PubMed Health⌕ Search

Biomedical subjects

C M Parsons

Publications and source records attributed to C M Parsons.

At least 109 records · Page 6Linked to original sources
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1987

Nutritive value of high oil corn for poultry.

Several experiments were conducted to evaluate the nutritional value of high oil corn for poultry relative to that of conventional (CONV) corn. The variety of high oil corn (HO1) evaluated in most trials contained 6.0% oil and 9.6% protein on a 10% moisture basis. The protein quality of HO1 and CONV corn was assessed with female crossbred chicks fed corn as the sole source of dietary protein. There was no difference in either protein efficiency ratio or in net protein ratio between the two types of corn. True metabolizable energy (TME) and nitrogen-corrected TME (TMEn) values of HO1 corn were determined using adult roosters. The TME and TMEn values of HO1 corn were approximately 4.5% higher than those of CONV corn. Two experiments were conducted to evaluate the use of high oil corn varieties, containing from 6 to 13% oil, in practical diets of commercial broiler chicks from 8 to 22 days posthatching. Weight gain, gain-to-feed ratio, and skin and plasma pigmentation were improved in chicks fed 24% protein diets containing high oil corns compared with those fed the same diet containing CONV corn; magnitude of response was highly correlated to oil content of the corn. The relative value of HO1 corn in practical laying hen diets was examined in a 15-wk experiment. Hens fed a 17% protein diet containing HO1 corn from 23 to 38 weeks of age had a better feed-to-egg ratio than those fed the same diet containing CONV corn when the corn sources were substituted on an isonitrogenous basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Lysine and sulfur amino acid utilization in Eimeria acervulina-infected chicks as affected by narasin.

The effects of supplemental narasin (80 mg/kg) on several dietary factors were investigated in chicks infected with Eimeria acervulina. In Trial 1, chicks were fed a lysine-deficient corn-corn gluten meal diet containing graded increments of crystalline L-lysine.HCl with or without narasin. Supplemental narasin increased weight gain and feed efficiency at all lysine levels fed. Based upon slope-ratio methodology, efficiency of L-lysine utilization was virtually the same in both narasin-fed and control chicks. Trials 2 and 3 evaluated the effect of narasin on methionine utilization in crossbred chicks fed a methionine-deficient soy-feather meal diet supplemented with graded levels of DL-methionine. Narasin supplementation increased weight gain, feed efficiency, and utilization of supplemental methionine in chicks infected with E. acervulina (Trial 2), but had no effect on any of the performance parameters in uninfected chicks (Trial 3). The effects of dietary protein level and source and dietary electrolyte balance on the narasin response of commercial broiler chicks infected with E. acervulina were studied in Trials 4 and 5, respectively. In Trial 4, narasin supplementation increased performance in all cases, and protein source or level had no effect on the narasin response. In Trial 5, rate and efficiency of gain were improved as the electrolyte balance (meq Na + K-Cl/kg diet) increased from 100 to 250, with no further improvement being observed from 250 to 350 meq. Supplemental narasin improved performance and no interaction between electrolyte balance and narasin was observed.

Animals↗
PubMed1987

Interactive effects of monensin, roxarsone, and copper in young chickens infected with Eimeria tenella or a combination of E: tenella and E. acervulina.

Experiments were conducted with crossbred male chicks to evaluate the interactions among roxarsone (50 mg/kg), monensin (121 mg/kg), and copper sulfate (100 mg/kg) as treatments for experimental Eimeria tenella and E. acervulina infections. When diets containing monensin, roxarsone, or a combination of both were offered to chicks for 15 min or 1, 3, 5, or 8 days prior to E. tenella challenge (5 X 10(4) sporulated oocysts), monensin fed for 15 min or roxarsone fed for 1 day prior to challenge prevented morbidity. A mixed infection of E. tenella and E. acervulina (5 X 10(4) and 4 X 10(5) sporulated oocysts, respectively) reduced gain and gain:feed conversion ratios and caused severe duodenal and cecal lesions at Day 6 of the experiment. Infected chicks gained faster when diets were supplemented with either monensin or roxarsone, but monensin produced a larger response than roxarsone. The mixed infection decreased shank pigmentation, with amelioration activity evident from monensin but not from roxarsone. Lesion scores at Day 6 indicated markedly reduced lesions in the duodenum due to monensin but not due to roxarsone; likewise, reductions in cecal lesions occurred in birds fed roxarsone but less so in birds fed monensin. Lesion scores showed little evidence of additivity due to monensin and roxarsone. In general, copper sulfate exerted no independent or interactive effect on any of the parameters evaluated. In a subsequent experiment, the effect of feeding roxarsone in combination with the biological reducing agent, cysteine, was evaluated in E. tenella-infected chicks. Rate and efficiency of gain were improved and lesion scores were reduced by supplementary roxarsone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Determination of digestible and available amino acids in meat meal using conventional and caecectomized cockerels or chick growth assays.

1. The present study was designed to compare true digestible amino acid values for meat meal with available amino acid values. True digestible values were determined with a 48 h excreta collection assay using conventional (CONV) and caecectomized (CEC) cockerels. Available values for lysine, methionine and cystine were estimated by chick growth assays. 2. True digestibilities of all sixteen measured amino acids (expressed as a proportion of the total) were lower for CEC than for CONV cockerels, with the average difference being approximately 0.10. 3. Chick growth assays based on total weight gain indicated that the availabilities of amino acids expressed as a proportion of the total amino acids in meat meal were: 0.70 for lysine, 0.75 for methionine and 0.48 for cystine. Partitioning weight gains to reflect only growth attributable to supplemental crystalline amino acid or meat meal intake consistently yielded higher availability values than when total weight gains were used. 4. True digestibility values determined with CEC cockerels were in better agreement with chick available values than were true digestibility values determined with CONV cockerels. 5. The amounts of amino acids present in the caeca of meat meal-fed CONV cockerels at 48 h after feeding were small when compared with those levels voided in the excreta and those levels consumed in the feed. 6. Multiple regression analyses of excreta and caecal amino acid profiles at 12 and 48 h after feeding suggested that significant amounts of non-digested dietary amino acids flowed into the caeca and were subsequently metabolized by the caecal microflora.

Amino Acids↗
PubMed1986

Further investigation of the dietary protein and monensin level interrelationship in broiler chicks: influence of Eimeria acervulina infection, increased dietary protein, and level of feed intake.

Three experiments were conducted to evaluate the influence of several dietary factors on the monensin response in commercial broiler chicks fed corn-soybean meal diets varying in crude protein (CP). All experiments were conducted between 8 and 22 days posthatching. Trial 1 had a 2 X 2 X 2 factorial design wherein diets containing 16 or 24% CP and 0 or 121 mg/kg monensin were fed in the presence and absence of Eimeria acervulina infection. The monensin-induced growth depression was greater at 16% CP than at 24% CP. Coccidial infection had no effect on the monensin X protein level interaction. Monensin supplementation markedly improved performance of chicks infected with E. acervulina. Trial 2 was conducted to determine if the monensin-induced depression in performance caused by feeding a high level of monensin (140 mg/kg) could be moderated by feeding a high protein diet. Monensin supplementation reduced growth rate 18 and 10% in chicks fed 20 and 24% CP, respectively. Increasing CP to 28% alleviated the adverse effects of monensin on weight gain. Pair-feeding was used in Trial 3 to determine the extent to which the monensin-induced growth depression observed in chicks fed low protein diets was due to reduced feed intake. As expected, reducing the dietary CP from 24 to 16% resulted in a marked increase in the growth depression caused by 121 mg/kg monensin. Pair-feeding indicated that most of monensin's adverse effects in low protein diets could be attributed to its anorexic properties.

Animals↗
PubMed1984

Influence of caecectomy and source of dietary fibre or starch on excretion of endogenous amino acids by laying hens.

Two experiments were conducted to evaluate the effects of caecectomy and source of dietary fibre and starch on excretion of amino acids by laying hens. In Expt 1, caecectomized hens excreted significantly higher levels of several amino acids than intact hens during a 24 h fasting period. These differences were greatest for threonine, proline and leucine. In Expt 2, caecectomized and intact hens were given either a nitrogen-free diet containing 500 g cellulose/kg or one containing 400 g uncooked potato starch/kg and 100 g citrus pectin/kg. The potato starch-pectin (PSP) diet increased excretion of most amino acids by both caecectomized and intact hens compared with the cellulose diet, with this response being larger for intact hens. When compared across diets, caecectomized hens excreted more threonine and serine than intact hens. Excreta voided by hens given PSP contained higher levels of alanine and valine and lower levels of aspartic acid, glutamic acid and methionine than excreta from the cellulose diet. When compared across diets, excreta from caecectomized hens contained more threonine, serine and isoleucine and less aspartic acid and alanine than excreta from intact hens. Multiple regression analyses of excreta amino acid profiles on profiles of endogenous and microbial protein suggested that the intestinal microflora had greater influence on amino acids excreted by caecectomized hens than on those excreted by intact hens.

Amino Acids↗
PubMed1984

Choline and methionine supplementation of layer diets varying in protein content.

Two experiments were conducted with White Leghorn laying hens to evaluate choline and methionine addition to diets containing various crude protein (CP) levels. Corn-soybean meal diets containing 25 g/kg meat and bone meal were used in all experiments. Either choline or methionine supplementation at 1.0 g/kg improved egg production and feed:egg ratio of hens fed 140 g/kg CP from 23 to 35 weeks of age in Experiment 1. The magnitude of response from methionine was significantly greater than that from choline. Egg production and feed: egg ratios were not affected by these supplements in diets containing 160 g/kg CP. Added methionine also improved egg yield and egg weight at both levels of CP, whereas choline had no effect. In Experiment 2, .5 g/kg choline or methionine increased egg weight of hens fed 140 g/kg CP from 33 to 45 weeks of age, but these supplements had no effect in diets containing 160 g/kg CP. In phase 2 of this experiment, either choline or methionine at 1.0 g/kg improved egg production and egg yield of hens fed either 150 or 130 g/kg CP from 45 to 57 weeks of age. The responses from methionine were greater than those from choline. Methionine also improved egg weight at the lower protein level, whereas choline had no effect. The results of this study indicate that laying hens respond to either dietary choline or methionine supplementation; the response to methionine was greater, however, than the response to choline.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Influence of dietary electrolyte balance, energy, and amino acid supplementation on the monensin response in chicks fed diets varying in protein content.

The effects of several dietary factors on the anorexigenic response to monensin in chicks fed corn-soybean meal diets varying in crude protein (CP) were investigated. In Trial 1, crossbred chicks (New Hampshire X Columbia) were fed a 16% CP diet with or without 160 mg/kg monensin and/or .53% potassium carbonate in a 2 X 2 factorial design. Monensin supplementation caused a 24.5% growth depression, and potassium carbonate had no effect on the monensin-induced depression. Trials 2 and 3 were designed to evaluate the effects of dietary energy level on the monensin response in commercial broiler chicks fed diets containing 24, 20, or 16% CP. As CP level was decreased, the depression in performance from 121 mg/kg monensin increased. Increasing the energy concentration of the 24 and 20% CP diets to that of the 16% CP diet had no consistent effect on the response of chicks to monensin. Trial 4 was conducted to determine the influence of amino acid (AA) supplementation on the monensin response in broiler chicks fed a low-protein diet. Supplementation of a 16% CP diet with an AA mixture (3% glutamic acid plus essential AA equal to the 24% CP diet) improved growth performance markedly. Deletion of methionine, arginine, and lysine from the AA mixture yielded performance well below that of chicks fed the unsupplemented 16% CP diet, indicating a severe AA imbalance. Monensin supplementation at 121 mg/kg caused a much greater growth depression in chicks fed 16% CP or 16% CP plus the complete AA mixture than in those fed 24% CP or the AA-imbalanced 16% protein diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1983

The choline-methionine interrelationship for growth of the chick.

Three experiments involving 1230 battery-reared crossbred chicks were conducted to evaluate the potential sparing effect of choline on methionine and vice versa. Experiment 1 employed a crystalline amino acid diet to establish the sulfur-amino acid (SAA) and choline requirement for maximal feed efficiency of chicks during the period 8 to 18 days posthatching. Six graded levels of DL-methionine (.20 to .45% in the presence of .20% L-cystine) and five of choline (0 to 1216 mg/kg) were employed in a 6 X 5 factorial treatment arrangement. Gain/feed ratio was maximized at 608 mg/kg choline at all levels of methionine and at .30 to .35% methionine at all levels of choline. Two identical experiments (8 to 25 days posthatching) with a corn-soybean meal diet were carried out to explore the relationship between supplemental methionine (0 to .20% in five equal increments) and supplemental choline (0, 217, and 434 mg/kg). Optimal performance occurred at .10% supplemental methionine regardless of choline level and at 217 mg/kg choline at supplemental methionine levels of 0 and .05%. At .10, .15, and .20% supplemental methionine, no gain or gain/feed response to supplemental choline was observed. It was thus apparent that excess levels of choline had minimal capacity to reduce the dietary requirement for methionine. Excess levels of methionine, however, seemed to have a consistent, although small, effect on the chick's dietary need for choline.

Animals↗
PubMed1983

Effects of dietary carbohydrate and of intestinal microflora on excretion of endogenous amino acids by poultry.

The effects of dietary carbohydrate and of intestinal microflora on excretion of endogenous amino acids by poultry were investigated. Excretion of endogenous amino acids was compared among fasted roosters, intact roosters fed low- or high-fiber, N-free diets, and surgically-modified (SM) roosters fed a low-fiber, N-free diet. The low-fiber diet contained 50% corn starch, 45% glucose, and 5% cellulose, whereas the high-fiber diet contained 25% each of corn starch, glucose, and raw potato starch, 17.5% cellulose, and 7.5% pectin. Digesta were obtained from the terminal ileum of SM roosters to eliminate effects of the microflora in the large intestine and ceca. The roosters were force-fed 60 g of the appropriate diet (30 g at the initiation of the trial followed by an additional 30 g 6 hours later). Excreta or digesta and urine were collected quantitatively for 48 hr after the first force-feeding. Roosters fed the high-fiber diet excreted substantially more (P less than .05) amino acids than did fasted roosters or roosters fed a low-fiber diet. Excreta from roosters fed the high-fiber diet contained higher (P less than .05) levels of alanine and aspartic acid than excreta from fasted or digesta from SM roosters, indicating substantial microbial synthesis of amino acids in the gut. In contrast, amino acid composition of excreta from fasted and intact roosters fed the low-fiber diet was similar to that of digesta from SM roosters, suggesting less microbial influence. Excretion of glucosamine plus galactosamine by SM roosters was approximately twice that of intact roosters fed the same diet. Glycine was the most abundant amino acid in digesta of SM roosters. Results of this study indicate that dietary carbohydrate substantially affects excretion of endogenous amino acids by poultry and that fasted birds may not provide an accurate estimate of endogenous amino acid excretion for birds fed high-fiber feedstuffs in amino acid digestibility trials.

Amino Acids↗
PubMed1983

Effect of dietary protein source and monensin on performance of chicks.

The effects of dietary protein source and monensin on growth performance of chicks fed diets containing 121 or 160 mg/kg monensin were investigated. Crossbred chicks (New Hampshire X Columbian) were fed a corn soybean meal diet (24% crude protein) containing 0, 5.0, or 13.0% animal-source protein supplied by various combinations of fish meal and meat and bone meal. Growth rate and gain/feed ratio were measured from 8 to 22 days posthatching. Growth performance was depressed by both 121 and 160 mg/kg monensin with the depression being greater at 160 mg/kg. The type or level of animal-source protein had no effect on the magnitude of growth depression caused by monensin. Growth performance was improved by addition of fish meal and meat and bone meal to the corn-soybean meal diet.

Animals↗
PubMed1982

Effect of dietary protein level and monensin on performance of chicks.

Four experiments were conducted to investigate a possible interaction between dietary protein level and monensin on growth performance of young chicks. Crossbred chicks (New Hampshire X Columbian) or commercial broiler chicks (Hubbard X Hubbard) were fed corn-soybean meal diets containing various protein levels with or without added monensin (160 or 121 mg/kg). Monensin had little or no effect on growth performance of crossbred chicks fed diets containing 24 or 20% protein. However, growth performance of chicks fed 16% protein diets was depressed 15 and 8% by 160 and 121 mg/kg monensin, respectively. With commercial broiler chicks a marked interaction was observed between dietary protein level and monensin. As dietary protein level decreased, the depression in performance from monensin increased. At 24.0, 21.5, 19.0, and 16.5% protein, weight gains at 4 weeks of age were depressed 20, 29, 35, and 45% by 160 mg/kg monensin and 7, 14, 19, and 28% by 121 mg/kg monensin, respectively. Linear regression analysis indicated that 121 mg/kg monensin depressed growth rate an additional 2.7% for each 1% reduction in dietary protein level. A large portion of the growth depression from monensin could be explained by reduced feed intake. The results of this study indicate that level of dietary protein has a profound effect on the magnitude of growth depression caused by addition of monensin to chick diets. Thus, deficient levels of dietary protein should be avoided when using this anticoccidial drug in broiler feeds.

Animal Feed↗
PubMed1981

Utilization of amino acid analogues in diets of young turkeys.

1. The relative potencies of three lysine, one tryptophan and six methionine analogues to their corresponding l-amino acids were determined. 2. Male poults, 9 d of age, were used in five 14 d experiments. Experimental diets were formed by adding increasing levels of an amino acid (L-isomer) or its analogues to a basal diet deficient in the test amino acid. Multiple-regression analyses of body-weight gain v. level of added or amount of consumed amino acid supplement were computed. Relative potencies of the analogues were calculated using the slope-ratio technique. 3. Type of independent variable used in the regression analyses did not significantly affect relative potency values. 4. From regression analyses with level of added amino acid supplement as the independent variable, relative potencies (with 95% confidence intervals) on a molar basis of each analogue as a percentage of the respective amino acid were: hydroxymethyl-L-tryptophan monohydrate 9(-12, 22), DL-methionine sulphone 3 (-68, 36), DL-methionine hydantoin - 10 (-63, 29), L-cystine 8 (-31, 40), DL-methionine sulphoxide 59 (24, 95) and 46 (18, 74), oleoyl-DL-methionine 77 (37,138), methionine hydroxy analogue calcium 93 (65, 128), dicocoyl-L-lysine 23 (5,41), bis-hydroxymethyl-L-lysine-calcium 69 (54, 84 and 41 (-1,80), mono-hydroxymethyl-L-lysine-calcium 89 (77, 101) and 99 (65, 134). 5. The first four analogues appeared to have little or no amino acid activity. DL-methionine sulphoxide, dicocoyl-L-lysine, and bis-hydroxymethyl-L-lysine -calcium were partially active. Relative potencies of oleoyl-DL-methionine, methionine hydroxy analogue calcium, and mono-hydroxymethyl-L-lysine- calcium were not significantly different from those of their corresponding amino acids.

Amino Acids↗
PubMed1980

Relative lysine potencies of eight analogues in diets of young turkeys.

Three experiments were conducted to determine the biological potencies of eight lysine analogues in diets of young turkeys. Diets containing increasing levels of added L-lysine or a lysine analogue were fed to 9-day-old male poults for periods of 12 or 14 days. Multiple regression analyses of body weight gains on levels of supplemental L-lysine or analogue were computed. Relative potencies of the lysine analogues were calculated using the slope-ratio technique. Relative potencies of 6-N-N-dimethylamino-2-hydroxyhexan-N,N-dimethylamide, 6-N-acetylamino-2-hydroxyhexanamide, 6-N-propionylamino-2-hydroxyhexanamide. 6-N-butyrylamino-2-hydroxyhexanamide, 6-N-methylamino-2-hydroxyhexan-N-methylamide and alpha-keto-epsilon-acetylamino-caproic acid were not significantly different from 0%. Mono-hydroxymethyl-L-lysine-calcium and bis-hydroxymethyl-L-lysine-calcium had relative potencies of 62 +/- 6 and 52 +/- 7%, respectively, on a molar basis.

Animals↗