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Effect of in Vitro Enzymatic Digestion of Raw Soybean Flakes on Chick Growth*
538
RESEARCH NOTES
less in the higher thiouracil groups indicating that the birds were more efficient in the utilization of mash. Discussion. Earlier experiments have demonstrated that the feeding of thiouracil to broilers may cause marked improvement in the market quality of the birds. This experiment indicates that under certain conditions it is also possible to secure superior weight gains in such animals fed thiouracil. Two conditions were different in this experiment as compared to previous ones. First, the birds were somewhat older and heavier and, second, the birds were kept under range conditions, which may have been a factor in maintaining the mash intake of the birds. It is significant also that the efficiency of utilization of the mash was greater in those groups having
t h e m o s t t h i o u r a c i l in t h e m a s h . J . P . MlXNER B. A. TOWER C. W. U P P University of Louisiana Received for publication July 18, 1946 REFERENCES
Andrews, F. N. and E. E. Schnetzler, 1946. Influence of thiouracil on growth and fattening in broilers. Poultry Sci. 25:124-129. Glazener, E. W. and M. A. Jull, 1946. Effects of thiouracil, desiccated thyroid and stilbestrol derivatives on various glands, body weight and dressing appearance in chickens. Poultry Sci. 25: 236-241. Kempster, H. L. and C. W. Turner, 1945. The effect of feeding thiouracil on the fleshing of New Hampshire Broilers. Poultry Sci. 24: 94-96. Mixner, J. P., E. P. Reineke and C. W. Turner, 1944. The effect of thiouracil and thiourea on the thyroid gland of the chick. Endocrinology 34: 168174.
EFFECT OF IN VITRO ENZYMATIC DIGESTION OF RAW SOYBEAN FLAKES ON CHICK GROWTH* Numerous experiments have shown that the nutritive value of raw soybean flakes is markedly improved by moist heat treatment. Evans and McGinnis (1946) showed that heat treatment of raw soybean flakes increased the availability and retention of methionine and cystine by the chick. The report of Ham, Sandstedt, and Mussehl (1945) showing that a fraction of raw soybean flakes containing a trypsin inhibitor, which is inactivated by heat, suggests that the poor nutritive value of raw soybeans may be partly due to the presence of a trypsin inhibitor. Since Kunitz (1945) showed that the trypsin inhibitor present in raw soybeans is a protein, it was of interest to determine whether the nutritive value of raw soy* Published as Scientific Paper No. 668, College of Agriculture and Agricultural Experiment Station, State College of Washington, Pullman, Washington.
bean flakes could be increased by altering the soybean proteins by in vitro digestion with papain. This possibility was also of interest since Evans (1946) showed by in vitro enzymatic digestion of the soybean meals used in the cystine and methionine availability study reported by Evans and McGinnis (1946) that the liberation of amino acid nitrogen by trypsin was about the same from both the heat-treated soybean meal and the raw soybean flakes digested with pepsin. The experimental diets were fed to duplicate groups of ten White Leghorn chicks kept in battery brooders. The composition of the basal diet was the same as the one used by Evans and McGinnis (1946) except that 0.2 percent choline chloride was added and the soybean oil was replaced with cerelose. The treatment of the soybean flakes used in the diets for the differ-
539
RESEARCH NOTES
ent groups was varied. The treatments of the soybean flakes and the growth results are given in Table 1. TABLE 1.—The eject of autoclaving and papain digestion of raw soybean flakes on its nutritive value for chicks. Treatment of raw f soybean flakes
rou_*
"
2 3
172
None
Papain digested 14 hours a t 37° C. Papain digested 14 hours at 37° C. after autoclaving 30 minutes a t 120° C.
at 4 wks. gms. 119 117 114
1
Autoclaved 30 minutes at 120° C.
Av. wt.
Mortality
10
% 5.0
0
JAMES MCGINNIS V. H. MENZIES
0 0.0
173 4
173
0
5
164
0
6
177
7
182
171
8
ver, McGinnis, McClary, and Evans (1946) have recently shown that raw soybean flakes is utilized by hens for egg production and maintenance of body weight as well as commercially heated soybean meal. The observations reported in this paper together with the results on the utilization of raw soybean flakes by hens indicate that the fraction of raw soybean flakes responsible for its low nutritive value for chicks may be inactivated by protelytic enzyme action.
10.0 20
Department of Poultry Husbandry Washington Agricultural Experiment Station Pullman, Washington Received for publication July 23, 1946.
10 183
183
5.0 0
* Each group contained ten chicks.
The chick growth results show that the nutritive value of raw soybean flakes was increased as much by papain digestion as by autoclaving. On the other hand, papain digestion of the autoclaved soybean flakes gave only slightly better growth than autoclaving alone. From these results, it appears that the fraction of raw soybean flakes responsible for the poor nutritive value of raw soybeans may be inactivated by in vitro papain digestion as well as by heating. Car-
REFERENCES
Carver, J. S., James McGinnis, C. F. McClary, and R. J. Evans, 1946. The utilization of raw andheattreated soybean oil meal for egg production and hatchability. Poultry Sci. (in press). Evans, R. J., 1946. Hydrolysis of soybean oil meal proteins by some proteolytic enzymes. Arch. Biochem. (in press). Evans, R. J., and James McGinnis, 1946. The influence of autoclaving soybean oil meal on the availability of cystine and methionine for the chick. J. Nutrition 31: 449-461. Ham, W. E., R. M. Sandstedt and F. E. Mussehl, 1945. The proteolytic inhibiting substance in the extract from unheated soybean meal and its effect upon growth in chicks. J. Biol. Chem. 161: 635-642. Kunitz, M., 1945. Crystallization of a trypsin inhibitor from soybeans. Science 101: 668-669.
SALT TOLERANCE OF TURKEYS* Scrivner (1946) has suggested that edema and ascites as observed in turkey poults may be caused by sodium chloride, or more specifically, by the sodium in the * Supported in part by a grant from the Yantic Grain and Products Company, Norwich, Connecticut.
diet. He based his conclusions on results of experiments in which day-old poults were fed a commercial mash containing 0.5% sodium chloride to which he added up to 3.0% sodium chloride and in another series, various percentages of other sodium salts. His data indicated that
RESEARCH NOTES
less in the higher thiouracil groups indicating that the birds were more efficient in the utilization of mash. Discussion. Earlier experiments have demonstrated that the feeding of thiouracil to broilers may cause marked improvement in the market quality of the birds. This experiment indicates that under certain conditions it is also possible to secure superior weight gains in such animals fed thiouracil. Two conditions were different in this experiment as compared to previous ones. First, the birds were somewhat older and heavier and, second, the birds were kept under range conditions, which may have been a factor in maintaining the mash intake of the birds. It is significant also that the efficiency of utilization of the mash was greater in those groups having
t h e m o s t t h i o u r a c i l in t h e m a s h . J . P . MlXNER B. A. TOWER C. W. U P P University of Louisiana Received for publication July 18, 1946 REFERENCES
Andrews, F. N. and E. E. Schnetzler, 1946. Influence of thiouracil on growth and fattening in broilers. Poultry Sci. 25:124-129. Glazener, E. W. and M. A. Jull, 1946. Effects of thiouracil, desiccated thyroid and stilbestrol derivatives on various glands, body weight and dressing appearance in chickens. Poultry Sci. 25: 236-241. Kempster, H. L. and C. W. Turner, 1945. The effect of feeding thiouracil on the fleshing of New Hampshire Broilers. Poultry Sci. 24: 94-96. Mixner, J. P., E. P. Reineke and C. W. Turner, 1944. The effect of thiouracil and thiourea on the thyroid gland of the chick. Endocrinology 34: 168174.
EFFECT OF IN VITRO ENZYMATIC DIGESTION OF RAW SOYBEAN FLAKES ON CHICK GROWTH* Numerous experiments have shown that the nutritive value of raw soybean flakes is markedly improved by moist heat treatment. Evans and McGinnis (1946) showed that heat treatment of raw soybean flakes increased the availability and retention of methionine and cystine by the chick. The report of Ham, Sandstedt, and Mussehl (1945) showing that a fraction of raw soybean flakes containing a trypsin inhibitor, which is inactivated by heat, suggests that the poor nutritive value of raw soybeans may be partly due to the presence of a trypsin inhibitor. Since Kunitz (1945) showed that the trypsin inhibitor present in raw soybeans is a protein, it was of interest to determine whether the nutritive value of raw soy* Published as Scientific Paper No. 668, College of Agriculture and Agricultural Experiment Station, State College of Washington, Pullman, Washington.
bean flakes could be increased by altering the soybean proteins by in vitro digestion with papain. This possibility was also of interest since Evans (1946) showed by in vitro enzymatic digestion of the soybean meals used in the cystine and methionine availability study reported by Evans and McGinnis (1946) that the liberation of amino acid nitrogen by trypsin was about the same from both the heat-treated soybean meal and the raw soybean flakes digested with pepsin. The experimental diets were fed to duplicate groups of ten White Leghorn chicks kept in battery brooders. The composition of the basal diet was the same as the one used by Evans and McGinnis (1946) except that 0.2 percent choline chloride was added and the soybean oil was replaced with cerelose. The treatment of the soybean flakes used in the diets for the differ-
539
RESEARCH NOTES
ent groups was varied. The treatments of the soybean flakes and the growth results are given in Table 1. TABLE 1.—The eject of autoclaving and papain digestion of raw soybean flakes on its nutritive value for chicks. Treatment of raw f soybean flakes
rou_*
"
2 3
172
None
Papain digested 14 hours a t 37° C. Papain digested 14 hours at 37° C. after autoclaving 30 minutes a t 120° C.
at 4 wks. gms. 119 117 114
1
Autoclaved 30 minutes at 120° C.
Av. wt.
Mortality
10
% 5.0
0
JAMES MCGINNIS V. H. MENZIES
0 0.0
173 4
173
0
5
164
0
6
177
7
182
171
8
ver, McGinnis, McClary, and Evans (1946) have recently shown that raw soybean flakes is utilized by hens for egg production and maintenance of body weight as well as commercially heated soybean meal. The observations reported in this paper together with the results on the utilization of raw soybean flakes by hens indicate that the fraction of raw soybean flakes responsible for its low nutritive value for chicks may be inactivated by protelytic enzyme action.
10.0 20
Department of Poultry Husbandry Washington Agricultural Experiment Station Pullman, Washington Received for publication July 23, 1946.
10 183
183
5.0 0
* Each group contained ten chicks.
The chick growth results show that the nutritive value of raw soybean flakes was increased as much by papain digestion as by autoclaving. On the other hand, papain digestion of the autoclaved soybean flakes gave only slightly better growth than autoclaving alone. From these results, it appears that the fraction of raw soybean flakes responsible for the poor nutritive value of raw soybeans may be inactivated by in vitro papain digestion as well as by heating. Car-
REFERENCES
Carver, J. S., James McGinnis, C. F. McClary, and R. J. Evans, 1946. The utilization of raw andheattreated soybean oil meal for egg production and hatchability. Poultry Sci. (in press). Evans, R. J., 1946. Hydrolysis of soybean oil meal proteins by some proteolytic enzymes. Arch. Biochem. (in press). Evans, R. J., and James McGinnis, 1946. The influence of autoclaving soybean oil meal on the availability of cystine and methionine for the chick. J. Nutrition 31: 449-461. Ham, W. E., R. M. Sandstedt and F. E. Mussehl, 1945. The proteolytic inhibiting substance in the extract from unheated soybean meal and its effect upon growth in chicks. J. Biol. Chem. 161: 635-642. Kunitz, M., 1945. Crystallization of a trypsin inhibitor from soybeans. Science 101: 668-669.
SALT TOLERANCE OF TURKEYS* Scrivner (1946) has suggested that edema and ascites as observed in turkey poults may be caused by sodium chloride, or more specifically, by the sodium in the * Supported in part by a grant from the Yantic Grain and Products Company, Norwich, Connecticut.
diet. He based his conclusions on results of experiments in which day-old poults were fed a commercial mash containing 0.5% sodium chloride to which he added up to 3.0% sodium chloride and in another series, various percentages of other sodium salts. His data indicated that