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Histidine and Tryptophan Requirement of Growing Chicks
Histidine and Tryptophan Requirement of Growing Chicks YANMING HAN, HTROYUKI SUZUKI,1 and DAVID H. BAKER2 Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801 (Received for publication February 21, 1991)
1991 Poultry Science 70:2148-2153 INTRODUCTION
There are several important reasons for deterrnining available amino acid requirements of chickens. They include 1) economical formulation of diets to provide sufficient and balanced amino acids to chickens while avoiding costly excesses; 2) interest in the possible need for supplemental amino acids in practice other than Met and Lys (Baker and Parsons, 1987); and 3) establishment of an ideal amino acid pattern that could be useful in feed formulation. The requirements of chicks for Lys and TSAA have been studied extensively. However, precise information regarding requirements for His and Trp is lacking. Previous Trp requirement estimates have varied extensively from values as low as .14% to those as high as .25% of the diet (Almquist, 1947; Boomgaardt and Baker, 1971; Hewitt and Lewis, 1972; Woodham and Deans, 1975; Steinhart and Kirchgessner, 1984; Rogers and Pesti, 1989). Much of the variation is due to problems in accurately determining Trp, and especially
Visiting scientist, Ajinomoto, Inc.; Technology Commercialization Laboratory, 2004 South Wright Street, Urbana, IL 61801. ^To whom correspondence should be addressed at 328 Mumford Hall, 1301 W. Gregory Drive, Urbana, IL 61801.
bioavailable Trp, in feed ingredients used to construct basal diets. Also, the requirements for Trp and other essential amino acids are dependent on both dietary protein and energy level (Boomgaardt and Baker, 1971; Baker, 1977). Regarding His requirements, there is very little information except for studies done with purified diets where protein levels, energy levels, and bioavailability factors are very different from those that exist in diets based upon practical ingredients. The purpose of the study reported in this paper was to determine requirements for available His and Trp in growing chicks fed a His- and Trp-deflcient intact protein diet containing 25% CP and 3,200 kcal MEJkg. MATERIALS AND METHODS
Basal Diet An intact protein basal diet (Table 1) was formulated to meet or exceed requirements (National Research Council, 1984) for all nutrients (except His and Trp) of broiler chicks between hatching and 3 wk posthatehing. Prior to formulation, dietary ingredients containing protein (corn, feather meal, and soybean meal) were analyzed for both CP (Association of Official Analytical Chemists, 1980) and amino acids (Spackman et al., 1958), the latter by ion-
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ABSTRACT Experiments were conducted to determine the His and Trp requirement of broiler chicks during the period 8 to 22 days posthatehing. A His- or Trp-deflcient diet (.32% total His; .18% total Trp; 25% CP; 3,200 kcal MBJkg) based upon corn, feather meal, and soybean meal was supplemented with graded increments of either L-His-HCl-HjO or L-Trp to produce growth responses. Growth rate and feed efficiency of birds fed the fully fortified experimental diet were similar to those of birds fed a corn and soybean meal positive control diet (23% CP; 3,200 kcal MEo/kg). True digestibility of the protein blend (corn, feather meal, and soybean meal) used in the basal diet was 81.4% for His and 83.3% for Trp as established in precision-fed, cecectomized adult cockerels. Requirements for digestible His and Trp were determined to be not greater than .31% (1.24% of CP) and .20% (.80% of CP), respectively, for maximal weight gain and feed efficiency. Translating the requirement estimates to practice, wherein a 23% corn and soybean meal diet would be fed, results in a total His requirement of .32% and a total Trp requirement of .22% of the diet during the broiler chick's 2nd and 3rd wk of life. (Key words: histidine, tryptophan, requirement, growing chicks, feed efficiency)
HISTIDINE AND TRYPTOPHAN TABLE 1. Composition of the histidine- and tryptophan-deficient com, feather meal, and soybean meal basal diet1
Ingredients
.23 64.02 5.00 20.66 4.50 2.00 1.00 .40 .05 .10 .10 .05 .40 .20 1.00
'The basal diet contained 25% CP, 3,200 kcal MEn/kg, .32% histidine, and .18% tryptophan. •'Trace mineral mix provided per kilogram of diet: iron, 75 mg; manganese, 75 mg; zinc, 75 mg; copper, 75 nag; iodine, 75 mg; selenium, .10 mg. 3 Vitamin mix supplied per kilogram of diet vitamin A, 4,400 IU; cholecalciferol, 1,000 ICU; vitamin E, 11 IU; vitamin B 1 2 , .011 mg; riboflavin, 4.4 mg; d-pantothenic acid, 10 mg; niacin, 22 mg; menadione sodium bisulfite complex, 2.33 mg. ''Provided 2.2 mg/kg of flavomycin.
exchange chromatography3 following 24-h acid hydrolysis. Tryptophan was determined by ionexchange chromatography following alkaline hydrolysis (Sato et al., 1984). Feather meal, a key ingredient in the basal diet, had previously been studied insofar as protein quality and amino acid limitations were concerned (Baker et al., 1981). The basal diet was formulated to contain 3,200 kcal MEJkg, 25% CP, 4 .32% His, and .18% Trp.5 Additions of His and Trp to the basal diet were provided as L-His-HQ-H20 (74% His) 6 respectively, and were made at the expense of cornstarch.
Growth Assays One-week-old male chicks resulting from the cross of New Hampshire males and Columbian Plymouth Rock females were used in three growth assays. A standard 23% CP corn and soybean meal (CS) diet was fed to the chicks during the 1st wk posthatching. On Day 8 following an overnight fast, the chicks were weighed, wing-banded, and allotted to dietary treatments according to procedures described by Sasse and Baker (1974). Quadruplicate groups of five chicks were assigned to each dietary treatment during the period 8 to 22 days posthatching. Chick trials were carried out in thermostatically controlled starter batteries with raised wire floors, located in an environmentally controlled room. Feed and water were supplied for ad libitum consumption, and a 24-h constant light schedule was maintained. Histidine and Tryptophan Digestibility Assay (Experiment 1) Ten adult, cecectomized, Single Comb White Leghorn cockerels were used to establish true digestibility of His and Trp in the corn, feather meal, and soybean meal (CFS) protein blend. Five cockerels were selected at random to receive a 30-g crop intubation of the protein blend (71.4% com, 23.0% feather meal, and 5.6% soybean meal) and the remaining five cockerels were used as fasted controls. Details of procedures used in the assay as well as cecectomy and bird care have been described previously (Han et al., 1990a; Han and Parsons, 1990). The birds were confined to individual collection cages, and excreta were collected in plastic trays during a 48-h quantitative collection period. Excreta from each cockerel were freeze-dried, weighed, ground through a 60-mesh screen, and men analyzed for His and Trp as previously described. True digestible His and Trp in the protein blend were calculated as described by Han et al. (1990a). Requirement Studies
3 Beckman Model 6300, Beckman Instruments, Palo Alto. CA 94302. T h e basal diet contained 23% CP from intact protein sources and 2% additional CP from supplemental free amino acids. 5 Corn contained 7.7% CP, .22% His, and .07% Trp; soybean meal contained 46.5% CP, 1.20% His, and .65% Tip; feather meal contained 76.2% CP, .59% His, and .49% Trp "Ajinomoto, Inc., Tokyo, Japan.
Experiment 2 was conducted to compare growth and feed efficiency values of chicks fed a conventional Met-fortified CS diet (23% CP; 3,200 MEn/kg) with those of chicks fed the experimental CFS, both with and without a surfeit level of His (.30%) or Tip (.12%) fortification. Experiment 3 and Experiment 4 involved feeding graded levels of His (from LHis-HC1H20) or L-Trp to chicks for the
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Cornstarch Com (7.7% CP) Dehulled soybean meal (46.5% CP) Feather meal (76.2% CP) Corn oil Dicalcium phosphate Limestone Salt Trace mineral mix Vitamin mix CholineO (60%) Flavomycin premix DL-metnionine L-arginine L-lysineHCl L-histidineHClH20 L- tryptophan
Percentage of diet
2149
2150
HAN ET AL. TABLE 2. Determination of digestible histidine and tryptophan in the basal diet (Experiment I)1 Tryptophan
Histidine Treatment
Intake
Excreted
, Fasted Fed SEM
0 107.1
x
18.5 38.4 1.3
Intake
Digestibility
(%) 0 60.0
81.4 1.1
Excreted
Digestibility
(%)
- (rag) 6.5 16.5 .7
83.3 1.3
Data are means of five cecectomized adult cockerels.
Statistical Analysis Data from the four chick experiments were subjected to ANOVA procedures appropriate for completely randomized designs (Steel and Torrie, 1980). Differences among treatment means in Experiment 2 were evaluated by the least significant difference pairwise multiple-comparison procedure (Carmer and Walker, 1985). Orthogonal polynomials (linear, quadratic, remainder) were used to establish treatment effects in Experiments 3 and 4. RESULTS
True digestibility in the basal diet was 81.4% for His and 83.3% for Trp (Table 2). Thus, the His- and Trp-deficient basal diet contained .26% digestible His (.32 x 81.4%) and .15% digestible Trp (.18 x 83.3%). Growth performance of chicks fed the CFS basal diet without fortification with His or Trp was significantly (P<.05) decreased compared with that of chicks fed the same diet fortified with either one or both of the amino acids (Table 3). This indicated that the basal diet was deficient in both His and Trp. Bom weight gain and the gain:feed ratio of chicks fed the His- and Trp-fortified experimental diet were equal to those of chicks fed the CS positive control diet. In the His requirement study, both weight gain and feed efficiency responded quadratically (P<.05) to His supplementation (Table 4). The results indicated mat the digestible His concentration needed for both maximal weight gain and gain:feed ratio did not exceed .31% of the diet.
Weight gain and the gain:feed ratio of chicks fed the Trp-deficient basal diet responded linearly (P<.05) to Trp supplementation (Table 5). Weight gain and feed efficiency in this assay did not reach a definitive plateau within the digestible Trp concentrations fed. In a subsequent trial, however, chicks did not respond to digestible Trp levels greater than .20% of the diet (Table 6). By examining the results from the two trials together, it was apparent that the digestible Tip requirement for maximal weight gain and gain:feed ratio of young chicks was not greater than .20% of the diet. DISCUSSION
The digestible His requirement of .31% from the present study is in close agreement with literature values (Woodham and Deans, 1975; Robbins et ah, 1977; Baker et ah, 1979).
TABLE 3. Evaluation of the histidine- and tryptophandeficient corn, feather meal, soybean meal (CFS) experimental diet (Experiment 2)1 Diet 1. 2. 3. 4.
CS control2 CFS + His + Trp As 2 - His As 2 - Trp Pooled SEM
Gain
Gamrfeed
(g) 247 A 245 A 207 B 178^ 5
(g:kg) 677 A 672 A 618 B 568 c 8
A Means within columns with no common superscripts differ (P<.01). *Data are means of four groups of five male chicks during the period 8 to 22 days postbatching; average initial weight was 74 g. 2 CS = com and soybean meal diet, which contained 50.4% com, 41.1% dehulled soybean meal, 4.5% com oil, .25% DL-methionine, and necessary vitamin, mineral, and antibiotic (flavomycin) fortification (Chung and Baker, 1990).
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purposes of establishing requirements for His and Tip, respectively. Based upon the results from Experiment 4, higher Tip supplementation levels were used in Experiment 5 to ensure that chick performance would reach a plateau.
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mSTTOINE AND TRYPTOPHAN
TABLE 4. Performance of chicks fed the histidine-deficient corn, feather meal, and soybean meal diet supplemented with graded levels of L-histidine (Experiment 3r Digestible His
Gahr
Gainifeed2
1. 2. 3. 4. 5. 6. 7.
.26 .27 .28 29 .30 .31 .32
(g) 193 191 195 214 220 231 230
Basal + .12% L-Trp As 1 + .01% L-His As 1 + .02% L-His As 1 + .03% L-His As 1 + .04% L-His As 1 + .05% L-His As 1 + .06% L-His Pooled SEM
'Data are means of four groups of five male chicks from 8 to 22 days posthatching; average initial weight was 68 g. Quadratic response (P<05).
2
Robbins et al. (1977) reported a His requirement of .32% for chicks fed a purified amino acid diet between 8 and 29 days posthatching. With diets containing intact ingredients, Woodham and Deans (1975) suggested that the His requirement was not greater than .34%, but Hewitt and Lewis (1972) reported a slightly higher value of .40%. It should be mentioned that in these studies the availability of His from the intact ingredients was not taken into account. There is clear evidence that the Tip requirement of young chicks is dependent on dietary protein level (Boomgaardt and Baker, 1971; Abebe and Morris, 1990). Abebe and Morris (1990) suggested that a fixed ratio of Tip to protein should be specified rather than a minimum dietary concentration of Trp. When expressing the estimated digestible Tip requirement of .20% as a ratio to dietary protein
concentration (25% CP fed), a value of .80% is obtained. This value is lower than the .87% value reported by Boomgaardt and Baker (1971) using a purified amino acid diet. Extrapolating the .80% ratio to a standard 23% protein diet (National Research Council, 1984), the digestible Tip requirement would be .184% of diet. Steinhart and Kirchgessner (1984) reported a total Trp requirement of .19 to .22% in a 24.7% protein diet. A number of investigators using diets containing intact protein sources supplemented with amino acids (Hewitt and Lewis, 1972; Freeman, 1979; Smith and Waldroup, 1988) have estimated total Trp requirements of around .17% of the diet. These estimates, however, were obtained at dietary protein levels (18 to 20%) lower than the 25% CP level employed herein or the 23 to 24% CP level used in commercial practice. Using diets containing intact protein
TABLE 5. Performance of chicks fed the tryptophan-deficient corn, feather meal, and soybean meal diet supplemented with graded levels of L-tryptophan (Experiment 4)1 Treatment
Digestible Trp
Gain'4
Gain:feedz
1. 2. 3. 4. 5. 6. 7.
.15 .16 .17 .18 .19 .20 .21
(g) 167 181 209 212 218 226 234
(g:kg) 535 585 616 632 645 650 663 14
Basal + .30% L-His As 1 + .01% L-Trp As 1 + .02% L-Trp As 1 + .03% L-Trp As 1 + .04% L-Trp As 1 + .05% L-Trp As 1 + .06% L-Trp Pooled SEM
5
Data are means of four groups of five male chicks from 8 to 22 days posthatching; average initial weight was 68 g. 2 Quadratic response (P<05).
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Treatment
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HAN ET AL.
TABLE 6. Performance of chicks fed the tryptophan-deficiem corn, feather meal, and soybean meal diet supplemented with graded levels of L-tryptophan (Experiment 5) Treatment 1. Basal + .3% L-His + .05% L-Trp 2. As 1 + .01% L-Trp 3. As 1 + .02% L-Trp Pooled SEM
Digestible Trp
Gain
Gaircfeed
(%)
(g)
(g:kg)
.20 .21 .22
224 223 226 6
685 665 692 19
ingredients, Abebe and Morris (1990) determined a Trp requirement at eight different dietary protein levels ranging from 16 to 30% and concluded that the Trp requirement was 12 g/kg protein (1.2% of dietary protein), which is equivalent to a requirement of .27% for a 23% protein diet. Bioavailability of Trp in their basal diet, however, was not considered. Almough the chicks used in the present study were from a slower growing strain, work in the authors' laboratory has suggested that the requirements (percentage of diet) for TSAA (Robbins and Baker, 1980) and Lys (Han and Baker, 1991) of this strain are essentially the same as those of commercial Hubbard chicks. Therefore, it is reasonable that the requirements for digestible His (1.24% of CP) and Trp (.80% of CP) established herein would be applicable to commercial strains as well. To translate these estimated requirements to a typical 23% CP, CS diet situation, where His digestibility is assumed to be 89% and Trp digestibility 85% (Heartland Lysine Digestibility Tables, Chicago, IL 60631), a total His requirement of .32% is obtained, and a total Trp requirement of .22% is arrived at for maximal gain and feed efficiency of chicks. These estimates are only slightly lower than the National Research Council (1984) recommended requirement values of .35% for His and .23% for Trp. That the total Trp requirement may be slightly lower than the National Research Council (1984) estimate seems reasonable in light of recent findings that Trp is not among the five most limiting amino acids in low protein CS diets (Edmonds et al., 1985; Han et al, 1990b). ACKNOWLEDGMENT
The authors wish to thank Ajinomoto, Inc., Tokyo, Japan for financial support of this work.
REFERENCES Abebe, S., and T. R. Morris, 1990. Effects of protein concentration on responses to dietary tryptophan by chicks. Br. Poult Sci. 31:267-272. Almquist, H. J., 1947. Evaluation of amino acid requirements by observation of the chick. J. Nutr. 34: 543-563. Association of Official Analytical Chemists, 1980. Official Methods of Analysis, 13th ed. Association of Official Analytical Chemists, Washington, DC. Baker, D. H., 1977. Amino acid nutrition of the chick. Pages 299-335 in: Advances in Nutrition Research, Vol. I. H. H. Draper, ed. Plenum Press, New York, NY. Baker, D. H., and C. M. Parsons, 1987. Recent Advances in Amino Acid Nutrition. Ajinomoto Co., Tokyo, Japan. Baker, D. H., K. R. Robbins, and J. S. Buck, 1979. Modification of the level of histidine and sodium bicarbonate in the Illinois crystalline amino acid diet Poultry Sci. 58:749-750. Baker, D. H., R. C. BlitenthaL K. P. Boebel, G. L. Czarnecki, L. L. Southern, and G. M. Willis, 1981. Protein-amino acid evaluation of steam-processed feather meal. Poultry Sci. 60:1865-1872. Boomgaardt, J., and D. H. Baker, 1971. Tryptophan requirement of growing chicks as affected by dietary protein level. J. Anim. Sci. 33:595-599. Carmer, S. G., and W. M. Walker, 1985. Pairwise multiple comparisons of treatment means in agronomic research. J. Agron. Ed. 14:19-26. Chung, T. K., and D. H. Baker, 1990. Riboflavin requirement of chicks fed purified amino acid and conventional corn-soybean meal diets. Poultry Sci. 69:1357-1363. Edmonds, M. S., C. M. Parsons, and D. H. Baker. 1985. Limiting amino acids in low protein corn-soybean meal diets fed to growing chicks. Poultry Sci. 64: 1519-1526. Freeman, C. P., 1979. The tryptophan requirement of broiler chicks. Br. Poult Sci. 20:27-37. Han, Y., and D. H. Baker, 1991. Lysine requirements of fast- and slow-growing broiler chicks. Poultry Sci. 70:2108-2114. Han, Y., F. Castanon, C. M. Parsons, and D. H. Baker, 1990a. Intestinal absorption and bioavailability of DL-methionine hydroxy analog compared to DLmethionine. Poultry Sci. 69:281-287. Han, Y., and C. M. Parsons, 1990. Determination of available amino acids and energy in alfalfa meal,
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Data are means of four groups of five male chicks from 8 to 22 days posthatching; average initial weight was 65 g.
mSTTDINE AND TRYPTOPHAN
68(Suppl. l):200.(Abstr.) Sasse, C. E„ and D. H. Baker, 1974. Factors affecting sulfate-sulfur utilization by the young chicks. Poultry Sci. 53:652-662. Sato, H., T. Seino, T. Kobayashi, A. Murai, and Y. Yugari, 1984. Determination of the tryptophan concentration by ion exchange liquid chromatography. Agric. Biol. Chem. 48:2961-2969. Smith, Jr., N. K., and P. W. Waldroup, 1988. Estimation of the tryptophan requirement of male broiler chickens. Poultry Sci. 67:1174-1177. Spackman, D. H., W. H. Stein, and S. Moore, 1958. Automatic recording apparatus for use in the chromatography of amino acids. Anal. Chem. 30: 1190-1206. Steel, R.G.D., and J. H. Torrie, 1980. Principles and Procedures of Statistics. A Biometrical Approach, 2nd ed. McGraw-Hill Book Co., New York, NY. Steinhart, H., and M. Kirchgessner, 1984. Investigations on the requirement of tryptophan for broilers. Arch. Geflfigelkd. 48:150-155. Woodham, A. A., and P. S. Deans, 1975. Amino acid requirements of growing chickens. Br. Poult Sci. 16: 269-287.
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feather meal and poultry by-product meal by various methods. Poultry Sci. 69:1544-1552. Han, Y., H. Suzuki, C. M. Parsons, and D. H. Baker, 1990b. Amino acid fortification of a low protein corn-soybean meal diet for young chicks. Poultry Sci. 69(Suppl. l):59.(Abstr.) Hewitt, D.. and D. Lewis, 1972. The amino acid requirements of the growing chick. 1. Determination of amino acid requirements. Br. Poult. Sci. 13: 449-463. National Research Council, 1984. Nutrient Requirements of Poultry. 8th rev. ed. National Academy Press, Washington, DC. Robbins, K. R., and D. H. Baker, 1980. Effect of sulfur amino acid level and source on the performance of chicks fed high levels of copper. Poultry Sci. 59: 1246-1253. Robbins, K. R., D. H. Baker, and H. W. Norton, 1977. Histidine status in the chick as measured by growth rate, plasma free histidine and breast muscle carnosine. J. Nutr. 107:2055-2061. Rogers, S. R., and G. M. Pesti, 1989. Effect of protein on the tryptophan requirement of the growing chick and subsequent effects on lipid metabolism. Poultry Sci.
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1991 Poultry Science 70:2148-2153 INTRODUCTION
There are several important reasons for deterrnining available amino acid requirements of chickens. They include 1) economical formulation of diets to provide sufficient and balanced amino acids to chickens while avoiding costly excesses; 2) interest in the possible need for supplemental amino acids in practice other than Met and Lys (Baker and Parsons, 1987); and 3) establishment of an ideal amino acid pattern that could be useful in feed formulation. The requirements of chicks for Lys and TSAA have been studied extensively. However, precise information regarding requirements for His and Trp is lacking. Previous Trp requirement estimates have varied extensively from values as low as .14% to those as high as .25% of the diet (Almquist, 1947; Boomgaardt and Baker, 1971; Hewitt and Lewis, 1972; Woodham and Deans, 1975; Steinhart and Kirchgessner, 1984; Rogers and Pesti, 1989). Much of the variation is due to problems in accurately determining Trp, and especially
Visiting scientist, Ajinomoto, Inc.; Technology Commercialization Laboratory, 2004 South Wright Street, Urbana, IL 61801. ^To whom correspondence should be addressed at 328 Mumford Hall, 1301 W. Gregory Drive, Urbana, IL 61801.
bioavailable Trp, in feed ingredients used to construct basal diets. Also, the requirements for Trp and other essential amino acids are dependent on both dietary protein and energy level (Boomgaardt and Baker, 1971; Baker, 1977). Regarding His requirements, there is very little information except for studies done with purified diets where protein levels, energy levels, and bioavailability factors are very different from those that exist in diets based upon practical ingredients. The purpose of the study reported in this paper was to determine requirements for available His and Trp in growing chicks fed a His- and Trp-deflcient intact protein diet containing 25% CP and 3,200 kcal MEJkg. MATERIALS AND METHODS
Basal Diet An intact protein basal diet (Table 1) was formulated to meet or exceed requirements (National Research Council, 1984) for all nutrients (except His and Trp) of broiler chicks between hatching and 3 wk posthatehing. Prior to formulation, dietary ingredients containing protein (corn, feather meal, and soybean meal) were analyzed for both CP (Association of Official Analytical Chemists, 1980) and amino acids (Spackman et al., 1958), the latter by ion-
2148
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on May 31, 2015
ABSTRACT Experiments were conducted to determine the His and Trp requirement of broiler chicks during the period 8 to 22 days posthatehing. A His- or Trp-deflcient diet (.32% total His; .18% total Trp; 25% CP; 3,200 kcal MBJkg) based upon corn, feather meal, and soybean meal was supplemented with graded increments of either L-His-HCl-HjO or L-Trp to produce growth responses. Growth rate and feed efficiency of birds fed the fully fortified experimental diet were similar to those of birds fed a corn and soybean meal positive control diet (23% CP; 3,200 kcal MEo/kg). True digestibility of the protein blend (corn, feather meal, and soybean meal) used in the basal diet was 81.4% for His and 83.3% for Trp as established in precision-fed, cecectomized adult cockerels. Requirements for digestible His and Trp were determined to be not greater than .31% (1.24% of CP) and .20% (.80% of CP), respectively, for maximal weight gain and feed efficiency. Translating the requirement estimates to practice, wherein a 23% corn and soybean meal diet would be fed, results in a total His requirement of .32% and a total Trp requirement of .22% of the diet during the broiler chick's 2nd and 3rd wk of life. (Key words: histidine, tryptophan, requirement, growing chicks, feed efficiency)
HISTIDINE AND TRYPTOPHAN TABLE 1. Composition of the histidine- and tryptophan-deficient com, feather meal, and soybean meal basal diet1
Ingredients
.23 64.02 5.00 20.66 4.50 2.00 1.00 .40 .05 .10 .10 .05 .40 .20 1.00
'The basal diet contained 25% CP, 3,200 kcal MEn/kg, .32% histidine, and .18% tryptophan. •'Trace mineral mix provided per kilogram of diet: iron, 75 mg; manganese, 75 mg; zinc, 75 mg; copper, 75 nag; iodine, 75 mg; selenium, .10 mg. 3 Vitamin mix supplied per kilogram of diet vitamin A, 4,400 IU; cholecalciferol, 1,000 ICU; vitamin E, 11 IU; vitamin B 1 2 , .011 mg; riboflavin, 4.4 mg; d-pantothenic acid, 10 mg; niacin, 22 mg; menadione sodium bisulfite complex, 2.33 mg. ''Provided 2.2 mg/kg of flavomycin.
exchange chromatography3 following 24-h acid hydrolysis. Tryptophan was determined by ionexchange chromatography following alkaline hydrolysis (Sato et al., 1984). Feather meal, a key ingredient in the basal diet, had previously been studied insofar as protein quality and amino acid limitations were concerned (Baker et al., 1981). The basal diet was formulated to contain 3,200 kcal MEJkg, 25% CP, 4 .32% His, and .18% Trp.5 Additions of His and Trp to the basal diet were provided as L-His-HQ-H20 (74% His) 6 respectively, and were made at the expense of cornstarch.
Growth Assays One-week-old male chicks resulting from the cross of New Hampshire males and Columbian Plymouth Rock females were used in three growth assays. A standard 23% CP corn and soybean meal (CS) diet was fed to the chicks during the 1st wk posthatching. On Day 8 following an overnight fast, the chicks were weighed, wing-banded, and allotted to dietary treatments according to procedures described by Sasse and Baker (1974). Quadruplicate groups of five chicks were assigned to each dietary treatment during the period 8 to 22 days posthatching. Chick trials were carried out in thermostatically controlled starter batteries with raised wire floors, located in an environmentally controlled room. Feed and water were supplied for ad libitum consumption, and a 24-h constant light schedule was maintained. Histidine and Tryptophan Digestibility Assay (Experiment 1) Ten adult, cecectomized, Single Comb White Leghorn cockerels were used to establish true digestibility of His and Trp in the corn, feather meal, and soybean meal (CFS) protein blend. Five cockerels were selected at random to receive a 30-g crop intubation of the protein blend (71.4% com, 23.0% feather meal, and 5.6% soybean meal) and the remaining five cockerels were used as fasted controls. Details of procedures used in the assay as well as cecectomy and bird care have been described previously (Han et al., 1990a; Han and Parsons, 1990). The birds were confined to individual collection cages, and excreta were collected in plastic trays during a 48-h quantitative collection period. Excreta from each cockerel were freeze-dried, weighed, ground through a 60-mesh screen, and men analyzed for His and Trp as previously described. True digestible His and Trp in the protein blend were calculated as described by Han et al. (1990a). Requirement Studies
3 Beckman Model 6300, Beckman Instruments, Palo Alto. CA 94302. T h e basal diet contained 23% CP from intact protein sources and 2% additional CP from supplemental free amino acids. 5 Corn contained 7.7% CP, .22% His, and .07% Trp; soybean meal contained 46.5% CP, 1.20% His, and .65% Tip; feather meal contained 76.2% CP, .59% His, and .49% Trp "Ajinomoto, Inc., Tokyo, Japan.
Experiment 2 was conducted to compare growth and feed efficiency values of chicks fed a conventional Met-fortified CS diet (23% CP; 3,200 MEn/kg) with those of chicks fed the experimental CFS, both with and without a surfeit level of His (.30%) or Tip (.12%) fortification. Experiment 3 and Experiment 4 involved feeding graded levels of His (from LHis-HC1H20) or L-Trp to chicks for the
Downloaded from http://ps.oxfordjournals.org/ at Rutgers University Libraries/Technical Services on May 31, 2015
Cornstarch Com (7.7% CP) Dehulled soybean meal (46.5% CP) Feather meal (76.2% CP) Corn oil Dicalcium phosphate Limestone Salt Trace mineral mix Vitamin mix CholineO (60%) Flavomycin premix DL-metnionine L-arginine L-lysineHCl L-histidineHClH20 L- tryptophan
Percentage of diet
2149
2150
HAN ET AL. TABLE 2. Determination of digestible histidine and tryptophan in the basal diet (Experiment I)1 Tryptophan
Histidine Treatment
Intake
Excreted
, Fasted Fed SEM
0 107.1
x
18.5 38.4 1.3
Intake
Digestibility
(%) 0 60.0
81.4 1.1
Excreted
Digestibility
(%)
- (rag) 6.5 16.5 .7
83.3 1.3
Data are means of five cecectomized adult cockerels.
Statistical Analysis Data from the four chick experiments were subjected to ANOVA procedures appropriate for completely randomized designs (Steel and Torrie, 1980). Differences among treatment means in Experiment 2 were evaluated by the least significant difference pairwise multiple-comparison procedure (Carmer and Walker, 1985). Orthogonal polynomials (linear, quadratic, remainder) were used to establish treatment effects in Experiments 3 and 4. RESULTS
True digestibility in the basal diet was 81.4% for His and 83.3% for Trp (Table 2). Thus, the His- and Trp-deficient basal diet contained .26% digestible His (.32 x 81.4%) and .15% digestible Trp (.18 x 83.3%). Growth performance of chicks fed the CFS basal diet without fortification with His or Trp was significantly (P<.05) decreased compared with that of chicks fed the same diet fortified with either one or both of the amino acids (Table 3). This indicated that the basal diet was deficient in both His and Trp. Bom weight gain and the gain:feed ratio of chicks fed the His- and Trp-fortified experimental diet were equal to those of chicks fed the CS positive control diet. In the His requirement study, both weight gain and feed efficiency responded quadratically (P<.05) to His supplementation (Table 4). The results indicated mat the digestible His concentration needed for both maximal weight gain and gain:feed ratio did not exceed .31% of the diet.
Weight gain and the gain:feed ratio of chicks fed the Trp-deficient basal diet responded linearly (P<.05) to Trp supplementation (Table 5). Weight gain and feed efficiency in this assay did not reach a definitive plateau within the digestible Trp concentrations fed. In a subsequent trial, however, chicks did not respond to digestible Trp levels greater than .20% of the diet (Table 6). By examining the results from the two trials together, it was apparent that the digestible Tip requirement for maximal weight gain and gain:feed ratio of young chicks was not greater than .20% of the diet. DISCUSSION
The digestible His requirement of .31% from the present study is in close agreement with literature values (Woodham and Deans, 1975; Robbins et ah, 1977; Baker et ah, 1979).
TABLE 3. Evaluation of the histidine- and tryptophandeficient corn, feather meal, soybean meal (CFS) experimental diet (Experiment 2)1 Diet 1. 2. 3. 4.
CS control2 CFS + His + Trp As 2 - His As 2 - Trp Pooled SEM
Gain
Gamrfeed
(g) 247 A 245 A 207 B 178^ 5
(g:kg) 677 A 672 A 618 B 568 c 8
A Means within columns with no common superscripts differ (P<.01). *Data are means of four groups of five male chicks during the period 8 to 22 days postbatching; average initial weight was 74 g. 2 CS = com and soybean meal diet, which contained 50.4% com, 41.1% dehulled soybean meal, 4.5% com oil, .25% DL-methionine, and necessary vitamin, mineral, and antibiotic (flavomycin) fortification (Chung and Baker, 1990).
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purposes of establishing requirements for His and Tip, respectively. Based upon the results from Experiment 4, higher Tip supplementation levels were used in Experiment 5 to ensure that chick performance would reach a plateau.
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TABLE 4. Performance of chicks fed the histidine-deficient corn, feather meal, and soybean meal diet supplemented with graded levels of L-histidine (Experiment 3r Digestible His
Gahr
Gainifeed2
1. 2. 3. 4. 5. 6. 7.
.26 .27 .28 29 .30 .31 .32
(g) 193 191 195 214 220 231 230
Basal + .12% L-Trp As 1 + .01% L-His As 1 + .02% L-His As 1 + .03% L-His As 1 + .04% L-His As 1 + .05% L-His As 1 + .06% L-His Pooled SEM
'Data are means of four groups of five male chicks from 8 to 22 days posthatching; average initial weight was 68 g. Quadratic response (P<05).
2
Robbins et al. (1977) reported a His requirement of .32% for chicks fed a purified amino acid diet between 8 and 29 days posthatching. With diets containing intact ingredients, Woodham and Deans (1975) suggested that the His requirement was not greater than .34%, but Hewitt and Lewis (1972) reported a slightly higher value of .40%. It should be mentioned that in these studies the availability of His from the intact ingredients was not taken into account. There is clear evidence that the Tip requirement of young chicks is dependent on dietary protein level (Boomgaardt and Baker, 1971; Abebe and Morris, 1990). Abebe and Morris (1990) suggested that a fixed ratio of Tip to protein should be specified rather than a minimum dietary concentration of Trp. When expressing the estimated digestible Tip requirement of .20% as a ratio to dietary protein
concentration (25% CP fed), a value of .80% is obtained. This value is lower than the .87% value reported by Boomgaardt and Baker (1971) using a purified amino acid diet. Extrapolating the .80% ratio to a standard 23% protein diet (National Research Council, 1984), the digestible Tip requirement would be .184% of diet. Steinhart and Kirchgessner (1984) reported a total Trp requirement of .19 to .22% in a 24.7% protein diet. A number of investigators using diets containing intact protein sources supplemented with amino acids (Hewitt and Lewis, 1972; Freeman, 1979; Smith and Waldroup, 1988) have estimated total Trp requirements of around .17% of the diet. These estimates, however, were obtained at dietary protein levels (18 to 20%) lower than the 25% CP level employed herein or the 23 to 24% CP level used in commercial practice. Using diets containing intact protein
TABLE 5. Performance of chicks fed the tryptophan-deficient corn, feather meal, and soybean meal diet supplemented with graded levels of L-tryptophan (Experiment 4)1 Treatment
Digestible Trp
Gain'4
Gain:feedz
1. 2. 3. 4. 5. 6. 7.
.15 .16 .17 .18 .19 .20 .21
(g) 167 181 209 212 218 226 234
(g:kg) 535 585 616 632 645 650 663 14
Basal + .30% L-His As 1 + .01% L-Trp As 1 + .02% L-Trp As 1 + .03% L-Trp As 1 + .04% L-Trp As 1 + .05% L-Trp As 1 + .06% L-Trp Pooled SEM
5
Data are means of four groups of five male chicks from 8 to 22 days posthatching; average initial weight was 68 g. 2 Quadratic response (P<05).
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Treatment
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TABLE 6. Performance of chicks fed the tryptophan-deficiem corn, feather meal, and soybean meal diet supplemented with graded levels of L-tryptophan (Experiment 5) Treatment 1. Basal + .3% L-His + .05% L-Trp 2. As 1 + .01% L-Trp 3. As 1 + .02% L-Trp Pooled SEM
Digestible Trp
Gain
Gaircfeed
(%)
(g)
(g:kg)
.20 .21 .22
224 223 226 6
685 665 692 19
ingredients, Abebe and Morris (1990) determined a Trp requirement at eight different dietary protein levels ranging from 16 to 30% and concluded that the Trp requirement was 12 g/kg protein (1.2% of dietary protein), which is equivalent to a requirement of .27% for a 23% protein diet. Bioavailability of Trp in their basal diet, however, was not considered. Almough the chicks used in the present study were from a slower growing strain, work in the authors' laboratory has suggested that the requirements (percentage of diet) for TSAA (Robbins and Baker, 1980) and Lys (Han and Baker, 1991) of this strain are essentially the same as those of commercial Hubbard chicks. Therefore, it is reasonable that the requirements for digestible His (1.24% of CP) and Trp (.80% of CP) established herein would be applicable to commercial strains as well. To translate these estimated requirements to a typical 23% CP, CS diet situation, where His digestibility is assumed to be 89% and Trp digestibility 85% (Heartland Lysine Digestibility Tables, Chicago, IL 60631), a total His requirement of .32% is obtained, and a total Trp requirement of .22% is arrived at for maximal gain and feed efficiency of chicks. These estimates are only slightly lower than the National Research Council (1984) recommended requirement values of .35% for His and .23% for Trp. That the total Trp requirement may be slightly lower than the National Research Council (1984) estimate seems reasonable in light of recent findings that Trp is not among the five most limiting amino acids in low protein CS diets (Edmonds et al., 1985; Han et al, 1990b). ACKNOWLEDGMENT
The authors wish to thank Ajinomoto, Inc., Tokyo, Japan for financial support of this work.
REFERENCES Abebe, S., and T. R. Morris, 1990. Effects of protein concentration on responses to dietary tryptophan by chicks. Br. Poult Sci. 31:267-272. Almquist, H. J., 1947. Evaluation of amino acid requirements by observation of the chick. J. Nutr. 34: 543-563. Association of Official Analytical Chemists, 1980. Official Methods of Analysis, 13th ed. Association of Official Analytical Chemists, Washington, DC. Baker, D. H., 1977. Amino acid nutrition of the chick. Pages 299-335 in: Advances in Nutrition Research, Vol. I. H. H. Draper, ed. Plenum Press, New York, NY. Baker, D. H., and C. M. Parsons, 1987. Recent Advances in Amino Acid Nutrition. Ajinomoto Co., Tokyo, Japan. Baker, D. H., K. R. Robbins, and J. S. Buck, 1979. Modification of the level of histidine and sodium bicarbonate in the Illinois crystalline amino acid diet Poultry Sci. 58:749-750. Baker, D. H., R. C. BlitenthaL K. P. Boebel, G. L. Czarnecki, L. L. Southern, and G. M. Willis, 1981. Protein-amino acid evaluation of steam-processed feather meal. Poultry Sci. 60:1865-1872. Boomgaardt, J., and D. H. Baker, 1971. Tryptophan requirement of growing chicks as affected by dietary protein level. J. Anim. Sci. 33:595-599. Carmer, S. G., and W. M. Walker, 1985. Pairwise multiple comparisons of treatment means in agronomic research. J. Agron. Ed. 14:19-26. Chung, T. K., and D. H. Baker, 1990. Riboflavin requirement of chicks fed purified amino acid and conventional corn-soybean meal diets. Poultry Sci. 69:1357-1363. Edmonds, M. S., C. M. Parsons, and D. H. Baker. 1985. Limiting amino acids in low protein corn-soybean meal diets fed to growing chicks. Poultry Sci. 64: 1519-1526. Freeman, C. P., 1979. The tryptophan requirement of broiler chicks. Br. Poult Sci. 20:27-37. Han, Y., and D. H. Baker, 1991. Lysine requirements of fast- and slow-growing broiler chicks. Poultry Sci. 70:2108-2114. Han, Y., F. Castanon, C. M. Parsons, and D. H. Baker, 1990a. Intestinal absorption and bioavailability of DL-methionine hydroxy analog compared to DLmethionine. Poultry Sci. 69:281-287. Han, Y., and C. M. Parsons, 1990. Determination of available amino acids and energy in alfalfa meal,
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Data are means of four groups of five male chicks from 8 to 22 days posthatching; average initial weight was 65 g.
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68(Suppl. l):200.(Abstr.) Sasse, C. E„ and D. H. Baker, 1974. Factors affecting sulfate-sulfur utilization by the young chicks. Poultry Sci. 53:652-662. Sato, H., T. Seino, T. Kobayashi, A. Murai, and Y. Yugari, 1984. Determination of the tryptophan concentration by ion exchange liquid chromatography. Agric. Biol. Chem. 48:2961-2969. Smith, Jr., N. K., and P. W. Waldroup, 1988. Estimation of the tryptophan requirement of male broiler chickens. Poultry Sci. 67:1174-1177. Spackman, D. H., W. H. Stein, and S. Moore, 1958. Automatic recording apparatus for use in the chromatography of amino acids. Anal. Chem. 30: 1190-1206. Steel, R.G.D., and J. H. Torrie, 1980. Principles and Procedures of Statistics. A Biometrical Approach, 2nd ed. McGraw-Hill Book Co., New York, NY. Steinhart, H., and M. Kirchgessner, 1984. Investigations on the requirement of tryptophan for broilers. Arch. Geflfigelkd. 48:150-155. Woodham, A. A., and P. S. Deans, 1975. Amino acid requirements of growing chickens. Br. Poult Sci. 16: 269-287.
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feather meal and poultry by-product meal by various methods. Poultry Sci. 69:1544-1552. Han, Y., H. Suzuki, C. M. Parsons, and D. H. Baker, 1990b. Amino acid fortification of a low protein corn-soybean meal diet for young chicks. Poultry Sci. 69(Suppl. l):59.(Abstr.) Hewitt, D.. and D. Lewis, 1972. The amino acid requirements of the growing chick. 1. Determination of amino acid requirements. Br. Poult. Sci. 13: 449-463. National Research Council, 1984. Nutrient Requirements of Poultry. 8th rev. ed. National Academy Press, Washington, DC. Robbins, K. R., and D. H. Baker, 1980. Effect of sulfur amino acid level and source on the performance of chicks fed high levels of copper. Poultry Sci. 59: 1246-1253. Robbins, K. R., D. H. Baker, and H. W. Norton, 1977. Histidine status in the chick as measured by growth rate, plasma free histidine and breast muscle carnosine. J. Nutr. 107:2055-2061. Rogers, S. R., and G. M. Pesti, 1989. Effect of protein on the tryptophan requirement of the growing chick and subsequent effects on lipid metabolism. Poultry Sci.
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