- Email: [email protected]
Low Erucic Acid Rapeseed Oils in Rations for Broiler Chickens: Oro and Hydrogenated Oro Oil1
Low Erucic Acid Rapeseed Oils in Rations for Broiler Chickens: Oro and Hydrogenated Oro Oil1 H . VOGTMANN AND D . R. CLANDININ
Department of Animal Science, University of Alberta, Edmonton, Alberta,
Canada
(Received for publication February 27, 1974)
POULTRY SCIENCE 53: 2108-2115, 1974
INTRODUCTION N previous studies (Vogtmann et al., 1973a, b) it was shown that inclusions of 5%, 10%, or 15% of low erucic acid rapeseed oil, originating from the Oro variety of rapeseed, in diets for broiler chickens was nutri-tionally as satisfactory as soybean oil or lard when the diets were fed to broiler chickens from one day old to four weeks of age. The objective of this study was to determine if and to what extent the commercial hydrogenation of Oro oil would change its nutritional properties.
I
MATERIALS AND METHODS One hundred and twenty female crossbred (Dominant White male x White Plymouth Rock female) chicks were divided into 12 1. Supported in part by grants from the National Research Council of Canada, the Alberta Agricultural Research Trust and the Rapeseed Association of Canada.
comparable groups of 10 chicks each. The chicks were housed in electrically heated, thermostatically controlled battery brooders with raised wire screen floors, in a well ventilated, temperature controlled brooding room. Electric light was provided on a continuous basis. Feed and water were provided ad libitum. Six rations were formulated to incorporate two low erucic acid rapeseed oils and one soybean oil at 5% and 15% levels in chick starter rations calculated to contain 23.2% protein and 3200 kcal. M.E./kg. ration. The formulae of the rations used are given in Table 1. The oils used in this study were of refined edible quality. No antioxidant was added during their production. The vitamin E contents of the oils were determined by the method of Vuilleumier et al. (1967) and DLa-tocopherolacetate* was added to the rape*DL-a-tocopherolacetate was supplied by F. Hoffmann La Roche & Co., A.G., Basel, Switzerland.
2108
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
ABSTRACT The effects of feeding broiler-type chickens rations containing 5% or 15% of a low erucic acid rapeseed oil prepared commercially from the Oro variety of rapeseed (ORO), a commercially hydrogenated Oro oil (HORO) and soybean oil (SBO) on body weight, apparent digestibility of total fatty acids, weights of heart, liver and spleen, total lipid and total fatty acid content of heart and liver and fatty acid composition of heart and liver lipids were studied. The experimental diets were fed ad libitum to the chickens from day old to four weeks of age. Body weight and weights of heart and liver were not influenced significantly by the dietary treatments. Spleen weight was smallest in the group fed the 15% ORO—containing diets. The apparent digestibilities of total fatty acids were similar for ORO and SBO (89.4% and 94.2% for 5% and 15% ORO; 90.9% and 94.7% for 5% and 15% SBO), however they were lower for HORO (85.7% and 90.2% for 5% and 15% HORO). Total lipid and total fatty acid contents of liver were not influenced significantly by the different dietary treatments. Feeding 5% ORO in the diet decreased the content of total fatty acids in heart as compared to feeding 5% HORO or 5% SBO in the diet. The fatty acid composition of heart and liver lipids was influenced by the fatty acid content of the diets. Only small amounts of erucic acid were found in the tissues of the birds fed diets containing ORO or HORO. The inclusion of 5% or 15% of low erucic acid rapeseed oils (ORO and HORO) in diets for broiler chickens proved nutritionally as satisfactory as the inclusion of SBO.
2109
ORO OIL FOR BROILERS
TABLE 1.—Composition of experimental rations
%
Constant components Ground wheat Soybean meal (48.5% protein) Dehydrated alfalfa meal Ground limestone Dicalcium phosphate Iodized salt Manganese sulphate monohydrate Zinc oxide Premix1 Celite2
27.97 40.00 1.00 1.75 1.50 0.25 0.02 0.01 0.20 1.30
Variable Components Oil3 Corn starch Cellulose
74.00
%
%
5.0 21.0
15.0
—
11.0
—
26.0 Total 26.0 Supplied per kilogram of ration: vitamin A, 4000 I.U.; vitamin D3, 400 I.C.U.; vitamin E, 20 I.U.; vitamin K, 2 nig.; riboflavin, 5 mg.; calcium pantothenate, 10 mg.; niacin, 20 mg.; choline chloride, 200 mg.; vitamin B12, 0.01 mg.; folic acid, 2 mg.; DL-methionine, 500 mg. 2 Index substance for the determination of digestibility. 3 The three oils used were: 1. Oil from the Oro variety of rapeseed (ORO). 2. As 1, but commercially hydrogenated (HORO). 3. Soybean oil (SBO). 1
seed oils to raise the vitamin E levels of same to that of the soybean oil. Duplicate groups of ten chicks were placed on each of the six experimental rations from day old to four weeks of age. Records were kept on body weight on a weekly basis. Fecal samples were collected at 24 hour intervals on days 21, 22 and 23 of the experiment. The fecal samples were dried daily at 110° C. for 24 hours. Feed and fecal samples were then digested with 4N HC1, washed free of acid, extracted with pentane and ashed at 650° C. for 12 hours to permit determi-
RESULTS Fatty Acid Content of the Rations. The total fatty acid contents and the percentages of the major individual fatty acids in the lipids present in the experimental rations are shown in Table 2. The linoleic acid concentration was high in the SBO-containing diets but the rations containing ORO or HORO were also fairly rich in linoleic acid. The ratio of saturated to monounsaturated fatty acids was highest in the diet containing 15% HORO (approximately 3). The highest level of erucic acid was found in the diet containing 15% ORO (3.2%). The content of total fatty acids was very similar in rations with the same level of added oil. The changes in the oleic acid contents of the rations with increasing levels of oil in the rations are explainable on the basis of the oleic acid composition of the oils which were 57.1, 73.1 and 27.0% for ORO, HORO and SBO, respectively. Thus, increasing the level of the oils in the rations from 5 to 10%
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
Total
nation of digestibility of total fatty acids and of fatty acid pattern in total fatty acids of feed and feces (McCarthy et al., 1974; Vogtmann et al., 1973a, b). At the end of the experiment all of the chickens were killed and heart, liver and spleen were removed. The tissues were freeze dried and extracted with chlorof orm-methanol (2:1) to remove lipids for subsequent fatty acid determinations by the method described by Vogtmann et al. (1973b). The data for digestibility, body weight and fatty acid composition of tissue lipids were analysed statistically by a multiway analysis of variance. Fats (n = 3) and levels (n = 2) were considered as fixed sources of variation. There were 2 replicates per treatment combination and 10 chicks per replicate. Statistical testing was conducted as outlined in Winer (1971). Comparison of treatment means was conducted by using Duncan's new multiple range test (Steel and Torrie, 1960).
2110
H . VOGTMANN AND D . R . C L A N D I N I N
TABLE 2.—Percentage acid composition and total fatty acid content of the experimental rations Rations 12
C 16:0 C 18:0 C 18:1 C 18:2 C 18:3 C 20:1 C 22:0 C 22:1 Others Total fatty acids
SBO
HORO
ORO Fatty acid 1
5%
15%
5%
15%
5%
15%
17.6 2.3 30.1 40.2 7.6 0.6 Tr. 0.3 1.3 6.7
13.4 2.1 37.0 34.3 8.1 1.7 0.6 3.2 0.6 16.3
17.5 3.2 37.2 36.0 4.4 0.4
13.2 3.7 50.4 27.4 3.1 0.6 0.1 0.4 0.9 16.4
19.2 3.3 15.7 54.7 6.8
16.4 3.4 17.7 54.8 7.5 Tr.
0.3 6.6
0.2 16.3
Tr.
0.1 1.1 6.7
Tr.3 — —
'Numbers before and after the colon represent the numbers of carbon atoms and double bonds, respectively. 2 See Table 1 for meaning of oil abbreviations. 3 Trace < 0.1%.
TABLE 3.—Body weight and apparent digestibility of total fatty acids
Oil 1 In ration Level, % ORO HORO SBO SE 3 Significance:
1 2
5 15 5 15 5 15
Oil Level Oil X level
Body weight, g./chicken
Apparent digestibility of total fatty acids, %
460 477 481 484 463 487
89.4 s2 94.2C 85.7" 90.2 a 90.9" 94.7C
12.58
3.55
NS 5 NS
**4
NS
NS
*#
See Table 1 for meaning of oilabbreviations. Values with a common letter are not significantly different. 'Standard error. 4 P < 0.01. 5 Non significant.
in the cases of ORO and HORO and no change in the case of SBO. Body Weight and Apparent Digestibility of Total Fatty Acids. Body weights and apparent digestibilities of total fatty acids are presented as means in Table 3. No significant treatment effects on 4 week body weights were observed. The apparent digestibility of total fatty acids increased when increasing amounts of oil were added to the diets. This increase was fairly similar in all groups. Feeding 5% or 15% HORO in the diets led to the lowest apparent digestibilities of total fatty acids with 85.7% or 90.2%, respectively. The apparent digestibilities for the total fatty acids in the diets containing the same level of ORO or SBO were not significantly different. Weight of Freeze Dried Tissues and Percentage of Total Lipids and Fatty Acids in Heart and Liver. Data on the average weights of freeze dried heart, liver and spleen are given in Table 4. No significant treatment effects occurred in the average weights of heart and liver. However, spleen weight decreased significantly (0.71 g. to 0.58 g.) when the level of ORO in the diet was increased from 5%
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
resulted in a greater increase in C18:l with HORO than with ORO or SBO. Similarly, the linoleic acid composition of the oils which were 21.1, 9.8 and 48.5% for ORO, HORO and SBO, respectively, resulted in decreases
2111
ORO OIL FOR BROILERS
TABLE 4.— Weights of freeze dried heart, liver, and spleen 1
Oil In rations ORO HORO SBO
Level, % 5 15 5 15 5 15
SE2 Significance:
Weight in grams Liver 11.47 13.22 12.83 12.92 11.39 12.68 0.54 NS NS NS
Spleen 0.71 0.58 0.75 0.69 0.76 0.89 0.06 *4
NS
*
TABLE 5.—Percentage total lipids and fatty acids in freeze dried heart and liver Oil*
Total lipids Fatty acids Heart Liver Heart Liver 22.0*2 10.3 17.3 23.2A 28.3A 10.7 17.0 a 20.9" 27.0 13.0 HORO 18.5 23.9* 11.9 29.4A 17.7 21.3b 11.0 25.5a SBO 18.5 10.4 22.2A 27.8A 17.6 3 SE 0.50 0.62 1.04 0.89 *4 **5 Significance: Oil NS6 NS Level NS NS ** ** Oil x level NS NS NS ** 1 See Table 1 for meaning of oil abbreviations. 2 Within an oil level precentages for total lipids or fatty acids with a common letter are not significantly different. 3 Standard error. 4 P s 0.05. 5 P<0.01. 6 Non significant. In rations ORO
Level, % 5 15 5 15 5 15
to 15%. The reverse was true for SBO, spleen weight increased from 0.76 g. to 0.89 g. when the oil level was increased from 5% to 15%. No significant difference in spleen weight was noted when diets containing 5% or 15% HORO were fed to the chickens. Percentage total lipids and fatty acids in freeze dried hearts and livers are presented as means in Table 5. No significant dif-
ferences in the total lipid and total fatty acid contents occurred in liver of chickens receiving the different oil containing diets. However, in heart tissue there were highly significant (P < 0.01) differences in the total lipid contents between the two levels of oils fed but within a level no significant differences occurred between the oils. On the overall average within an oil, chickens fed
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
Oil Level Oil x level 'See Table 1 for meaning of oil abbreviations. 2 Standard error. 3 Non significant. 4 P s 0.05.
Heart 2.59 2.95 2.65 2.57 2.49 2.65 0.08 NS3 NS NS
Fatty acids Heart 27.6 18.3 Saturated fatty acids 49.9 41.7 Monounsaturated fatty acids 46,7 37.5 —oleic acid 1.2 1.7 —gadoleic acid 0.2 0.2 —erucic acid 31.8 30.7 Polyunsaturated fatty acids 27.1 27.1 —linoleic acid type 4.7 3.6 —linolenic acid type Liver 35.2 43.7 Saturated fatty acids 28.7 30.5 Monounsaturated fatty acids 26.8 25.3 —oleic acid 1.3 0.8 —gadoleic acid 0.4 1.0 —erucic acid 36.0 25.8 Polyunsaturated fatty acids 23.6 32.8 —linoleic acid type 3.2 2.2 —linolenic acid type 1 See Table 1 for meaning of oil abbreviations. 2 Standard error. 3 P < 0.001. 4 P < 0.01. 5 P < 0.05. 6 Non significant.
ORO(' 15% 5% 2.85 7.97 7.49 0.28 0.01 5.79 5.20 0.92 3.97 8.70 8.30 0.17 0.13 5.19 4.92 0.34
24.2 30.3 28.4 0.5 50.5 46.0 4.5 36.6 15.1 13.5 0.5 0.3 48.5 45.3 3.2
36.3 33.9 29.3 0.7 0.2 29.8 28.4 1.4 43.1 21.5 18.8 0.4 0.5 35.5 33.3 2.2
16.5 65.8 62.5 1.6 0.1 17.7 17.2 0.5 24.0 52.2 49.0 0.9 Tr. 23.9 22.4 1.5
25.2 52.3 47.2 1.3 0.2 22.6 21.2 1.4 31.4 44.1 40.0 0.8 0.4 24.6 22.8 1.8
—
SE 2
15%
5%
HORO 1 15% 5% SBO I Oil S
TABLE 6.—Fatty acid composition of heart and liver lipids expressed as percen
ownloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
ORO OIL FOR BROILERS
the ORO-containing diets showed a significantly (P < 0.05) lower concentration of total lipids in the heart. The same held true for the fatty acid concentrations in heart tissue but, in addition, the content of fatty acids in the groups fed the 5% ORO-containing diets was significantly (P < 0.05) lower than in the other two groups receiving 5% HORO or 5% SBO in the diet.
DISCUSSION The apparent digestibilities of the total fatty acids of the oils fed were high and increased with increasing levels of oil in the diets (Table 3). Similar results were obtained in previous studies with laying hens (Vogtmann, 1971) and chickens (Vogtmann et al., 1973a). The results may be explained by taking into account the fact that on diets high in carbohydrates and low in fat (5% oil added) an extensive production of very low density lipoproteins (VLDL) takes place in the liver and therefore, a high concentration of VLDL is present in the blood stream where eventually 90% of the fatty acids absorbed have to enter into the portal system in the form of VLDL (Noyan et al., cited by Annison, 1971). For diets low in carbohydrates and high in fat (15% oil added) the reverse would be true, which means that the VLDL produced from the absorbed fatty acids could enter the blood stream against a lower concentration of VLDL and as a consequence the apparent digestibility would be higher. In addition, a change in bacterial flora of the gut, caused by varying levels of carbohydrates in the diet, could lead to changes in
the amount of bacterial fat excreted in the feces. This in turn, would tend to lower the apparent digestibility of fat on the high carbohydrate-low fat diet. Oro and SBO showed similar apparent digestibilities when added to the diets. The values agree well with those found in a previous experiment with chickens (Vogtmann et al., 1973a). The hydrogenation of ORO caused a decrease of approximately 4% in the apparent digestibility of this oil (HORO). From the gas chromatograms it was apparent that considerable amounts of trans -C18:1 fatty acids were present in the HORO. This could account for the reduction in the apparent digestibility of HORO. Since our GLC method does not permit a complete separation of cis- and trans- C 18:1 fatty acids the data in Table 2 includes all C 18:1 fatty acids. The increase in digestibility of total fatty acids, when the level of oil in the diets was increased from 5% to 15%, did not lead to any significant increase in the body weights of the chickens (Table 3). Heart and liver weights of the chickens were not influenced significantly by the dietary treatments. However spleen weight was significantly (P < 0.05) affected by the kind of oil being smallest for ORO. These results agree with the observations in a previous study (Vogtmann et al., 1973b). The percentages of total lipids and of total fatty acids in heart increased significantiy (P < 0.01) when the level of oil in the diets increased from 5% to 15% (Table 5). On the average, significant differences were also obtained, between oils for total lipids (P < 0.05) and total fatty acids (P < 0.01) in heart tissue. It would appear that feeding diets containing 5% ORO led to a lower content of fatty acids in heart tissue than feeding diets containing HORO and SBO. The results obtained from feeding ORO or SBO to chickens are in agreement with data reported previously (Vogtmann et al., 1973b). These
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
Fatty Acid Composition of Heart and Liver Lipids. The fatty acid compositions of heart and liver lipids are given as means for certain major fatty acids and fatty acid classes in Table 6. The main influence of the dietary fatty acids was an alteration of the fatty acid composition of heart and liver lipids as indicated in the above referred to table.
2113
2114
H . VOGTMANN AND D . R . CLANDININ
The incorporation of erucic acid (C 22:1) into heart and liver lipids was negligible as might be expected since low levels of this fatty acid were present in the diets. The occurrence of gadoleic acid (C 20:1) in the
tissues would indicate a partial degradation of C 22:1 to C 20:1 as demonstrated in rats by Craig and Beare (1967) and Morhauer et al. (1967). From the results of this study it can be concluded that the inclusion of 5% to 15% of low erucic acid rapeseed oils (ORO and HORO) in diets for broiler chickens was nutritionally as satisfactory as 5% or 15% SBO. The principal difference in the nutritional value of HORO as compared to ORO and SBO was a decreased apparent digestibility. No evidence was obtained which indicated that the balance of saturated to monounsaturated fatty acids in HORO influenced its nutritional value. ACKNOWLEDGMENTS The assistance of Mr. A. Pringle and Mr. J. Watson in the collection of the data and Mrs. M. Coull in the analytical determinations is greatly appreciated. The authors wish to acknowledge the assistance of Dr. R. T. Hardin, Associate Professor in Poultry Genetics, and Mr. R. Weingardt in connection with the statistical analyses of the data. REFERENCES Annison,E.F., 1971. In: Bell and Freeman, Physiology and Biochemistry of the Domestic Fowl. Academic Press, London. Craig, B. M., and J. L. Beare, 1967. The p-oxidative degradation of docosenoic acids to eicosenoic and octadecenoic acids in the rat. Can. J. Biochem. Physiol. 45: 1075-1079. Ivy, C. A., and M. C. Nesheim, 1973. Factors influencing the liver fat content of laying hens. Poultry Sci. 52: 281-291. McCarthy, J. F., F. X. Aherne and D. B. Okai, 1974. Use of HC1 insoluble ash as an index material for determining apparent digestibility with pigs. Can. J. Anim. Sci. 54: 107-109. Morhauer, H., J. J. Rahn, J. Seufert and R. T. Holman, 1967. Metabolism of linoleic acid in relation to dietary monoenoic acids in the rat. J. Nutr. 91: 521-527. Steel, R. G. D., and J. H. Torrie. 1960. Principles and Procedures of Statistics. McGraw-Hill Book Company, New York.
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
data clearly demonstrate that feeding diets containing 5% or 15% of low erucic acid rapeseed oils (ORO and HORO) does not increase the total lipid or total fatty acid contents of heart or liver tissue of chickens as compared to those receiving diets containing SBO. The fatty acid composition of heart and liver lipids was influenced markedly by the kind and the amount of oil included in the diets (Table 6). On the same treatment the liver showed higher concentrations of saturated and lower concentrations of monounsaturated fatty acids than heart. Whenever the level of saturated fatty acids decreased and that of monounsaturated fatty acids increased in the tissues, the concentration of polyunsaturated fatty acids tended to maintain at the same level or even decrease. On the other hand, decreases in the amounts of saturated and monounsaturated fatty acids in the tissue, led to increases in the concentrations of polyunsaturated fatty acids in heart and liver tissues. Those results suggest that in heart and liver tissues of chickens, a certain relationship exists between saturated, monounsaturated and polyunsaturated fatty acids. This is determined by the amount of structural fatty acids present in the tissues and by the melting point of the tissue lipids which has to be maintained in a physiological range. This implies that dietary fatty acids can alter the fatty acid composition of heart and liver lipids in chickens only within certain limits. If changes in the fatty acid composition of tissues occur beyond these limits one might expect to encounter metabolic disorders like the fatty-liver-syndrome in which the oleic acid level in the liver is elevated (Ivy and Nesheim, 1973).
2115
O R O O I L FOR BROILERS
Vogtmann, H., 1971. Der Einfluss von Art und Meng des Futterfettes auf die Verwertung von Canthaxanthin sowie der Vitamine A und E durch die Legehenne. Thesis no. 4549, ETHZ, Switzerland. Vogtmann, H., D. R. Clandinin and R. T. Hardin, 1973a. Utilization of rapeseed oils of high and low erucic acid contents. 1. Digestibility and energy utilization. Nutr. Metabol. 15: 252-266. Vogtmann, H., D. R. Clandinin and R. T. Hardin,
1973b. Utilization of rapeseed oils of high and low erucic acid contents. 2. Influence on tissues. Nutr. Metabol., submitted for publication. Vuilleumier, J. P., H. P. Probst und G. Brubacher, 1967. In Handbuch der Lebensmittelchemie Bd. II, 2. Teil, Vitamine, Provitamine und Carotinoide, p. 669-876. Winer, B. G., 1971. Statistical Principles in Experimental Design. McGraw-Hill, New York.
The Effect of Dietary Aflatoxin on Semen Characteristics of Mature Broiler Breeder Males1-23 University,
(Received for-publication March 1, 1974)
ABSTRACT Aflatoxin (20 p.p.m.) incorporated into the feed of mature broiler breeder males for four weeks caused clinical aflatoxicosis as evidence by a significant (P < 0.05) decrease in body weight. Neither spermatozoa counts nor semen volume were altered significantly by the dietary aflatoxin. Chemical analyses of the semen for deoxyribonucleic acidfDNA), ribonucleic acid (RNA), and protein content revealed no significant alterations in these parameters associated with the treatment. Product moment correlations showed significant (P < 0.01) correlations between sperm count, DNA, RNA, and protein but not between these parameters and semen volume. It seems reasonable to conclude that aflatoxin does not affect significantly the semen characteristics of mature broiler breeder males. The refractoriness of sperm and associated nucleic acid and protein synthesis to aflatoxin would appear to be a divergence from the generally accepted mode of action based on the general inhibition of RNA polymerase. POULTRY SCIENCE 53: 2115-2119, 1974
INTRODUCTION
A
FLATOXIN is a mycotoxin produced in feedstuffs by the flavus-parasiticus group of the genus Aspergillus. It has been demonstrated to cause increased condemnations, poor feed conversion, decreased growth rate, and increased mortality in broiler 'Paper Number 4273 of the Journal Series of North Carolina State University Agriculture Experiment Station, Raleigh, North Carolina. 2 A preliminary report of part of this paper was given at the 52nd Annual Meeting of the Poultry Science Association, Brookings, South Dakota, August, 1973. 3 The use of trade names in this publication does not imply endorsement by the North Carolina Experiment Station of the product named, nor criticism of similar ones not mentioned.
chickens (Smith and Hamilton, 1970). An increased susceptibility to bruising (Tung et al., 1971), interference with lipid metabolism (Tung et al, 1972a; Donaldson et al., 1972) and interactions with infectious agents and other stresses (Hamilton and Harris, 1971) are further examples of how aflatoxin causes severe economic losses to the broiler industry. The primary manifestation of aflatoxicosis in the adult female chicken is a condition apparently identical to fatty liver syndrome (Hamilton and Garlich, 1971, 1972) in which aflatoxin causes a dose-related decrease in egg production. The effect of aflatoxin in the mature male has received little attention, except for a general survey of the physiolo-
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
D . M . BRIGGS, R. D . W Y A T T AND P . B . HAMILTON
Department of Poultry Science and Department of Microbiology, North Carolina State Raleigh, North Carolina 27607
Department of Animal Science, University of Alberta, Edmonton, Alberta,
Canada
(Received for publication February 27, 1974)
POULTRY SCIENCE 53: 2108-2115, 1974
INTRODUCTION N previous studies (Vogtmann et al., 1973a, b) it was shown that inclusions of 5%, 10%, or 15% of low erucic acid rapeseed oil, originating from the Oro variety of rapeseed, in diets for broiler chickens was nutri-tionally as satisfactory as soybean oil or lard when the diets were fed to broiler chickens from one day old to four weeks of age. The objective of this study was to determine if and to what extent the commercial hydrogenation of Oro oil would change its nutritional properties.
I
MATERIALS AND METHODS One hundred and twenty female crossbred (Dominant White male x White Plymouth Rock female) chicks were divided into 12 1. Supported in part by grants from the National Research Council of Canada, the Alberta Agricultural Research Trust and the Rapeseed Association of Canada.
comparable groups of 10 chicks each. The chicks were housed in electrically heated, thermostatically controlled battery brooders with raised wire screen floors, in a well ventilated, temperature controlled brooding room. Electric light was provided on a continuous basis. Feed and water were provided ad libitum. Six rations were formulated to incorporate two low erucic acid rapeseed oils and one soybean oil at 5% and 15% levels in chick starter rations calculated to contain 23.2% protein and 3200 kcal. M.E./kg. ration. The formulae of the rations used are given in Table 1. The oils used in this study were of refined edible quality. No antioxidant was added during their production. The vitamin E contents of the oils were determined by the method of Vuilleumier et al. (1967) and DLa-tocopherolacetate* was added to the rape*DL-a-tocopherolacetate was supplied by F. Hoffmann La Roche & Co., A.G., Basel, Switzerland.
2108
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
ABSTRACT The effects of feeding broiler-type chickens rations containing 5% or 15% of a low erucic acid rapeseed oil prepared commercially from the Oro variety of rapeseed (ORO), a commercially hydrogenated Oro oil (HORO) and soybean oil (SBO) on body weight, apparent digestibility of total fatty acids, weights of heart, liver and spleen, total lipid and total fatty acid content of heart and liver and fatty acid composition of heart and liver lipids were studied. The experimental diets were fed ad libitum to the chickens from day old to four weeks of age. Body weight and weights of heart and liver were not influenced significantly by the dietary treatments. Spleen weight was smallest in the group fed the 15% ORO—containing diets. The apparent digestibilities of total fatty acids were similar for ORO and SBO (89.4% and 94.2% for 5% and 15% ORO; 90.9% and 94.7% for 5% and 15% SBO), however they were lower for HORO (85.7% and 90.2% for 5% and 15% HORO). Total lipid and total fatty acid contents of liver were not influenced significantly by the different dietary treatments. Feeding 5% ORO in the diet decreased the content of total fatty acids in heart as compared to feeding 5% HORO or 5% SBO in the diet. The fatty acid composition of heart and liver lipids was influenced by the fatty acid content of the diets. Only small amounts of erucic acid were found in the tissues of the birds fed diets containing ORO or HORO. The inclusion of 5% or 15% of low erucic acid rapeseed oils (ORO and HORO) in diets for broiler chickens proved nutritionally as satisfactory as the inclusion of SBO.
2109
ORO OIL FOR BROILERS
TABLE 1.—Composition of experimental rations
%
Constant components Ground wheat Soybean meal (48.5% protein) Dehydrated alfalfa meal Ground limestone Dicalcium phosphate Iodized salt Manganese sulphate monohydrate Zinc oxide Premix1 Celite2
27.97 40.00 1.00 1.75 1.50 0.25 0.02 0.01 0.20 1.30
Variable Components Oil3 Corn starch Cellulose
74.00
%
%
5.0 21.0
15.0
—
11.0
—
26.0 Total 26.0 Supplied per kilogram of ration: vitamin A, 4000 I.U.; vitamin D3, 400 I.C.U.; vitamin E, 20 I.U.; vitamin K, 2 nig.; riboflavin, 5 mg.; calcium pantothenate, 10 mg.; niacin, 20 mg.; choline chloride, 200 mg.; vitamin B12, 0.01 mg.; folic acid, 2 mg.; DL-methionine, 500 mg. 2 Index substance for the determination of digestibility. 3 The three oils used were: 1. Oil from the Oro variety of rapeseed (ORO). 2. As 1, but commercially hydrogenated (HORO). 3. Soybean oil (SBO). 1
seed oils to raise the vitamin E levels of same to that of the soybean oil. Duplicate groups of ten chicks were placed on each of the six experimental rations from day old to four weeks of age. Records were kept on body weight on a weekly basis. Fecal samples were collected at 24 hour intervals on days 21, 22 and 23 of the experiment. The fecal samples were dried daily at 110° C. for 24 hours. Feed and fecal samples were then digested with 4N HC1, washed free of acid, extracted with pentane and ashed at 650° C. for 12 hours to permit determi-
RESULTS Fatty Acid Content of the Rations. The total fatty acid contents and the percentages of the major individual fatty acids in the lipids present in the experimental rations are shown in Table 2. The linoleic acid concentration was high in the SBO-containing diets but the rations containing ORO or HORO were also fairly rich in linoleic acid. The ratio of saturated to monounsaturated fatty acids was highest in the diet containing 15% HORO (approximately 3). The highest level of erucic acid was found in the diet containing 15% ORO (3.2%). The content of total fatty acids was very similar in rations with the same level of added oil. The changes in the oleic acid contents of the rations with increasing levels of oil in the rations are explainable on the basis of the oleic acid composition of the oils which were 57.1, 73.1 and 27.0% for ORO, HORO and SBO, respectively. Thus, increasing the level of the oils in the rations from 5 to 10%
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
Total
nation of digestibility of total fatty acids and of fatty acid pattern in total fatty acids of feed and feces (McCarthy et al., 1974; Vogtmann et al., 1973a, b). At the end of the experiment all of the chickens were killed and heart, liver and spleen were removed. The tissues were freeze dried and extracted with chlorof orm-methanol (2:1) to remove lipids for subsequent fatty acid determinations by the method described by Vogtmann et al. (1973b). The data for digestibility, body weight and fatty acid composition of tissue lipids were analysed statistically by a multiway analysis of variance. Fats (n = 3) and levels (n = 2) were considered as fixed sources of variation. There were 2 replicates per treatment combination and 10 chicks per replicate. Statistical testing was conducted as outlined in Winer (1971). Comparison of treatment means was conducted by using Duncan's new multiple range test (Steel and Torrie, 1960).
2110
H . VOGTMANN AND D . R . C L A N D I N I N
TABLE 2.—Percentage acid composition and total fatty acid content of the experimental rations Rations 12
C 16:0 C 18:0 C 18:1 C 18:2 C 18:3 C 20:1 C 22:0 C 22:1 Others Total fatty acids
SBO
HORO
ORO Fatty acid 1
5%
15%
5%
15%
5%
15%
17.6 2.3 30.1 40.2 7.6 0.6 Tr. 0.3 1.3 6.7
13.4 2.1 37.0 34.3 8.1 1.7 0.6 3.2 0.6 16.3
17.5 3.2 37.2 36.0 4.4 0.4
13.2 3.7 50.4 27.4 3.1 0.6 0.1 0.4 0.9 16.4
19.2 3.3 15.7 54.7 6.8
16.4 3.4 17.7 54.8 7.5 Tr.
0.3 6.6
0.2 16.3
Tr.
0.1 1.1 6.7
Tr.3 — —
'Numbers before and after the colon represent the numbers of carbon atoms and double bonds, respectively. 2 See Table 1 for meaning of oil abbreviations. 3 Trace < 0.1%.
TABLE 3.—Body weight and apparent digestibility of total fatty acids
Oil 1 In ration Level, % ORO HORO SBO SE 3 Significance:
1 2
5 15 5 15 5 15
Oil Level Oil X level
Body weight, g./chicken
Apparent digestibility of total fatty acids, %
460 477 481 484 463 487
89.4 s2 94.2C 85.7" 90.2 a 90.9" 94.7C
12.58
3.55
NS 5 NS
**4
NS
NS
*#
See Table 1 for meaning of oilabbreviations. Values with a common letter are not significantly different. 'Standard error. 4 P < 0.01. 5 Non significant.
in the cases of ORO and HORO and no change in the case of SBO. Body Weight and Apparent Digestibility of Total Fatty Acids. Body weights and apparent digestibilities of total fatty acids are presented as means in Table 3. No significant treatment effects on 4 week body weights were observed. The apparent digestibility of total fatty acids increased when increasing amounts of oil were added to the diets. This increase was fairly similar in all groups. Feeding 5% or 15% HORO in the diets led to the lowest apparent digestibilities of total fatty acids with 85.7% or 90.2%, respectively. The apparent digestibilities for the total fatty acids in the diets containing the same level of ORO or SBO were not significantly different. Weight of Freeze Dried Tissues and Percentage of Total Lipids and Fatty Acids in Heart and Liver. Data on the average weights of freeze dried heart, liver and spleen are given in Table 4. No significant treatment effects occurred in the average weights of heart and liver. However, spleen weight decreased significantly (0.71 g. to 0.58 g.) when the level of ORO in the diet was increased from 5%
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
resulted in a greater increase in C18:l with HORO than with ORO or SBO. Similarly, the linoleic acid composition of the oils which were 21.1, 9.8 and 48.5% for ORO, HORO and SBO, respectively, resulted in decreases
2111
ORO OIL FOR BROILERS
TABLE 4.— Weights of freeze dried heart, liver, and spleen 1
Oil In rations ORO HORO SBO
Level, % 5 15 5 15 5 15
SE2 Significance:
Weight in grams Liver 11.47 13.22 12.83 12.92 11.39 12.68 0.54 NS NS NS
Spleen 0.71 0.58 0.75 0.69 0.76 0.89 0.06 *4
NS
*
TABLE 5.—Percentage total lipids and fatty acids in freeze dried heart and liver Oil*
Total lipids Fatty acids Heart Liver Heart Liver 22.0*2 10.3 17.3 23.2A 28.3A 10.7 17.0 a 20.9" 27.0 13.0 HORO 18.5 23.9* 11.9 29.4A 17.7 21.3b 11.0 25.5a SBO 18.5 10.4 22.2A 27.8A 17.6 3 SE 0.50 0.62 1.04 0.89 *4 **5 Significance: Oil NS6 NS Level NS NS ** ** Oil x level NS NS NS ** 1 See Table 1 for meaning of oil abbreviations. 2 Within an oil level precentages for total lipids or fatty acids with a common letter are not significantly different. 3 Standard error. 4 P s 0.05. 5 P<0.01. 6 Non significant. In rations ORO
Level, % 5 15 5 15 5 15
to 15%. The reverse was true for SBO, spleen weight increased from 0.76 g. to 0.89 g. when the oil level was increased from 5% to 15%. No significant difference in spleen weight was noted when diets containing 5% or 15% HORO were fed to the chickens. Percentage total lipids and fatty acids in freeze dried hearts and livers are presented as means in Table 5. No significant dif-
ferences in the total lipid and total fatty acid contents occurred in liver of chickens receiving the different oil containing diets. However, in heart tissue there were highly significant (P < 0.01) differences in the total lipid contents between the two levels of oils fed but within a level no significant differences occurred between the oils. On the overall average within an oil, chickens fed
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
Oil Level Oil x level 'See Table 1 for meaning of oil abbreviations. 2 Standard error. 3 Non significant. 4 P s 0.05.
Heart 2.59 2.95 2.65 2.57 2.49 2.65 0.08 NS3 NS NS
Fatty acids Heart 27.6 18.3 Saturated fatty acids 49.9 41.7 Monounsaturated fatty acids 46,7 37.5 —oleic acid 1.2 1.7 —gadoleic acid 0.2 0.2 —erucic acid 31.8 30.7 Polyunsaturated fatty acids 27.1 27.1 —linoleic acid type 4.7 3.6 —linolenic acid type Liver 35.2 43.7 Saturated fatty acids 28.7 30.5 Monounsaturated fatty acids 26.8 25.3 —oleic acid 1.3 0.8 —gadoleic acid 0.4 1.0 —erucic acid 36.0 25.8 Polyunsaturated fatty acids 23.6 32.8 —linoleic acid type 3.2 2.2 —linolenic acid type 1 See Table 1 for meaning of oil abbreviations. 2 Standard error. 3 P < 0.001. 4 P < 0.01. 5 P < 0.05. 6 Non significant.
ORO(' 15% 5% 2.85 7.97 7.49 0.28 0.01 5.79 5.20 0.92 3.97 8.70 8.30 0.17 0.13 5.19 4.92 0.34
24.2 30.3 28.4 0.5 50.5 46.0 4.5 36.6 15.1 13.5 0.5 0.3 48.5 45.3 3.2
36.3 33.9 29.3 0.7 0.2 29.8 28.4 1.4 43.1 21.5 18.8 0.4 0.5 35.5 33.3 2.2
16.5 65.8 62.5 1.6 0.1 17.7 17.2 0.5 24.0 52.2 49.0 0.9 Tr. 23.9 22.4 1.5
25.2 52.3 47.2 1.3 0.2 22.6 21.2 1.4 31.4 44.1 40.0 0.8 0.4 24.6 22.8 1.8
—
SE 2
15%
5%
HORO 1 15% 5% SBO I Oil S
TABLE 6.—Fatty acid composition of heart and liver lipids expressed as percen
ownloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
ORO OIL FOR BROILERS
the ORO-containing diets showed a significantly (P < 0.05) lower concentration of total lipids in the heart. The same held true for the fatty acid concentrations in heart tissue but, in addition, the content of fatty acids in the groups fed the 5% ORO-containing diets was significantly (P < 0.05) lower than in the other two groups receiving 5% HORO or 5% SBO in the diet.
DISCUSSION The apparent digestibilities of the total fatty acids of the oils fed were high and increased with increasing levels of oil in the diets (Table 3). Similar results were obtained in previous studies with laying hens (Vogtmann, 1971) and chickens (Vogtmann et al., 1973a). The results may be explained by taking into account the fact that on diets high in carbohydrates and low in fat (5% oil added) an extensive production of very low density lipoproteins (VLDL) takes place in the liver and therefore, a high concentration of VLDL is present in the blood stream where eventually 90% of the fatty acids absorbed have to enter into the portal system in the form of VLDL (Noyan et al., cited by Annison, 1971). For diets low in carbohydrates and high in fat (15% oil added) the reverse would be true, which means that the VLDL produced from the absorbed fatty acids could enter the blood stream against a lower concentration of VLDL and as a consequence the apparent digestibility would be higher. In addition, a change in bacterial flora of the gut, caused by varying levels of carbohydrates in the diet, could lead to changes in
the amount of bacterial fat excreted in the feces. This in turn, would tend to lower the apparent digestibility of fat on the high carbohydrate-low fat diet. Oro and SBO showed similar apparent digestibilities when added to the diets. The values agree well with those found in a previous experiment with chickens (Vogtmann et al., 1973a). The hydrogenation of ORO caused a decrease of approximately 4% in the apparent digestibility of this oil (HORO). From the gas chromatograms it was apparent that considerable amounts of trans -C18:1 fatty acids were present in the HORO. This could account for the reduction in the apparent digestibility of HORO. Since our GLC method does not permit a complete separation of cis- and trans- C 18:1 fatty acids the data in Table 2 includes all C 18:1 fatty acids. The increase in digestibility of total fatty acids, when the level of oil in the diets was increased from 5% to 15%, did not lead to any significant increase in the body weights of the chickens (Table 3). Heart and liver weights of the chickens were not influenced significantly by the dietary treatments. However spleen weight was significantly (P < 0.05) affected by the kind of oil being smallest for ORO. These results agree with the observations in a previous study (Vogtmann et al., 1973b). The percentages of total lipids and of total fatty acids in heart increased significantiy (P < 0.01) when the level of oil in the diets increased from 5% to 15% (Table 5). On the average, significant differences were also obtained, between oils for total lipids (P < 0.05) and total fatty acids (P < 0.01) in heart tissue. It would appear that feeding diets containing 5% ORO led to a lower content of fatty acids in heart tissue than feeding diets containing HORO and SBO. The results obtained from feeding ORO or SBO to chickens are in agreement with data reported previously (Vogtmann et al., 1973b). These
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
Fatty Acid Composition of Heart and Liver Lipids. The fatty acid compositions of heart and liver lipids are given as means for certain major fatty acids and fatty acid classes in Table 6. The main influence of the dietary fatty acids was an alteration of the fatty acid composition of heart and liver lipids as indicated in the above referred to table.
2113
2114
H . VOGTMANN AND D . R . CLANDININ
The incorporation of erucic acid (C 22:1) into heart and liver lipids was negligible as might be expected since low levels of this fatty acid were present in the diets. The occurrence of gadoleic acid (C 20:1) in the
tissues would indicate a partial degradation of C 22:1 to C 20:1 as demonstrated in rats by Craig and Beare (1967) and Morhauer et al. (1967). From the results of this study it can be concluded that the inclusion of 5% to 15% of low erucic acid rapeseed oils (ORO and HORO) in diets for broiler chickens was nutritionally as satisfactory as 5% or 15% SBO. The principal difference in the nutritional value of HORO as compared to ORO and SBO was a decreased apparent digestibility. No evidence was obtained which indicated that the balance of saturated to monounsaturated fatty acids in HORO influenced its nutritional value. ACKNOWLEDGMENTS The assistance of Mr. A. Pringle and Mr. J. Watson in the collection of the data and Mrs. M. Coull in the analytical determinations is greatly appreciated. The authors wish to acknowledge the assistance of Dr. R. T. Hardin, Associate Professor in Poultry Genetics, and Mr. R. Weingardt in connection with the statistical analyses of the data. REFERENCES Annison,E.F., 1971. In: Bell and Freeman, Physiology and Biochemistry of the Domestic Fowl. Academic Press, London. Craig, B. M., and J. L. Beare, 1967. The p-oxidative degradation of docosenoic acids to eicosenoic and octadecenoic acids in the rat. Can. J. Biochem. Physiol. 45: 1075-1079. Ivy, C. A., and M. C. Nesheim, 1973. Factors influencing the liver fat content of laying hens. Poultry Sci. 52: 281-291. McCarthy, J. F., F. X. Aherne and D. B. Okai, 1974. Use of HC1 insoluble ash as an index material for determining apparent digestibility with pigs. Can. J. Anim. Sci. 54: 107-109. Morhauer, H., J. J. Rahn, J. Seufert and R. T. Holman, 1967. Metabolism of linoleic acid in relation to dietary monoenoic acids in the rat. J. Nutr. 91: 521-527. Steel, R. G. D., and J. H. Torrie. 1960. Principles and Procedures of Statistics. McGraw-Hill Book Company, New York.
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
data clearly demonstrate that feeding diets containing 5% or 15% of low erucic acid rapeseed oils (ORO and HORO) does not increase the total lipid or total fatty acid contents of heart or liver tissue of chickens as compared to those receiving diets containing SBO. The fatty acid composition of heart and liver lipids was influenced markedly by the kind and the amount of oil included in the diets (Table 6). On the same treatment the liver showed higher concentrations of saturated and lower concentrations of monounsaturated fatty acids than heart. Whenever the level of saturated fatty acids decreased and that of monounsaturated fatty acids increased in the tissues, the concentration of polyunsaturated fatty acids tended to maintain at the same level or even decrease. On the other hand, decreases in the amounts of saturated and monounsaturated fatty acids in the tissue, led to increases in the concentrations of polyunsaturated fatty acids in heart and liver tissues. Those results suggest that in heart and liver tissues of chickens, a certain relationship exists between saturated, monounsaturated and polyunsaturated fatty acids. This is determined by the amount of structural fatty acids present in the tissues and by the melting point of the tissue lipids which has to be maintained in a physiological range. This implies that dietary fatty acids can alter the fatty acid composition of heart and liver lipids in chickens only within certain limits. If changes in the fatty acid composition of tissues occur beyond these limits one might expect to encounter metabolic disorders like the fatty-liver-syndrome in which the oleic acid level in the liver is elevated (Ivy and Nesheim, 1973).
2115
O R O O I L FOR BROILERS
Vogtmann, H., 1971. Der Einfluss von Art und Meng des Futterfettes auf die Verwertung von Canthaxanthin sowie der Vitamine A und E durch die Legehenne. Thesis no. 4549, ETHZ, Switzerland. Vogtmann, H., D. R. Clandinin and R. T. Hardin, 1973a. Utilization of rapeseed oils of high and low erucic acid contents. 1. Digestibility and energy utilization. Nutr. Metabol. 15: 252-266. Vogtmann, H., D. R. Clandinin and R. T. Hardin,
1973b. Utilization of rapeseed oils of high and low erucic acid contents. 2. Influence on tissues. Nutr. Metabol., submitted for publication. Vuilleumier, J. P., H. P. Probst und G. Brubacher, 1967. In Handbuch der Lebensmittelchemie Bd. II, 2. Teil, Vitamine, Provitamine und Carotinoide, p. 669-876. Winer, B. G., 1971. Statistical Principles in Experimental Design. McGraw-Hill, New York.
The Effect of Dietary Aflatoxin on Semen Characteristics of Mature Broiler Breeder Males1-23 University,
(Received for-publication March 1, 1974)
ABSTRACT Aflatoxin (20 p.p.m.) incorporated into the feed of mature broiler breeder males for four weeks caused clinical aflatoxicosis as evidence by a significant (P < 0.05) decrease in body weight. Neither spermatozoa counts nor semen volume were altered significantly by the dietary aflatoxin. Chemical analyses of the semen for deoxyribonucleic acidfDNA), ribonucleic acid (RNA), and protein content revealed no significant alterations in these parameters associated with the treatment. Product moment correlations showed significant (P < 0.01) correlations between sperm count, DNA, RNA, and protein but not between these parameters and semen volume. It seems reasonable to conclude that aflatoxin does not affect significantly the semen characteristics of mature broiler breeder males. The refractoriness of sperm and associated nucleic acid and protein synthesis to aflatoxin would appear to be a divergence from the generally accepted mode of action based on the general inhibition of RNA polymerase. POULTRY SCIENCE 53: 2115-2119, 1974
INTRODUCTION
A
FLATOXIN is a mycotoxin produced in feedstuffs by the flavus-parasiticus group of the genus Aspergillus. It has been demonstrated to cause increased condemnations, poor feed conversion, decreased growth rate, and increased mortality in broiler 'Paper Number 4273 of the Journal Series of North Carolina State University Agriculture Experiment Station, Raleigh, North Carolina. 2 A preliminary report of part of this paper was given at the 52nd Annual Meeting of the Poultry Science Association, Brookings, South Dakota, August, 1973. 3 The use of trade names in this publication does not imply endorsement by the North Carolina Experiment Station of the product named, nor criticism of similar ones not mentioned.
chickens (Smith and Hamilton, 1970). An increased susceptibility to bruising (Tung et al., 1971), interference with lipid metabolism (Tung et al, 1972a; Donaldson et al., 1972) and interactions with infectious agents and other stresses (Hamilton and Harris, 1971) are further examples of how aflatoxin causes severe economic losses to the broiler industry. The primary manifestation of aflatoxicosis in the adult female chicken is a condition apparently identical to fatty liver syndrome (Hamilton and Garlich, 1971, 1972) in which aflatoxin causes a dose-related decrease in egg production. The effect of aflatoxin in the mature male has received little attention, except for a general survey of the physiolo-
Downloaded from http://ps.oxfordjournals.org/ by guest on May 31, 2015
D . M . BRIGGS, R. D . W Y A T T AND P . B . HAMILTON
Department of Poultry Science and Department of Microbiology, North Carolina State Raleigh, North Carolina 27607