APPARENT DIGESTIBILTY OF AMINO ACIDS AND OTHER NITROGENOUS COMPOUNDS IN THE SMALL INTESTINE OF WETHERS EXPOSED TO A COLD ENVIRONMENT

1989 ◽  
Vol 69 (4) ◽  
pp. 921-929
Author(s):  
J. M. KELLY ◽  
R. J. CHRISTOPHERSON ◽  
R. J. EARLY

Digestion studies were conducted with eight shorn yearling Suffolk wethers to assess the effects of environmental temperature on intestinal digestion of nonammonia nitrogen (NAN) and amino acid N. The wethers were cannulated in the rumen, abomasum, and terminal ileum and subsequently chronically exposed to either cold (0–2 °C) or warm (21–25 °C) temperatures in a crossover experiment. Sheep were fed a diet of chopped bromegrass hay and digesta flows through the abomasum and terminal ileum were estimated by reference to 103ruthenium-phenanthroline and 51chromium-EDTA. Microbial N contributions to total N in abomasal digesta were estimated with 35sulphur. During cold exposure, mean rumen ammonia concentration was reduced (P < 0.01) by 20%, while net appearance of NAN across the forestomach increased from 2.7 to 7.3 g d−1 (P < 0.05) resulting in a 14% increase in flow of NAN from the abomasum. The latter was associated with a 63% increase in flow of undegraded feed N (P < 0.05) and a nonsignificant decrease in microbial NAN. There was a small increase in flow of most amino acids from the abomasum due to cold exposure, with significant effects for lysine, histidine and tyrosine (P < 0.05). Disappearances of lysine (P < 0.05) and tyrosine (P < 0.005) in the small intestine were increased by the cold environment. Cold exposure increased small intestinal digestion of amino acid N relative to digestible organic matter intake (P < 0.08) suggesting maintenance of amino acid supply relative to that of energy in a cold environment. Key words: Amino acids, digestion, small intestine, sheep, cold environment

1990 ◽  
Vol 63 (3) ◽  
pp. 489-502 ◽  
Author(s):  
D. E. Beever ◽  
M. Gill ◽  
J. M. Dawson ◽  
P. J. Buttery

The effect of two levels of fishmeal substitution (50 (FM1) and 150 (FM2) g/kg) of a grass silage control diet (C) on the rumen digestion of organic matter and nitrogen, and the small intestinal disappearance of amino acids was examined in young growing cattle each equipped with simple PVC cannulas in the dorsal sac of the reticulo-rumen, the proximal duodenum and the terminal ileum. The silage was a primary growth of perennial ryegrass (Lnlium pevenne) (+formic acid) with a total N content of 22 g/kg dry matter (DM) (diet C). Fishmeal substitution increased this to 26 (diet FM1) and 34 (diet FM2) g/kg DM. On diets C and FM1, approximately 0.71 of digestible organic matter intake was apparently digested in the rumen, but this was significantly (P < 0.05) reduced on diet FM2 (0.60). Whilst duodenal flows of non-ammonia N and total amino acids were significantly (P < 001) increased at the highest level of fishmeal inclusion only, the synthesis of microbial N was significantly (P < 0.001) reduced by fishmeal inclusion, and feed N degradability declined progressively in response to increased fishmeal. Both levels of fishmeal addition caused a significant (P< 0.05) reduction in the fractional outflow rate of water from the rumen, and on the highest level of fishmeal significant (P< 0.05) increases in rumen ammonia concentration and rumen propionate molar proportions were observed. The net effect of the highest level of fishmeal substitution was to increase amino acid absorption from the small intestine by 0.47 compared with the control diet (P< 0.05), but due to an elevated ileal flow of amino acid no such effect was detected at the lowest level of fishmeal substitution. Composition of the absorbed amino acid fraction was relatively unaffected by the treatments imposed, despite large changes in the composition of the duodenal protein. The apparent non-linearity of response to fishmeal substitution is discussed and the amino acid supply findings are compared with the protein retention findings obtained in an earlier study by Gill et al. (1987). By two methods of calculation it was estimated that the amino acid N fraction disappearing from the small intestine was utilized with an efficiency of between 0.51 and 0.53 and no apparent effects due to diet or level of amino acid supply were detected.


1972 ◽  
Vol 27 (1) ◽  
pp. 39-50 ◽  
Author(s):  
J. C. Macrae ◽  
M. J. Ulyatt ◽  
P. D. Pearce ◽  
Jane Hendtlass

1. In two experiments, sheep prepared with a rumen cannula and with re-entrant cannulas in the duodenum and ileum were continuously fed on diets of dried grass, dried grass plus formalin-treated casein, or dried grass plus untreated casein. Paper impregnated with chromic oxide was given once daily via the rumen fistula.2. In ten 24 h collections of digesta entering the duodenum and eleven 24 h collections of digesta reaching the ileum of sheep given dried grass, there were highly significant correlations between the 24 h flows of Cr marker and the corresponding flows of dry matter, organic matter, nitrogen, gross energy, hemicellulose and cellulose (P < 0.01) at both sites.3. Daily amounts of non-ammonia N and of individual amino acids entering and leaving the small intestine and of total N excreted in faeces and urine are given.4. Net retention of supplementary N was 36% when the supplement was administered as formalin-treated casein, but only 17% when it was administered as untreated casein.5. Formalin treatment of casein significantly increased the daily amounts of non-ammonia N entering the small intestine (P < 0.01) and the amounts of non-ammonia N apparently absorbed therein (P < 0.05).6. Apparent absorption of amino acids from the small intestine was significantly greater (P < 0.05) with treated casein than with untreated casein. There were relative increases in the small amounts of several free amino acids measured, including taurine, in the ileal digesta of sheep receiving the treated casein supplement.


1974 ◽  
Vol 54 (3) ◽  
pp. 305-313 ◽  
Author(s):  
H. R. SHARMA ◽  
J. R. INGALLS ◽  
R. J. PARKER

Four Holstein steers fitted with T-type soft plastic cannulae in the rumen, abomasum and terminal ileum were fed four semipurified pelleted diets containing 19% rapeseed meal (RSM) or 7.5% casein, both untreated or treated with formaldehyde (FA), during the four experimental periods. The diets were fed from an automatic belt feeder device. FA treatment of casein increased (P < 0.01) the flow of total N and non-ammonia-N (NAN) as a percentage of intake through the abomasum of steers. Significantly more (P < 0.05) bacterial N passed through the abomasum of steers fed RSM diets than those receiving the casein diets. FA treatment caused a nonsignificant (P > 0.05) depression in the apparent digestibility of dry matter (DM) in the small intestine of steers receiving the treated diets. Significantly greater (P < 0.05) quantities of total N and NAN passed through the terminal ileum of steers consuming the RSM diets compared to those fed casein diets. Total determined amino acids in the abomasum as a percentage of amino acid intake were lower (P < 0.01) for untreated casein diet compared to the other three treatments. FA treatment increased (P < 0.05) the flow of lysine, histidine, valine, isoleucine, leucine and tyrosine in the abomasum of steers receiving FA casein compared with untreated casein, but had no effect in the case of treated RSM. FA treatment increased the absorption of most of the essential amino acids in the small intestine of steers receiving the FA casein compared to casein diet. Treatment of RSM resulted in reduced (P < 0.05) fecal excretion of threonine, valine, isoleucine, leucine, phenylalanine and tyrosine.


1989 ◽  
Vol 69 (4) ◽  
pp. 911-919 ◽  
Author(s):  
J. M. KELLY ◽  
R. J. CHRISTOPHERSON

Eight shorn yearling Suffolk wethers cannulated in the rumen, abomasum, and terminal ileum were exposed to temperatures of 0 to + 2 °C or 21–25 °C in a crossover experiment to determine effects on the apparent digestibilities of dry matter (DM), organic matter (OM) and nonammonia nitrogen (NAN) in the forestomach and small intestine. Animals were housed in metabolic crates and fed 1600 g d−1 chopped bromegrass hay. After 30 d acclimation, feed, ruminal, abomasal, terminal ileal and fecal samples were acquired for the determination of DM, OM, cell wall constituents (CWC), acid detergent fiber (ADF) and NAN. Rumen volatile fatty acid composition was also determined. Digesta flows at the abomasum and terminal ileum were estimated from the dilution of 103ruthenium-phenanthroline and 51chromium-EDTA during continuous infusion of these markers into the rumen. Dry matter (P < 0.10), OM (P < 0.05) and NAN (P < 0.05) flows to the abomasum were increased during cold exposure. The apparent digestibilities of DM (P < 0.10), OM (P < 0.05) and NAN (P < 0.05) in the rumen were decreased during cold exposure but the apparent digestibilities of these components did not change in the small intestine. Consequently, during cold exposure the proportion of OM and NAN digested in the small intestine relative to OM digested in the entire gastrointestinal tract was increased. Total ruminal VF A concentration was not affected by temperature; however, the molar proportion of acetate declined (P < 0.05) and that of propionate increased (P < 0.01). This, together with a greater proportion of the digestion taking place in the small intestine, may improve the efficiency of utilization of metabolizable energy and partly compensate for the decreased ruminal digestion of OM during cold exposure. Key words: Organic matter, nitrogen, digestion, sheep, cold environment


1979 ◽  
Vol 93 (1) ◽  
pp. 181-188 ◽  
Author(s):  
N. P. McMeniman ◽  
D. G. Armstrong

SUMMARYThe effect of substituting different amounts of heated and unheated beans for barley in diets to cows, on the flow of total nitrogen (N), total amino acid nitrogen (TAA-N) and individual amino acids into the proximal duodenum was studied. Neither heating of the beans nor increasing their proportion in the diet significantly increased the flow of total N at the duodenum; however, increasing the proportion of beans did increase the flow of TAA-N. The substitution of both forms of cracked beans for barley, and at both levels significantly increased the flows of leucine and aspartic acid; flows of histidine, isoleucine, phenylalanine and serine were increased by substitution of both forms of beans but only at the higher level. In the bean supplemented diets significant proportions of all of the ingested amino acids except methionine were apparently destroyed in the forestomachs. The substitution of beans for barley resulted in a net increase of 0·2 g TAA-N flow into the proximal small intestine for each gram of additional dietary N.


1982 ◽  
Vol 48 (3) ◽  
pp. 527-541 ◽  
Author(s):  
B. R. Cottrill ◽  
D. E. Beever ◽  
A. R. Austin ◽  
D. F. Osbourn

1. A total of six diets based on maize silage were formulated to examine the effect of protein- and non-protein-nitrogen, and energy supplementation on the flow of amino acids to the small intestine and the synthesis of microbial amino acids in the rumen of growing cattle. All diets contained 24 g totai nitrogen (N)/kg dry matter (DM), of which 550 g N/kg total N was supplied by either urea or fish meal. Four diets contained low levels of barley (estimated total dietary metabolizable energy content of 10·4 M J/kgDM) and urea-N and fish meal-N were supplied in the ratios 3:1, 1·4:1, 0·6:1 and 0·3:1. The other two diets contained between 300 and 400 g barley/kg total diet (11·3 MJ metabolizable energy/kg DM) and the urea-N to fish meal-N ratios were 3:1 and 0·3:1.2. On the four low-energy diets, fish meal inclusion tended to reduce the extent of organic matter (OM) digestion in the rumen but significantly increased duodenal amino acid supply (P< 0·05) in a quadratic manner. Microbial-N synthesis was increased by the two intermediate levels of fish meal supplementation but declined at the highest level of inclusion. With increasing levels of fish meal inclusion, a greater proportion of the dietary protein was found to escape rumen degradation and the apparent degradabilities of fish meal and maize-silage protein of all four diets were estimated to be 0·22 and 0·73 respectively.3. The substitution of barley for part of the maize silage enhanced duodenal supply of amino acids, irrespective of the form of the N supplement, and stimulated microbial amino acid synthesis. For all diets efficiency of microbial-N synthesis was found to vary between 22·5 and 46 g N/kg rumen-digested OM. Contrary to what was found for low-energy diets, the inclusion of fish meal tended to reduce the flow of dietary protein to the small intestine, but these differences were not statistically significant.4. The results appertaining to microbial synthesis, dietary protein degradabilities and duodenal amino acid flow for all diets are discussed in relation to the Agricultural Research Council (1980) proposals for the protein requirements of ruminants, and the production responses observed when similar diets were fed to growing cattle.


1998 ◽  
Vol 64 (8) ◽  
pp. 2836-2843 ◽  
Author(s):  
Cengiz Atasoglu ◽  
Carmen Valdés ◽  
Nicola D. Walker ◽  
C. James Newbold ◽  
R. John Wallace

ABSTRACT The influence of peptides and amino acids on ammonia assimilation and de novo synthesis of amino acids by three predominant noncellulolytic species of ruminal bacteria, Prevotella bryantii B14, Selenomonas ruminantiumHD4, and Streptococcus bovis ES1, was determined by growing these bacteria in media containing 15NH4Cl and various additions of pancreatic hydrolysates of casein (peptides) or amino acids. The proportion of cell N and amino acids formed de novo decreased as the concentration of peptides increased. At high concentrations of peptides (10 and 30 g/liter), the incorporation of ammonia accounted for less than 0.16 of bacterial amino acid N and less than 0.30 of total N. At 1 g/liter, which is more similar to peptide concentrations found in the rumen, 0.68, 0.87, and 0.46 of bacterial amino acid N and 0.83, 0.89, and 0.64 of total N were derived from ammonia by P. bryantii, S. ruminantium, andS. bovis, respectively. Concentration-dependent responses were also obtained with amino acids. No individual amino acid was exhausted in any incubation medium. For cultures of P. bryantii, peptides were incorporated and stimulated growth more effectively than amino acids, while cultures of the other species showed no preference for peptides or amino acids. Apparent growth yields increased by between 8 and 57%, depending on the species, when 1 g of peptides or amino acids per liter was added to the medium. Proline synthesis was greatly decreased when peptides or amino acids were added to the medium, while glutamate and aspartate were enriched to a greater extent than other amino acids under all conditions. Thus, the proportion of bacterial protein formed de novo in noncellulolytic ruminal bacteria varies according to species and the form and identity of the amino acid and in a concentration-dependent manner.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245739
Author(s):  
Inês Vieira da Silva ◽  
Bárbara P. Soares ◽  
Catarina Pimpão ◽  
Rui M. A. Pinto ◽  
Teresa Costa ◽  
...  

The regulation of glycerol permeability in the gastrointestinal tract is crucial to control fat deposition, lipolysis and gluconeogenesis. Knowing that the amino acid glutamine is a physiological regulator of gluconeogenesis, whereas cystine promotes adiposity, herein we investigated the effects of dietary supplementation with glutamine and cystine on the serum biochemical parameters of piglets fed on amino acid-enriched diets, as well as on the transcriptional profile of membrane water and glycerol channels aquaporins (AQPs) in the ileum portion of the small intestine and its impact on intestinal permeability. Twenty male piglets with an initial body weight of 8.8 ± 0.89 kg were allocated to four dietary treatments (n = 5) and received, during a four week-period, a basal diet without supplementation (control) or supplemented with 8 kg/ton of glutamine (Gln), cystine (Cys) or the combination of the two amino acids in equal proportions (Gln + Cys). Most biochemical parameters were found improved in piglets fed Gln and Cys diet. mRNA levels of AQP3 were found predominant over the others. Both amino acids, individually or combined, were responsible for a consistent downregulation of AQP1, AQP7 and AQP10, without impacting on water permeability. Conversely, Cys enriched diet upregulated AQP3 enhancing basolateral membranes glycerol permeability and downregulating glycerol kinase (GK) of intestinal cells. Altogether, our data reveal that amino acids dietary supplementation can modulate intestinal AQPs expression and unveil AQP3 as a promising target for adipogenesis regulation.


1998 ◽  
Vol 78 (1) ◽  
pp. 81-87 ◽  
Author(s):  
S. X. Huang ◽  
W. C. Sauer ◽  
M. Pickard ◽  
S. Li ◽  
R. T. Hardin

Studies were carried out to determine the effect of micronization on energy, starch and amino acid digestibilities in hulless barley. Six pigs (Canabrid × Camborough) were weaned at 21 d of age and fitted with a simple T-cannula at the distal ileum on days 23 or 24. The pigs were fed one of three diets with major constituents of hulless barley and soybean meal (HB + SBM), micronized hulless barley and soybean meal (MHB + SBM) and corn starch and soybean meal (C + SBM) according to a repeated Latin square design. The pigs were fed three times daily, equal amounts at 8-h intervals. The diets were supplied at a rate of 5% (wt/wt) of body weight. The average body weight of the pigs was 9.3 kg at start and 15.9 kg at the conclusion of the experiment at 58 d of age. Faeces were collected for 48 h on days 6 and 7 and ileal digesta for 24 h on days 8 and 9. Chromic oxide was used as digestibility marker. The apparent ileal amino acid digestibilities in HB and MHB were determined by the difference method. The apparent ileal digestibilities of the indispensable amino acids were higher in MHB than in HB and ranged from 5.3 to 10.0 percentage units. Of the indispensable amino acids, the differences were significant (P < 0.05) for arginine, histidine, isoleucine, phenylalanine and valine. Micronization of HB improved (P < 0.05) the ileal digestibility of starch from 79.0 to 97.3%. Micronization resulted in an increase in the digestion of energy in the small intestine and a decrease in microbial fermentation of energy in the large intestine. This shift in the disappearance of energy from the large to the small intestine should also result in an improvement in the efficiency of energy utilization. These studies show a positive effect of micronization on the digestibilities of energy and amino acids in young pigs fed HB. Key words: Micronization, barley, digestibility, pigs


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