Biliary tract duplication cyst with gastric heterotopia.
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Adolescent↗
Biomedical subjects
D H Baker
Publications and source records attributed to D H Baker.
Bioavailability of lysine in L-lysine.HCl.
True digestibility of lysine (LYS) in crystalline L-LYS.HCl and casein determined in cecectomized adult roosters was not significantly different from 100%. Subsequent 9-d growth assays were conducted to determine the bioavailability of LYS in casein, in L-LYS.HCl, and in a mixture of crystalline amino acids simulating casein's amino acid profile. Based on slope-ratio methodology, LYS bioavailability relative to casein was estimated to be 101.4 and 99.9% in L-LYS.HCl and in the casein-simulated amino acid mixture, respectively. Procedures also were developed for assessment of LYS bioavailability in crystalline L-LYS.HCl by comparing growth responses to intraperitoneally injected (IP-LYS) and crop-intubated LYS (CI-LYS) in chicks fed LYS-deficient corn-sesame meal diets. Graded increments of pH-adjusted L-LYS.HCl were administered twice daily in .5-ml doses during the course of 8-d growth assays. Chicks receiving CI-LYS also received .5 ml of IP saline at each dosing, and those receiving IP-LYS also received CI saline at each dosing. Slope-ratio multiple linear regression of gain (g) regressed on LYS administered (mg) was assessed for both ad libitum-fed and meal-fed chicks. Linear growth responses to LYS were obtained with both routes of administration and in both feeding regimens. The CI-LYS slopes ranged from 103 to 125% of those obtained with IP-LYS administration. These results support the view that crystalline L-LYS.HCl is 100% digestible and bioavailable.
Animals↗
Histidine requirement of the young pig.
A histidine (HIS)-deficient, feather meal-corn-dried whey basal diet (19% protein and 3,200 Kcal ME/kg), supplemented with lysine, methionine and tryptophan, was employed to determine the HIS requirement of the growing pig between 10 and 20 kg live weight. Using a chick bioavailability growth assay, the HIS-deficient basal diet was found to contain .19% bioavailable HIS. A preliminary pig study established that the HIS-deficient basal diet was capable of supporting good growth of pigs when supplemented with sufficient L-HIS.HCl.H2O. In the second pig experiment, crossbred pigs with an average initial weight of 10 kg were kept in individual metabolism crates and were fed to appetite in two feedings the HIS-deficient basal diet supplemented with 0, .06, .12 or .18% L-HIS. Rate and efficiency of weight gain increased linearly between 0 and .12% supplemental HIS, but the highest supplemental level of HIS did not improve performance further. Plasma HIS increased, whereas plasma urea-N remained unchanged, as the level of dietary HIS increased. The third pig experiment employed narrower increments of .06, .09 or .12% supplemental HIS, and a linear response in both gain and feed efficiency occurred. Viewing all experiments together, the bioavailable HIS requirement of the 10- to 20-kg pig was .31% of the diet. Assuming an 85% bioavailability of HIS in commercial diets based on corn and soybean meal, the total HIS level needed in practice would be .36%.
Animal Nutritional Physiological Phenomena↗
Characterization of the growth response obtained from Eimeria acervulina infection in chicks fed lysine-deficient diets.
Five assays were conducted with crossbred chicks to define the gain and feed efficiency response elicited when chicks fed lysine-deficient diets are infected with Eimeria acervulina. Crystalline amino acid diets that were either severely deficient in lysine (.12 or 20%) or adequate (.91%) were fed in the presence or absence of E. acervulina infection in the first four assays. In Assay 5, intact protein-based diets (corn-corn gluten meal) containing either .43 or 1.44% lysine were used to study the effects of lysine status on morbidity caused by E. acervulina infection. The infection was produced by crop intubating 1 X 10(6) sporulated E. acervulina oocysts either every other day in Assays 1, 2, and 5, or once at assay initiation in Assays 3 and 4. At deficient levels of dietary lysine, chicks by Day 6 after inoculations commenced exhibited marked gain and feed efficiency responses to E. acervulina inoculation. The same inoculation regimen in chicks fed diets adequate in lysine resulted in marked depressions in gain and feed efficiency. Monensin feeding diminished but did not entirely eliminate the inoculation response in lysine-deficient chicks. Throughout the assays, typical duodenal lesions were evident in infected chicks at necropsy, and dietary lysine status appeared to have no effect on the severity of lesions.
Animals↗
In vivo utilization of lysine and arginine in young chicks fed monensin.
Three chick growth assays were conducted to investigate the effects of monensin on lysine and arginine utilization in crossbred chicks (New Hampshire X Columbian). Chicks were fed either a low lysine corn-sesame meal diet containing graded increments of crystalline lysine.HCl (Assay 1) or an arginine-deficient casein-dextrose diet (Assay 2) supplemented with graded levels of L-arginine.HCl in the presence or absence of supplemental monensin (121 mg/kg). Based upon analysis by slope-ratio methodology (i.e., gain regressed on supplemental amino acid intake), the efficiency of L-lysine or L-arginine utilization was found to be the same in both monensin-fed and control chicks. In Assay 3, effects of monensin on the lysine-arginine antagonism were studied. Chicks were fed an arginine-deficient casein-dextrose diet supplemented with 1 or 2% L-lysine.acetate in the presence or absence of supplemental monensin. Growth performance was depressed by feeding both levels of supplemental L-lysine.acetate. Monensin had no effect on the magnitude of the growth depression caused by supplemental lysine. These results support the view that neither lysine nor arginine utilization is impaired by feeding monensin.
Animals↗
Further investigation of the dietary protein level-monensin interrelationship in broiler chicks: influence of dietary protein source and type of anticoccidial drug.
Three experiments were conducted to evaluate the influence of dietary protein source on the monensin response in healthy chicks fed diets varying in CP. The interrelationship between dietary CP level and four different anticoccidial drugs was evaluated in a fourth experiment. The experiments were conducted from 8 to 21 or 22 days posthatching. In Experiment 1, crossbred chicks were fed corn-soybean meal (SBM) diets containing either 24 or 16% CP or casein-dextrose diets containing 20, 15, or 10% CP in the presence or absence of 160 mg/kg monensin. When CP level was decreased in the corn-SBM treatments, the resulting monensin-induced growth depression was greater. However, this interaction was not observed in chicks fed casein-dextrose diets. Experiments 2 and 3 were conducted to determine if the monensin-protein level interrelationship is influenced by the source of dietary soybean protein or by high levels of animal protein (AP). Monensin at 140 mg/kg produced a much greater growth depression at 16 than at 24% CP in chicks fed a corn-SBM diet, whereas amounts of monensin depression in chicks fed a corn-isolated soy protein diet were similar for both CP levels. As dietary protein was reduced from 24 to 16% in Experiment 3, 140 mg/kg monensin caused growth depressions of 10 and 40%, and 14 and 28%, respectively, in broiler chicks fed corn-SBM and corn-AP diets.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Gastrointestinal manifestations of cystic fibrosis.
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Adolescent↗
Construction of assay diets for sulfur-containing amino acids.
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Amino Acids, Sulfur↗
Pharmacologic role of cysteine in ameliorating or exacerbating mineral toxicities.
Cysteine, via chelation reactions, ameliorates biochemical lesions caused by excessive ingestion of several trace elements. Because oral cysteine per se is considerably more protective than the in vivo metabolic cysteine precursors, methionine or cystine, chelation of cysteine with trace elements likely occurs primarily in the gut, thereby decreasing absorption of both cysteine and the trace element in question. Hence, using copper as an example, orally administered cysteine markedly improves growth and reduces liver copper deposition in chicks or rats fed a high level of inorganic copper. Likewise, excessive copper ingestion impairs sulfur amino acid (SAA) utilization and increases the dietary requirement for SAA. Cobalt and selenium toxicities are also ameliorated by oral cysteine ingestion, with the responses being even more striking than those occurring with copper toxicity. While inorganic arsenic poisonings are generally ameliorated by administering cysteine or a cysteine derivative (e.g., dimercaptopropanol), organic pentavalent arsenic toxicity is exacerbated by cysteine administration. Cysteine in this instance acts as a reducing agent, facilitating conversion of organic pentavalent arsenicals such as roxarsone and arsanilic acid to the more toxic trivalent state.
Animals↗
Failure of excess dietary lysine to antagonize arginine in young pigs.
Experiments were conducted with young pigs to evaluate the effects of excess lysine when added to diets marginal in arginine. The basal diet was formulated to contain 1.15% lysine and 0.53% arginine. Lysine levels above this were achieved by incremental additions of L-lysine.HCl (experiment 1) or L-lysine acetate (experiment 2). Neither weight gain nor gain-feed ratio was lowered in pigs fed twice the recommended level of lysine (i.e., 2.30%). Lysine levels three or four times the basal level, however, lowered both weight gain and feed intake with no commensurate reduction in feed efficiency. Therefore, lysine appeared to reduce growth via amino acid imbalance rather than antagonism. In pigs equally fed isonitrogenous diets, urea N excretion in the urine was lower in those fed 3.45% supplemental lysine (4.6% total lysine) than in those fed the basal diet. This was offset by a dramatic elevation in urinary excretion of basic amino acids. Urinary excretion of lysine accounted for 26.2% of the lysine consumed by pigs fed 3.45% supplemental lysine. Free lysine levels as well as alpha-aminoadipic acid levels were markedly higher in plasma, liver, kidney and muscle of pigs fed excess lysine than in those fed the basal diet. Tissue levels of arginase and ornithine transcarbamoylase were uninfluenced by the level of lysine ingested.
Amino Acids↗
Utilization of the L- and DL-isomers of alpha-keto-beta-methylvaleric acid by rats and comparative efficacy of the keto analogs of branched-chain amino acids provided as ornithine, lysine and histidine salts.
Three experiments were conducted to quantitatively evaluate the growth-promoting capacity of alpha-keto analogs of the branched-chain amino acids (BCAA). Basal chemically defined diets were formulated to be singly deficient in the BCAA under study; analogs therefore were evaluated as sources of supplemental amino acid activity. Analogs of isoleucine tested included alpha-keto-beta-L-methylvalerate (L-KMV) as the Na salt (L-KMV-Na) and alpha-keto-beta-DL-methylvalerate (DL-KMV) as the Na (DL-KMV-Na), ornithine (DL-KMV-Orn) and lysine (DL-KMV-Lys) salts. Slope-ratio efficacy values were L-KMV-Na, 65%; DL-KMV-Na, 44%; DL-KMV-Orn, 41%; DL-KMV-Lys, 43%. Alloisoleucine accumulated in the plasma of rats fed all sources of KMV, but its concentration was three times greater when DL-KMV was fed than when L-KMV was fed. The analog of valine tested was alpha-ketoisovalerate as the ornithine (KIV-Orn) or lysine (KIV-Lys) salts. There was no significant difference in efficacy between salts (47 versus 44%, respectively). The analog of leucine, alpha-ketoisocaproate, was given as the ornithine (KIC-Orn), lysine (KIC-Lys) and histidine (KIC-His) salts with resulting efficacies of 50, 38 and 49%, respectively. Slope-ratio efficacies of KIC-Orn and KIC-His were statistically similar and efficacy of KIC-Lys was inferior to both KIC-Orn and KIC-His.
Amino Acids, Branched-Chain↗
Amino acid excesses for young pigs: effects of excess methionine, tryptophan, threonine or leucine.
Five experiments involving 359 weanling (8 kg) pigs were conducted to evaluate the effects of dietary excesses of DL-methionine (Met), L-tryptophan (Trp), L-threonine (Thr) or L-leucine (Leu) when added to a 20% crude protein corn-soybean meal (C-SBM) diet. Experiments involved supplementing the basal diet with 0, .5, 1.0, 2.0 or 4.0% excesses of Met, Trp or Thr, or in the case of Leu, a 0, 1.0, 2.0, 4.0 or 6.0% excess. Levels of .5 and 1.0% excess Met did not depress feed intake (FI), weight gain (G) or gain/feed (G/F); 2.0 and 4.0% additions, however, depressed both FI and G but not G/F. Free Met in blood plasma increased linearly as dietary Met level increased, reaching over a 100-fold elevation at the highest Met level fed. Plasma Thr and serine (Ser) increased, and glycine (Gly) decreased, with each added increment of Met. With Trp, only the 4.0% addition depressed FI and G (but not G/F). None of the levels of excess Thr depressed performance. Excess Thr, in fact, tended to increase G/F. Free Thr, Ser and Gly in plasma increased linearly as graded increments of excess Thr were added to the diet. With Leu, a 6% addition depressed weight gain and food intake (but not G/F) but 1, 2 or 4% excesses were without effect. Plasma free Leu increased linearly while free isoleucine and valine decreased as graded increments of Leu were added to the diet. These results suggest that pigs can tolerate considerable excesses of Met, Trp, Thr and Leu without experiencing decreased voluntary feed intake or weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acids↗
Effect of excess levels of methionine, tryptophan, arginine, lysine or threonine on growth and dietary choice in the pig.
Six experiments were conducted with newly weaned pigs (8 kg) to evaluate the effects of 4% excesses of DL-methionine, L-tryptophan, L-threonine, L-lysine or L-arginine on growth or "choice" (i.e., self-selection) when added to 20% protein, corn-soybean meal (C-SBM) diets. Arginine was supplied as the free base and lysine as lysine acetate to avoid acid-base problems. In the growth study, gain was reduced 52, 31, 28, 16 and 5% by additions of methionine, arginine, tryptophan, lysine and threonine, respectively. Small decreases in gain/feed occurred in pigs fed diets with excess methionine or lysine. Feed intake depressions were evident in pigs fed excess methionine or excess tryptophan within 1 d after initiation of the growth trial. Self-selection studies revealed that pigs strongly preferred the control diet over any of the diets containing excess amino acids. Further studies indicated that pigs preferred diets with excess threonine, lysine or arginine over those containing an equal excess (i.e., 4%) of methionine or tryptophan. Moreover, there was a tendency for pigs to prefer the diet with excess threonine over the one containing excess lysine or arginine. Also, pigs clearly preferred the diet with excess methionine over the diet containing excess tryptophan. When given a choice between a protein-free diet and a C-SBM diet containing 4% excess tryptophan, pigs initially (d 0 to 4) preferred the protein-free diet, but later adapted to the extent that during the last 4 d of the 12-d trial they consumed more of the tryptophan-imbalanced diet than of the protein-free diet.
Amino Acids, Essential↗
Comparative effects of individual amino acid excesses when added to a corn-soybean meal diet: effects on growth and dietary choice in the chick.
Six experiments were conducted with 8-d-old crossbred chicks to evaluate the effects of 4% excesses of DL-methionine (Met), L-phenylalanine (Phe), L-tryptophan (Trp), L-lysine (Lys), L-histidine (His), L-threonine (Thr), L-isoleucine (Ile), L-arginine (Arg), L-valine (Val) or L-leucine (Leu) on growth or dietary "choice" (i.e., self-selection) when added to 23% protein corn-soybean meal (C-SBM) diets. Arginine and His were supplied as the free base and Lys as Lys X acetate to avoid acid-base problems. In the growth studies, weight gain was reduced 92, 79, 53, 50, 47, 31, 29, 15, 9, 4 and 0% by additions of 4% Met, Phe, Trp, His, Lys, Tyr, Thr, Ile, Arg, Val and Leu, respectively. Improvements (P less than .05) in weight gain, feed intake and gain/feed occurred by addition of 1% Arg to the C-SBM diet supplemented with 4% excess Phe or Tyr. Addition of 1% Arg to the C-SBM diet supplemented with 4% excesses of most of the other amino acids also tended to improve performance, although diets imbalanced with Lys, Val or Leu did not respond to supplemental Arg. Self-selection studies revealed that chicks preferred the C-SBM diet containing 4% excess Lys over diets containing 4% excesses of Met, Thr, Arg or Trp. Moreover, chicks preferred diets with 4% excess Met, Thr or Arg over those containing an equal excess of Trp. When given a choice between the C-SBM diet and this diet supplemented with 4% Leu, chicks consumed similar quantities of both diets.
Amino Acids↗
Urea cycle metabolism: effects of supplemental ornithine or citrulline on performance, tissue amino acid concentrations and enzymatic activity in young pigs fed arginine-deficient diets.
Two experiments were conducted with young pigs to determine the efficacy of ornithine (Orn) or citrulline (Cit) as precursors of arginine (Arg). In Exp. 1, pigs were individually fed an Arg-deficient, semipurified diet (.18% Arg) supplemented with .3% Arg or an equimolar quantity of Orn or Cit. Supplemental Arg or Cit increased rate and efficiency of weight gain, but Orn addition was without effect. Free Arg in plasma 3 h post-prandial was increased by addition of either Arg or Cit to the basal diet. Liver Arg was elevated by dietary addition of Arg, Orn or Cit; kidney Arg and Orn were elevated only in pigs receiving supplemental Cit. Arginine or Cit addition to the diet increased Arg concentration in muscle tissue, but muscle Orn was unresponsive to any of the supplements fed. In Exp. 2, pigs were again fed the Arg-deficient, semipurified diet supplemented with .3% Arg or four times an isomolar quantity of ornithine. Arginine addition to the diet increased weight gain and feed efficiency, while Orn supplementation was without effect. Plasma Orn was increased by excess Orn, while plasma Cit was unaffected by supplemental Arg or Orn. Moreover, excess Orn increased free Orn and proline (Pro) in liver, kidney and muscle. Free Cit, however, increased only in liver from feeding excess Orn. In addition, excess Orn decreased both plasma ammonia and free glutamine (Gln) concentration in brain. Arginase activity was roughly 10, 40 and 100 times greater in hepatic tissue than in renal cortex, renal medulla or intestinal mucosa, respectively, while hepatic ornithine transcarbamoylase (OTC) activity was about 15 times greater than the activity present in mucosa tissue. Renal OTC activity was too low to be accurately measured.
Animals↗
Effect of efrotomycin on gain and feed efficiency for pigs from weaning until market weight.
Six studies involving 700 pigs were conducted in five separate swine research facilities to evaluate weight gain and efficiency of feed utilization in pigs fed the antibiotic efrotomycin. Pigs averaging 8.4 kg at the beginning of the studies were fed fortified corn-soybean meal diets that contained efrotomycin at 0, 2, 4, 8 or 16 ppm for an average of 120 d to market weight, about 92.1 kg. Pigs fed efrotomycin gained 5.9 to 8.9% faster (P less than .01) and were 1.7 to 4.0% more efficient (P less than .01) than those fed control diets. The improvement in growth rate was linear from 2 through 16 ppm, while feed efficiency (gain/feed) plateaued at 4 ppm efrotomycin. Treatment X study interactions were not significant for average daily gain or feed efficiency, showing that the response to efrotomycin was similar in each study. These studies indicate that efrotomycin is effective in improving gain and efficiency of feed utilization in swine from weaning until market weight.
Administration, Oral↗
Effects of fasting on tissue amino acid concentrations and urea-cycle enzymatic activities in young pigs.
Weanling pigs were fed a 30% crude protein (CP) diet for 18 d and then assigned to one of three regimens for either 4 or 8 d: 1) fasting, 2) 3% CP, i.e., maintenance or 3) 30% CP after which they were bled, then sacrificed for tissue assessment. Relative to pigs fasted or fed 30% CP, feeding 3% CP resulted in decreased urea-N and NH3-N excretion in the urine. Arginase and ornithine transcarbamoylase (OTC) activities in liver, and arginase activity in kidney cortex were markedly lower in pigs fed 3% CP compared with those either fasted or fed 30% CP. Hepatic arginase and OTC, however, were higher in fasted pigs than in those fed 30% CP. Pigs fed 3% CP had much lower levels of free threonine, tyrosine, cystathionine, taurine and branched-chain amino acids in plasma, liver, kidney, muscle and brain than fasted pigs or those fed 30% CP. Threonine concentration in brain, liver, muscle and plasma increased as length of the fast increased. Fasted pigs had decreased free alanine levels in plasma, and decreased free serine levels in plasma and liver when compared with fed pigs. Inter-organ comparisons provided evidence that both alanine and serine were important gluconeogenic amino acids during fasting. In general, free amino acid levels in brain were similar between fasted pigs and those fed 30% CP. Fasting for 8 d caused a 10-fold elevation in urinary taurine excretion relative to that observed for 4-d fasted pigs.
Amino Acids↗
Mechanism of the tissue manganese-lowering effect of corn, soybean meal, fish meal, wheat bran, and rice bran.
Experiments were conducted with young chicks to investigate the mechanism by which various feed ingredients reduce the bioavailability of inorganic Mn. Although corn, soybean meal (SBM), fish meal (FM), wheat bran (WB), and rice bran (RB) contain significant quantities of Mn, these feed ingredients when added to a casein-dextrose diet have been shown to reduce Mn deposition in key tissues (i.e., bone, pancreas, and gallbladder). Studies reported herein indicate that reduction in tissue Mn concentration due to feed ingredient supplementation resulted from reduced Mn absorption, rather than from enhanced Mn excretion. Feedstuffs exerted their effect primarily at the gut level, although some Mn binding may also have occurred in body fluids. Fractionation of each feed ingredient indicated that the neutral detergent fiber (NDF) fraction of WB and a corn-SBM mixture accounted for virtually all of the Mn-binding capabilities of these ingredients. In contrast, ash fraction was responsible for tissue Mn-lowering capabilities of FM. Both NDF and ash fractions of RB significantly lowered tissue Mn concentrations, but not to the same extent as that caused by RB itself. A significant portion (11 to 27%) of the total quantity of copper was found in the NDF fraction of all feed ingredients. Over 12% of the magnesium and iron in FM was contained in the NDF fraction, while 20% of the magnesium in WB and 15% of the iron in RB was likewise present in the NDF fraction. Very little K, Zn, or Mn was associated with the NDF fraction of any feed ingredients. All Ca in WB but less than 1% of Ca in RB were present in the NDF.
Animal Feed↗