in feed by the protein quality ratio (PQR). Systems with NPC >1 positively contribute to meeting human protein requirements; NPC < 1 indicates competition with humans for HeP. NPC was regressed on year to evaluate temporal change in NPC. Feedlots were categorized as increasing NPC (INC; slope > 0) or constant NPC (CON; slope = 0) according to regression parameter estimates. Four feedlots were categorized as INC and four were CON. The rate of change in PQR was similar for CON and INC (P ≥ 0.79), although rates of change among INC and CON differed for byproduct and cereal grain inclusion (P ≤ 0.01) across years evaluated. Feedlots categorized as INC reduced HeP consumed by 2.39% per year, but CON feedlots did not reduce HeP consumed each year (0.28%). Cattle received and shipped by INC were lighter than those in CON feedlots (P < 0.01). Across years, INC produced more HeP (20.9 vs. 19.2 kg/hd) than CON (P < 0.01), and both feedlot types tended to improve HeP gained over time (0.1 kg per year; P = 0.10). Differences in slope over time for INC and CON were observed for conversion efficiency of HeP (P < 0.01). NPC increased 0.027 units per year for INC (P < 0.01) and was 0.94 in 2017. NPC by the feedlot sector improved from 2006 to 2017, decreasing the amount of human-edible feeds required to produce more high-quality protein from beef.


Sign in / Sign up

Export Citation Format

Share Document