Effects of increasing dietary grain on viscosity of duodenal digesta and plasma hormone, glucose and amino acid concentrations in steers

2000 ◽  
Vol 80 (4) ◽  
pp. 703-712 ◽  
Author(s):  
P. S. Mir ◽  
G. J. Mears ◽  
E. K. Okine ◽  
T. Entz ◽  
C. M. Ross ◽  
...  

Effects of increasing the proportions of dietary barley grain or corn on viscosity of duodenal digesta supernatant and concentrations of cholecystokinin (CCK), glucose and amino acids in portal plasma and concentrations of CCK, insulin and glucose in jugular plasma were determined. Four steers (374 ± 6.4 kg) were surgically fitted with ruminal and duodenal cannulae and indwelling portal vein catheters. The steers were fed diets containing 20, 40, 60, and 80% rolled barley or cracked corn (DM basis) replacing respective silages, in two experiments with 4 × 4 Latin square design. After adjusting the steers to the diets for 14 d, digesta samples from the duodenum and blood samples from the portal and jugular veins were collected twice daily for 5 d. Increasing the proportion of dietary barley or corn increased the viscosity [measured as centipoise (cP)] of duodenal supernatant (from 1.3 to 2.0 and from 1.5 to 2.8 cP, P < 0.05), respectively. Portal plasma CCK concentration increased linearly (2.4 to 4.9 pmol, P < 0.05) as the proportion of dietary barley increased. However, in corn-fed steers, the highest portal CCK concentrations were observed in steers receiving 20% corn and these concentrations were not affected by corn content of the diet. Increasing dietary barley resulted in a linear increase in jugular plasma CCK concentration of steers, but a linear (P < 0.05) decline was noted when corn was fed to steers in increasing proportions. Portal and jugular plasma glucose concentrations were not altered in barley-fed steers, but both portal and jugular glucose increased (P < 0.05) with increasing dietary corn. Jugular insulin concentration was higher in steers fed 80% barley or corn than in those receiving the diets with less grain. Total amino acid concentrations in portal plasma were higher by 30% in steers fed corn than in those fed barley, but were not affected by relative proportion of dietary corn. These data suggest that feeding cattle increasing proportions of barley or corn grain increases duodenal viscosity, which, together with components of digesta, may be involved in affecting the secretion of hormones, such as CCK, and the concentrations of absorbed nutrients in portal plasma, which can be expected to influence animal performance. Key words: Steers, dietary barley, corn, portal and jugular hormones, glucose, amino acids

1974 ◽  
Vol 32 (3) ◽  
pp. 479-489 ◽  
Author(s):  
J. H. G. Holmes ◽  
H. S. Bayley ◽  
P. A. Leadbeater ◽  
F. D. Horney

1. Six 45 kg pigs with re-entrant ileal cannulas were used in two 3 × 3 Latin-square design experiments to study the site of absorption of protein and amino acids. Semi-purified diets containing soya-bean meal (SBM), rapeseed meal (RSM) or no protein source (protein-free) were offered at the rate of 1 kg dry matter/d.2. Flow-rates of ileal contents for 24 h collection periods, corrected for recovery of marker, were 3135, 3127 and 1243 ml (SE 390) for SBM, RSM and protein-free diets respectively.3. Amounts of dry matter digested in the small intestine were 730, 669 and 809 g/d for SBM, RSM and protein-free diets respectively, all values being significantly different (P < 0·001).4. Nitrogen intakes were 32·6, 29·9 and 5·9 g/d, and amounts digested in the small intestine were 25·7, 20·2 and 1·6 g/d for SBM, RSM and protein-free diets respectively, all values being significantly different (P < 0·001). Amounts digested in the large intestine were 2·6, 3·7 and 0·7 g/d.5. Total amino acid intakes and amounts collected at the ileum and in the faeces were (g/d): SBM, 177, 24 and 18; RSM, 149, 28 and 22; protein-free 3, 9 and 12. Digestibility in the small intestine was higher for SBM than RSM for seventeen of the eighteen amino acids estimated. Greater quantities of arginine, methionine, cystine and tyrosine were voided in the faeces than passed through the ileal cannulas for pigs receiving the SBM and RSM diets. For those receiving the protein-free diet this was true for each amino acid except proline.6. Significant differences were found between all diets in the concentration of some amino acids in ileal and faecal amino-N, and endogenous protein secretions did not mask the differences between diets.7. Differences in digestibility between SBM and RSM were greater at the ileum than in the faeces. Amino acid fermentation in the large intestine obscured or reduced differences between SBM and RSM.


1996 ◽  
Vol 76 (2) ◽  
pp. 163-169 ◽  
Author(s):  
R. J. Boila ◽  
S. C. Stothers ◽  
L. D. Campbell

The concentrations of protein and individual amino acids were determined in the grain from three cultivars of wheat and three cultivars of barley, each grown at 12 locations throughout Manitoba over 3 consecutive years. Protein concentration differed (P < 0.05) among the cultivars of wheat but not (P > 0.05) among cultivars of barley. Although the concentrations of several amino acids differed (P < 0.05) among cultivars of wheat or barley the differences among cultivars of each grain were not considered to be critical in relation to the requirements for indispensable amino acids for swine or poultry. The percentage of an ammo acid in the DM of wheat and barley increased (P < 0.05) linearly with an increase in percentage of protein in the grain. The wide range of r2 (0.29 to 0.88) obtained for this amino acid-protein relationship may be due to the different effect of environment (location and year of growth) on the concentration of individual amino acids, compared to protein, among cultivars of wheat or barley. The percentage of total variance due to an interaction between cultivar and environment was low for protein but was several fold higher for individual amino acids. The error in the prediction of amino acid concentrations with regression equations may be no different than the error associated with predicting the mean concentrations of amino acids in the protein of wheat or barley as g (100 g protein)−1, and obtained from tabulations of analyses. However, regression equations for lysine in wheat and barley did account for the significant (P < 0.05) decrease in concentration of lysine in the protein as the percentage of protein in these grains increased. Key words: Grain, wheat, barley, protein, amino acids, Manitoba


1977 ◽  
Vol 166 (1) ◽  
pp. 49-55 ◽  
Author(s):  
A Palou ◽  
L Arola ◽  
M Alemany

Plasma amino acid concentrations were determined in virgin female rats, in pregnant rats (12 and 21 days after impregnation) and in 21-day foetuses. The total amino acid concentration in plasma decreases significantly with pregnancy, being lower at 12 than at 21 days. Alanine, glutamine+glutamate and other ‘gluconeogenic’ amino acids decrease dramatically by mid-term, but regain their original concentrations at the end of the pregnancy. With most other amino acids, mainly the essential ones, the trend is towards lower concentrations which are maintained throughout pregnancy. These data agree with known nitrogen-conservation schemes in pregnancy and with the important demands on amino acids provoked by foetal growth. In the 21-day foetuses, concentrations of individual amino acids are considerably higher than in their mothers, with high plasma foetal/maternal concentration ratios, especially for lysine, phenylalanine and hydroxy-proline, suggesting active protein biosynthesis and turnover. All other amino acids also have high concentration ratios, presumably owing to their requirement by the foetuses for growth. Alanine, glutamine+glutamate, asparagine+aspartate, glycine, serine and threonine form a lower proportion of the total amino acids in foetuses than in the virgin controls or pregnant rats, probably owing to their role primarily in energy metabolism in the adults. The results indicate that at this phase of foetal growth, the placental amino acid uptake is considerable and seems to be higher than immediately before birth.


2012 ◽  
Vol 12 (7) ◽  
pp. 17367-17396 ◽  
Author(s):  
E. Scalabrin ◽  
R. Zangrando ◽  
E. Barbaro ◽  
N. M. Kehrwald ◽  
J. Gabrieli ◽  
...  

Abstract. Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids to quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (<0.49 μm) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanics.


2012 ◽  
Vol 12 (21) ◽  
pp. 10453-10463 ◽  
Author(s):  
E. Scalabrin ◽  
R. Zangrando ◽  
E. Barbaro ◽  
N. M. Kehrwald ◽  
J. Gabrieli ◽  
...  

Abstract. Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids and quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (< 0.49 μm) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanic emissions.


1973 ◽  
Vol 53 (4) ◽  
pp. 717-724 ◽  
Author(s):  
H. A. SALEM ◽  
T. J. DEVLIN ◽  
J. R. INGALLS ◽  
G. D. PHILLIPS

The effects of a semipurified diet containing 0 (0% urea-N diet), 50 (39% urea-N diet), or 100% (76% urea-N diet) of added dietary nitrogen (N) as urea on the amino acid concentrations in ruminant tissues was investigated. Three rumen-fistulated bull calves averaging 240 kg were used in a latin square design. The calves were fed using a continuous feeder to provide 7 kg of feed daily. Each experimental period of the latin square was 40 days divided into four 10-day intervals. Liver samples were obtained on the 9th day of each 10-day interval and rumen epithelium and rumen microorganisms were obtained on the 10th day of each 10-day interval. Blood samples were collected on the 6th, 8th, and 10th day of each 10-day interval for the determination of plasma amino acid patterns as well as the amino acid concentrations in the tissues. Plasma amino acid patterns indicated that when the 76% urea-N diet was fed the levels of aspartic acid, citrulline, glutamic acid, glycine, and proline were increased. Most of the essential amino acids were decreased on the 76% urea-N diet as compared with the 0% urea-N diet. All amino acids of rumen microorganisms were increased on the 39% urea-N diet with the exception of arginine, lysine, and threonine, which decreased slightly or did not show any change. Most amino acids were lower on the 76% urea-N diet as compared with the 39% or 0% urea-N diets. All essential amino acids measured in the liver were reduced on the 76% urea-N diet. Cystine, glutamic acid, glycine, isoleucine, leucine, lysine, tryptophan, and valine were also reduced on the 39% urea-N diet. In rumen epithelium, there was a reduction of the essential amino acids and an increase of the nonessential amino acids on the 76% urea-N diet.


2021 ◽  
Vol 57 (No. 2) ◽  
pp. 140-147
Author(s):  
Geoffrey Dixon

Soil-borne pathogens such as Verticillium species, invade into the roots of many herbaceous and woody hosts.  The xylem environment supplies these pathogens with a continuous flow of nitrogen-rich nutrition. Detailed quantitative increases in amino acids in the stems, petioles, leaflets and roots of young tomato plants infected with Verticillium. albo-atrum the causal agent of wilt disease, are described in this paper for the first time. Results focus in particular on the vascular environment prior to the emergence of visual symptoms. Total amino acid concentrations in infected stems and petioles increased substantially at 144 and 216 h after inoculation. This effect was evident in leaflets at 216 h after inoculation. By 216 h most amino acid concentrations were substantially increased in stems, petioles and leaflets of infected plants relative to healthy controls. Earlier at 144 h in stems substantial increases were recorded for aspartic acid, threonine, serine, glutamic acid, glycine and ethanolamine. A similar picture emerged for petioles with the addition of increases in proline but not glycine. Amino acids increasing substantially in infected leaflets at 216 h were aspartic acid, glutamic acid and ethanolamine. In the infected roots there was relatively little difference in amino acid concentrations relative to healthy controls with the particular exceptions of proline and ethanolamine. By 18 days (432h), when visual symptoms were well advanced marked increases in amino acid concentrations were found for threonine, serine, α-alanine, valine, methionine, iso-leucine, leucine, tyrosine, ethanolamine, ornithine, lysine, histidine and arginine.


1974 ◽  
Vol 54 (2) ◽  
pp. 157-167 ◽  
Author(s):  
H. R. SHARMA ◽  
J. R. INGALLS

Four rumen-fistulated young Holstein steers (189 kg average weight) were used in a latin square design. The steers were fed four semipurified pelleted diets, containing either 19% rapeseed meal (RSM) or 7.5% casein protein untreated or formaldehyde (FA)-treated (0.7 g FA/100 g protein), at frequent intervals. FA treatment of RSM or casein tended to reduce the ammonia production in the rumen of steers receiving the experimental diets and showed little effect on apparent digestibilities of dry matter (DM), crude protein (CP) or nitrogen (N) retention. FA treatment of casein but not of RSM increased (P < 0.05) the flow of total N, non-ammonia N (NAN) and digesta from the rumen. The bacterial N in the rumen digesta varied from 40–61% of the dietary N for the steers fed the experimental diets. FA treatment significantly increased total amino acid concentrations (P < 0.01) in the rumen digesta of steers fed the FA-casein diet and resulted in a nonsignificant (P > 0.05) increase for FA-RSM steers compared with those given untreated diets. Treatment of casein with FA reduced the catabolism of essential amino acids which resulted in larger quantities of these amino acids being transported out of the rumen as compared to the untreated casein diet. However, FA treatment of RSM protein did not promote a significant increase in the quantities of amino acids leaving the rumen of steers receiving the FA-RSM diet compared with those on the RSM diet.


2000 ◽  
Vol 83 (3) ◽  
pp. 307-315 ◽  
Author(s):  
G. D. Milano ◽  
A. Hotston-Moore ◽  
G. E. Lobley

The mass transfers of O2, glucose, NH3, urea and amino acids across the portal-drained viscera (PDV) and the liver were quantified, by arterio–venous techniques, during the last 4 h of a 100 h infusion of 0 (basal), 150 or 400 μmol NH4HCO3/min into the mesenteric vein of three sheep given 800 g grass pellets/d and arranged in a 3 × 3 Latin-square design. Urea irreversible loss rate (ILR) was also determined by continuous infusion of [14C]urea over the last 52 h of each experimental period. PDV and liver movements of glucose, O2and amino acids were unaltered by NH4HCO3administration, although there was an increase in PDV absorption of non-essential amino acids (P= 0·037) and a trend for higher liver O2consumption and portal appearance of total amino acid-N, glucogenic and non-essential amino acids at the highest level of infusion. PDV extraction of urea-N (P= 0·015) and liver removal of NH3(P< 0·001), release of urea-N (P= 0·002) and urea ILR (P= 0·001) were all increased by NH4HCO3infusion. Hepatic urea-N release (y) and NH3extraction(x) were linearly related (R20·89), with the slope of the regression not different from unity, both for estimations based on liver mass transfers (1·16; SE 0·144;PB≠ 1= 0·31) AND [14C]UREA (0·97; se 0·123;Pb≠ 1= 0·84). The study indicates that a sustained 1·5 or 2·4-fold increase in the basal NH3supply to the liver did not impair glucose or amino acid supply to non-splanchnic tissues; nor were additional N inputs to the ornithine cycle necessary to convert excess NH3to urea. Half of the extra NH3removed by the liver was, apparently, utilized by periportal glutamate dehydrogenase and aspartate aminotransferase for sequential glutamate and aspartate synthesis and converted to urea as the 2-amino moiety of aspartate.


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