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Deficient Amino Acids in Protein of Dehulled Soybean Meal for Young Turkeys
Deficient Amino Acids in Protein of Dehulled Soybean Meal for Young Turkeys M. E. BLAIR and L. M. POTTER1 Department of Poultry Science, Virginia Polytechnic Institute and State University Blacksburg, Virginia 24061 (Received for publication September 25, 1986)
1987 Poultry Science 66:1813-1817 INTRODUCTION
The sulfur amino acids methionine and cystine have been established as the first-limiting amino acids in corn-soybean meal diets for young turkeys (Baldini et al., 1954; Fisher et al., 1956; Waibel, 1959). Stas and Potter (1982) and Jackson et al. (1983) reported deficiencies of valine, lysine, threonine, and isoleucine in a methionine-adequate, 22% protein corn-soybean meal diet when fed to young turkeys from 7 to 18 or 20 days of age. Edmonds et al. (1985) reported that methionine, arginine, lysine, threonine, and valine were critical limiting amino acids in low protein corn-soybean meal diets for broiler chicks. The identification of the deficient amino acids in a particular feedstuff, such as dehulled soybean meal, would allow a more precise and economical formulation of diets when using linear programming. Berry et al. (1962) reported that threonine, rather than lysine, may be the second-limiting amino acid in a soybean meal
'To whom correspondence should be addressed.
diet for swine. They also reported the order of limiting amino acids in soybean protein for rats to be methionine, threonine, and lysine. Warnick and Anderson (1968) reported that threonine, valine, and lysine were limiting after methionine in an 18% protein diet in which soybean meal served as the only protein source for chicks. Similar experiments with turkeys using soybean meal as the sole source of protein have not been conducted. The purpose of this study was to determine which amino acids were deficient in a methionine-adequate diet containing dehulled soybean meal as the sole source of protein for young turkeys using an amino acid deletion technique. MATERIALS AND METHODS
Two similar experiments initiated within a 1-mo period were conducted using a total of 768 Large White turkeys. Poults were obtained from the Virginia Polytechnic Institute and State University hatchery, sexed, and placed in starter batteries. For each experiment, a 30% protein corn-soybean meal diet, formulated to meet the National Research Council's (NRC, 1984) requirements for poults under 4 wk of age, was
1813
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
ABSTRACT Two 12-day experiments were conducted with Large White turkeys to determine which amino acids are deficient in a diet containing dehulled soybean meal as the sole source of protein. A 22% protein basal diet composed of 43.3% glucose monohydrate, 45.4% dehulled soybean meal, .5% DL-methionine, 6% stabilized fat, and added minerals and vitamins served as the negative control. Two positive control diets were formed by substituting either 16.5% dehulled soybean meal or a mixture containing amounts of essential amino acids equivalent to those in the added dehulled soybean meal in place of an equal amount of glucose monohydrate in the basal diet. Nine additional diets were formed by removing one or more amino acids from the mixture. Each of the 12 diets in a block design was fed to two pens of males and two pens of females with 8 birds per pen from 7 to 19 days of age in each experiment. Average body weight gain of poults fed the 22% protein diet with added amino acids approached that of poults fed the 30% protein diet (288 vs. 300 g, respectively). Removal of the amino acid mixture from the 22% protein diet depressed body weight gain by 19.0%. Depressions of 19, 16, 11, 7, and 6% in body weight gains resulted from the removal of valine, threonine, lysine, phenylalanine (or tyrosine or glycine), and isoleucine, respectively. A decrease of 5% was required for significance (P=£.05). When evaluated by this deletion technique, effects of valine and threonine deficiency were more pronounced than effects of lysine deficiency in dehulled soybean meal for young turkeys. (Key words: deficient amino acids, soybean meal, lysine, valine, threonine, turkeys)
BLAIR AND POTTER
1814 TABLE 1. Basal diet (22% protein) Ingredient
Amount (g/kg)
Glucose monohydrate Dehulled soybean meal Stabilized fat Defluorinated phosphate Iodized salt Trace mineral premix1 Vitamin and feed additive mix 2 DL-Methionine
433.1 454 60 37.5 4 1 5.4 5
Total
1,000.0
2
Supplied per kilogram of diet: 14,300 IU vitamin A; 7,150 ICU vitamin D 3 ; 55 IU vitamin E; 11 mg menadione sodium bisulfite; 3.3 mg thiamine HCI; 11 mg riboflavin; 22 mg D-calcium pantothenate; 110 mg niacin; 2,204 mg choline chloride; .0155 mg vitamin B , 2 ; 2.2 mg folic acid; .22 mg biotin; 5.5 g pyridoxine HCI; 125 mg ethoxyquin; .2 mg selenium; and 44 mg bacitracin from zinc bacitracin.
fed to the poults until 7 days of age. To assure similar average starting weights, poults within a sex were individually weighed and assigned
TABLE 2. Protein and amino acid composition of 22 and 30% protein diets* Ingredient
22% Protein
30% Protein
Protein Arginine Glycine Serine Histidine Isoleucine Leucine Lysine Methionine 3 Cystine Phenylalanine Tyrosine Threonine Tryptophan Valine
22.50 1.67 1.04 1.31
30.50 2.28 1.42 1.79 .82 1.59 2.36 1.97
Difference2
(%)
1
.60
1.17 1.73 1.44 .83 .33 .96
.91 .87 .30 1.23
.95
.45 1.31 1.24 1.18 .41 1.68
8.00 .61 .38 .48 .22 .42 .63 .53 .12 .12 .35 .33 .31 .11 .45
Calculated from values given by the National Research Council (1984).
2
Concentration of amino acids in essential amino acid mixture, except the amounts of glycine and serine were combined and added as glycine. 3
Including .5% DL-methionine in each diet.
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
'Supplied per kilogram of diet: 150 mg manganese, 120 mg zinc, 40 mg iron, 6 mg copper, and 1.5 mg iodine from manganese oxide, zinc oxide, ferrous sulfate monohydrate, copper oxide, and calcium iodate, respectively, with calcium carbonate as a diluent.
according to weight to 24 pens of males and 24 pens of females with 8 poults/pen. The 22% protein basal diet prepared separately for each experiment (Table 1) served as a negative control and contained dehulled soybean meal as the sole source of protein. The sulfur amino acids were assumed to be first limiting, thus, .5% DL-methionine was added to the basal diet to meet the requirement for methionine plus cystine (NRC, 1984). A 30% protein positive control diet was formed by substituting 16.5% dehulled soybean meal for an equal amount of glucose monohydrate. The amino acid levels of both the 22 and 30% protein diets were calculated using NRC (1984) values and are presented in Table 2. Differences between these two diets with respect to essential amino acids were used to determine the amounts of amino acids added as a mixture to the 22% protein diet to form a second positive control diet. The amounts of serine and glycine were combined and added as glycine to the mixture. Nine additional diets were formed by individually removing test amino acids from the mixture, except for glycine, phenylalanine, and tyrosine, which were removed together. All amino acids were added to the mixture in the L-form, and L-arginine and L-lysine were added as the hydrochloride on an equimolar basis.
DEFICIENT AMINO ACIDS IN DEHULLED SOYBEAN MEAL
1815
TABLE 3. Mean body weight gains, feed consumptions, and feed efficiencies of turkeys from 7 to 19 days of age (Experiments 1 and 2) fed 12 experimental diets1 Body weight gain
22% Protein (basal) 30% Protein 22% Protein + AA2 22% Protein + AA: —Arginine -Gly, Phe, Tyr — Histidine — Iso leucine — Leucine — Lysine —Threonine —Tryptophan —Valine
232***
—
(g)
362 362 365 359 351 355
280 267**
283 272*
285 256*** 241 * * *
341 * *
289
369
233***
319***
343*
13
Feed efficiency (g/g)
339** 398***
300 288
Difference required for significance3
Feed consumption
15
.687*** .755** .794 .773 .733*** .788 .774 .802 .752** .702*** .782 .730*** .022
1 Each value represents the average of 8 pens, 2 pens of males and 2 pens of females, in each experiment for a total of 64 poults per value. 2
Essential amino acid mixture (see Table 2 for composition).
3
P«.05.
'Significantly different from corresponding value for 22% protein + AA diet (P<.05). * 'Significantly different from corresponding value for 22% protein + AA diet (P<.01). ***Significantly different from corresponding value for 22% protein + AA diet (P«S.001).
Each experimental diet was fed to two pens of males and two pens of females by blocking the 12 experimental diets within 12 adjacent pens of a sex in each experiment. Poults were group weighed by pen at 7, 13, and 19 days of age. Average body weight gain, feed consumption, and feed efficiency were determined for the poults in each pen. Data from the two experiments were subjected to a common analysis of variance and the least significant difference between treatments was calculated. RESULTS
Mean body weight gain, feed consumption, and feed efficiency from feeding each diet from 7 to 19 days of age are presented in Table 3. With the exception of feed efficiency, results of these measurements from poults through 13 or 19 days of age or from either of the two experiments produced similar effects. The analyses of variance of these data are shown in Table 4. Body weight gain was depressed 19% (P=s .001), feed consumption, 6% (P«.01), and feed efficiency, 13% (P=s.001) by removal of the amino acid mixture from the 22% protein-supplemented diet. Average body weight gain of poults
fed the 30% protein diet was not significantly different from that of poults fed the 22% proteinsupplemented diet (.10>P>.05). However, feed consumption increased (10%) and feed efficiency decreased (5%) for birds fed the 30% protein diet in comparison with birds fed the 22% protein-supplemented diet. Removal of valine, threonine, or lysine from the amino acid mixture of the 22% protein-supplemented diet depressed (P=£ .001) body weight gains 19, 16, and 11%, respectively (Table 3). These depressions in body weight gain were accompanied by depressions in feed consumption and feed efficiency. When the combination of glycine, phenylalanine, and tyrosine was removed, body weight gain was reduced by 7% (P=£.01) and feed efficiency was reduced by 8% (P^.001). The exclusion of isoleucine depressed body weight gain 6% (P=s.05). The removal of valine caused a depression of body weight gain similar to that of the 22% proteinunsupplemented diet. Significantly lower (P^.05) body weight gains were obtained by the removal of valine or threonine from the amino acid mixture than by the removal of lysine.
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
Diet
1816
BLAIR AND POTTER TABLE 4. Analysis of variance of 7 to 19-day body weight gains, feed and feed efficiencies of turkeys (Experiments 1 and 2)
consumptions,
Mean square Source
Feed consumption
Body weight gain 4,282***
11
3,024** 956*
16 138
11 11 11
44
127
22,801***
32,701***
191 65 222 405
87 0 205 292
1,216**
1,440*
47 23 179
428 18 231
Feed efficiency (X10 6 ) 10,779*** 2,424* 958* 1,681 896 383 378 504 465 404 1 474
*P«.05. **P<.01. ***P«.001.
DISCUSSION
When 16.5% dehulled soybean meal replaced an equal amount of glucose monohydrate forming the 30% protein diet from the 22% protein diet, body weight gain, feed consumption, and feed efficiency were increased. These increases were expected as the negative control diet was calculated to be deficient in crude protein and in several amino acids (i.e., lysine, threonine,
leucine, and phenylalanine) based on the NRC (1984) requirements for the young turkey 0 to 4 wk of age (Table 5). The 22% protein diet supplemented with the amino acid mixture and the 30% protein diet produced nearly equal average body weight gains, indicating that the mixture corrected most of the deficiency of specific amino acids and apparent deficiency of protein or nitrogen. Al-
TABLE 5. Comparison of the National Research Council (NRC) requirements and amino acid composition of the 22% protein diet expressed as a percentage of the requirement
Amino acid
Arginine Glycine and serine Phenylalanine and tyrosine Phenylalanine Histidine Isoleucine Leucine Lysine Threonine Tryptophan Valine Methionine and cystine 1 Methionine 1 1
NRC (1984) amino acid requirement
1.60 1.00 1.80 1.00 .58
1.10 1.90 1.70 1.00
Amino acid composition of 22% protein diet
Percent of NRC requirement
1.67 2.35 1.87
104 235 104 96 103 106 91 85 87 115 102 110 157
.96 .60
1.17 1.73 1.44
.26
.87 .30
1.20 1.05
1.23 1.16
.53
.83
The diet was supplemented with .5% DL-methionine.
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
Diets (D) Experiment (E) DX E Sex (S) DX S E X S DX EX S Block (B) EX B SX B E X SX B Error
Degrees of freedom
DEFICIENT AMINO ACIDS IN DEHULLED SOYBEAN MEAL
both amino acid addition and deletion methods and reported the order of limiting amino acids was dependent upon the method used. Additional investigations with turkeys using the addition method are needed to ascertain whether the addition of the amino acid mixture caused an imbalance of amino acids. In conclusion, valine and threonine are more deficient than lysine in dehulled soybean meal when evaluated by the deletion method. ACKNOWLEDGMENTS
Amino acids were provided by Ajinomoto, Inc., Tokyo, Japan. REFERENCES Anderson, J. O., andR. E. Wamick, 1970. Effect of replacing part of the soybean meal in turkey poult rations with amino acid and carbohydrate mixtures. Poultry Sci. 49:459^*67. Baldini, J. T., H. R. Rosenberg, and J. Waddell, 1954. The protein requirement of the turkey poult. Poultry Sci. 33:539-543. Berry, T. H., D. E. Becker, O. G. Rasmussen, A. H. Jensen, and H. W. Norton, 1962. The limiting amino acids in soybean protein. J. Anim. Sci. 21:558-561. D'Mello, J.P.F., 1975. Amino acid requirements of the young turkey: leucine, isoleucine and valine. Br. Poult. Sci. 16:607-615. 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 Fisher, H., J. Dowling, Jr., and K. H. Maddy, 1956. Low protein diets for turkeys raised under practical conditions. Poultry Sci. 35:239-241. Jackson, S., and L. M. Potter, 1984. Influence of basic and branched chain amino acid interactions on the lysine and valine requirements of young turkeys. Poultry Sci. 63:2391-2398. Jackson, S., R. J. Stas, and L. M. Potter, 1983. Relative deficiencies of amino acids and nitrogen per se in low protein diets for young turkeys. Poultry Sci. 62:11171119. National Research Council, 1984. Nutrient Requirements of Domestic Animals. 1. Nutrient Requirements of Poultry. 8th rev. ed. Natl. Acad. Sci., Washington, DC. Stas, R. J., and L. M. Potter, 1982. Deficient amino acids in a 22% protein corn-soybean meal diet for young turkeys. Poultry Sci. 61:933-938. Tuttle, W. L., and S. L. Balloun, 1976. Leucine, isoleucine and valine interactions in turkey poults. Poultry Sci. 55:1737-1743. Waibel, P. E., 1959. Methionine and lysine in rations for turkey poults under various dietary conditions. Poultry Sci. 38:712-721. Warnick, R. E., and J. O. Anderson, 1968. Limiting essential amino acids in soybean meal for growing chickens and the effects of heat upon availability of the essential amino acids. Poultry Sci. 47:281-287.
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
though body weight gains were nearly equal for these two diets, feed consumption of poults fed the 30% protein diet was significantly higher and feed efficiency significantly lower than for birds fed the 22% protein diet supplemented with the amino acid mixture. The above differences are attributed to the lower metabolizable energy content of the 30% protein diet than that of the 22% protein diet (2,922 vs. 3,025 kcal/ kg). Only 85, 87, 91, and 96% of the required lysine, threonine, leucine, and phenylalanine, respectively, were supplied by the 22% basal diet (Table 5). As expected, removal of lysine, threonine, or the combination of glycine, phenylalanine, and tyrosine resulted in significantly lower body weight gains and feed efficiencies. Feed consumptions were also lower when lysine or threonine was removed. Lysine and threonine have been shown to be limiting in corn-soybean meal diets for young turkeys (Anderson and Warnick, 1970; Stas and Potter, 1982; Jackson et al., 1983). In our study where soybean meal supplied all of the protein, threonine was found more deficient than lysine or phenylalanine in dehulled soybean meal protein. Leucine was calculated to be deficient and valine and isoleucine adequate in the 22% protein diet (Table 5). However, the removal of leucine had no effect on poult performance whereas removal of isoleucine and valine resulted in significantly lower body weight gains. Removal of valine from the mixture resulted in lower feed efficiency and a severe depression in feed consumption, indicating imbalances among the branched chained amino acids. Excess leucine has been shown to depress growth and increase the requirements for valine and isoleucine, with valine being the more sensitive (D'Mello, 1975; Tuttle and Balloun, 1976; Jackson and Potter, 1984). Data of the present study support these earlier observations. When valine was removed from the amino acid mixture, the leucine:valine ratio was 1.9:1 compared with 1.4:1 in the 22% protein-supplemented diet and in the 30% protein diet. Therefore, valine and isoleucine deficiencies observed in this study appeared to be caused by an excess amount of leucine in relation to that of either valine or isoleucine. The type of assay used appears to influence the order of limiting amino acids. Edmonds et al. (1985), in studies with broiler chicks, used
1817
1987 Poultry Science 66:1813-1817 INTRODUCTION
The sulfur amino acids methionine and cystine have been established as the first-limiting amino acids in corn-soybean meal diets for young turkeys (Baldini et al., 1954; Fisher et al., 1956; Waibel, 1959). Stas and Potter (1982) and Jackson et al. (1983) reported deficiencies of valine, lysine, threonine, and isoleucine in a methionine-adequate, 22% protein corn-soybean meal diet when fed to young turkeys from 7 to 18 or 20 days of age. Edmonds et al. (1985) reported that methionine, arginine, lysine, threonine, and valine were critical limiting amino acids in low protein corn-soybean meal diets for broiler chicks. The identification of the deficient amino acids in a particular feedstuff, such as dehulled soybean meal, would allow a more precise and economical formulation of diets when using linear programming. Berry et al. (1962) reported that threonine, rather than lysine, may be the second-limiting amino acid in a soybean meal
'To whom correspondence should be addressed.
diet for swine. They also reported the order of limiting amino acids in soybean protein for rats to be methionine, threonine, and lysine. Warnick and Anderson (1968) reported that threonine, valine, and lysine were limiting after methionine in an 18% protein diet in which soybean meal served as the only protein source for chicks. Similar experiments with turkeys using soybean meal as the sole source of protein have not been conducted. The purpose of this study was to determine which amino acids were deficient in a methionine-adequate diet containing dehulled soybean meal as the sole source of protein for young turkeys using an amino acid deletion technique. MATERIALS AND METHODS
Two similar experiments initiated within a 1-mo period were conducted using a total of 768 Large White turkeys. Poults were obtained from the Virginia Polytechnic Institute and State University hatchery, sexed, and placed in starter batteries. For each experiment, a 30% protein corn-soybean meal diet, formulated to meet the National Research Council's (NRC, 1984) requirements for poults under 4 wk of age, was
1813
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
ABSTRACT Two 12-day experiments were conducted with Large White turkeys to determine which amino acids are deficient in a diet containing dehulled soybean meal as the sole source of protein. A 22% protein basal diet composed of 43.3% glucose monohydrate, 45.4% dehulled soybean meal, .5% DL-methionine, 6% stabilized fat, and added minerals and vitamins served as the negative control. Two positive control diets were formed by substituting either 16.5% dehulled soybean meal or a mixture containing amounts of essential amino acids equivalent to those in the added dehulled soybean meal in place of an equal amount of glucose monohydrate in the basal diet. Nine additional diets were formed by removing one or more amino acids from the mixture. Each of the 12 diets in a block design was fed to two pens of males and two pens of females with 8 birds per pen from 7 to 19 days of age in each experiment. Average body weight gain of poults fed the 22% protein diet with added amino acids approached that of poults fed the 30% protein diet (288 vs. 300 g, respectively). Removal of the amino acid mixture from the 22% protein diet depressed body weight gain by 19.0%. Depressions of 19, 16, 11, 7, and 6% in body weight gains resulted from the removal of valine, threonine, lysine, phenylalanine (or tyrosine or glycine), and isoleucine, respectively. A decrease of 5% was required for significance (P=£.05). When evaluated by this deletion technique, effects of valine and threonine deficiency were more pronounced than effects of lysine deficiency in dehulled soybean meal for young turkeys. (Key words: deficient amino acids, soybean meal, lysine, valine, threonine, turkeys)
BLAIR AND POTTER
1814 TABLE 1. Basal diet (22% protein) Ingredient
Amount (g/kg)
Glucose monohydrate Dehulled soybean meal Stabilized fat Defluorinated phosphate Iodized salt Trace mineral premix1 Vitamin and feed additive mix 2 DL-Methionine
433.1 454 60 37.5 4 1 5.4 5
Total
1,000.0
2
Supplied per kilogram of diet: 14,300 IU vitamin A; 7,150 ICU vitamin D 3 ; 55 IU vitamin E; 11 mg menadione sodium bisulfite; 3.3 mg thiamine HCI; 11 mg riboflavin; 22 mg D-calcium pantothenate; 110 mg niacin; 2,204 mg choline chloride; .0155 mg vitamin B , 2 ; 2.2 mg folic acid; .22 mg biotin; 5.5 g pyridoxine HCI; 125 mg ethoxyquin; .2 mg selenium; and 44 mg bacitracin from zinc bacitracin.
fed to the poults until 7 days of age. To assure similar average starting weights, poults within a sex were individually weighed and assigned
TABLE 2. Protein and amino acid composition of 22 and 30% protein diets* Ingredient
22% Protein
30% Protein
Protein Arginine Glycine Serine Histidine Isoleucine Leucine Lysine Methionine 3 Cystine Phenylalanine Tyrosine Threonine Tryptophan Valine
22.50 1.67 1.04 1.31
30.50 2.28 1.42 1.79 .82 1.59 2.36 1.97
Difference2
(%)
1
.60
1.17 1.73 1.44 .83 .33 .96
.91 .87 .30 1.23
.95
.45 1.31 1.24 1.18 .41 1.68
8.00 .61 .38 .48 .22 .42 .63 .53 .12 .12 .35 .33 .31 .11 .45
Calculated from values given by the National Research Council (1984).
2
Concentration of amino acids in essential amino acid mixture, except the amounts of glycine and serine were combined and added as glycine. 3
Including .5% DL-methionine in each diet.
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
'Supplied per kilogram of diet: 150 mg manganese, 120 mg zinc, 40 mg iron, 6 mg copper, and 1.5 mg iodine from manganese oxide, zinc oxide, ferrous sulfate monohydrate, copper oxide, and calcium iodate, respectively, with calcium carbonate as a diluent.
according to weight to 24 pens of males and 24 pens of females with 8 poults/pen. The 22% protein basal diet prepared separately for each experiment (Table 1) served as a negative control and contained dehulled soybean meal as the sole source of protein. The sulfur amino acids were assumed to be first limiting, thus, .5% DL-methionine was added to the basal diet to meet the requirement for methionine plus cystine (NRC, 1984). A 30% protein positive control diet was formed by substituting 16.5% dehulled soybean meal for an equal amount of glucose monohydrate. The amino acid levels of both the 22 and 30% protein diets were calculated using NRC (1984) values and are presented in Table 2. Differences between these two diets with respect to essential amino acids were used to determine the amounts of amino acids added as a mixture to the 22% protein diet to form a second positive control diet. The amounts of serine and glycine were combined and added as glycine to the mixture. Nine additional diets were formed by individually removing test amino acids from the mixture, except for glycine, phenylalanine, and tyrosine, which were removed together. All amino acids were added to the mixture in the L-form, and L-arginine and L-lysine were added as the hydrochloride on an equimolar basis.
DEFICIENT AMINO ACIDS IN DEHULLED SOYBEAN MEAL
1815
TABLE 3. Mean body weight gains, feed consumptions, and feed efficiencies of turkeys from 7 to 19 days of age (Experiments 1 and 2) fed 12 experimental diets1 Body weight gain
22% Protein (basal) 30% Protein 22% Protein + AA2 22% Protein + AA: —Arginine -Gly, Phe, Tyr — Histidine — Iso leucine — Leucine — Lysine —Threonine —Tryptophan —Valine
232***
—
(g)
362 362 365 359 351 355
280 267**
283 272*
285 256*** 241 * * *
341 * *
289
369
233***
319***
343*
13
Feed efficiency (g/g)
339** 398***
300 288
Difference required for significance3
Feed consumption
15
.687*** .755** .794 .773 .733*** .788 .774 .802 .752** .702*** .782 .730*** .022
1 Each value represents the average of 8 pens, 2 pens of males and 2 pens of females, in each experiment for a total of 64 poults per value. 2
Essential amino acid mixture (see Table 2 for composition).
3
P«.05.
'Significantly different from corresponding value for 22% protein + AA diet (P<.05). * 'Significantly different from corresponding value for 22% protein + AA diet (P<.01). ***Significantly different from corresponding value for 22% protein + AA diet (P«S.001).
Each experimental diet was fed to two pens of males and two pens of females by blocking the 12 experimental diets within 12 adjacent pens of a sex in each experiment. Poults were group weighed by pen at 7, 13, and 19 days of age. Average body weight gain, feed consumption, and feed efficiency were determined for the poults in each pen. Data from the two experiments were subjected to a common analysis of variance and the least significant difference between treatments was calculated. RESULTS
Mean body weight gain, feed consumption, and feed efficiency from feeding each diet from 7 to 19 days of age are presented in Table 3. With the exception of feed efficiency, results of these measurements from poults through 13 or 19 days of age or from either of the two experiments produced similar effects. The analyses of variance of these data are shown in Table 4. Body weight gain was depressed 19% (P=s .001), feed consumption, 6% (P«.01), and feed efficiency, 13% (P=s.001) by removal of the amino acid mixture from the 22% protein-supplemented diet. Average body weight gain of poults
fed the 30% protein diet was not significantly different from that of poults fed the 22% proteinsupplemented diet (.10>P>.05). However, feed consumption increased (10%) and feed efficiency decreased (5%) for birds fed the 30% protein diet in comparison with birds fed the 22% protein-supplemented diet. Removal of valine, threonine, or lysine from the amino acid mixture of the 22% protein-supplemented diet depressed (P=£ .001) body weight gains 19, 16, and 11%, respectively (Table 3). These depressions in body weight gain were accompanied by depressions in feed consumption and feed efficiency. When the combination of glycine, phenylalanine, and tyrosine was removed, body weight gain was reduced by 7% (P=£.01) and feed efficiency was reduced by 8% (P^.001). The exclusion of isoleucine depressed body weight gain 6% (P=s.05). The removal of valine caused a depression of body weight gain similar to that of the 22% proteinunsupplemented diet. Significantly lower (P^.05) body weight gains were obtained by the removal of valine or threonine from the amino acid mixture than by the removal of lysine.
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
Diet
1816
BLAIR AND POTTER TABLE 4. Analysis of variance of 7 to 19-day body weight gains, feed and feed efficiencies of turkeys (Experiments 1 and 2)
consumptions,
Mean square Source
Feed consumption
Body weight gain 4,282***
11
3,024** 956*
16 138
11 11 11
44
127
22,801***
32,701***
191 65 222 405
87 0 205 292
1,216**
1,440*
47 23 179
428 18 231
Feed efficiency (X10 6 ) 10,779*** 2,424* 958* 1,681 896 383 378 504 465 404 1 474
*P«.05. **P<.01. ***P«.001.
DISCUSSION
When 16.5% dehulled soybean meal replaced an equal amount of glucose monohydrate forming the 30% protein diet from the 22% protein diet, body weight gain, feed consumption, and feed efficiency were increased. These increases were expected as the negative control diet was calculated to be deficient in crude protein and in several amino acids (i.e., lysine, threonine,
leucine, and phenylalanine) based on the NRC (1984) requirements for the young turkey 0 to 4 wk of age (Table 5). The 22% protein diet supplemented with the amino acid mixture and the 30% protein diet produced nearly equal average body weight gains, indicating that the mixture corrected most of the deficiency of specific amino acids and apparent deficiency of protein or nitrogen. Al-
TABLE 5. Comparison of the National Research Council (NRC) requirements and amino acid composition of the 22% protein diet expressed as a percentage of the requirement
Amino acid
Arginine Glycine and serine Phenylalanine and tyrosine Phenylalanine Histidine Isoleucine Leucine Lysine Threonine Tryptophan Valine Methionine and cystine 1 Methionine 1 1
NRC (1984) amino acid requirement
1.60 1.00 1.80 1.00 .58
1.10 1.90 1.70 1.00
Amino acid composition of 22% protein diet
Percent of NRC requirement
1.67 2.35 1.87
104 235 104 96 103 106 91 85 87 115 102 110 157
.96 .60
1.17 1.73 1.44
.26
.87 .30
1.20 1.05
1.23 1.16
.53
.83
The diet was supplemented with .5% DL-methionine.
Downloaded from http://ps.oxfordjournals.org/ at University of Otago on March 12, 2015
Diets (D) Experiment (E) DX E Sex (S) DX S E X S DX EX S Block (B) EX B SX B E X SX B Error
Degrees of freedom
DEFICIENT AMINO ACIDS IN DEHULLED SOYBEAN MEAL
both amino acid addition and deletion methods and reported the order of limiting amino acids was dependent upon the method used. Additional investigations with turkeys using the addition method are needed to ascertain whether the addition of the amino acid mixture caused an imbalance of amino acids. In conclusion, valine and threonine are more deficient than lysine in dehulled soybean meal when evaluated by the deletion method. ACKNOWLEDGMENTS
Amino acids were provided by Ajinomoto, Inc., Tokyo, Japan. REFERENCES Anderson, J. O., andR. E. Wamick, 1970. Effect of replacing part of the soybean meal in turkey poult rations with amino acid and carbohydrate mixtures. Poultry Sci. 49:459^*67. Baldini, J. T., H. R. Rosenberg, and J. Waddell, 1954. The protein requirement of the turkey poult. Poultry Sci. 33:539-543. Berry, T. H., D. E. Becker, O. G. Rasmussen, A. H. Jensen, and H. W. Norton, 1962. The limiting amino acids in soybean protein. J. Anim. Sci. 21:558-561. D'Mello, J.P.F., 1975. Amino acid requirements of the young turkey: leucine, isoleucine and valine. Br. Poult. Sci. 16:607-615. 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 Fisher, H., J. Dowling, Jr., and K. H. Maddy, 1956. Low protein diets for turkeys raised under practical conditions. Poultry Sci. 35:239-241. Jackson, S., and L. M. Potter, 1984. Influence of basic and branched chain amino acid interactions on the lysine and valine requirements of young turkeys. Poultry Sci. 63:2391-2398. Jackson, S., R. J. Stas, and L. M. Potter, 1983. Relative deficiencies of amino acids and nitrogen per se in low protein diets for young turkeys. Poultry Sci. 62:11171119. National Research Council, 1984. Nutrient Requirements of Domestic Animals. 1. Nutrient Requirements of Poultry. 8th rev. ed. Natl. Acad. Sci., Washington, DC. Stas, R. J., and L. M. Potter, 1982. Deficient amino acids in a 22% protein corn-soybean meal diet for young turkeys. Poultry Sci. 61:933-938. Tuttle, W. L., and S. L. Balloun, 1976. Leucine, isoleucine and valine interactions in turkey poults. Poultry Sci. 55:1737-1743. Waibel, P. E., 1959. Methionine and lysine in rations for turkey poults under various dietary conditions. Poultry Sci. 38:712-721. Warnick, R. E., and J. O. Anderson, 1968. Limiting essential amino acids in soybean meal for growing chickens and the effects of heat upon availability of the essential amino acids. Poultry Sci. 47:281-287.
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though body weight gains were nearly equal for these two diets, feed consumption of poults fed the 30% protein diet was significantly higher and feed efficiency significantly lower than for birds fed the 22% protein diet supplemented with the amino acid mixture. The above differences are attributed to the lower metabolizable energy content of the 30% protein diet than that of the 22% protein diet (2,922 vs. 3,025 kcal/ kg). Only 85, 87, 91, and 96% of the required lysine, threonine, leucine, and phenylalanine, respectively, were supplied by the 22% basal diet (Table 5). As expected, removal of lysine, threonine, or the combination of glycine, phenylalanine, and tyrosine resulted in significantly lower body weight gains and feed efficiencies. Feed consumptions were also lower when lysine or threonine was removed. Lysine and threonine have been shown to be limiting in corn-soybean meal diets for young turkeys (Anderson and Warnick, 1970; Stas and Potter, 1982; Jackson et al., 1983). In our study where soybean meal supplied all of the protein, threonine was found more deficient than lysine or phenylalanine in dehulled soybean meal protein. Leucine was calculated to be deficient and valine and isoleucine adequate in the 22% protein diet (Table 5). However, the removal of leucine had no effect on poult performance whereas removal of isoleucine and valine resulted in significantly lower body weight gains. Removal of valine from the mixture resulted in lower feed efficiency and a severe depression in feed consumption, indicating imbalances among the branched chained amino acids. Excess leucine has been shown to depress growth and increase the requirements for valine and isoleucine, with valine being the more sensitive (D'Mello, 1975; Tuttle and Balloun, 1976; Jackson and Potter, 1984). Data of the present study support these earlier observations. When valine was removed from the amino acid mixture, the leucine:valine ratio was 1.9:1 compared with 1.4:1 in the 22% protein-supplemented diet and in the 30% protein diet. Therefore, valine and isoleucine deficiencies observed in this study appeared to be caused by an excess amount of leucine in relation to that of either valine or isoleucine. The type of assay used appears to influence the order of limiting amino acids. Edmonds et al. (1985), in studies with broiler chicks, used
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