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1.
The amino acid requirements of the growing chick have been determined using a diet based on soybean meal and maize meal. The diet contained 18% protein (N% x 6.25, dry matter basis) made up to 14% contributed by conventional ingredients and 4% protein equivalent in the form of amino acids. Starting with a diet formulated to meet the reference levels recommended by Dean and Scott (1965) a programme of experiments was carried out to improve this amino acid balance. The results indicated that the growing chick requires not more than 0.53% threonine, 0.61% glycine, 0.79% valine, 0.62% isoleucine, 1.34% leucine, 0.75% phenylalanine (or 1.3% phenylalanine plus tyrosine), 0.85 % lysine, 0.4% histidine, 0.86% arginine, 0.17% tryptophan and 0.39% methionine (or 0.79% methionine plus cystine).  相似文献   

2.
The influence of protein deficiency, rehabilitation and total starvation on the free amino acid levels in the blood plasma of pigs has been investigated. It was found that the concentration of most amino acids was reduced during protein deficiency. The levels of leucine, isoleucine and valine were diminished by the greatest proportion, followed by threonine, tyrosine and citrulline. During the first few weeks of protein deficiency the levels of lysine, histidine and arginine were slightly increased, but later decreased below control values. Concentrations of glycine and alanine were altered in a similar way except that the initial increase was much more pronounced. The concentrations of most of these amino acids returned to control levels after rehabilitation. Total starvation led to an increase in concentration of leucine, isoleucine, valine, threonine and to a smaller extent phenylalanine, lysine, citrulline and arginine. The concentration of glycine, alanine and glutamic acid were very much reduced. The level of urea in the circulation dropped reversibly during protein deficiency and increased very much during total starvation.  相似文献   

3.
1. Diets 50% deficient in single essential amino acids were fed to chicks from day 8 to day 18 after hatching to evaluate body-weight gain, food consumption, body composition, nitrogen (N) and energy utilisation. 2. Body-weight gain was reduced most severely by deficiency of isoleucine followed in decreasing order by threonine, arginine, valine, histidine, tryptophan, methionine plus cystine, phenylalanine plus tyrosine, leucine and lysine, and possible reasons for the differences are discussed. 3. Body-weight gain and food efficiency were highly correlated with food consumption but metabolisable energy value of diets was not affected by single essential amino acid deficiencies. 4. Generally N retention (N retained/N consumed) and energy retention (energy retained/energy consumed) reflected food consumption, except for a lower N retention by chicks fed on the methionine plus cystine-deficient diet and for a lower energy retention by chicks fed on the valine deficient diet. 5. The amino acid deficient in the diet was present at very low concentration in the blood plasma.  相似文献   

4.
南板蓝根氨基酸的分析   总被引:5,自引:0,他引:5  
利用氨基酸分析仪对南板蓝根氨基酸进行分离测定,证实其含有脯氨酸、甘氨酸、苏氨酸、蛋氨酸、丙氨酸、天门冬氨酸、谷氨酸、半胱氨酸、苯丙氨酸、酪氨酸、缬氨酸、异亮氨酸、亮氨酸、丝氨酸等十四种氨基酸,但未发现精氨酸、赖氨酸和组氨酸。  相似文献   

5.
Amino acid responses to exercise stress in well-trained racehorses and human athletes are well characterised, but the knowledge of amino acid metabolism during and after exercise in inactive animal species is limited. To study this, plasma amino acid concentrations were measured in previously unexercised pigs which performed two exercise tests on a treadmill with an interval of one week. In general, the changes in amino acids were more pronounced after the second than after the first exercise bout. Alanine, glutamine, phenylalanine and tyrosine were elevated for one hour only after the latter exercise. Twenty-four hours after the second exercise isoleucine, leucine, phenylalanine, tyrosine and valine were increased, but only isoleucine was increased after the first test. These differences between the two tests might be explained by adaptation of the amino acid metabolism after a single exercise bout and suggest that domestic pigs are well suited to study the early effects of exercise.  相似文献   

6.
A series of N balance experiments using growing pigs was conducted to study the efficiency of utilization of lysine, threonine, sulphur amino acids and tryptophan and to estimate their maintenance requirements. Purified diets based on casein and crystalline amino acids as the sole source of N contained graded levels of each amino acid, corresponding to expected protein accretion rate of 0, 33, 66, 99 and 132 g/day, respectively. N retention increased linearly (p < 0.01) as the dietary concentration of the limiting amino acid increased. Based on linear regression equations relating amino acid deposition in body protein to amino acid intake, marginal efficiencies of ileal digestible amino acid utilization were calculated to be lysine 0.91, threonine 0.83, sulphur amino acids 0.85 and tryptophan 0.66. Extrapolating the regression equations to zero N retention, the daily requirements of amino acids for N equilibrium were estimated to be (mg/kg(0.75)) lysine 39, threonine 49, sulphur amino acids 46 and tryptophan 16.  相似文献   

7.
1. Using 18% protein diets (N times 6-25), consisting mainly of conventional ingredients of known amino acid composition, the amino acid requirements as percentages of diet and of dietary protein respectively for broiler chickens between 14 and 28 d of age were found to be: threonine 0-50-0-52% of diet (2-8-2-9% of dietary protein); glycine 0-48-0-50 (2-7-2-8); valine 0-69-0-71 (3-8-3-9); methionine+cystine 0-58 (3-2); isoleucine smaller than 0-48 (smaller than 2-7); leucine smaller than 1-05 (smaller than 5-8); tyrosine+phenylalanine 1-09-1-12 (6-1-6-2); lysine 0-87 (4-8); histidine smaller than 0-34 (smaller than 1-9); arginine smaller than 0-76 (smaller than 4-2); tryptophan smaller than 0-14 (smaller than 0-78). 2. Values found were in general lower than those determined using diets consisting entirely of purified amino acids and the reasons for this are discussed.  相似文献   

8.
Three experiments were conducted to determine the fifth-limiting amino acid for growing pigs in an 11% CP, corn-soybean meal diet. In each experiment, 36 gilts (initial weight 19.5, 21.9, and 21.0 kg, respectively) were penned individually and fed one of six diets in a randomized block design for 35 d. Diets containing 16, 12, and 11% CP were fed in each experiment. All 12 and 11% CP diets were supplemented with lysine, tryptophan, threonine, and methionine to provide the same total concentrations as those in the 16% CP diet. In Exp. 1, the 11% CP diet was supplemented with isoleucine, valine, or isoleucine + valine to concentrations equal to those in the 16% CP diet. In Exp. 2, the 11% CP diet was supplemented with histidine, histidine + valine, or histidine + isoleucine + valine. In Exp. 3, the 11% CP diet was supplemented with valine, histidine + valine, or isoleucine + valine. Gilts were allowed free access to feed and water. In all experiments, ADG and feed efficiency (G/F) were reduced (P < or = 0.07) as dietary protein was reduced. Supplementation of isoleucine alone further reduced (P < 0.05) ADG, ADFI, G/F, and fat-free lean gain. In contrast, supplementation of valine alone resulted in numerical increases in ADG and ADFI in two experiments, although the differences were not significant (P > 0.05). Supplementation with histidine and valine together resulted in growth performance equal to or greater than that of pigs fed the 12% CP diet, but less than that of pigs fed the 16% CP diet. Supplementation of isoleucine and valine together resulted in better growth performance (P < 0.05) than supplementation of either amino acid alone. In two experiments (Exp. 1 and 3), supplementation of the 11% CP diet with isoleucine and valine together resulted in ADG that were not significantly different (P > 0.05) from those of pigs fed the 16% CP diet. Supplementation of all three amino acids (Exp. 2) did not improve performance over supplementations with histidine and valine. Plasma urea concentrations were reduced (P < 0.05) as dietary protein was lowered from 16 to 12%. Additions of crystalline amino acids did not affect plasma urea levels. Plasma amino acid concentrations reflected the dietary additions of crystalline amino acids, but did not assist in the identification of the sequence of limiting amino acids. These data suggest that valine is the fifth-limiting amino acid and that either histidine or isoleucine is the sixth-limiting amino acid in an 11% CP diet.  相似文献   

9.
Concentrations of amino acids in the plasma of 13 neonatal foals with septicemia were compared with the concentrations of amino acids in the plasma of 13 age-matched neonatal foals without septicemia. Analysis of the results revealed significantly lower concentrations of arginine, citrulline, isoleucine, proline, threonine, and valine in the plasma of foals with septicemia. The ratio of the plasma concentrations of the branched chain amino acids (isoleucine, leucine, and valine) to the aromatic amino acids (phenylalanine and tyrosine), was also significantly lower in the foals with septicemia. In addition, the concentrations of alanine, glycine, and phenylalanine were significantly higher in the plasma of foals with septicemia. Therefore, neonatal foals with septicemia had significant differences in the concentrations of several amino acids in their plasma, compared with concentrations from healthy foals. These differences were compatible with protein calorie inadequacy and may be related to an alteration in the intake, production, use, or clearance of amino acids from the plasma pool in sepsis.  相似文献   

10.
The apparent digestibility of nitrogen and amino acids was measured by the ileal and faecal methods in pigs fed nine barleys differing in nitrogen content (from 1.73 to 2.16 per cent/DM). A positive (r = 0.87) and significant relationship was found between the apparent nitrogen digestibility at the end of the ileum and the crude protein content of barley. Generally, the higher the protein of the grain, the higher the ileal digestibilities of the amino acids. For most amino acids the faecal values were greater than the ileal ones. This being specially so for threonine, tryptophan, histidine and cystine belonging to the nutritionally important amino acid group. When the relationship between the amino acid and nitrogen digestibilities at the level of ileum is considered, the values were found to be similar to that of nitrogen in the case of tryptophan, higher for isoleucine, valine (both 2-3 units), cystine, histidine, leucine, methionine (all 5-6 units) and phenylalanine (10 units) and lower only for lysine and threonine (7-8 dig. units).  相似文献   

11.
大肠杆菌新菌毛抗原的研究Ⅱ.菌毛抗原蛋白质特性测定   总被引:2,自引:0,他引:2  
用保温法和裂解法可以有效提取F_(1987)新菌毛抗原蛋白质;该菌毛蛋白经区带电泳显示主、次两个组分,在0.06mol/LpH8.6巴比妥缓冲液电泳条件下,均向阳极泳动;免疫电泳显示两条沉淀线;其分子量为19100Da;等电点为3.0;由天门冬氨酸、苏氨酸、丝氨酸、谷氨酸、甘氨酸、丙氨酸、缬氨酸、异亮氨酸、亮氨酸、酪氨酸、苯丙氨酸、赖氨酸、组氨酸、精氨酸、脯氨酸、胱氨酸等16种氨基酸组成。  相似文献   

12.

Background

The branched chain amino acid leucine is a potent stimulator of insulin secretion. Used in combination with glucose it can increase the insulin response and the post exercise re-synthesis of glycogen in man. Decreased plasma amino acid concentrations have been reported after intravenous or per oral administration of leucine in man as well as after a single per oral dose in horses. In man, a negative correlation between the insulin response and the concentrations of isoleucine, valine and methionine have been shown but results from horses are lacking. This study aims to determine the effect of repeated per oral administration with a mixture of glucose and leucine on the free amino acid profile and the insulin response in horses after glycogen-depleting exercise.

Methods

In a crossover design, after a glycogen depleting exercise, twelve Standardbred trotters received either repeated oral boluses of glucose, 1 g/kg body weight (BW) at 0, 2 and 4 h with addition of leucine 0.1 g/kg BW at 0 and 4 h (GLU+LEU), or repeated boluses of water at 0, 2 and 4 h (CON). Blood samples for analysis of glucose, insulin and amino acid concentrations were collected prior to exercise and over a 6 h post-exercise period. A mixed model approach was used for the statistical analyses.

Results

Plasma leucine, isoleucine, valine, tyrosine and phenylalanine concentrations increased after exercise. Post-exercise serum glucose and plasma insulin response were significantly higher in the GLU+LEU treatment compared to the CON treatment. Plasma leucine concentrations increased after supplementation. During the post-exercise period isoleucine, valine and methionine concentrations decreased in both treatments but were significantly lower in the GLU+LEU treatment. There was no correlation between the insulin response and the response in plasma leucine, isoleucine, valine and methionine.

Conclusions

Repeated post-exercise administration with a mixture of leucine and glucose caused a marked insulin response and altered the plasma amino acid profile in horses in a similar manner as described in man. However, the decreases seen in plasma amino acids in horses seem to be related more to an effect of leucine and not to the insulin response as seen in man.  相似文献   

13.
Three sheep with a small isolated rumen (after Gridin et al., 1964) were studied for the passage of amino acids from the blood to the isolated rumen before feeding and 1, 2, 3, 4 and 5 hours after feeding. It was found that, on an average for all the time intervals mentioned above, the passage of glycine was the largest of all the amino acids studied (0.512 muMol per 100 ml), followed, in descending order, by lysine, alanine, glutamic acid, aspartic acid, serine, leucine, threonine, isoleucine, arginine, tyrosine, and phenylalanine (0.038 muMol per 100 ml). Before feeding and one hour after feeding, lysine shared the greatest proportion of all amino acids that had passed into the isolated rumen (0.565-0.43 muMol per 100 ml), followed, in descending order, by glycine, alanine, valine, aspartic acid, glutamic acid, leucine, serine, threonine, isoleucine, tyrosine, phenylalanine; arginine was, in this case, represented by the smallest proportion (0.042-0.030 muMol per 100 ml). It is inferred from the results that the amount of amino acids passing from the blood through the rumen wall changes with the time that has elapsed from feeding, and that before feeding this passage is more intensive than after feeding. These changes are held to be related with an increased passage of endogenous nitrogen to the rumen in the period of a relative deficiency of substances which are derived from the feed and are essential for maintaining homeostasis in the rumen.  相似文献   

14.
This study was conducted to test the hypothesis that porcine jejunal mucosal cells can degrade all essential amino acids (EAA). Jejunal mucosal cells (primarily enterocytes) were isolated from 50-day-old healthy pigs and incubated at 37 °C for 45 min in Krebs buffer containing plasma concentrations of amino acids and one of the following l-[1-14C]- or l-[U-14C]-amino acids plus unlabeled tracers at 0.5, 2, or 5 mM: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. There was active transamination of leucine, isoleucine and valine in the cells (1.35–2.5 nmol/mg protein per 45 min at 2 mM), with most (67–71%) of their -ketoacids released into the medium. In contrast, catabolism of methionine and phenylalanine was negligible (0.04–0.05 nmol/mg protein per 45 min at 2 mM) and that of other EAA was completely absent in these cells. These results indicate that intestinal mucosal cells are a site for the substantial degradation of branched-chain amino acids but not other EAA in pigs.  相似文献   

15.
Cyst membranes of Cysticercus tenuicollis, the larval stage of Taenia hydatigena, contained 14 amino acids, namely lysine, histidine, arginne, aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, isoleucine and leucine. Methionine was present in traces. In comparison, the cyst fluid was deficient in histidine, arginne, threonine, methionine and valine and the scolices did not have threonine, serine, glutamic acid and methionine. The membrane contained large quantities of amino acids in comparison to the other components of the cyst.  相似文献   

16.
The aim of this study was to investigate the effect of short intense exercise on plasma amino acid concentrations in trotters and to test the repeatability of plasma amino acids concentration in samples obtained on two independent days under field conditions. Plasma amino acid concentrations were analysed in blood samples of 36 standardbred trotters before and after intense exercise over a distance of 2000 m. Sampling was repeated in 20 horses after 35 days. Exercise intensity was estimated from post‐exercise lactate levels. Horses were divided in two groups according to a cut‐off lactate concentration at 15 mmol/l. The plasma concentrations of alanine, aspartate, glutamate, isoleucine, leucine, lysine and taurine increased and arginine, asparagine, citrulline, glutamine, glycine, histidine, methionine, serine, tryptophan and 3‐methylhistidine decreased after exercise. Ornithine, threonine, tyrosine, phenylalanine and valine concentrations remained constant. Higher intensity of exercise significantly decreased tryptophan and increased taurine concentrations. Sampling day had a significant effect on the absolute pre‐ and post‐exercise amino acid concentrations. Exercise had a significant influence on the concentrations of most plasma amino acids in trotters. These changes could reflect shifts between the free amino acid compartments, but there were also some indications for muscle catabolism. The amino acid supply of sporting horses could be of specific significance for maintaining muscle integrity and for the improvement of post‐exercise recovery of competition horses.  相似文献   

17.
Ideal amino acid pattern for 10-kilogram pigs.   总被引:10,自引:0,他引:10  
Two growth assays and one nitrogen balance experiment were conducted to develop an ideal amino acid pattern for 10-kg pigs. Crossbred pigs were fed chemically defined amino acid diets containing four indispensable amino acid (AA) patterns: 1) the Illinois final amino acid pattern (IFP), a recently developed AA profile for purified diets; 2) the Illinois ideal amino acid pattern (IIP), a modification of IFP; 3) the Wang and Fuller ideal amino acid pattern (WFIP); and 4) the 1988 National Research Council (NRC) amino acid requirement pattern for 10-kg pigs (NRCP). A mixture of dispensable AA consisting of glutamate, glycine, and proline that had been proven to be an efficient mixture of dispensable AA nitrogen was fed together with the indispensable AA patterns. Diets were made isonitrogenous and isoenergetic within experiments. In Exp. 1, pigs were given ad libitum access to experimental diets with AA levels set above the NRC AA requirements. Regardless of which AA pattern was fed, pigs had similar (P greater than .05) daily gains, daily feed intakes, and gain:feed ratios. In Exp. 2, all levels of indispensable and dispensable AA were reduced to 50% of levels present in Exp. 1. When pigs had ad libitum access to these diets, daily gains of pigs fed IIP were superior (P greater than .05) to those of pigs fed IFP or NRCP, but similar (P greater than .05) weight gains occurred in pigs fed IFP, WFIP, and NRCP. In Exp. 3, the efficiency of nitrogen utilization of the four indispensable AA patterns was evaluated by a nitrogen balance experiment in pigs equally fed the same experimental diets fed in Exp. 2. Pigs fed NRCP utilized nitrogen with an efficiency of 74%, which was less (P less than .001) than the efficiencies of 79 to 80% obtained in pigs fed IFP, IIP, and WFIP. Nitrogen retained (grams) per gram of nitrogen intake from indispensable AA was greater (P less than .01) for IIP than for either IFP or WFIP. The results of these experiments indicate that WFIP contains excesses of leucine, valine, phenylalanine plus tyrosine, methionine plus cystine, and threonine for pigs between 10 and 20 kg BW. Also, NRCP is probably first-limiting in leucine and also limiting in other AA, resulting in lower nitrogen utilization than IIP. The pattern of indispensable AA in IIP (grams of AA/100 g lysine) is as follows: lysine (100), methionine+cystine (60), threonine (65), tryptophan (18), phenylalanine+tyrosine (95), leucine (100), isoleucine (60), valine (68), arginine (42), and histidine (32).  相似文献   

18.
The effects of branched-chain amino acids on sow and litter performance   总被引:2,自引:0,他引:2  
Sows (n = 306; PIC, Line C-19; average parity 2.1) were used to evaluate the interrelationship between valine, isoleucine, and leucine on sow and litter performance. Our objective was to determine whether the increase in litter weaning weight associated with added dietary valine is specific for valine or a result of the total branched-chain amino acid (i.e., isoleucine and[or] leucine) concentration of the diet. Eight dietary treatments (36 to 41 sows/treatment) were arranged as a 2 x 2 x 2 factorial with two levels of valine (.80 and 1.20%), isoleucine (.68 and 1.08%), and leucine (1.57 and 1.97%). This provided total branched-chain amino acid levels of 3.05, 3.45, 3.85, and 4.25%. The lowest level of each branched-chain amino acid was similar to that in a .90% lysine corn-soybean meal diet containing .15% L-lysine HCl. Amino acids other than valine, isoleucine, and leucine met or exceeded their suggested estimates relative to lysine using ratios derived from the National and Agricultural Research Councils. Average number of pigs on d 2 of lactation was 11.2, and average lactation length was 20.9 d. Number of pigs weaned (x = 10.6), sow ADFI (x = 5.85 kg), and sow weight loss (x = 4.25 kg) were not affected by dietary treatment (P > .10). Sow backfat loss (P < .02), litter weaning weight (P < .04), and litter weight gain from d 2 to weaning (P > .05) increased as dietary valine increased. Litter weight at weaning and litter weight gain were not affected by dietary isoleucine (P > .80) or leucine (P > .60). Sixteen or 17 sows per treatment (129 total) were milked manually on d 14 to 16 of lactation. Increasing dietary valine tended to increase milk urea N (P < .07) but did not affect milk DM, CP, fat, lactose, or ash. Increasing dietary isoleucine or leucine had no effects on milk composition. These results confirm the importance of dietary valine for increased litter weaning weight, independent of either additional dietary leucine or isoleucine.  相似文献   

19.
1. The apparent ileal and excreta digestibilities of amino acids in 15 samples representing 12 food ingredients were determined using 5-week-old male broiler chickens. The ingredients included 3 samples of cereals (wheat, maize and sorghum), 6 samples of plant protein meals (soyabean meal, cottonseed meal, canola meal and sunflower meal) and 6 samples of animal protein meals (meat meal, meat-and-bone meal, feather meal and fish meal). 2. The test ingredients were incorporated as the sole source of dietary protein in assay diets. Each diet was offered ad libitum to 3 pens (4 birds/pen) from d 35 to d 42 post-hatching. Total collection of excreta was carried out during the last 4 d. All birds were killed on d 42 and the contents of the lower half of the ileum were collected. Apparent ileal and excreta amino acid digestibilities were calculated using acid-insoluble ash as the indigestible marker. 3. The influence of site of measurement was found to vary among food ingredients, among samples within an ingredient and among different amino acids within an ingredient. Ileal amino acid digestibility values were similar in some ingredients, but significantly lower or higher in others than the corresponding excreta values. 4. Average ileal and excreta amino acid digestibilities in sorghum and maize were similar, but significant differences were observed for individual amino acids. In contrast, ileal amino acid digestibility values were higher than the corresponding excreta digestibility values in wheat. 5. The average ileal and excreta digestibilites of amino acids in the 3 soyabean meal samples were similar although small, but significant differences were noted for individual amino acids. Site of measurement had no effect on the digestibility of amino acids in canola meal. Digestibilities of valine, isoleucine, phenylalanine, histidine, glutamic acid, alanine and tyrosine in sunflower meal and those of valine, methionine, isoleucine, leucine, lysine, glutamic acid and alanine in cottonseed meal were lower by excreta analysis. 6. Digestibilities in animal protein meals, with the exception of blood meal and fish meal, were consistently higher by excreta analysis. Ileal-excreta differences in individual amino acid digestibilities were more evident in feather meal, meat meal and meat-and-bone meal. 7. Threonine and valine were the indispensable amino acids that were more frequently influenced by the site of measurement. Of the dispensable amino acids, aspartic acid, serine, glutamic acid and alanine were the most affected. 8. Differences determined between ileal and excreta digestibilities in the present study clearly demonstrate that amino acid metabolism by hindgut microflora in chickens may be substantial and that digestibilities measured in the terminal ileum are more accurate measures of amino acid availability than those measured in the excreta.  相似文献   

20.
The aim of this work was to evaluate the changes in the concentrations, after two rides different for distance covered, of different amino acids in endurance horses. Blood samples have been collected from horses just before the start, at the top of a steep slope (819 m difference in height) and just at the end of a 32-km endurance ride. A second group, competing in a 72 km endurance ride, has also been sampled immediately before and after the race. In serum samples, the concentrations of alanine, arginine, asparagine, glycine, isoleucine, histidine, leucine, lysine, methionine, ornithine, phenylalanine, tryptophan, tyrosine and valine have been measured by high-performance liquid chromatography (HPLC). anova and t-test have been used to study the differences in the concentrations of the amino acids. The pre-ride concentrations of the free amino acids were different between the two races, except for methionine and leucine. Differences between start and end race have been found for both groups for all the considered parameters except asparagine, isoleucine, leucine and lysine for the 72 km ride. Increases have been recorded for the shorter and decreases for the longer ride in the blood serum concentrations. Significant increases have also been found between the starting sampling and the second, at the top of the slope, only for alanine, arginine, asparagines, phenylalanine and lysine. The ride length has a significant impact on blood serum amino acids mobilization and uptake; in the shorter race the increases stand only for mobilization, whereas in the longer the decrease can be considered the effect of the onset of the amino acids catabolism.  相似文献   

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