scholarly journals Degradation and outflow of amino acids from the rumen of sheep

1989 ◽  
Vol 61 (2) ◽  
pp. 397-408 ◽  
Author(s):  
D. J. Cottle ◽  
W. Velle

1. In hay-fed, cannulated sheep the apparent degradation in and outflow from the rumen were determined for graded doses of mixtures of the amino acids lysine, threonine and methionine, administered intraruminally and using polyethylene glycol (PEG) as a liquid marker. The doses ranged between 2.5 and 15 g for each amino acid in the mixtures.2. Relative rate of apparent degradation in the first 4 h was highest for lysine, and lowest for methionine. The apparent degradation in 24 h was highest for lysine and lowest for threonine. Conversely the fraction flowing out of the rumen in intact form in 24 h was highest for threonine and lowest for lysine. Rates of apparent degradation as well as outflow were dose-dependent.3. The validity of the estimated outflow of amino acids from the rumen was corroborated by measurements of concentrations of the amino acids in duodenal contents and in blood plasma which were also dose-dependent.4. It was concluded that part of the requirement for the essential amino acids threonine and methionine may be met, even when these amino acids are delivered in unprotected form, given as a feed supplement.

2003 ◽  
Vol 70 (4) ◽  
pp. 373-378 ◽  
Author(s):  
Martin J Auldist ◽  
Catherine M Menzies ◽  
Colin G Prosser

Effects of atropine on blood plasma amino acid profile and on the yields and concentration of milk components were investigated in 12 Friesian cows in early lactation. Cows were housed indoors and fed with cut pasture ad libitum. Each cow received four treatments over 12 d during a replicated 4×4 Latin square experiment. Treatments were: control (saline); low dose (L; 30 μg atropine/kg body weight (BW)); medium dose (M; 40 μg atropine/kg BW); and 2×L dose, 2 h apart (2×L). On each of four treatment days, cows were milked at about 7.00, after which treatments were administered by subcutaneous injection. Cows were milked again at 2 h, 6 h and 10 h after injection. Milk samples were collected at each milking. Immediately after the 2 h milking, blood samples were drawn from each cow and the second injection was given for the 2×L treatment. Atropine reduced hourly milk yield, and concentrations and hourly yields of total protein, casein, whey protein, α-casein, β-casein, κ-casein, β-lactoglobulin and α-lactalbumin, but by differing amounts. Milk concentrations of bovine serum albumin and immunoglobulin G were increased by atropine, and overall yields of these proteins were mostly unchanged. Atropine lowered concentrations of most, but not all, amino acids in blood plasma, with essential amino acids reduced more than non-essential amino acids. Concentrations of α-amino N in whole blood, and glucose and insulin in blood plasma, fell after atropine injection. There was no difference between the L and M doses of atropine, but the 2×L dose had greater effects on milk composition than the single doses. For yields of milk and milk components, the effect of the 2×L dose was also more persistent. The results highlight the differential synthesis of individual milk proteins, and suggest that atropine might be useful for evaluating the mechanisms regulating milk protein composition.


1997 ◽  
Vol 272 (4) ◽  
pp. E592-E599 ◽  
Author(s):  
B. B. Poindexter ◽  
C. A. Karn ◽  
J. A. Ahlrichs ◽  
J. Wang ◽  
C. A. Leitch ◽  
...  

To determine how increased amino acid availability alters rates of whole body proteolysis and the irreversible catabolism of the essential amino acids leucine and phenylalanine throughout the neonatal period, leucine and phenylalanine kinetics were measured under basal conditions and in response to intravenous amino acids in two separate groups of healthy, full-term newborns (at 3 days and 3 wk of age). The endogenous rates of appearance of leucine and phenylalanine (reflecting proteolysis) were suppressed equally in both groups and in a dose-dependent fashion (by approximately 10% with 1.2 g x kg(-1) x day(-1) and by approximately 20% with 2.4 g x kg(-1) x day(-1)) in response to intravenous amino acid delivery. Insulin concentrations remained unchanged from basal values during amino acid administration. The irreversible catabolism of leucine and phenylalanine increased in a stepwise fashion in response to intravenous amino acids; again, no differences were observed between the two groups. This study clearly demonstrates that the capacity to acutely increase rates of leucine oxidation and phenylalanine hydroxylation is fully present early in the neonatal period in normal newborns. Furthermore, these data suggest that amino acid availability is a primary regulator of proteolysis in normal newborns throughout the neonatal period.


2017 ◽  
pp. 67-71
Author(s):  
V. M. Sheybak ◽  
A. Y. Pavliukovets ◽  
V. Yu. Smirnov

Objective: to analyze the pool of free amino acids and their nitrogen-containing metabolites of blood plasma of animals being administered lead acetate for 21 or 28 days. Material and methods. The experiments were carried out on white male rats with the initial weight of 140-160 g. During the experiment the animals received a total amount of 0.67 g of lead acetate (21 days), the second group - 1.12 g (28 days). The determination of free amino acids in blood plasma was performed by the method of reversed-phase HPLC. Results. As a result of the research it has been found out that the most significant contribution to the formation of the amino acid imbalance in blood plasma as a result of the long-term intake of lead acetate according to the value of the Fisher test is caused by changes in the concentrations of α-aminobutyric acid, isoleucine, aspartate, arginine, glycine, serine, histidine, and methionine. Conclusion. The long-term intake of lead acetate with drinking water leads to a statistically significant increase of general content of free amino acids and their nitrogen-containing metabolites, as well as to a decrease of the concentration the essential amino acid threonine in blood plasma.


1975 ◽  
Vol 55 (2) ◽  
pp. 257-268 ◽  
Author(s):  
D. D. RONY ◽  
G. J. BRISSON ◽  
M. DESMARAIS

Six groups of Holstein male calves, 4–5 days of age, were fed milk replacers containing, on a dry matter basis, 24.8% of either butter oil, lard, lard and corn oil (2:1), hydrogenated corn oil, or corn oil. Whole milk was used as control and the experiment lasted 56 days. The calves were fed, twice each day, a milk replacer containing 13% solids which was offered at a maximum daily rate of 12% of body weight as measured weekly. On the 28th and 56th day of the experiment, blood samples were drawn from the left jugular vein before the morning meal, and then 1, 2, 3, 4, 5, 7, 9, 11 and 13 h after feeding. Dry matter intake and growth rate were the lowest with calves receiving the corn oil diet. The calves fed corn oil also exhibited more frequent diarrhea. The vegetable fats, as compared to the animal fats, tended to induce a lower concentration of essential amino acids in blood plasma, but this trend was not statistically significant [Formula: see text] in all cases. The concentration of nonessential amino acids followed the same general trend as noted with essential amino acids. The concentration of total amino acids was the lowest for calves fed corn oil. Amino acid levels in blood varied with time after feeding, and exhibited postprandial patterns that differed from one amino acid to another or one group of amino acids to another. It would appear that type of dietary fat, under the conditions of this experiment, had an influence on amino acid metabolism in the young calf.


2020 ◽  
pp. 25-30
Author(s):  
T. V. Bogdan ◽  
V. O. Onishchenko ◽  
V. V. Bogdan ◽  
O. V. Savchenko

Background. Despite the significant achievements of clinical medicine in the prevention, diagnosis and treatment of coronary heart disease, the levels of morbidity, disability and mortality among the population of Ukraine from this pathology remain consistently high. The purpose. To improve the treatment of patients with stable angina by studying the effect of L-arginine on the balance of essential amino acids in blood plasma. Material and methods. It was examined 67 patients with stable angina. They were divided into two groups: group Ipatients received antianginal basic therapy, group II patients received basic antianginal therapy and L-arginine. The amino acid spectrum of patients' blood plasma was studied by ion-exchange liquid column chromatography, using an automatic amino acid analyzer T-339 Microtechna (Czech Republic, Prague). Results and discussion. In patients with stable angina who received basic therapy and L-arginine, in contrast to patients who received only basic therapy, plasma levels of arginine became normalized, which probably contributes to the synthesis of NO. The level of valine, leucine and isoleucine, which provide the synthesis of acyl-CoA and succinyl-CoA, became also normalized. Conclusion. Administration of L-arginine to patients with stable angina together with antianginal therapy helps to correct plasma amino acid imbalances, which is likely to effectively affect the course of the disease and prognosis.


2016 ◽  
Vol 5 (10) ◽  
pp. 4972
Author(s):  
Lata Birlangi

The date palm (Phoenix dactylifera L.) is one of mankind’s oldest cultivated plants. The fruit of the date palm is an important crop of the hot arid and semi-arid regions of the world. It has always played a genuine economic and social part in the lives of the people of these areas. The present objective in examining the amino acid content of different varieties of date palm fruits from Middle-East region; is to determine whether its protein could effectively supplement the nutritional value and it is also aimed in finding which variety is rich in number of amino acids. The phytochemical screening revealed the presence of eight essential amino acids and five non-essential amino acids in the date fruits. Among all the date fruit varieties taken as samples for the study, Dabbas cultivar of United Arab Emirates found to exhibit eight types of amino acids which includes five as non-essential ones. Total of thirteen amino acids were detected in the seven date cultivars. Determination of amino acid can serve as a guide to the possible nutritional value.


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.


EvoDevo ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Celeste R. Banfill ◽  
Alex C. C. Wilson ◽  
Hsiao-ling Lu

Abstract Background Host/symbiont integration is a signature of evolutionarily ancient, obligate endosymbioses. However, little is known about the cellular and developmental mechanisms of host/symbiont integration at the molecular level. Many insects possess obligate bacterial endosymbionts that provide essential nutrients. To advance understanding of the developmental and metabolic integration of hosts and endosymbionts, we track the localization of a non-essential amino acid transporter, ApNEAAT1, across asexual embryogenesis in the aphid, Acyrthosiphon pisum. Previous work in adult bacteriomes revealed that ApNEAAT1 functions to exchange non-essential amino acids at the A. pisum/Buchnera aphidicola symbiotic interface. Driven by amino acid concentration gradients, ApNEAAT1 moves proline, serine, and alanine from A. pisum to Buchnera and cysteine from Buchnera to A. pisum. Here, we test the hypothesis that ApNEAAT1 is localized to the symbiotic interface during asexual embryogenesis. Results During A. pisum asexual embryogenesis, ApNEAAT1 does not localize to the symbiotic interface. We observed ApNEAAT1 localization to the maternal follicular epithelium, the germline, and, in late-stage embryos, to anterior neural structures and insect immune cells (hemocytes). We predict that ApNEAAT1 provisions non-essential amino acids to developing oocytes and embryos, as well as to the brain and related neural structures. Additionally, ApNEAAT1 may perform roles related to host immunity. Conclusions Our work provides further evidence that the embryonic and adult bacteriomes of asexual A. pisum are not equivalent. Future research is needed to elucidate the developmental time point at which the bacteriome reaches maturity.


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