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Rapeseed Oil Meal Studies
Rapeseed Oil Meal Studies EFFECTS OF VARIETY OF RAPESEED, GROWING ENVIRONMENT AND PROCESSING TEMPERATURES ON THE NUTRITIVE VALUE AND CHEMICAL COMPOSITION OF RAPESEED OIL MEAL 1 D. R. CLANDININ, RUTH RENNER 2 AND A. R. ROBBLEE University of Alberta, Edmonton, Alberta, Canada (Received for publication April IS, 1959)
/ C O M M E R C I A L rapeseed oil meal ^ - ^ (RSOM) is generally considered to be a rather inferior protein supplement for growth of poultry. This is because of the fact that when this protein supplement is included in the rations of growing poultry at the expense of other protein feedstuffs, such as soybean oil meal, depressed growth rate and reduced feed efficiency are obtained. A number of factors are believed to contribute to the inferior quality of RSOM as a protein supplement. While Kratzer el al. (1954) have shown that the amino acid content of rapeseed protein is reasonably well balanced, commercial rapeseed oil meal has been shown (Blakely and Anderson, 1948; Kratzer et al., 1954; Klain et al., 1956) to be somewhat limiting in lysine. In addition it has been established (Astwood el al: 1949a, b; Carroll, 1949) that rapeseed contains a goitrogen, L-5-vinyl-2-thiooxazolidone and possibly other toxic principles (Charipper and Gordon, 1947; Matet et al., 1949; Bell and Williams, 1953). Of interest, too, was the recent identification by Kjaer, Conti and Jensen (1953) of the main mustard oil of rapeseed as 3-butenyl isothiocyanate (allylcarbinyl isothiocyanate) and the
suggestion by Pitt-Rivers (1950) that this compound might be converted by oxidation to L-5-vinyl-2-thiooxazolidone. Possible oxidative conversion of 3-butenyl isothiocyanate to L-5-vinyl-2-thiooxazolidone is shown in Figure 1. Since rapeseed production in Canada is on the increase and since it would appear that this is a crop that can be grown to advantage in Canada's temperate climate, studies were initiated to learn more about factors that contribute to the variability in the nutritive value of RSOM for poultry. The investigations to be reported relate to the effect of: (1) variety of rapeseed used in the production of RSOM on the nutritive value of the meal, (2) variety of rapeseed grown and environmental conditions under which the seed is grown on the level of isothiocyanate and L-5vinyl-2-thiooxazolidone in rapeseed and (3) temperatures employed during expeller processing of rapeseed on the nutritive value and chemical composition of RSOM. Enzyme? Heat?
CH, * CH - CH,
CH. » CH - CH
1
Supported in part by grants from the Alberta Research Council and from the National Research Council of Canada. 2 Present address, Cornell University, Ithaca, New York, U.S.A.
FIG. 1. Possible oxidative conversion of 3-butenyl isothiocyanate (I) to L-5-vinyl-2-thiooxazolidone
en).
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D. R. CLANDININ, R. RENNER AND A. R. ROBBLEE TABLE 1.—Composition of constant portion of the rations Ingredient
Lb. 30.S 10.0 10.0 S.O 2.0 1.5 0.5 0.25 0.25
Ground wheat Wheat bran Wheat middlings Dehydrated alfalfa meal Limestone Bone meal Iodized salt Fish oil (2,2S0A, 300D) DL methionine Miscellaneous*
+
* The following were added per ton of starter: manganese sulphate, 0.25 lb.; riboflavin, 3 gm.; calcium pantothenate, 9 gm.; niacin, 15 gm.
(1) Effect of Variety of Rapeseed on the Nutritive Value of Rapeseed Oil Meal Experimental. Two samples of expeller processed RSOM; one prepared from Argentine rapeseed (Brassica napus L.), the other from Polish rapeseed {Brassica campeslris L.), were obtained from a Saskatchewan processor* and incorporated in a chick starter ration at levels varying from 0 to 28% replacing soybean oil meal. The protein (NX6.25) content of all rations was maintained at approximately 22.5 percent. The composition of the constant portion of the rations is shown in Table 1 while the actual composition of the rations is shown in Table 2. Duplicate groups of 13 White Leghorn * Vegetable Oils Division, Saskatchewan Wheat Pool, Saskatoon, Saskatchewan, Canada. TABLE 2.—Effect Ration number Constant portion 1 Ground corn Soybean oil meal Argentine RSOM* Polish RSOM3 Number of chicks Av. wt.—4 wk., gm. Thyroid-to-body weight ratio—8 wk., mg./lOO gm. 4
chicks of mixed sexes were placed on each ration. The chicks were maintained in Petersime batteries. At the end of four weeks on experiment the chicks were weighed individually. Any tendency for the droppings to adhere to the screens was recorded. At the end of eight weeks on experiment, eight male and eight female chicks were chosen at random from each treatment for the determination of thyroid-to-body weight ratios. Results and Discussion. The results obtained, Table 2, indicate that the RSOM prepared from the Argentine variety of rapeseed was more detrimental to growth and more goitrogenic than the meal originating from the Polish variety of rapeseed. Ten percent of Argentine RSOM in the ration depressed chick growth, while as much as 15% Polish RSOM in the ration did not result in appreciable growth depression. Five percent of Argentine RSOM caused a doubling of the thyroid-to-body weight ratio while it took 15% of Polish RSOM to produce a similar effect. A greater severity of screen pasting was noted in the groups receiving Polish RSOM than in those fed Argentine RSOM. In this regard screen pasting was noted in groups receiving 10% or more of Polish meal or 20% or more of Argentine RSOM. One might wish to explain the poorer
of variety of rapeseed on the nutritive value of rapeseed oil meal 1
2
3
60 12 28
60 12 23 5
60 12 18 10
60 12 13 15
60 12 8 20
60 12 0 28
60 12 28
24 265
26 249
25 241
26 225
24 197
24 262
— 26 270 12.3
24.1
i See Table 1. 2NX6.25=43.3. "NX6.25=33.9. * Average of eight male and eight female chicks.
28.4
4
35.7
5
6
38.5
7
50.6
8
10.6
9 60 10.5 24.5 5 26 260 16.5
10 60 9 21 10 24 258 17.4
60 7.5 17.5 15 25 251 20.6
60 6 14 20 26 243 24.5
60 3.6 8.4 28 26 233 31.9
RAPESEED OIL MEAL STUDIES
growth obtained from the Argentine RSOM purely on the basis of its greater goitrogenicity. It should be mentioned in this regard that L-5-vinyl-2-thiooxazolidone determinations by the method of Astwood, Greer and Ettlinger (1949b) showed that the Argentine RSOM contained 4.64 mg./gm. of L-5-vinyl-2-thiooxazolidone as compared to 1.59 mg./gm. for the Polish RSOM. However, investigation into the lysine content of these two meals by the microbiological procedure (Clandinin, 1949) showed that the protein (NX6.25) of the Argentine RSOM contained only 3.6% of lysine while that of the Polish RSOM yielded 4.2% of lysine. When one takes into account the lower protein content of the Polish RSOM as compared to the Argentine RSOM (33.9% versus 43.3%) and the consequent greater percentage of soybean oil meal that had to be used in the 28% Polish RSOM ration (Table 2, ration 12) as compared to the 28% Argentine RSOM ration (ration 6) the former would contain approximately 0.2% more lysine. This could have had an appreciable effect on the growth of the chicks, since by calculation, the 28% Polish RSOM ration was in itself borderline in lysine content. That the 28% Argentine RSOM ration is actually low in lysine was demonstrated in another experiment by supplementing this diet with 0.5% L-lysine. Five-week-old growth of White Leghorn chicks of mixed sexes on the unsupplemented diet averaged 222 grams while on the lysine fortified ration an average weight of 352 grams was obtained. It would, therefore, appear that the poorer growth obtained from the Argentine RSOM rations as compared to growth obtained from the Polish RSOM rations might be at least partly attributable to the lower lysine content of the rations containing Argentine RSOM as
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compared to the rations containing Polish RSOM. (2) Effect of Variety of Rapeseed and Environmental Conditions under Which Seed Is Grown on Isothiocyanate and Thiooxazolidone Content Experimental. Samples of six varieties of rapeseed from the 1955 Co-operative Rapeseed Tests* grown at three widely separated points in Alberta, Beaverlodge (North), Edmonton (central) and Lethbridge (South), were analyzed for isothiocyanate by the A.O.A.C. method using 1 ml. of 0.1 N AgN0 3 equivalent to 0.005659 gm. of allylcarbinyl isothiocyanate and for L-5-vinyl-2-thiooxazolidone by the method of Astwood et al. (1949b). Determinations were done twice in duplicate. Results and Discussion. Results obtained are summarized in Table 3. The data indicate that isothiocyanate content is markedly affected by variety; however, no consistent location effect on isothiocyanate content is apparent. Thiooxazolidone content, on the other hand, is not only affected by variety, but also appears to be influenced by the environmental conditions under which the seed is grown. In view of the above it would appear that plant breeders should consider the possibility of developing varieties of rapeseed that are not only high oil yielders but which are low in isothiocyanate and thiooxazolidone content. While no one has, as yet, demonstrated that allylcarbinyl isothiocyanate, the principal isothiocyanate in rapeseed is detrimental to poultry, limited evidence has been obtained that this material is converted to the goitrogen by heat. In this connection rapeseed from * Supplied by W. E. Smith, Department of Plant Science, University of Alberta, Edmonton, Alberta, Canada.
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D. R. CLANDININ, R. RENNER AND A. R. ROBBLEE
TABLE 3.—Effect of variety of rapeseed and environmental conditions under which seed is grown on allylcarbinyl isothiocyanate and L-S-vinyl-2-thiooxazolidone content of rapeseed
Sample No.
Variety
1 2 3 4 5 6
P.I. 169085-Turkish s/s-122-l-8-2-4-Argentine-low I 2 AC/s-1221-8-2-54-Argentine-low I 2 Argentine Polish Golden
Allylcarbinyl isothiocyanate, mg./gm.
L-5-vinyl-2-thiooxazolidone, mg./gm.
Beaver- Edmon- Lethlodge* ton* bridge*
Beaver- Edmon- Lethlodge* ton* bridge*
1.02 .86 .76 .92 .91 .68
1.14 1.13 .58 1.19 .98 .59
1.15 1.05 .78 .87 .76 .56
.06 1.42 1.35 1.05 .05 1.51
.18 1.28 1.67 .75 .08 1.00
.02 2.20 1.77 1.99 .10 2.23
.85
.94
.86
.91
.83
1.38
Average
* Locations in Alberta where seed was grown. which the isothiocyanate had been removed by adding to ground rapeseed 1§ times its weight of water and fermenting at 98°F. for 16 hours and drying at 125°F. for 48 hours contained less L-5-vinyl-2thiooxazolidone after heating at 250°F. for 4 hours than similarly heated ground rapeseed not previously fermented and dried to remove the isothiocyanate. Values obtained are shown in Table 4. (3) Effect of Temperatures Employed During Expeller Processing of Rapeseed on the Nutritive Value and Chemical Composition of Rapeseed Oil Meal
Experimental. For this study three samples of RSOM produced from similar raw material but expeller-extracted under three different sets of processing conditions, were obtained from the Saskatchewan processing plant referred to previTABLE 4.—Conversion of isothiocyanate to
L-5-vinyl-2-thiooxazolidone Treatment None Fermented and dried Fermented, dried and heated at 250°F. for four hours Dried Dried and heated at 250°F. for four hours
Polish Argentine seed seed mg./gm. mg./gm. .07 3.21 .57 3.70 .07 .06
2.02 3.82
1.08
5.91
ously. These meals were incorporated as the sole source of supplementary protein in a 22% protein chick starter. A soybean oil meal starter was used as a positive control. Duplicate groups of 15 White Rock mixed chicks in batteries were placed on each ration. The chicks were weighed individually at four weeks of age. Thyroid-to-body weight ratios were determined for each treatment by removing the thyroid glands of six male and six female chicks on each ration at six weeks of age. Protein, fat and lysine determinations were done on each of the RSOMs and on a sample of the crushed seed from which the meals were prepared by the methods previously mentioned with a view to correlating biological data with chemical values. Results and Discussion. The treatments used, biological data and results of chemical analyses are shown in Table 5. The data show that the higher the processing temperatures the poorer the quality of the resultant meal from the feeding point of view. Higher processing temperatures, however, did result in meals of slightly lower fat content. With respect to lysine content, even the lowest temperatures employed resulted in appreciable reduction in the amount of lysine present as compared to the amount of lysine in the pro-
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RAPESEED OIL MEAL STUDIES TABLE 5.—Effect
Ration No.
1 2
3
4
of processing temperatures on the nutritive value and chemical composition of rapeseed oil meal Thyroidto-body wt. ratio—6 protein wk., mg. (NX6.25) 1 /100 gm.
%
No. chicks
Av. wt. 4 wks.
Soybean oil meal Solvent process
30
381.5
9.0
44.2
.4
6.11
Rapeseed oil meal Cooker2 250°F. Conditioner2 280°F.
30
274.5
25.1
36.4
5.9
4.12
Rapeseed oil meal Cooker2 234°F. Conditioner2 260°F.
30
324.0
19.5
35.0
6.6
4.86
Rapeseed oil meal Cooker2 220°F. Conditioner2 240°F.
30
365.0
20.0
34.8
7.3
5.69
31.8
35.0
6.42
Treatment
Average run of rapeseed
%fat
lysine in protein
1
Average of six male and six female chicks. Crushed seed took approximately 30 minutes to pass through the cooker and 5 minutes to pass through the conditioner. 2
tein of the unheated seed from which the RSOMs were produced. The highest processing temperatures employed, which on the basis of information provided by the processor, were slightly higher than "normal" processing temperatures, caused a drastic reduction in the lysine content of the protein of the resultant meal. The data also show that all three meals are definitely goitrogenic, the meal processed at the highest temperatures producing the highest thyroid-to-body weight ratio. The above results from RSOMs processed at varying temperatures would seem to warrant the conclusion that, if damage to protein quality and increase in goitrogenicity of the meal are to be avoided, great care should be exercised in the processing of rapeseed to ensure that it is not exposed to higher than necessary temperatures.
for poultry would appear to justify the following conclusions: (1) The growth promoting value and goitrogenic property of rapeseed oil meal are affected by the variety of seed from which the rapeseed oil meal is produced. (2) The level of "toxic principles" in rapeseed is related to the variety of rapeseed and to the environmental conditions under which the rapeseed is grown. (3) Heat increases the goitrogenic property of the rapeseed oil meal by converting isothiocyanate to L-5-vinyl-2-thiooxazolidone. (4) Excessive amounts of heat employed during extraction of oil from rapeseed adversely affect the nutritive value of the resulting rapeseed oil meal. The main adverse effect of excessive heat treatment is to reduce the lysine content of the resultant meal.
SUMMARY
REFERENCES Astwood, E. B., M. A. Greer and M. G. Ettlinger, 1949a. The antithyroid factor of yellow turnip. Science, 109: 631.
Results of studies on factors affecting the nutritive quality of rapeseed oil meal
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D. R. CLANDININ, R. RENNER AND A. R. ROBBLEE
Astwood, E. B., M. A. Greer and M. G. Ettlinger, 1949b. L-S-vinyl-2-thiooxazolidone, an antithyroid compound from yellow turnip and from Brassica seeds. J. Biol. Chem. 181: 121-130. Bell, J. M., and K. Williams, 1953. Growth depressing factors in rapeseed oil meal. Can J. Agr. Sci. 33:201-209. Blakely, R. M., and R. W. Anderson, 1948. Studies with rape-seed oilcake meal. I I . The effect of the inclusion of Protamone in the diet, on the thyroid enlargement induced by the feeding of rapeseed oilcake meal to turkey poults. Sci. Agr. 28: 398-402. Carroll, K. K., 1949. Isolation of an anti-thyroid compound from rape seed (Brassica napus). Proc. Soc. Exptl. Biol. Med. 71: 622-624. Charipper, H. A., and A. S. Gordon, 1947. The biology of antithyroid hormones. Vitamins and Hormones, Academic Press, New York. Clandinin, D. R., 1949. The effects of methods of
processing on the nutritive value of herring meals. Poultry Sci. 28: 128-133. Kjaer, A., J. Conti and K. A. Jensen, 1953. Isothiocyanates. I I I . The volatile isothiocyanates in seeds of rape (Brassica napus). Acta Chem. Scand. 7: 1271-1275. Klain, G. J., D. C. Hill, H. D. Branion and J. A. Gray, 1956. The value of rapeseed oil meal and sunflower seed oil meal in chick starter rations. Poultry Sci. 35: 1315-1326. Kratzer, F. H., P. N. Davis, D. E. Williams and B. J. Marshall, 1954. Factors influencing the growth of chicks and poults fed rations containing rapeseed oil meal. J. Nutr. 53: 407-418. Matet, J., R. Montagne and A. Buchy, 1949. Food value of the rapeseed press cake. Oleagineux, 4: 145-154. Pitt-Rivers, R., 1950. Mode of action of antithyroid compounds. Physiol. Rev. 30: 194-203.
Heterosis in Poultry 2. CROSSBREDS VERSUS
TOP-CROSSBREDS
A. W. NORDSKOG, L. T. SMITH AND R. E. PHILLIPS Department of Poultry Husbandry, Iowa State University, Ames, Iowa (Received for publication April 17, 1959)
H
YBRIDIZATION, as a tool for the production of commercial chickens, is a well established practice today. Whether inbreeding the parental lines enhances such hybridization is still a highly debatable issue. Arguments favoring inbreeding as a means to develop lines of high potential combining ability rest more on theoretical logic than on a basis of factual experimental evidence. This is because the experimental information so far reported in the literature is inconclusive. Journal Paper No. J-3619 of the Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa. Project 1040. This work is in cooperation with the North Central Regional Poultry Breeding Project, NC-47.
Some workers have reported an advantage in using inbred lines for crosses. Waters (1938) found improved fertility, hatchability and livability by use of inbred Leghorn males. Maw (1942) found that top-crossing inbred Leghorn males on Leghorn females gave better results in both viability and egg production than non-inbred Leghorn controls. He also reported that crosses between unrelated inbred lines were superior to top-crosses. Other workers have not been able to demonstrate any clear-cut advantage in using inbred lines for crossing purposes. Dudley and Pease (1948), for example, reported that top-crossing held no advantage over outcrossing. Hays (1935) reported that the progeny of inbred Rhode
/ C O M M E R C I A L rapeseed oil meal ^ - ^ (RSOM) is generally considered to be a rather inferior protein supplement for growth of poultry. This is because of the fact that when this protein supplement is included in the rations of growing poultry at the expense of other protein feedstuffs, such as soybean oil meal, depressed growth rate and reduced feed efficiency are obtained. A number of factors are believed to contribute to the inferior quality of RSOM as a protein supplement. While Kratzer el al. (1954) have shown that the amino acid content of rapeseed protein is reasonably well balanced, commercial rapeseed oil meal has been shown (Blakely and Anderson, 1948; Kratzer et al., 1954; Klain et al., 1956) to be somewhat limiting in lysine. In addition it has been established (Astwood el al: 1949a, b; Carroll, 1949) that rapeseed contains a goitrogen, L-5-vinyl-2-thiooxazolidone and possibly other toxic principles (Charipper and Gordon, 1947; Matet et al., 1949; Bell and Williams, 1953). Of interest, too, was the recent identification by Kjaer, Conti and Jensen (1953) of the main mustard oil of rapeseed as 3-butenyl isothiocyanate (allylcarbinyl isothiocyanate) and the
suggestion by Pitt-Rivers (1950) that this compound might be converted by oxidation to L-5-vinyl-2-thiooxazolidone. Possible oxidative conversion of 3-butenyl isothiocyanate to L-5-vinyl-2-thiooxazolidone is shown in Figure 1. Since rapeseed production in Canada is on the increase and since it would appear that this is a crop that can be grown to advantage in Canada's temperate climate, studies were initiated to learn more about factors that contribute to the variability in the nutritive value of RSOM for poultry. The investigations to be reported relate to the effect of: (1) variety of rapeseed used in the production of RSOM on the nutritive value of the meal, (2) variety of rapeseed grown and environmental conditions under which the seed is grown on the level of isothiocyanate and L-5vinyl-2-thiooxazolidone in rapeseed and (3) temperatures employed during expeller processing of rapeseed on the nutritive value and chemical composition of RSOM. Enzyme? Heat?
CH, * CH - CH,
CH. » CH - CH
1
Supported in part by grants from the Alberta Research Council and from the National Research Council of Canada. 2 Present address, Cornell University, Ithaca, New York, U.S.A.
FIG. 1. Possible oxidative conversion of 3-butenyl isothiocyanate (I) to L-5-vinyl-2-thiooxazolidone
en).
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D. R. CLANDININ, R. RENNER AND A. R. ROBBLEE TABLE 1.—Composition of constant portion of the rations Ingredient
Lb. 30.S 10.0 10.0 S.O 2.0 1.5 0.5 0.25 0.25
Ground wheat Wheat bran Wheat middlings Dehydrated alfalfa meal Limestone Bone meal Iodized salt Fish oil (2,2S0A, 300D) DL methionine Miscellaneous*
+
* The following were added per ton of starter: manganese sulphate, 0.25 lb.; riboflavin, 3 gm.; calcium pantothenate, 9 gm.; niacin, 15 gm.
(1) Effect of Variety of Rapeseed on the Nutritive Value of Rapeseed Oil Meal Experimental. Two samples of expeller processed RSOM; one prepared from Argentine rapeseed (Brassica napus L.), the other from Polish rapeseed {Brassica campeslris L.), were obtained from a Saskatchewan processor* and incorporated in a chick starter ration at levels varying from 0 to 28% replacing soybean oil meal. The protein (NX6.25) content of all rations was maintained at approximately 22.5 percent. The composition of the constant portion of the rations is shown in Table 1 while the actual composition of the rations is shown in Table 2. Duplicate groups of 13 White Leghorn * Vegetable Oils Division, Saskatchewan Wheat Pool, Saskatoon, Saskatchewan, Canada. TABLE 2.—Effect Ration number Constant portion 1 Ground corn Soybean oil meal Argentine RSOM* Polish RSOM3 Number of chicks Av. wt.—4 wk., gm. Thyroid-to-body weight ratio—8 wk., mg./lOO gm. 4
chicks of mixed sexes were placed on each ration. The chicks were maintained in Petersime batteries. At the end of four weeks on experiment the chicks were weighed individually. Any tendency for the droppings to adhere to the screens was recorded. At the end of eight weeks on experiment, eight male and eight female chicks were chosen at random from each treatment for the determination of thyroid-to-body weight ratios. Results and Discussion. The results obtained, Table 2, indicate that the RSOM prepared from the Argentine variety of rapeseed was more detrimental to growth and more goitrogenic than the meal originating from the Polish variety of rapeseed. Ten percent of Argentine RSOM in the ration depressed chick growth, while as much as 15% Polish RSOM in the ration did not result in appreciable growth depression. Five percent of Argentine RSOM caused a doubling of the thyroid-to-body weight ratio while it took 15% of Polish RSOM to produce a similar effect. A greater severity of screen pasting was noted in the groups receiving Polish RSOM than in those fed Argentine RSOM. In this regard screen pasting was noted in groups receiving 10% or more of Polish meal or 20% or more of Argentine RSOM. One might wish to explain the poorer
of variety of rapeseed on the nutritive value of rapeseed oil meal 1
2
3
60 12 28
60 12 23 5
60 12 18 10
60 12 13 15
60 12 8 20
60 12 0 28
60 12 28
24 265
26 249
25 241
26 225
24 197
24 262
— 26 270 12.3
24.1
i See Table 1. 2NX6.25=43.3. "NX6.25=33.9. * Average of eight male and eight female chicks.
28.4
4
35.7
5
6
38.5
7
50.6
8
10.6
9 60 10.5 24.5 5 26 260 16.5
10 60 9 21 10 24 258 17.4
60 7.5 17.5 15 25 251 20.6
60 6 14 20 26 243 24.5
60 3.6 8.4 28 26 233 31.9
RAPESEED OIL MEAL STUDIES
growth obtained from the Argentine RSOM purely on the basis of its greater goitrogenicity. It should be mentioned in this regard that L-5-vinyl-2-thiooxazolidone determinations by the method of Astwood, Greer and Ettlinger (1949b) showed that the Argentine RSOM contained 4.64 mg./gm. of L-5-vinyl-2-thiooxazolidone as compared to 1.59 mg./gm. for the Polish RSOM. However, investigation into the lysine content of these two meals by the microbiological procedure (Clandinin, 1949) showed that the protein (NX6.25) of the Argentine RSOM contained only 3.6% of lysine while that of the Polish RSOM yielded 4.2% of lysine. When one takes into account the lower protein content of the Polish RSOM as compared to the Argentine RSOM (33.9% versus 43.3%) and the consequent greater percentage of soybean oil meal that had to be used in the 28% Polish RSOM ration (Table 2, ration 12) as compared to the 28% Argentine RSOM ration (ration 6) the former would contain approximately 0.2% more lysine. This could have had an appreciable effect on the growth of the chicks, since by calculation, the 28% Polish RSOM ration was in itself borderline in lysine content. That the 28% Argentine RSOM ration is actually low in lysine was demonstrated in another experiment by supplementing this diet with 0.5% L-lysine. Five-week-old growth of White Leghorn chicks of mixed sexes on the unsupplemented diet averaged 222 grams while on the lysine fortified ration an average weight of 352 grams was obtained. It would, therefore, appear that the poorer growth obtained from the Argentine RSOM rations as compared to growth obtained from the Polish RSOM rations might be at least partly attributable to the lower lysine content of the rations containing Argentine RSOM as
1369
compared to the rations containing Polish RSOM. (2) Effect of Variety of Rapeseed and Environmental Conditions under Which Seed Is Grown on Isothiocyanate and Thiooxazolidone Content Experimental. Samples of six varieties of rapeseed from the 1955 Co-operative Rapeseed Tests* grown at three widely separated points in Alberta, Beaverlodge (North), Edmonton (central) and Lethbridge (South), were analyzed for isothiocyanate by the A.O.A.C. method using 1 ml. of 0.1 N AgN0 3 equivalent to 0.005659 gm. of allylcarbinyl isothiocyanate and for L-5-vinyl-2-thiooxazolidone by the method of Astwood et al. (1949b). Determinations were done twice in duplicate. Results and Discussion. Results obtained are summarized in Table 3. The data indicate that isothiocyanate content is markedly affected by variety; however, no consistent location effect on isothiocyanate content is apparent. Thiooxazolidone content, on the other hand, is not only affected by variety, but also appears to be influenced by the environmental conditions under which the seed is grown. In view of the above it would appear that plant breeders should consider the possibility of developing varieties of rapeseed that are not only high oil yielders but which are low in isothiocyanate and thiooxazolidone content. While no one has, as yet, demonstrated that allylcarbinyl isothiocyanate, the principal isothiocyanate in rapeseed is detrimental to poultry, limited evidence has been obtained that this material is converted to the goitrogen by heat. In this connection rapeseed from * Supplied by W. E. Smith, Department of Plant Science, University of Alberta, Edmonton, Alberta, Canada.
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D. R. CLANDININ, R. RENNER AND A. R. ROBBLEE
TABLE 3.—Effect of variety of rapeseed and environmental conditions under which seed is grown on allylcarbinyl isothiocyanate and L-S-vinyl-2-thiooxazolidone content of rapeseed
Sample No.
Variety
1 2 3 4 5 6
P.I. 169085-Turkish s/s-122-l-8-2-4-Argentine-low I 2 AC/s-1221-8-2-54-Argentine-low I 2 Argentine Polish Golden
Allylcarbinyl isothiocyanate, mg./gm.
L-5-vinyl-2-thiooxazolidone, mg./gm.
Beaver- Edmon- Lethlodge* ton* bridge*
Beaver- Edmon- Lethlodge* ton* bridge*
1.02 .86 .76 .92 .91 .68
1.14 1.13 .58 1.19 .98 .59
1.15 1.05 .78 .87 .76 .56
.06 1.42 1.35 1.05 .05 1.51
.18 1.28 1.67 .75 .08 1.00
.02 2.20 1.77 1.99 .10 2.23
.85
.94
.86
.91
.83
1.38
Average
* Locations in Alberta where seed was grown. which the isothiocyanate had been removed by adding to ground rapeseed 1§ times its weight of water and fermenting at 98°F. for 16 hours and drying at 125°F. for 48 hours contained less L-5-vinyl-2thiooxazolidone after heating at 250°F. for 4 hours than similarly heated ground rapeseed not previously fermented and dried to remove the isothiocyanate. Values obtained are shown in Table 4. (3) Effect of Temperatures Employed During Expeller Processing of Rapeseed on the Nutritive Value and Chemical Composition of Rapeseed Oil Meal
Experimental. For this study three samples of RSOM produced from similar raw material but expeller-extracted under three different sets of processing conditions, were obtained from the Saskatchewan processing plant referred to previTABLE 4.—Conversion of isothiocyanate to
L-5-vinyl-2-thiooxazolidone Treatment None Fermented and dried Fermented, dried and heated at 250°F. for four hours Dried Dried and heated at 250°F. for four hours
Polish Argentine seed seed mg./gm. mg./gm. .07 3.21 .57 3.70 .07 .06
2.02 3.82
1.08
5.91
ously. These meals were incorporated as the sole source of supplementary protein in a 22% protein chick starter. A soybean oil meal starter was used as a positive control. Duplicate groups of 15 White Rock mixed chicks in batteries were placed on each ration. The chicks were weighed individually at four weeks of age. Thyroid-to-body weight ratios were determined for each treatment by removing the thyroid glands of six male and six female chicks on each ration at six weeks of age. Protein, fat and lysine determinations were done on each of the RSOMs and on a sample of the crushed seed from which the meals were prepared by the methods previously mentioned with a view to correlating biological data with chemical values. Results and Discussion. The treatments used, biological data and results of chemical analyses are shown in Table 5. The data show that the higher the processing temperatures the poorer the quality of the resultant meal from the feeding point of view. Higher processing temperatures, however, did result in meals of slightly lower fat content. With respect to lysine content, even the lowest temperatures employed resulted in appreciable reduction in the amount of lysine present as compared to the amount of lysine in the pro-
1371
RAPESEED OIL MEAL STUDIES TABLE 5.—Effect
Ration No.
1 2
3
4
of processing temperatures on the nutritive value and chemical composition of rapeseed oil meal Thyroidto-body wt. ratio—6 protein wk., mg. (NX6.25) 1 /100 gm.
%
No. chicks
Av. wt. 4 wks.
Soybean oil meal Solvent process
30
381.5
9.0
44.2
.4
6.11
Rapeseed oil meal Cooker2 250°F. Conditioner2 280°F.
30
274.5
25.1
36.4
5.9
4.12
Rapeseed oil meal Cooker2 234°F. Conditioner2 260°F.
30
324.0
19.5
35.0
6.6
4.86
Rapeseed oil meal Cooker2 220°F. Conditioner2 240°F.
30
365.0
20.0
34.8
7.3
5.69
31.8
35.0
6.42
Treatment
Average run of rapeseed
%fat
lysine in protein
1
Average of six male and six female chicks. Crushed seed took approximately 30 minutes to pass through the cooker and 5 minutes to pass through the conditioner. 2
tein of the unheated seed from which the RSOMs were produced. The highest processing temperatures employed, which on the basis of information provided by the processor, were slightly higher than "normal" processing temperatures, caused a drastic reduction in the lysine content of the protein of the resultant meal. The data also show that all three meals are definitely goitrogenic, the meal processed at the highest temperatures producing the highest thyroid-to-body weight ratio. The above results from RSOMs processed at varying temperatures would seem to warrant the conclusion that, if damage to protein quality and increase in goitrogenicity of the meal are to be avoided, great care should be exercised in the processing of rapeseed to ensure that it is not exposed to higher than necessary temperatures.
for poultry would appear to justify the following conclusions: (1) The growth promoting value and goitrogenic property of rapeseed oil meal are affected by the variety of seed from which the rapeseed oil meal is produced. (2) The level of "toxic principles" in rapeseed is related to the variety of rapeseed and to the environmental conditions under which the rapeseed is grown. (3) Heat increases the goitrogenic property of the rapeseed oil meal by converting isothiocyanate to L-5-vinyl-2-thiooxazolidone. (4) Excessive amounts of heat employed during extraction of oil from rapeseed adversely affect the nutritive value of the resulting rapeseed oil meal. The main adverse effect of excessive heat treatment is to reduce the lysine content of the resultant meal.
SUMMARY
REFERENCES Astwood, E. B., M. A. Greer and M. G. Ettlinger, 1949a. The antithyroid factor of yellow turnip. Science, 109: 631.
Results of studies on factors affecting the nutritive quality of rapeseed oil meal
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D. R. CLANDININ, R. RENNER AND A. R. ROBBLEE
Astwood, E. B., M. A. Greer and M. G. Ettlinger, 1949b. L-S-vinyl-2-thiooxazolidone, an antithyroid compound from yellow turnip and from Brassica seeds. J. Biol. Chem. 181: 121-130. Bell, J. M., and K. Williams, 1953. Growth depressing factors in rapeseed oil meal. Can J. Agr. Sci. 33:201-209. Blakely, R. M., and R. W. Anderson, 1948. Studies with rape-seed oilcake meal. I I . The effect of the inclusion of Protamone in the diet, on the thyroid enlargement induced by the feeding of rapeseed oilcake meal to turkey poults. Sci. Agr. 28: 398-402. Carroll, K. K., 1949. Isolation of an anti-thyroid compound from rape seed (Brassica napus). Proc. Soc. Exptl. Biol. Med. 71: 622-624. Charipper, H. A., and A. S. Gordon, 1947. The biology of antithyroid hormones. Vitamins and Hormones, Academic Press, New York. Clandinin, D. R., 1949. The effects of methods of
processing on the nutritive value of herring meals. Poultry Sci. 28: 128-133. Kjaer, A., J. Conti and K. A. Jensen, 1953. Isothiocyanates. I I I . The volatile isothiocyanates in seeds of rape (Brassica napus). Acta Chem. Scand. 7: 1271-1275. Klain, G. J., D. C. Hill, H. D. Branion and J. A. Gray, 1956. The value of rapeseed oil meal and sunflower seed oil meal in chick starter rations. Poultry Sci. 35: 1315-1326. Kratzer, F. H., P. N. Davis, D. E. Williams and B. J. Marshall, 1954. Factors influencing the growth of chicks and poults fed rations containing rapeseed oil meal. J. Nutr. 53: 407-418. Matet, J., R. Montagne and A. Buchy, 1949. Food value of the rapeseed press cake. Oleagineux, 4: 145-154. Pitt-Rivers, R., 1950. Mode of action of antithyroid compounds. Physiol. Rev. 30: 194-203.
Heterosis in Poultry 2. CROSSBREDS VERSUS
TOP-CROSSBREDS
A. W. NORDSKOG, L. T. SMITH AND R. E. PHILLIPS Department of Poultry Husbandry, Iowa State University, Ames, Iowa (Received for publication April 17, 1959)
H
YBRIDIZATION, as a tool for the production of commercial chickens, is a well established practice today. Whether inbreeding the parental lines enhances such hybridization is still a highly debatable issue. Arguments favoring inbreeding as a means to develop lines of high potential combining ability rest more on theoretical logic than on a basis of factual experimental evidence. This is because the experimental information so far reported in the literature is inconclusive. Journal Paper No. J-3619 of the Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa. Project 1040. This work is in cooperation with the North Central Regional Poultry Breeding Project, NC-47.
Some workers have reported an advantage in using inbred lines for crosses. Waters (1938) found improved fertility, hatchability and livability by use of inbred Leghorn males. Maw (1942) found that top-crossing inbred Leghorn males on Leghorn females gave better results in both viability and egg production than non-inbred Leghorn controls. He also reported that crosses between unrelated inbred lines were superior to top-crosses. Other workers have not been able to demonstrate any clear-cut advantage in using inbred lines for crossing purposes. Dudley and Pease (1948), for example, reported that top-crossing held no advantage over outcrossing. Hays (1935) reported that the progeny of inbred Rhode