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Toxicity of Linseed Meal for Chicks*
Toxicity of Linseed Meal for Chicks H. I. MACGREGOR AND JAMES MCGINNIS
Division of Poultry Husbandry, Washington Agricultural Experiment Station, Pullman, Washington (Received for publication August 26,1947)
O E V E R A L investigators have shown ^ that linseed meal gave poor growth when substituted for other protein supplements in chick starting diets. Heuser, Norris and McGinnis (1946) showed that as little as fifteen percent of linseed meal in the diet caused poor growth in White Leghorn chicks. McGinnis and Polis (1946) tried several methods of treating linseed meal to improve its nutritive value for growing chicks. They found that a marked improvement resulted when the linseed meal was water-treated. This treatment consisted of wetting the linseed meal with approximately two times its weight of water and allowing the mixture to stand for 18 hours at 37°C. The linseed meal treated in this manner gave a greatly increased growth response with chicks when compared with untreated linseed meal when each kind of linseed meal was included in the diet as the only source of supplementary protein. In the first series of experiments, McGinnis and Polis (1946) added the treated linseed meal to the diet in the moist state. In later experiments it was dried before mixing in the diet. More recently, Kratzer (1946, 1947) showed that "water treatment" in which a 1:3 linseed meal-tap water mixture was a allowed to stand at 22°C. for 12 hours (with subsequent drying before incorporation into the diet) gave as good growth
* Published as Scientific Paper No. 735, College of Agriculture and Agricultural Experiment Stations, Institute of Agricultural Sciences, State College of Washington, Pullman, Washington.
response as treatment for longer periods of time. Kratzer, Williams and Baker (1947) found that water-treated linseed meal was deficient only in lysine for chicks, when this treated linseed meal supplied all of the dietary protein at a 20 percent level. The other essential amino acids apparently were supplied in sufficient amounts by this level of protein to meet the chicks' requirements. This experiment was planned in order to test the growth depressing effect of linseed meal when added to an adequate diet containing 20 percent of crude protein from other sources. EXPERIMENTAL
Experiment 1: Day-old White Leghorn cockerel chicks were randomized into 18 groups of approximately 12 chicks each to provide duplicate groups for testing each diet. The chicks were then wing banded, weighed individually and placed in electrically heated battery brooders which had wire floors. Water and the experimental diets were available ad libitum. Weekly body weight and feed consumption data were obtained. The experiment was terminated at the end of four weeks. As outlined in Table 1, four different levels of linseed meal were added to an adequate diet (diet 8) to test the effect of linseed meal on chick growth and mortality. In order to eliminate protein toxicity as a factor, equivalent increases in crude protein were supplied by four different levels of soybean oil meal. The linseed 141
142
H. I. MACGREGOR AND JAMES M C G I N N I S
TABLE 1, Experiment 1.—Composition of diets, body weight, feed consumption and number of survivors at four weeks of age Diet numbers
Basal mixture* Cerelose Linseed meal Soybean oil meal (expeller)
8
9
10
11
12
13
14
15
16
%
%
%
%
% 40.0 — 30.0
%
%
%
%
40.0 30.0
— 30.0
40.0 22.5 7.5 30.0
40.0 15.0 15.0 30.0
100.0 Total Percentage of crude protein (calculated) 20.0
100.0 22.4
100.0 24.8
40.0 7.5 22.5 30.0 100.0 27.2
30.0 100.0 29.6
40.0 24.2
40.0 18.3
— 35.8 100.0 22.4
— 41.7 100.0 24.8
40.0 12.5 - — •
47.5 100.0 27.2
40.0 6.6
— 53.4 100.0 29.6
12-12 13-12 13-12 13-12 13-12 13-12 13-12 13-12 13-13 Initial number of chicks No. survivors at 4 wks. 12-12 13-11 13-13 12-12 11-11 13-11 13-12 13-12 11-12 Av. body wt. by lots (gms.) 277-279 252-245 214-218 174-177 147-156 285-274 267-287 290-278 258-278 Av. body wt. by diets (gms.) 278 248 216 176 151 280 277 284 268 Av. feed consumption to 4 wks. (gms.) 531 535 450 398 381 545 516 555 579 * Basal mixture composition: Ground yellow corn 10.9, ground wheat 10.9, dehydrated alfalfa meal 5.0, fish meal 6.0, dried brewers' yeast 2.0, ground limestone 2.5, dicalcium phosphate 1.5, iodized salt 0.5, B-Y feed 0.4, choline chloride 0.1, vitamin D supplement (2,000 D/gm.) 0.05, manganese sulphate 0.02, methionine 0.08.
meal and soybean oil meal were added to the diet at the expense of "cerelose." RESULTS
As shownin Table 1, but more strikingly in Figure 1, growth of the chicks fed adequate diets containing different levels of linseed meal was negatively correlated
with the percentage of linseed meal in the diet—the correlation coefficient was —0.7944. This indicates that linseed meal contains a toxic substance per se because the diets containing these different levels of linseed meal were adequate in protein, as shown by the growth of chicks*receiving diet 8. The growth depression which re-
290-
270.
850 — SOYBEAN OIL MEAL DIETS 23
LINSEED MEAL DIETS REGRESSION EQUATIONS W» 2 8 0 - 7 - 0-6 88 Yi
210
W« 8 8 0 . 7 - 13.79 Y»
>. *
W • body weight in grams
$
190
Yi'Xadditional soybean protein Y>k%addiiiond linseed protein
170
150
130
2.4
4.8
7.2
9.6
PERCENT ADDITIONAL PROTEIN FROM UNSEE0 MEAL OR SOYBEAN OIL MEAL .
FIG. 1. The effect on chick body weight of linseed meal and soybean oil meal supplements added to an adequate diet containing 20 percent crude protein.
143
TOXICITY OF LINSEED MEAL FOR CHICKS TABLE 2, Experiment 1.—Comparison of final body weights of chicks receiving the various diets
Treatments
30% soybean oil meal 7 . 5 % linseed meal 15.0% linseed meal 2 2 . 5 % linseed meal 30.0% linseed meal 35.85% soybean oil meal 41.70% soybean oil meal 47.55% soybean oil meal 53.40% soybean oil meal
Av. body wt. at four wks.
Diet
grams 278 248 216 176 151 280 277 284 268
8 9 10 11 12 13 14 15 16
Body weight comparison by diets 9
10
11
12
13
14
15
16
**
** **
** ** **
** ** ** *
ns
ns
ns
** ** ** **
** ** ** **
** ** ** **
ns ns
ns
** ** **
ns ns
ns ns ns
*—significant at 5 percent point. **—significant at 1 percent point, ns—not significant at 5 percent point.
suited from the addition of linseed meal does not appear to be due to excessive protein as approximately equal amounts of additional protein from soybean oil meal did not depress growth. Table 2 shows the statistical analysis of the average body weight data of chicks at four weeks of age. The significance of differences between the pooled data of duplicate groups was tested by analysis of variance. No significant differences were
found between duplicate groups for any of the diets. The regression lines were obtained by the method of least squares using the averages for each diet as the crude data. Significance of differences of body weights are indicated. Experiment 2: Unsexed New Hampshire chicks were used in this experiment. During the first week they were fed a standard chick start-
TABLE 3, Experiment 2.—Composition of diets and average body weights of chicks at four weeks Diets Ingredients
Basal mixture* Cerelose Soybean oil meal Linseed meal Water-treated linseed meal** Total—percent Initial no. of chicks (1 week) No. of survivors at 4 weeks Av. body weights by groups—gms. Av. body weights by diets—gms.
1
2
3
4
5
6
percent
percent
percent
percent
percent
percent
70.00 30.00
70.00 8.00 22.00
70.00 20.00
70.00 10.00
70.00
70.00
— —
— —
— — —
30.00
—
•
— —
100.00 12-12 12-12 270-248 259
—
10.00 — 100.00 100.00 12-12 12-12 12-12 12-12 294-271 278-273 282 275
20.00 100.00 12-12 12-12 244-282 263
30.00 100.00 11-12 11-12 257-251 254
— — —
100.00 12-12 11-12 187-193 190
* The basal mixture was composed as follows: Ground corn 12.5, ground wheat 12.45, soybean oil meal 27.0, fish meal 5.0, dehydrated alfalfa meal 5.0, dried brewers' yeast 3.0, ground oyster shell 2.0, dicalcium phosphate 1.8, vitamin D supplement (2,000 D/gm) 0.05, liver paste O.l.iodized salt 0.53,B-Y feed 0.5, choline chloride 0.05, manganese sulphate 0.02. ** The water-treated linseed meal consisted of linseed meal mixed with two and one-half times its weight of water which was then allowed to stand at 25°C. for 18 hours. This mixture was then oven dried at about 70°C. The dry product was ground medium fine before mixing in the diets.
144
H. I. MACGREGOR AND JAMES MCGINNIS
ing ration. At the end of this time they were randomized into twelve groups of approximately twelve chicks each to provide duplicate groups for testing each experimental diet. Treatment of the chicks was essentially the same as outlined in Experiment 1. The experiment was terminated at the end of four weeks of age. RESULTS
In Table 3 the composition of the various diets is given; also included in this table are data pertaining to body weight and number of survivors at the termination of the experiment. Table 4 shows the statistical analysis of the final body weights of chick receiving the various diets. Analysis of variance showed that these differences in body weight were statistically significant as noted. The data on final body weight of the chicks receiving the various diets are shown in graphical form in Figure 2.
In comparison with the basal diet, the diets containing water-treated linseed meal showed no significant growth depressing effect, whereas, the growth depression caused by untreated linseed meal was highly significant. As noted elsewhere, the basal diet possibly was inadequate in methionine and choline. This may explain the significant increase in body weight of the chicks fed diet 2, which contained 22 percent of additional soybean oil meal. The protein adequacy of the basal diet in Experiment 1 was proved by the addition of soybean oil meal which caused no growth increase in the chicks, whereas the adequacy of the basal diet in Experiment 2 was questionable in that the addition of soybean oil meal to this basal diet caused a significant increase in chick growth. The basal diet in Experiment 1 contained 0.08 percent added methionine and 0.10 percent added choline, whereas the basal diet in Experiment 2 contained no added
2 90n 1. BASAL (contains 2 7 % soybean oil meal) Z.BASAL + 2 2 % soybean oil meal 3- BASAL + 1 0 % treated linseed oil meal 4. BASAL+20% " 5. B A S A L + 3 0 % 6.BASAL + 30%untreated linseed oil meal
280 1—, 270 K>
260
E «T Z.
S
—
2 50
•s ts
240 JL •* cr •
• *
230
I-H
2 20
: • : • : • :
III 1 Diet contains soybean oil meal |
:;y^y
j Diet contains treated linseed meal
210
• i
B
Diet contains intreoted linseed meal
200 190
H 1
2
3
4
01 ET
N U M B ! :R
5
6
FIG. 2. The effect on chick body weight of water-treated linseed meal added to a basal diet containine 20 percent crude protein.
145
TOXICITY OF LINSEED MEAL FOR CHICKS TABLE 4, Experiment 2.—Comparison of final body weights'of chicks receiving the various diets
Treatments
Av. body weight at
four weeks 27% soybean oil meal 49% soybean oil meal 10% water-treated linseed meal 20% water-treated linseed meal 30% water-treated linseed meal 30% untreated Unseed meal
grams 259.1 282.1 275.2 263.0 253.9 190.4
Body weight comparison by diets
Diet
1 2 3 4 5 6
2
3
4
5
6
*
ns ns
ns ns ns
ns
** ** ** ** **
** *
ns
*—significant at 5 percent point. **—significant at 1 percent point, ns—not significant at 5 percent point.
methionine and only 0.05 percent added choline. SUMMARY AND CONCLUSIONS Diets containing varying amounts of linseed meal, water-treated linseed meal, and soybean oil meal were fed to day-old White Leghorn cockerel chicks and to week-old unsexed New Hampshire chicks. The growth results obtained permit the following conclusions: 1. Linseed meal contains a toxic substance which depresses chick growth, when linseed meal is added to an adequate diet. This growth depression was observed in single comb White Leghorn cockerel chicks at four weeks of age, when their diets containing linseed meal were available from one day of age. Similar growth depression was noted in four-week old unsexed New Hampshire chicks that had received the "adequate" diets containing linseed meal from one through four weeks of age. 2. The addition of water-treated linseed meal at 30 percent of an "adequate" diet did not cause growth depression of New Hampshire chicks, when compared with
the results obtained on the "adequate" diet containing no water-treated linseed meal. . 3. The addition of soybean oil meal to an adequate diet (to supply additional protein equivalent to that supplied by linseed meal) did not cause a growth depressing effect. 4. The toxic principle in linseed meal was apparently destroyed by a simple water-treatment. REFERENCES
Goulden, C. H. Methods of Statistical Analysis, John Wiley and Sons, 1939. Heuser, G. F., L. C. Norris and James McGinnis, 1946. Vegetable protein concentrates fed alone and in combination with soybean oil mean and fish meal as the chief supplementary protein in chick starting rations. Poultry Sci. 25:130-136. Kratzer, F. H., 1946. The treatment of linseed meal to improve its feeding value for chicks. Poultry Sci. 25:541-542. , 1947. The effect of duration of water treatment on the nutritive value of linseed meal. Poultry Sci. 26:90-91. , D. Williams and E. F. Baker, 1947. Amino acid requirements to supplement linseed protein for chick growth. J. Nutri. 33:313-318. McGinnis, James and H. L. Polis, 1946. Factors affecting the nutritive value of linseed meal for growing chicks. Poultry Sci. 25: 408 (abstract).
Division of Poultry Husbandry, Washington Agricultural Experiment Station, Pullman, Washington (Received for publication August 26,1947)
O E V E R A L investigators have shown ^ that linseed meal gave poor growth when substituted for other protein supplements in chick starting diets. Heuser, Norris and McGinnis (1946) showed that as little as fifteen percent of linseed meal in the diet caused poor growth in White Leghorn chicks. McGinnis and Polis (1946) tried several methods of treating linseed meal to improve its nutritive value for growing chicks. They found that a marked improvement resulted when the linseed meal was water-treated. This treatment consisted of wetting the linseed meal with approximately two times its weight of water and allowing the mixture to stand for 18 hours at 37°C. The linseed meal treated in this manner gave a greatly increased growth response with chicks when compared with untreated linseed meal when each kind of linseed meal was included in the diet as the only source of supplementary protein. In the first series of experiments, McGinnis and Polis (1946) added the treated linseed meal to the diet in the moist state. In later experiments it was dried before mixing in the diet. More recently, Kratzer (1946, 1947) showed that "water treatment" in which a 1:3 linseed meal-tap water mixture was a allowed to stand at 22°C. for 12 hours (with subsequent drying before incorporation into the diet) gave as good growth
* Published as Scientific Paper No. 735, College of Agriculture and Agricultural Experiment Stations, Institute of Agricultural Sciences, State College of Washington, Pullman, Washington.
response as treatment for longer periods of time. Kratzer, Williams and Baker (1947) found that water-treated linseed meal was deficient only in lysine for chicks, when this treated linseed meal supplied all of the dietary protein at a 20 percent level. The other essential amino acids apparently were supplied in sufficient amounts by this level of protein to meet the chicks' requirements. This experiment was planned in order to test the growth depressing effect of linseed meal when added to an adequate diet containing 20 percent of crude protein from other sources. EXPERIMENTAL
Experiment 1: Day-old White Leghorn cockerel chicks were randomized into 18 groups of approximately 12 chicks each to provide duplicate groups for testing each diet. The chicks were then wing banded, weighed individually and placed in electrically heated battery brooders which had wire floors. Water and the experimental diets were available ad libitum. Weekly body weight and feed consumption data were obtained. The experiment was terminated at the end of four weeks. As outlined in Table 1, four different levels of linseed meal were added to an adequate diet (diet 8) to test the effect of linseed meal on chick growth and mortality. In order to eliminate protein toxicity as a factor, equivalent increases in crude protein were supplied by four different levels of soybean oil meal. The linseed 141
142
H. I. MACGREGOR AND JAMES M C G I N N I S
TABLE 1, Experiment 1.—Composition of diets, body weight, feed consumption and number of survivors at four weeks of age Diet numbers
Basal mixture* Cerelose Linseed meal Soybean oil meal (expeller)
8
9
10
11
12
13
14
15
16
%
%
%
%
% 40.0 — 30.0
%
%
%
%
40.0 30.0
— 30.0
40.0 22.5 7.5 30.0
40.0 15.0 15.0 30.0
100.0 Total Percentage of crude protein (calculated) 20.0
100.0 22.4
100.0 24.8
40.0 7.5 22.5 30.0 100.0 27.2
30.0 100.0 29.6
40.0 24.2
40.0 18.3
— 35.8 100.0 22.4
— 41.7 100.0 24.8
40.0 12.5 - — •
47.5 100.0 27.2
40.0 6.6
— 53.4 100.0 29.6
12-12 13-12 13-12 13-12 13-12 13-12 13-12 13-12 13-13 Initial number of chicks No. survivors at 4 wks. 12-12 13-11 13-13 12-12 11-11 13-11 13-12 13-12 11-12 Av. body wt. by lots (gms.) 277-279 252-245 214-218 174-177 147-156 285-274 267-287 290-278 258-278 Av. body wt. by diets (gms.) 278 248 216 176 151 280 277 284 268 Av. feed consumption to 4 wks. (gms.) 531 535 450 398 381 545 516 555 579 * Basal mixture composition: Ground yellow corn 10.9, ground wheat 10.9, dehydrated alfalfa meal 5.0, fish meal 6.0, dried brewers' yeast 2.0, ground limestone 2.5, dicalcium phosphate 1.5, iodized salt 0.5, B-Y feed 0.4, choline chloride 0.1, vitamin D supplement (2,000 D/gm.) 0.05, manganese sulphate 0.02, methionine 0.08.
meal and soybean oil meal were added to the diet at the expense of "cerelose." RESULTS
As shownin Table 1, but more strikingly in Figure 1, growth of the chicks fed adequate diets containing different levels of linseed meal was negatively correlated
with the percentage of linseed meal in the diet—the correlation coefficient was —0.7944. This indicates that linseed meal contains a toxic substance per se because the diets containing these different levels of linseed meal were adequate in protein, as shown by the growth of chicks*receiving diet 8. The growth depression which re-
290-
270.
850 — SOYBEAN OIL MEAL DIETS 23
LINSEED MEAL DIETS REGRESSION EQUATIONS W» 2 8 0 - 7 - 0-6 88 Yi
210
W« 8 8 0 . 7 - 13.79 Y»
>. *
W • body weight in grams
$
190
Yi'Xadditional soybean protein Y>k%addiiiond linseed protein
170
150
130
2.4
4.8
7.2
9.6
PERCENT ADDITIONAL PROTEIN FROM UNSEE0 MEAL OR SOYBEAN OIL MEAL .
FIG. 1. The effect on chick body weight of linseed meal and soybean oil meal supplements added to an adequate diet containing 20 percent crude protein.
143
TOXICITY OF LINSEED MEAL FOR CHICKS TABLE 2, Experiment 1.—Comparison of final body weights of chicks receiving the various diets
Treatments
30% soybean oil meal 7 . 5 % linseed meal 15.0% linseed meal 2 2 . 5 % linseed meal 30.0% linseed meal 35.85% soybean oil meal 41.70% soybean oil meal 47.55% soybean oil meal 53.40% soybean oil meal
Av. body wt. at four wks.
Diet
grams 278 248 216 176 151 280 277 284 268
8 9 10 11 12 13 14 15 16
Body weight comparison by diets 9
10
11
12
13
14
15
16
**
** **
** ** **
** ** ** *
ns
ns
ns
** ** ** **
** ** ** **
** ** ** **
ns ns
ns
** ** **
ns ns
ns ns ns
*—significant at 5 percent point. **—significant at 1 percent point, ns—not significant at 5 percent point.
suited from the addition of linseed meal does not appear to be due to excessive protein as approximately equal amounts of additional protein from soybean oil meal did not depress growth. Table 2 shows the statistical analysis of the average body weight data of chicks at four weeks of age. The significance of differences between the pooled data of duplicate groups was tested by analysis of variance. No significant differences were
found between duplicate groups for any of the diets. The regression lines were obtained by the method of least squares using the averages for each diet as the crude data. Significance of differences of body weights are indicated. Experiment 2: Unsexed New Hampshire chicks were used in this experiment. During the first week they were fed a standard chick start-
TABLE 3, Experiment 2.—Composition of diets and average body weights of chicks at four weeks Diets Ingredients
Basal mixture* Cerelose Soybean oil meal Linseed meal Water-treated linseed meal** Total—percent Initial no. of chicks (1 week) No. of survivors at 4 weeks Av. body weights by groups—gms. Av. body weights by diets—gms.
1
2
3
4
5
6
percent
percent
percent
percent
percent
percent
70.00 30.00
70.00 8.00 22.00
70.00 20.00
70.00 10.00
70.00
70.00
— —
— —
— — —
30.00
—
•
— —
100.00 12-12 12-12 270-248 259
—
10.00 — 100.00 100.00 12-12 12-12 12-12 12-12 294-271 278-273 282 275
20.00 100.00 12-12 12-12 244-282 263
30.00 100.00 11-12 11-12 257-251 254
— — —
100.00 12-12 11-12 187-193 190
* The basal mixture was composed as follows: Ground corn 12.5, ground wheat 12.45, soybean oil meal 27.0, fish meal 5.0, dehydrated alfalfa meal 5.0, dried brewers' yeast 3.0, ground oyster shell 2.0, dicalcium phosphate 1.8, vitamin D supplement (2,000 D/gm) 0.05, liver paste O.l.iodized salt 0.53,B-Y feed 0.5, choline chloride 0.05, manganese sulphate 0.02. ** The water-treated linseed meal consisted of linseed meal mixed with two and one-half times its weight of water which was then allowed to stand at 25°C. for 18 hours. This mixture was then oven dried at about 70°C. The dry product was ground medium fine before mixing in the diets.
144
H. I. MACGREGOR AND JAMES MCGINNIS
ing ration. At the end of this time they were randomized into twelve groups of approximately twelve chicks each to provide duplicate groups for testing each experimental diet. Treatment of the chicks was essentially the same as outlined in Experiment 1. The experiment was terminated at the end of four weeks of age. RESULTS
In Table 3 the composition of the various diets is given; also included in this table are data pertaining to body weight and number of survivors at the termination of the experiment. Table 4 shows the statistical analysis of the final body weights of chick receiving the various diets. Analysis of variance showed that these differences in body weight were statistically significant as noted. The data on final body weight of the chicks receiving the various diets are shown in graphical form in Figure 2.
In comparison with the basal diet, the diets containing water-treated linseed meal showed no significant growth depressing effect, whereas, the growth depression caused by untreated linseed meal was highly significant. As noted elsewhere, the basal diet possibly was inadequate in methionine and choline. This may explain the significant increase in body weight of the chicks fed diet 2, which contained 22 percent of additional soybean oil meal. The protein adequacy of the basal diet in Experiment 1 was proved by the addition of soybean oil meal which caused no growth increase in the chicks, whereas the adequacy of the basal diet in Experiment 2 was questionable in that the addition of soybean oil meal to this basal diet caused a significant increase in chick growth. The basal diet in Experiment 1 contained 0.08 percent added methionine and 0.10 percent added choline, whereas the basal diet in Experiment 2 contained no added
2 90n 1. BASAL (contains 2 7 % soybean oil meal) Z.BASAL + 2 2 % soybean oil meal 3- BASAL + 1 0 % treated linseed oil meal 4. BASAL+20% " 5. B A S A L + 3 0 % 6.BASAL + 30%untreated linseed oil meal
280 1—, 270 K>
260
E «T Z.
S
—
2 50
•s ts
240 JL •* cr •
• *
230
I-H
2 20
: • : • : • :
III 1 Diet contains soybean oil meal |
:;y^y
j Diet contains treated linseed meal
210
• i
B
Diet contains intreoted linseed meal
200 190
H 1
2
3
4
01 ET
N U M B ! :R
5
6
FIG. 2. The effect on chick body weight of water-treated linseed meal added to a basal diet containine 20 percent crude protein.
145
TOXICITY OF LINSEED MEAL FOR CHICKS TABLE 4, Experiment 2.—Comparison of final body weights'of chicks receiving the various diets
Treatments
Av. body weight at
four weeks 27% soybean oil meal 49% soybean oil meal 10% water-treated linseed meal 20% water-treated linseed meal 30% water-treated linseed meal 30% untreated Unseed meal
grams 259.1 282.1 275.2 263.0 253.9 190.4
Body weight comparison by diets
Diet
1 2 3 4 5 6
2
3
4
5
6
*
ns ns
ns ns ns
ns
** ** ** ** **
** *
ns
*—significant at 5 percent point. **—significant at 1 percent point, ns—not significant at 5 percent point.
methionine and only 0.05 percent added choline. SUMMARY AND CONCLUSIONS Diets containing varying amounts of linseed meal, water-treated linseed meal, and soybean oil meal were fed to day-old White Leghorn cockerel chicks and to week-old unsexed New Hampshire chicks. The growth results obtained permit the following conclusions: 1. Linseed meal contains a toxic substance which depresses chick growth, when linseed meal is added to an adequate diet. This growth depression was observed in single comb White Leghorn cockerel chicks at four weeks of age, when their diets containing linseed meal were available from one day of age. Similar growth depression was noted in four-week old unsexed New Hampshire chicks that had received the "adequate" diets containing linseed meal from one through four weeks of age. 2. The addition of water-treated linseed meal at 30 percent of an "adequate" diet did not cause growth depression of New Hampshire chicks, when compared with
the results obtained on the "adequate" diet containing no water-treated linseed meal. . 3. The addition of soybean oil meal to an adequate diet (to supply additional protein equivalent to that supplied by linseed meal) did not cause a growth depressing effect. 4. The toxic principle in linseed meal was apparently destroyed by a simple water-treatment. REFERENCES
Goulden, C. H. Methods of Statistical Analysis, John Wiley and Sons, 1939. Heuser, G. F., L. C. Norris and James McGinnis, 1946. Vegetable protein concentrates fed alone and in combination with soybean oil mean and fish meal as the chief supplementary protein in chick starting rations. Poultry Sci. 25:130-136. Kratzer, F. H., 1946. The treatment of linseed meal to improve its feeding value for chicks. Poultry Sci. 25:541-542. , 1947. The effect of duration of water treatment on the nutritive value of linseed meal. Poultry Sci. 26:90-91. , D. Williams and E. F. Baker, 1947. Amino acid requirements to supplement linseed protein for chick growth. J. Nutri. 33:313-318. McGinnis, James and H. L. Polis, 1946. Factors affecting the nutritive value of linseed meal for growing chicks. Poultry Sci. 25: 408 (abstract).