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Evaluation of Rapeseed Meal as a Protein Supplement for Laying Hen Diets
1382
P. E. DORR AND C. F. NOCKELS Perek, M., and J. Kendler, 1963. Ascorbic acid as a dietary supplement for White Leghorn hens under conditions of climatic stress. British Poultry Sci. 4 : 191-200. Ray, S. N., 1934. A note on the presence of vitamin C in the chick embryo. Biochem. J. 28: 189-191. Roy, R. N., and B. C. Guha, 1958. Species difference in regard to the biosynthesis of ascorbic acid. Nature, 182: 319-320. Satterfield, G. H., T. A. Bell, F. W. Cook and A. D. Holmes, 1945. Effects of ascorbic acid injections on the amount in the blood plasma of laying hens. Poultry Sci. 24: 139-141. Satterfield, G. H., T. A. Bell, F. W. Cook and A. D. Holmes, 1947. Vitamin C content of hen's vital organs after long continued ascorbic acid injections. Poultry Sci. 26: 163-166. Thornton, P. A., and R. E. Moreng, 1958. The effects of ascorbic acid on egg quality factors. Poultry Sci. 37: 691-698. Thornton, P. A., and R. E. Moreng, 1959. Further evidence on the value of ascorbic acid for maintenance of shell quality in warm environmental temperature. Poultry Sci. 38: 594-599.
Evaluation of Rapeseed Meal as a Protein Supplement for Laying Hen Diets J. D. SUMMERS, G. RAJARATNAM AND W. F. PEPPER Department of Poultry Science, University of Guelph, Guelph, Ontario, Canada (Received for publication February 19, 1971)
A
SUBSTANTIAL amount of work has been reported regarding the use of rapeseed meal in poultry diets (O'Neil, 1957; MacGregor and Blakely, 1964; Bowland et al., 1965; Summers et al., 1967, 1969; Jackson, 1969; and others). Although the results, in general, indicate that poultry can utilize fairly high levels of rapeseed meal, this product has not been readily accepted by the feed industry. Inferior quality, as compared to soybean meal, and the presence of "toxic factors" are criticisms most commonly voiced against rapeseed meal. Since there is a limited amount of work reported on the feeding value of rapeseed
meal to laying hens and one of the latter reports (Jackson, 1969) has indicated that there may be a difference in strain of bird with respect to "toxicity," the present study was undertaken to gain additional information on the nutritive value of rapeseed meal for the laying hen. In view of the lower nitrogen and amino acid digestibility values reported for rapeseed, as compared to soybean meal (Lodhi et al., 1970; Veena, 1970; Cho and Bayley, 1970; Guo et al., 1971) and the well established goitrogenic affect of rapeseed (Greer, 1962; Bowland et al., 1965; and Jackson, 1969) the influence of "toxic factors" and amino acid supplementation were studied.
Downloaded from http://ps.oxfordjournals.org/ at University of Hong Kong on May 9, 2015
Herrick, R. B., and C. F. Nockels, 1969. Effects of a high level of dietary ascorbic acid on egg quality. Poultry Sci. 48: 1518-1519. Heywang, B. W., and A. R. Kemmerer, 1955. The effects of procaine penicillin and ascorbic acid on egg weight and shell thickness during hot weather. Poultry Sci. 34: 1032-1036. Holmes, A. D., F. Tripp and G. H. Satterfield, 1939. The ascorbic acid content of blood plasma of laying hens. Poultry Sci. 18: 192-200. Hunt J. R., and J. R. Aitken, 1952. Studies on the influence of ascorbic acid on shell quality. Poultry Sci. 4 1 : 219-226. Li, J. C. R., 1964. Statistical Inference I. Edwards Brothers, Inc., Ann Arbor, Michigan. Manual for Nutrition Surveys, 1963. Second Edition, Interdepartmental Committee on Nutrition for National Defense. U.S. Government Printing Office, Washington, D.C. Nockels, C. F., R. B. Herrick and J. V. Shutze, 1968. Effects of ascorbic acid withdrawal on interior egg quality. Poultry Sci. 47: 1702. Perek, M., and J. Kendler, 1962. Vitamin C supplementation to hen's diet in a hot climate. Poultry Sci. 4 1 : 677-678.
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RAPESEED MEAL FOE LAYERS TABLE 1.—Composition of experimental diets Ingredients Corn Soybean meal (50% protein) Rapeseed meal Alphafloc Animal tallow Limestone Calcium phosphate Vitamin mix1 Mineral mix2 Iodized salt (0.015% KI)
Diets (%) 2 3
58.25 10.00
58.25
—
12. C4 9.96 6.75 2.00 0.50 0.25 0.25
13.25 8.87 10.03 6.74 1.86 0.50 0.25 0.25
10.0 2.95 3.01 0.51
10.0 2.95 3.05 0.51
—
4
5
(a) 6
7
58.25
58.25
58.25
5.50 6.60 6.85 1.80 0.50 0.25 0.25
58.25 10.00 13.25 2.33 6.72 6.75 1.70 0.50 0.25 0.25
6.84 6.60 1.51 0.50 0.25 0.25
3.70 6.60 1.45 0.50 0.25 0.25
9.09 6.60 1.51 0.50 0.25 0.25
15.0 2.95 3.03 0.51
15.0 2.95 3.04 0.52
15.0 2.93 3.00 0.50
16.0 2.76 3.01 0.50
15.0 3.02 3.01 0.50
58.25 20.00
—•
—
26.25
•—
—
29.0
—
—
27.05
—
1 Supplied per'kg. of diet: Vitamin A, (I.U.) 7511, vitamin D 3 , (I.C.U.) 1652, riboflavin,5.5mg.,pantothenic acid, 5.7 mg., vitamin Bi2, 6.6 meg., vitamin E (I.U.) 5.5; niacin, 11 mg., choline choride, 246.7 mg., ethoxyquin, 125.1 mg., folic acid, 1.32 mg., and menadione sodium bisulfite, 1.1 mg. 2 Supplied per kg. of diet: manganese, 53.1 mg., zinc, 51.1 mg., copper, 7.9 mg., and iron, 20.3 mg. (a) In experiment 2 the following levels (%) of amino acids were added to Diet #5 to give treatments 4 and 5: Treatment #4: Arginine, 0.14, lysine, 0.07, tryptophan, 0.01, phenylalanine 0.11, leucine, 0.03, isoleucine, 0.15 and glycine, 0.473. Treatment #5: Arginine, 0.235; lysine, 0.146; tryptophan, 0.03; phenylalanine, 0.189; threonine, 0.013; valine, 0.073; leucine, 0.162; isoleucine, 0.231 and glycine, 0.941.
EXPERIMENTAL PROCEDURE
Experiment 1 was undertaken to study the extent of "toxic effect" with various levels of dietary rapeseed meal, on laying performance during three 28 day experimental periods. Six replicate groups of caged layers (each replicate consisting of ten individually caged birds) were randomly assigned to each of the experimental diets (Table 1). All diets contained 5% protein from corn with the remaining dietary protein coming from either soybean meal, solvent extracted rapeseed meal or a combination of both. Diets were formulated in such a manner that differences in amino acid composition were due entirely to the two protein supplements under study. Diet 1 contained 10% protein; half being supplied from corn and half from soybean meal. Similarly diet 2 contained 10% protein; half supplied by corn and half from rapeseed meal. With the stress of
a protein deficiency it was felt that differences in response due to protein quality would be greater. The remainder of the dietary treatments are shown in Tables 1 and 2. In order to verify whether protein availability or energy level of the rapeseed meal diets, were influencing performance of the birds, diet 6 contained an additional 1 % of protein from rapeseed meal, while diet 7 contained a higher level of energy. Experiment 2 was carried out to study the effect of amino acid and thyroprotein1 supplementation of rapeseed meal diets. [Earlier work by Blakely and Anderson (1948) had indicated that thyroprotein would partially counteract the "toxic effects" of rapeseed meal.] Hens from experiment 1 were used in this study after a 4 week changeover period during which time they were fed a 17% protein commercial 1
Thyroprotein (trade name Protamone) contains approximately 1% thyroxine activity.
Downloaded from http://ps.oxfordjournals.org/ at University of Hong Kong on May 9, 2015
Calcidaled analysis Protein % (NX6.25) Metabolizable Energy (Kcal • /g.) Calcium (%) Available phosphorus (%)
1
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J. D. SUMMERS, G. RAJAEATNAM AND W. F. PEPPER TABLE 2.—Laying performance, feed consumption, body weight gains and thyroid weights of White Leghorn hens fed various levels of rapeseed meal
Treatments Source of protein
Egg_ production H.D.B.
5% corn, 5% soya 5% corn, 5% rape 5% corn, 10% soya 5% corn, 5% soya, 5% rape 5% corn, 10% rape 5% corn, 11 % rape as 5 plus 2 % tallow
60.8" 64.3" 90.2 b 84.8° 79.7
(%) 1. 2. 3. 4. 5. 6. 7.
Feed intake (g./day/ hen)
Feed/doz. eggs (kg.)
Egg weight (g.)
Weight gain (g.)
Thyroid weights (mg./kg. body wt.)
80.6" 83.5" 103.2" 94.7<= 92.5" 98.8" 91.8"
1.589" 1.543" 1.362b" 1.316b 1.362b" 1.407" 1.407°
50.1" 50.7" 55.1" 54.4 b " 53.3" 53.7" 53.6"
-212" -249" 145" 5" -53" 4" -25d
88 152 186 268 175
laying diet. Similar to the first experiment, six replicate groups of caged layers (ten birds per replicate) were assigned to each of the dietary treatments. These were allotted in such a manner that the treatments were balanced with respect to hens from previous treatments of experiment 1. Three diets employed in the first experiment (Table 1, diets 3, 4, 5) served as controls for this test. Another treatment, consisted of essential amino acids added to diet S, to bring the levels equivalent to those found in the soybean meal diet (diet 3). In view of a possible poor amino acid(s) availability from rapeseed meal, another treatment consisted of the addition of 10% excess of essential amino acids (based on diet 3) to diet 5. Further treatments consisted of diet 5 plus 0.01% thyroprotein, both in the presence and absence of amino TABLE 3.-
RESULTS AND DISCUSSION
At the low level of protein (treatments 1 and 2) there were no significant differences in response due to the type of protein supplement (Table 2). Since both diets were
and thyroid -Laying performance, feed consumption, body weig of White Leghorn hens fed rapeseed meal diets
Treatments Source of protein 1. 2. 3. 4. 5.
acid supplementation (amino acids to bring diet 5 up to diet 3). These treatments are outlined in Table 3. The test was run for two 28 day periods. In both experiments feed intake and egg production were recorded for every four week period. Egg weights were obtained on three consecutive days of each period and weight gains were calculated at the end of each experiment. Thyroid glands were removed from a representative sample of birds from each replicate, weighed as a pair and sections stained with haematoxylin-eosin for histological study.
5% corn, 10% soya 5% corn, 5% soya, 5% rape 5% corn, 10% rape as 3 plus E.A.A. to equal 1. as 3 plus 10% excess of E.A.A. compared to 1 6. as 3 plus 0.01% thyroprotein 7. as 4 plus 0.01% thyroprotein
(%)
Feed intake (g./day/ hen)
86.3" 80.4»b 71.2"d 74.3 b "
110.6" 103.4"b 98.6" b 97.4 b
1.498" 1.543" 1.634" 1.543"
56.5" 56.7" 55.7" 56.4"
74.5'"= 67.2 d 73.3"
98.6" b 92.2 b 95.9 b
1.589" 1.634" 1.543"
56.3" 56.1" 56.7"
production H.D.B.
ed/doz. eggs (kg.)
Egg weight (g-)
Weight
118.8" 54.1" b -7.7" 13.0 b
gain (g.)
8.4 b -149.2" -129.9"
Means followed by the same superscript are not significantly different (P<0.05).
Thyroid weights (mg./kg. body wt.) 152. l b ° 161.7" 130.4"b" 141.0"b" 48. l d 99 9"bd
Downloaded from http://ps.oxfordjournals.org/ at University of Hong Kong on May 9, 2015
Means followed by the same superscript are not significantly different (P<0.05).
RAPESEED MEAL FOR LAYERS
3, experiment 1, gave similar results. The results (Table 3) add further confirmation to the depressing effect on performance when rapeseed meal is added to laying hen diets. Egg weight was not depressed to the same extent as in experiment 1; possibly due to the higher level of feed intake of the older birds (approximately 3 months older). Amino acid supplementation of the rapeseed meal diets to equal the level of essential amino acids found in the soybean meal diet or 10% excess of all the essential amino acids, did not significantly alter hen performance. However, small increases were observed in egg production, egg weight and body weight gain. Thyroprotein addition, with or without amino acid supplementation, had no beneficial effect on any of the parameters measured. Thyroid weights were significantly larger with the rapeseed meal diets as compared with the soybean meal diet. The significant reduction in thyroid weight with thyroprotein feeding is in agreement with results reported for growing turkeys (Blakely and Anderson, 1948). However, where the above authors noted a marked growth response by the addition of thyroprotein to a rapeseed meal diet, no effect on hen performance was noted in this study. It is of interest to note that amino acid supplementation of the rapeseed meal diets reduced thyroid weight (although the differences were not significant from the rapeseed meal diet). Addition of thyroprotein along with amino acids to the rapeseed meal diets tended to increase thyroid weight. It is also of interest that amino acid supplement resulted in thyroids nearer to a normal size (e.g. diet 1) even though entirely opposite effects were noted in the presence and absence of thyroprotein. Histological study of thyroid sections from rapeseed meal fed birds revealed evidence of inhibition of thyroxine biosynthesis as indicated by enlargement of the follicles and sparsely distributed colloid.
Downloaded from http://ps.oxfordjournals.org/ at University of Hong Kong on May 9, 2015
deficient in essential amino acids any "toxic effect" of rapeseed meal may have been masked by amino acid(s) deficiency. Although not significant, it is of interest to note that the rapeseed meal diet resulted in slightly higher performance than the soybean meal diet. Such a response may have been due to the higher level of methionine (0.33% versus 0.26%) in the rapeseed meal diet since Moran et al. (1969) have shown that a marked response can be obtained with the addition of methionine to a similar low protein diet. Comparing treatments 4 (half soya and half rape) and 5 (all rape) with treatment 3 (all soya) it will be noted that the addition of rapeseed meal to the diet resulted in significantly less production, less feed intake, smaller egg size and loss of weight gain. In general the higher the level of rapeseed meal the less favourable was egg production and egg weight. This strongly suggests an amino acid imbalance (resulting in a deficiency of protein) since a decrease in production does not usually coincide with a decrease in egg size, unless protein is limiting. Adding an additional one percent rapeseed meal protein (treatment 6; 11% protein from rape) gave results superior to that of diet 5 (10% protein from rape) and, in fact, the results were very similar to diet 4 ( 5 % protein from rape and 5% from soya). This suggests that amino acid balance or low amino acid availability may be the reason for poor performance of the rapeseed meal diets rather than "toxic factors." Increasing the level of dietary energy (diet 7) failed to improve performance, thus demonstrating that energy was not a limiting factor with the rapeseed meal diets. An increase in weight of the thyroids was observed when the level of rapeseed meal was raised in the diet, thus suggesting that the thioglucoside activity was not completely destroyed during processing. In experiment 2, diets 3, 4 and 5 (Table 1), which were used as treatments 1, 2 and
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J. D. SUMMERS, G. RAJARATNAM AND W. F. PEPPER
point. SUMMARY
A study was undertaken to investigate the nutritive value of rapeseed meal in laying diets. Rapeseed meal supplementation significantly lowered weight gain, egg production, egg size and feed consumption as compared to similar diets containing soybean meal. Amino acid and energy supplementation to rapeseed meal diets did not significantly improve performance of the hens. The addition of thyroprotein to the rapeseed meal ration did not alter performance though a significant reduction in thyroid weight was noted. An increase in thyroid weight was observed in hens fed the higher levels of rapeseed meal. Histological study of thyroid glands revealed enlargement of follicles and sparsely distributed colloid indicating inhibition of thyroxine biosynthesis. ACKNOWLEDGEMENTS
The authors wish to acknowledge the financial assistance of the Ontario Department of Agriculture and Food and the Canada Department of Industry in the conduct of this work.
REFERENCES Blakely, R. M., and R. W. Anderson, 1948. Studies with rapeseed oil cake meal. ii. The effect of inclusion of protamone in the diet on the thyroid enlargement induced by the feeding of rapeseed oil cake meal to turkey poults. Sci. Agri. 28: 398-402. Bowland, J. P., D. R. Clandinin and L. R. Wetter, 1965. Rapeseed meal for livestock and poultry. A review. Can. Dept. Agr. Publ. 1257. Cho, C. Y., and H. S. Bayley, 1970. Evaluation of rapeseed and soybean meals as protein sources for swine: apparent digestibilities of amino acids. Can. J. Anim. Sci. 50: 521-528. Guo, L. S., J. D. Summers and E. T. Moran, Jr., 1971. Assaying feedstuffs for available lysine content using a feather meal basal diet. Can. J. Animal Sci. 51: 161-169. Greer, M. A., 1962. The isolation and identification of progoitrin from Brassica seed. Arch. Biochem. Biophy. 99: 369-371. Jackson, N., 1969. Toxicity of rapeseed meal and its use as a protein supplement in the diet of two hybrid strains of caged laying hens. J. Sci. Food Agr. 20: 734-740. Lodhi, G. N., R. Renner and D. R. Clandinin, 1970. Factors affecting the metabolizable energy value of rapeseed meal. 2. Nitrogen absorbability. Poultry Sci. 49: 991-999. MacGregor, H. I., and R. M. Blakely, 1964. Rapeseed oil meal as a supplement to a turkey breeder ration. Poultry Sci. 4 3 : 189-192. Moran, Jr., E. T., W. F. Pepper and J. D. Summers, 1969. Processed feather and hog hair meal as sources of dietary protein for the laying hen with emphasis on their use in meeting maintenance needs. Poultry Sci. 48: 1245-1251. O'Neil, J. G., 1957. Rapeseed oil meal as a vegetable protein supplement in the diet of laying and breeding hens. Poultry Sci. 36: 1146. Summers, J. D., H. S. Bayley, W. F. Pepper and S. J. Slinger, 1969. The value of rapeseed meal for growing pullets and laying hens. Can. J. Animal Sci. 49: 97-103. Summers, J. D., W. F. Pepper, E. T. Moran, Jr. and H. S. Bayley, 1967. Utilization of rapeseed meal as a source of protein for turkeys. Can. J. Animal Sci. 47: 131-136. Veena, J., 1970. Protein value of rapeseed meal for the chick. M.Sc. Thesis. Department of Nutrition, University of Guelph, Guelph, Ontario.
Downloaded from http://ps.oxfordjournals.org/ at University of Hong Kong on May 9, 2015
The present study suggests that inclusion of rapeseed meal at relatively high levels in laying diets may be detrimental to the normal physiological function of the laying hen. Although thyroid weight is increased with rapeseed meal feeding there is little evidence from the work reported to indicate any real "toxic effects" from rapeseed meal. The data presented also suggest that amino acid balance may be responsible for the decreased performance with high levels of rapeseed meal. Further work is required to shed more light on this particular
P. E. DORR AND C. F. NOCKELS Perek, M., and J. Kendler, 1963. Ascorbic acid as a dietary supplement for White Leghorn hens under conditions of climatic stress. British Poultry Sci. 4 : 191-200. Ray, S. N., 1934. A note on the presence of vitamin C in the chick embryo. Biochem. J. 28: 189-191. Roy, R. N., and B. C. Guha, 1958. Species difference in regard to the biosynthesis of ascorbic acid. Nature, 182: 319-320. Satterfield, G. H., T. A. Bell, F. W. Cook and A. D. Holmes, 1945. Effects of ascorbic acid injections on the amount in the blood plasma of laying hens. Poultry Sci. 24: 139-141. Satterfield, G. H., T. A. Bell, F. W. Cook and A. D. Holmes, 1947. Vitamin C content of hen's vital organs after long continued ascorbic acid injections. Poultry Sci. 26: 163-166. Thornton, P. A., and R. E. Moreng, 1958. The effects of ascorbic acid on egg quality factors. Poultry Sci. 37: 691-698. Thornton, P. A., and R. E. Moreng, 1959. Further evidence on the value of ascorbic acid for maintenance of shell quality in warm environmental temperature. Poultry Sci. 38: 594-599.
Evaluation of Rapeseed Meal as a Protein Supplement for Laying Hen Diets J. D. SUMMERS, G. RAJARATNAM AND W. F. PEPPER Department of Poultry Science, University of Guelph, Guelph, Ontario, Canada (Received for publication February 19, 1971)
A
SUBSTANTIAL amount of work has been reported regarding the use of rapeseed meal in poultry diets (O'Neil, 1957; MacGregor and Blakely, 1964; Bowland et al., 1965; Summers et al., 1967, 1969; Jackson, 1969; and others). Although the results, in general, indicate that poultry can utilize fairly high levels of rapeseed meal, this product has not been readily accepted by the feed industry. Inferior quality, as compared to soybean meal, and the presence of "toxic factors" are criticisms most commonly voiced against rapeseed meal. Since there is a limited amount of work reported on the feeding value of rapeseed
meal to laying hens and one of the latter reports (Jackson, 1969) has indicated that there may be a difference in strain of bird with respect to "toxicity," the present study was undertaken to gain additional information on the nutritive value of rapeseed meal for the laying hen. In view of the lower nitrogen and amino acid digestibility values reported for rapeseed, as compared to soybean meal (Lodhi et al., 1970; Veena, 1970; Cho and Bayley, 1970; Guo et al., 1971) and the well established goitrogenic affect of rapeseed (Greer, 1962; Bowland et al., 1965; and Jackson, 1969) the influence of "toxic factors" and amino acid supplementation were studied.
Downloaded from http://ps.oxfordjournals.org/ at University of Hong Kong on May 9, 2015
Herrick, R. B., and C. F. Nockels, 1969. Effects of a high level of dietary ascorbic acid on egg quality. Poultry Sci. 48: 1518-1519. Heywang, B. W., and A. R. Kemmerer, 1955. The effects of procaine penicillin and ascorbic acid on egg weight and shell thickness during hot weather. Poultry Sci. 34: 1032-1036. Holmes, A. D., F. Tripp and G. H. Satterfield, 1939. The ascorbic acid content of blood plasma of laying hens. Poultry Sci. 18: 192-200. Hunt J. R., and J. R. Aitken, 1952. Studies on the influence of ascorbic acid on shell quality. Poultry Sci. 4 1 : 219-226. Li, J. C. R., 1964. Statistical Inference I. Edwards Brothers, Inc., Ann Arbor, Michigan. Manual for Nutrition Surveys, 1963. Second Edition, Interdepartmental Committee on Nutrition for National Defense. U.S. Government Printing Office, Washington, D.C. Nockels, C. F., R. B. Herrick and J. V. Shutze, 1968. Effects of ascorbic acid withdrawal on interior egg quality. Poultry Sci. 47: 1702. Perek, M., and J. Kendler, 1962. Vitamin C supplementation to hen's diet in a hot climate. Poultry Sci. 4 1 : 677-678.
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RAPESEED MEAL FOE LAYERS TABLE 1.—Composition of experimental diets Ingredients Corn Soybean meal (50% protein) Rapeseed meal Alphafloc Animal tallow Limestone Calcium phosphate Vitamin mix1 Mineral mix2 Iodized salt (0.015% KI)
Diets (%) 2 3
58.25 10.00
58.25
—
12. C4 9.96 6.75 2.00 0.50 0.25 0.25
13.25 8.87 10.03 6.74 1.86 0.50 0.25 0.25
10.0 2.95 3.01 0.51
10.0 2.95 3.05 0.51
—
4
5
(a) 6
7
58.25
58.25
58.25
5.50 6.60 6.85 1.80 0.50 0.25 0.25
58.25 10.00 13.25 2.33 6.72 6.75 1.70 0.50 0.25 0.25
6.84 6.60 1.51 0.50 0.25 0.25
3.70 6.60 1.45 0.50 0.25 0.25
9.09 6.60 1.51 0.50 0.25 0.25
15.0 2.95 3.03 0.51
15.0 2.95 3.04 0.52
15.0 2.93 3.00 0.50
16.0 2.76 3.01 0.50
15.0 3.02 3.01 0.50
58.25 20.00
—•
—
26.25
•—
—
29.0
—
—
27.05
—
1 Supplied per'kg. of diet: Vitamin A, (I.U.) 7511, vitamin D 3 , (I.C.U.) 1652, riboflavin,5.5mg.,pantothenic acid, 5.7 mg., vitamin Bi2, 6.6 meg., vitamin E (I.U.) 5.5; niacin, 11 mg., choline choride, 246.7 mg., ethoxyquin, 125.1 mg., folic acid, 1.32 mg., and menadione sodium bisulfite, 1.1 mg. 2 Supplied per kg. of diet: manganese, 53.1 mg., zinc, 51.1 mg., copper, 7.9 mg., and iron, 20.3 mg. (a) In experiment 2 the following levels (%) of amino acids were added to Diet #5 to give treatments 4 and 5: Treatment #4: Arginine, 0.14, lysine, 0.07, tryptophan, 0.01, phenylalanine 0.11, leucine, 0.03, isoleucine, 0.15 and glycine, 0.473. Treatment #5: Arginine, 0.235; lysine, 0.146; tryptophan, 0.03; phenylalanine, 0.189; threonine, 0.013; valine, 0.073; leucine, 0.162; isoleucine, 0.231 and glycine, 0.941.
EXPERIMENTAL PROCEDURE
Experiment 1 was undertaken to study the extent of "toxic effect" with various levels of dietary rapeseed meal, on laying performance during three 28 day experimental periods. Six replicate groups of caged layers (each replicate consisting of ten individually caged birds) were randomly assigned to each of the experimental diets (Table 1). All diets contained 5% protein from corn with the remaining dietary protein coming from either soybean meal, solvent extracted rapeseed meal or a combination of both. Diets were formulated in such a manner that differences in amino acid composition were due entirely to the two protein supplements under study. Diet 1 contained 10% protein; half being supplied from corn and half from soybean meal. Similarly diet 2 contained 10% protein; half supplied by corn and half from rapeseed meal. With the stress of
a protein deficiency it was felt that differences in response due to protein quality would be greater. The remainder of the dietary treatments are shown in Tables 1 and 2. In order to verify whether protein availability or energy level of the rapeseed meal diets, were influencing performance of the birds, diet 6 contained an additional 1 % of protein from rapeseed meal, while diet 7 contained a higher level of energy. Experiment 2 was carried out to study the effect of amino acid and thyroprotein1 supplementation of rapeseed meal diets. [Earlier work by Blakely and Anderson (1948) had indicated that thyroprotein would partially counteract the "toxic effects" of rapeseed meal.] Hens from experiment 1 were used in this study after a 4 week changeover period during which time they were fed a 17% protein commercial 1
Thyroprotein (trade name Protamone) contains approximately 1% thyroxine activity.
Downloaded from http://ps.oxfordjournals.org/ at University of Hong Kong on May 9, 2015
Calcidaled analysis Protein % (NX6.25) Metabolizable Energy (Kcal • /g.) Calcium (%) Available phosphorus (%)
1
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J. D. SUMMERS, G. RAJAEATNAM AND W. F. PEPPER TABLE 2.—Laying performance, feed consumption, body weight gains and thyroid weights of White Leghorn hens fed various levels of rapeseed meal
Treatments Source of protein
Egg_ production H.D.B.
5% corn, 5% soya 5% corn, 5% rape 5% corn, 10% soya 5% corn, 5% soya, 5% rape 5% corn, 10% rape 5% corn, 11 % rape as 5 plus 2 % tallow
60.8" 64.3" 90.2 b 84.8° 79.7
(%) 1. 2. 3. 4. 5. 6. 7.
Feed intake (g./day/ hen)
Feed/doz. eggs (kg.)
Egg weight (g.)
Weight gain (g.)
Thyroid weights (mg./kg. body wt.)
80.6" 83.5" 103.2" 94.7<= 92.5" 98.8" 91.8"
1.589" 1.543" 1.362b" 1.316b 1.362b" 1.407" 1.407°
50.1" 50.7" 55.1" 54.4 b " 53.3" 53.7" 53.6"
-212" -249" 145" 5" -53" 4" -25d
88 152 186 268 175
laying diet. Similar to the first experiment, six replicate groups of caged layers (ten birds per replicate) were assigned to each of the dietary treatments. These were allotted in such a manner that the treatments were balanced with respect to hens from previous treatments of experiment 1. Three diets employed in the first experiment (Table 1, diets 3, 4, 5) served as controls for this test. Another treatment, consisted of essential amino acids added to diet S, to bring the levels equivalent to those found in the soybean meal diet (diet 3). In view of a possible poor amino acid(s) availability from rapeseed meal, another treatment consisted of the addition of 10% excess of essential amino acids (based on diet 3) to diet 5. Further treatments consisted of diet 5 plus 0.01% thyroprotein, both in the presence and absence of amino TABLE 3.-
RESULTS AND DISCUSSION
At the low level of protein (treatments 1 and 2) there were no significant differences in response due to the type of protein supplement (Table 2). Since both diets were
and thyroid -Laying performance, feed consumption, body weig of White Leghorn hens fed rapeseed meal diets
Treatments Source of protein 1. 2. 3. 4. 5.
acid supplementation (amino acids to bring diet 5 up to diet 3). These treatments are outlined in Table 3. The test was run for two 28 day periods. In both experiments feed intake and egg production were recorded for every four week period. Egg weights were obtained on three consecutive days of each period and weight gains were calculated at the end of each experiment. Thyroid glands were removed from a representative sample of birds from each replicate, weighed as a pair and sections stained with haematoxylin-eosin for histological study.
5% corn, 10% soya 5% corn, 5% soya, 5% rape 5% corn, 10% rape as 3 plus E.A.A. to equal 1. as 3 plus 10% excess of E.A.A. compared to 1 6. as 3 plus 0.01% thyroprotein 7. as 4 plus 0.01% thyroprotein
(%)
Feed intake (g./day/ hen)
86.3" 80.4»b 71.2"d 74.3 b "
110.6" 103.4"b 98.6" b 97.4 b
1.498" 1.543" 1.634" 1.543"
56.5" 56.7" 55.7" 56.4"
74.5'"= 67.2 d 73.3"
98.6" b 92.2 b 95.9 b
1.589" 1.634" 1.543"
56.3" 56.1" 56.7"
production H.D.B.
ed/doz. eggs (kg.)
Egg weight (g-)
Weight
118.8" 54.1" b -7.7" 13.0 b
gain (g.)
8.4 b -149.2" -129.9"
Means followed by the same superscript are not significantly different (P<0.05).
Thyroid weights (mg./kg. body wt.) 152. l b ° 161.7" 130.4"b" 141.0"b" 48. l d 99 9"bd
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Means followed by the same superscript are not significantly different (P<0.05).
RAPESEED MEAL FOR LAYERS
3, experiment 1, gave similar results. The results (Table 3) add further confirmation to the depressing effect on performance when rapeseed meal is added to laying hen diets. Egg weight was not depressed to the same extent as in experiment 1; possibly due to the higher level of feed intake of the older birds (approximately 3 months older). Amino acid supplementation of the rapeseed meal diets to equal the level of essential amino acids found in the soybean meal diet or 10% excess of all the essential amino acids, did not significantly alter hen performance. However, small increases were observed in egg production, egg weight and body weight gain. Thyroprotein addition, with or without amino acid supplementation, had no beneficial effect on any of the parameters measured. Thyroid weights were significantly larger with the rapeseed meal diets as compared with the soybean meal diet. The significant reduction in thyroid weight with thyroprotein feeding is in agreement with results reported for growing turkeys (Blakely and Anderson, 1948). However, where the above authors noted a marked growth response by the addition of thyroprotein to a rapeseed meal diet, no effect on hen performance was noted in this study. It is of interest to note that amino acid supplementation of the rapeseed meal diets reduced thyroid weight (although the differences were not significant from the rapeseed meal diet). Addition of thyroprotein along with amino acids to the rapeseed meal diets tended to increase thyroid weight. It is also of interest that amino acid supplement resulted in thyroids nearer to a normal size (e.g. diet 1) even though entirely opposite effects were noted in the presence and absence of thyroprotein. Histological study of thyroid sections from rapeseed meal fed birds revealed evidence of inhibition of thyroxine biosynthesis as indicated by enlargement of the follicles and sparsely distributed colloid.
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deficient in essential amino acids any "toxic effect" of rapeseed meal may have been masked by amino acid(s) deficiency. Although not significant, it is of interest to note that the rapeseed meal diet resulted in slightly higher performance than the soybean meal diet. Such a response may have been due to the higher level of methionine (0.33% versus 0.26%) in the rapeseed meal diet since Moran et al. (1969) have shown that a marked response can be obtained with the addition of methionine to a similar low protein diet. Comparing treatments 4 (half soya and half rape) and 5 (all rape) with treatment 3 (all soya) it will be noted that the addition of rapeseed meal to the diet resulted in significantly less production, less feed intake, smaller egg size and loss of weight gain. In general the higher the level of rapeseed meal the less favourable was egg production and egg weight. This strongly suggests an amino acid imbalance (resulting in a deficiency of protein) since a decrease in production does not usually coincide with a decrease in egg size, unless protein is limiting. Adding an additional one percent rapeseed meal protein (treatment 6; 11% protein from rape) gave results superior to that of diet 5 (10% protein from rape) and, in fact, the results were very similar to diet 4 ( 5 % protein from rape and 5% from soya). This suggests that amino acid balance or low amino acid availability may be the reason for poor performance of the rapeseed meal diets rather than "toxic factors." Increasing the level of dietary energy (diet 7) failed to improve performance, thus demonstrating that energy was not a limiting factor with the rapeseed meal diets. An increase in weight of the thyroids was observed when the level of rapeseed meal was raised in the diet, thus suggesting that the thioglucoside activity was not completely destroyed during processing. In experiment 2, diets 3, 4 and 5 (Table 1), which were used as treatments 1, 2 and
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J. D. SUMMERS, G. RAJARATNAM AND W. F. PEPPER
point. SUMMARY
A study was undertaken to investigate the nutritive value of rapeseed meal in laying diets. Rapeseed meal supplementation significantly lowered weight gain, egg production, egg size and feed consumption as compared to similar diets containing soybean meal. Amino acid and energy supplementation to rapeseed meal diets did not significantly improve performance of the hens. The addition of thyroprotein to the rapeseed meal ration did not alter performance though a significant reduction in thyroid weight was noted. An increase in thyroid weight was observed in hens fed the higher levels of rapeseed meal. Histological study of thyroid glands revealed enlargement of follicles and sparsely distributed colloid indicating inhibition of thyroxine biosynthesis. ACKNOWLEDGEMENTS
The authors wish to acknowledge the financial assistance of the Ontario Department of Agriculture and Food and the Canada Department of Industry in the conduct of this work.
REFERENCES Blakely, R. M., and R. W. Anderson, 1948. Studies with rapeseed oil cake meal. ii. The effect of inclusion of protamone in the diet on the thyroid enlargement induced by the feeding of rapeseed oil cake meal to turkey poults. Sci. Agri. 28: 398-402. Bowland, J. P., D. R. Clandinin and L. R. Wetter, 1965. Rapeseed meal for livestock and poultry. A review. Can. Dept. Agr. Publ. 1257. Cho, C. Y., and H. S. Bayley, 1970. Evaluation of rapeseed and soybean meals as protein sources for swine: apparent digestibilities of amino acids. Can. J. Anim. Sci. 50: 521-528. Guo, L. S., J. D. Summers and E. T. Moran, Jr., 1971. Assaying feedstuffs for available lysine content using a feather meal basal diet. Can. J. Animal Sci. 51: 161-169. Greer, M. A., 1962. The isolation and identification of progoitrin from Brassica seed. Arch. Biochem. Biophy. 99: 369-371. Jackson, N., 1969. Toxicity of rapeseed meal and its use as a protein supplement in the diet of two hybrid strains of caged laying hens. J. Sci. Food Agr. 20: 734-740. Lodhi, G. N., R. Renner and D. R. Clandinin, 1970. Factors affecting the metabolizable energy value of rapeseed meal. 2. Nitrogen absorbability. Poultry Sci. 49: 991-999. MacGregor, H. I., and R. M. Blakely, 1964. Rapeseed oil meal as a supplement to a turkey breeder ration. Poultry Sci. 4 3 : 189-192. Moran, Jr., E. T., W. F. Pepper and J. D. Summers, 1969. Processed feather and hog hair meal as sources of dietary protein for the laying hen with emphasis on their use in meeting maintenance needs. Poultry Sci. 48: 1245-1251. O'Neil, J. G., 1957. Rapeseed oil meal as a vegetable protein supplement in the diet of laying and breeding hens. Poultry Sci. 36: 1146. Summers, J. D., H. S. Bayley, W. F. Pepper and S. J. Slinger, 1969. The value of rapeseed meal for growing pullets and laying hens. Can. J. Animal Sci. 49: 97-103. Summers, J. D., W. F. Pepper, E. T. Moran, Jr. and H. S. Bayley, 1967. Utilization of rapeseed meal as a source of protein for turkeys. Can. J. Animal Sci. 47: 131-136. Veena, J., 1970. Protein value of rapeseed meal for the chick. M.Sc. Thesis. Department of Nutrition, University of Guelph, Guelph, Ontario.
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The present study suggests that inclusion of rapeseed meal at relatively high levels in laying diets may be detrimental to the normal physiological function of the laying hen. Although thyroid weight is increased with rapeseed meal feeding there is little evidence from the work reported to indicate any real "toxic effects" from rapeseed meal. The data presented also suggest that amino acid balance may be responsible for the decreased performance with high levels of rapeseed meal. Further work is required to shed more light on this particular