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Sunflower Seed in Laying Hen Rations1
METABOLISM AND NUTRITION Sunflower Seed in Laying Hen Rations1 M. G. UWAYJAN, E. J. AZAR, and N. J. DAGHIR Department of Animal Sciences, American University of Beirut, Lebanon (Received for publication August 6, 1981) ABSTRACT Unprocessed whole sunflower seed was evaluated as a partial replacement for soybean meal (SBM) and yellow corn in rations for Single Comb White Leghorn hens. Two experiments were conducted in floor pens using four pens of 25 birds per pen in the first experiment and 32 in the second per treatment. The criteria studied in both experiments were egg production, egg weight, feed consumption, feed conversion, and body weight change. In addition, Experiment 2 included various egg quality studies. In Experiment 1, 10, 20, and 30% of sunflower seed replaced 15, 30, and 45% of the SBM and 9.5, 19, and 28.6% of the corn in the ration. Results of Experiment 1 showed that none of these treatments had any adverse effect on hen performance. Experiment 2 was conducted to investigate if the highest level of sunflower used, supplemented with . 1 % lysine or with . 1 % lysine plus .01% methionine, improved hen performance and egg quality. Results of Experiment 2 showed that lysine or lysine plus methionine supplementation did not improve hen performance. Rations containing sunflower meal gave a significantly lower yolk color score and a significant rise in yolk cholesterol content (P<.01). (Key words: sunflower seed, laying hens, methionine, lysine, egg quality) 1983 Poultry Science 62:1247-1253
INTRODUCTION
Sunflowers are a highly adaptable plant to many parts of Lebanon. They have been recently introduced as a substitute for certain cash crops in some areas of the country. Although the present production remains too low to warrant oil extraction on a commercial scale, enough of the seed is being annually produced to justify investigating the possibility of its use in poultry rations. Almost all the work on sunflowers in poultry rations has been done with the meal. A number of studies have been conducted to determine the nutritional value of sunflower seed meal (SSM) in poultry rations. We have recently reviewed (Daghir et al., 1980) work on the use of this meal for growing chickens. Few studies have dealt with the value of SSM for laying hens. Pettit et al. (1944) observed satisfactory laying hen performance when a low level (6%) of sunflower seed meal was used in mash-grain rations. Also using mash-grain rations, Hale and Brown (1957) concluded that sunflower seed meal was satis-
1 Contribution from the Faculty of Agricultural and Food Sciences, American University of Beirut, as Journal No. 564B.
factory for egg production, but they realized that rations high in sunflower seed meal were also high in fiber and low in energy. In all-mash rations for laying hens, Walter et al. (1959) completely replaced meat meal or soybean meal with sunflower meal. They observed no influence on egg production, egg weight, or maintenance of body weight when those diets included 2.0 or 2.5% fish meal. However, feed consumption seemed to be increased when the diets contained 9.5 or 13% sunflower seed meal. Trying to evaluate SSM obtained from two different processing methods as a protein replacement for soybean meal in rations for laying hens, Rose et al. (1972) reported that 50% replacement of the soybean protein by SSM protein did not adversely affect hen performance. However, 100% replacement of SBM protein with SSM resulted in decreased egg production and feed efficiency. The same authors also observed that although the two SSM's generally produced similar effects, the SSM of highest fiber content resulted in increased feed consumption only at the 100% replacement level in mash rations, and lysine supplementation did not consistently improve utilization of the diets used. Sunflower seed contains a widely variable oil content (25 to 32%) depending on variety, soil, and climatic conditions (Vaughan, 1970).
1247
1248
UWAYJAN ET AL.
The protein content of the unhulled seed is about 16%. Its crude fiber content varies from as low as 13% to as high as 28%, depending on the variety and the extent to which the seed was cleaned prior to its analysis. Because of the increased need to utilize unprocessed sunflower crops, justified by the scarcity of both energy and protein sources in Lebanon, the present study was initiated to evaluate whole sunflower seed as a partial replacement of soybean meal and corn in laying hen rations. Also, part of the objective was to establish the highest possible replacement level within the physical and nutritional limitations of the seed and to attempt improving the feeding value of such rations by methionine and/or lysine supplementation.
MATERIALS AND METHODS
Two experiments were conducted for seven and eight 28-day periods between November 1978 and July 1980. In both experiments, commercial Single Comb White Leghorn pullets of the Shaver strain were housed in floor pens at the rate of 25 birds per pen for the first experiment and 32 birds per pen for the second study and were provided with 14 hr of light daily. The first experiment was initiated during November when the birds were 42 weeks of age whereas the second experiment was initiated during December of the following year when the birds were 28 weeks of age. Egg production and mortality data were recorded daily for each pen whereas feed consumption for each pen was determined at the end of each 28-day period. Feed and water were provided ad libitum in both experiments. The criteria of response were egg production, feed consumption, feed efficiency, egg weight, and average body weight change. All forementioned criteria except body weight change were summarized at 28-day intervals. In addition, the second experiment included various egg quality measurements such as shell thickness, albumen quality, yolk color, and egg yolk cholesterol. Data on egg weight were collected during the last 3 days of every 28-day period in both experiments. Data on egg quality studies in the second experiment were collected in a manner similar to that in the first experiment except that eggs for the cholesterol study were collected at the end of every other period. All eggs collected from each pen during the 3-day collection period were pooled together, and aver-
age egg weight was recorded for every pen. Eggs for egg yolk cholesterol determination were collected randomly, 3 eggs from each pen daily, in the same manner and were hard boiled for 12 min. The yolks were then separated from their whites, pooled, sealed in plastic bags, and frozen at —20 C until analyzed. Yolk cholesterol determinations were made using the method employed by Harris and Wilcox (1963). Albumen and shell thickness were measured by an Ames Albumen Thickness Measure Gauge Model S-6428 and Ames Paper Thickness Measure Model 25, respectively. Egg yolk color was scored using the Hoffman La Roche yolk color fan. In both experiments, average hen weights for birds in each pen were taken at the start of the experiment and when the experiment was terminated. All data were subjected to standard analysis of variance according to Snedecor and Cochran (1967). Duncan's (1955) multiple range test was applied when treatment effects were found to be significant. Sunflower seed grown in Lebanon was obtained from the local market and was used in both experiments in its crude state without cleaning. It had about 10.4% impurities, which came mainly from the head and stem of the
TABLE 1. Composition of sunflower seed used Composition Moisture Crude protein Ether extract Crude fiber Nitrogen free extract Ash Calcium Phosphorus (total) Methionine 1 Methionine and cystine 1 Lysine1 Metabolizable energy, kcal/kg2 Linoleic acid3
(%) 6.81 15.80 16.73 14.20 43.03 3.43 .50 .35 .25 .50 .59 3882 9.7
1 Methionine, sulfur amino acids, and lysine were calculated on the basis of protein content with reference to dehulled sunflower meal (45.4%) as reported in National Research Council (1977) feed composition tables. 2 Calculated from chemical composition using the equation of Carpenter and Clegg (1956). 3 Calculated from oil content of sunflower seed as reported by Scott et al. (1976).
SUNFLOWER SEED FOR LAYERS sunflower plant. The composition of the seed in its crude form (Table 1) does not differ greatly from the clean seed, which normally contains an average of 5.9% moisture, 17.5% oil, 14.8% crude fiber, and 16.5% crude protein. Experiment 1. Four hundred hens were randomly distributed among four ration treatments with four replicates of 25 hens per treatment. Levels of 10, 20, and 30% sunflower seed replaced 15, 30, and 45% of the total SBM and 9.5, 19, and 28.6% of the corn in a practical, corn-soybean basal diet (Table 2). The rations for this experiment were formulated to be within 1% difference in protein content and a maximum difference of 75 kcal metabolizable energy (ME)/kg. The sunflower seed was ground, mixed with the other ration ingredients, and fed in mash form. Experiment 2. To investigate if the highest level of replacement of sunflower seed used in the first experiment could be improved by supplementation with . 1 % lysine or with . 1 % lysine plus .01% methionine, we conducted Experiment 2. Supplemental amino acid levels were chosen to equalize the experimental diets in those amino acids with that of the control. The study involved 512 hens distributed among four ration treatments with four replications of 32
1249
hens per treatment. The rations for Experiment 2 (Table 3) were similar to those in Experiment 1 and were fed in mash form.
RESULTS AND DISCUSSION
The sunflower seed used in both experiments was of the low oil variety. Values for crude protein and ash (Table 1) are similar to those reported by Titus and Fritz (1971), whereas ether extract, crude fiber, and phosphorus values are considerably lower. The calcium value, however, was a little higher and this may be due to the calcareous soil of the area in which the seed was grown. The lower phosphorus value may be also explained by the soil as well as the climatic conditions as suggested by Vaughan (1970). The difference in the crude fiber content is not explained by the rather thorough cleaning of the seeds as suggested by Daghir et al. (1980), because the analysis reported herein, performed on both crude and cleaned seeds, did not account for such a difference. However, it may be interpreted as a possible varietal difference. Experiment 1. The results of this experiment are summarized on the basis of the replacement level of sunflower seed used (Table
TABLE 2. Composition of diets used in Experiment 1 Diets (%) Ingredients Ground yellow corn Soybean meal (44%) Sunflower seed Soybean oil Constant ingredients1 Calculated analysis ME, kcal/kg Protein, % Ca, % P (total), % Methionine, % Lysine, % Linoleic acid, %
IV
I
II
III
63.00 20.00
51.00 14.00 20.00 1.00 14.00
45.00 11.00 30.00
3.00 14.00
57.00 17.00 10.00 2.00 14.00
2997 16.42 3.30 .70 .29 .90 2.87
3030 16.00 3.32 .74 .28 .85 3.25
3062 15.77 3.34 .78 .28 .80 3.57
3072 15.63 3.36 .82 .28 .76 3.88
14.00
'Constant ingredients were the following as percent of the diet: alfalfa meal (17%), 2.00; fish meal (70%), 2.00; limestone, 6.Off; steamed bone meal, 3.00; salt, .50; and vitamin and trace mineral premix, .50. The premix supplied the following per kilogram of diet: vitamin A, 10,000 IU: vitamin D 3 , 1000 ICU; vitamin E, 7.5 IU; menadione sodium bisulfite, 2.5 mg; thiamine, 2.5 mg; riboflavin, 4 mg; pantothenic acid, 7.5 mg; niacin, 30 mg; pyridoxine, 4.5 mg; biotin, .2 mg; folic acid, .4 mg; vitamin B 1 2 , 8 Mg; antioxidant, 150 mg; iron, 40 mg; copper, 10 mg; iodine, .35 mg; manganese, 60 mg; zinc, 70 mg; selenium, .15 mg; and choline chloride, 625 mg.
1250
UWAYJAN ET AL.
4). Hen-day egg production was slightly depressed in all sunflower diets, but this depression was not statistically significant for any treatment. Egg production was reduced equally at the 10 and 20% replacement levels. However, the largest reduction occurred with the 30% level. Feed consumption (g/hen/day) revealed an unexpected but definite drop with increasing sunflower levels. The most significant drop in consumption (P<.01) was noticed at 10
and 30% but not at 20%. This drop in feed consumption could be partially explained on the basis of differences in energy content. The largest drop in feed consumption occurred at the 30% level. The use of sunflower seed in the experimental diets did not seem to increase feed consumption as would have been expected, because those 'diets had their fiber content increased due to the relatively high fiber content of the
TABLE 3. Composition of diets used in Experiment 2 Diets (%) 1
11
III
63.00 20.00
45.00 11.00 30.00
44.90 11.00 30.00
44.89 11.00 30.00
.10
Ingredients G r o u n d yellow corn S o y b e a n meal (44%) Sunflower seed Soybean oil L-Lysine HC1 DL-Methionine Constant ingredients 1 Calculated analysis ME, kcal/kg Protein, % Ca, % P (total), % Methionine, %
Lysine, % Linoleic acid, %
IV
3.00
14.00
14.00
14.00
.10 .01 14.00
2961 16.04 2.78 .66 .28 .87 2.87
3037 15.25 2.85 .79 .27 .73 3.88
3033 15.24 2.85 .79 .27 .83 3.88
3033 15.24 2.85 .79 .28 .83 3.88
'Constant ingredients were the following as percent of the diet: alfalfa meal (17%), 2.00; fish meal (70%), 2.00; limestone, 7.00; polyphos (a product containing 17% phosphorus from phosphoric acid, obtained from Division of Rhone Poulene Industries, 25, Quai Paul Doumer, 92408 Courberole, France), 2.00; salt, .50; and vitamin and trace mineral premix, .50. For composition of vitamin and trace mineral premix refer to footnote of Table 2.
TABLE 4. Effect of dietary level of sunflower seed on laying hen performance (Experiment 1)'
Dietary sunflower seed
Hen-day production
(">) 0 10 20 30
74.8 72.1 72.3 70.6
Feed consumed
Feed efficiency
(g/hen/day)
(kg feed/ doz eggs)
a
117 112b H4ab lllb
1.88 1.87 1.91 1.88
Average body weight change
Egg weight
(%)
(g) 64 64 65 66
+ 102 + 32 -13 +68
a' b Within the column, means without a common superscript differ significantly (P<.01). 1
Average data for seven, 28-day periods.
Mortality
5 6 9 4
SUNFLOWER SEED FOR LAYERS seed. Actually, feed consumption was least with the ration highest in fiber content. However, looking at the diets' composition, as the fiber of the diet was elevated due to increased sunflower seed incorporation there was a simultaneous increase in the energy content (Table 2). This energy increment seemed to have accounted for the reduced feed consumption observed. Feed efficiency (kilograms of feed per dozen eggs) and egg weight were not affected by any of the sunflower seed replacement levels, but there was a noticeable tendency toward an egg weight increase as the sunflower level increased. This may be due to the reduced production rates of those birds. Feed efficiency reflected a parallel effect of feed consumption on egg production. Again this was most evident at the 10 and 30% levels. Mortality seemed to be normal, ranging between 4 and 9%, and was not influenced by dietary treatment. All hens gained weight except those on the 20% sunflower diet for which there was no justifiable explanation. The SBM-control group had the highest weight gain (Table 4). Experiment 2. Results are summarized on the basis of 30% sunflower replacement level with a) no amino acid supplementation, b) . 1 % lysine, and c) . 1 % lysine plus .01% methionine supplementation (Table 5). Statistical analysis of the data on egg production, feed efficiency, feed consumption, and egg weight did not show significant differences among any of the above treatments. However, the . 1 % lysine-supplemented diet appeared to have produced a slightly inferior result reflected mainly in egg production, feed efficiency, and egg weight. Overall egg production in this experiment was lower than that in the previous experiment although birds were placed on the experimental diets at 28 weeks of age rather than 42 weeks as in the first experiment. Experiment 2 was started on December 15 whereas Experiment 1 was started on November 15. The start of this Experiment 2 corresponded with severe winter conditions, which prevented birds from reaching their peak of performance and contributed to reduced overall production. The results produced by the 30% sunflower diet, with no amino acid supplementation, indicated that a 30% sunflower seed substitution was a good practice and that no amino acid supplementation was necessary under the conditions of this study. Our results concerning lysine supple-
1251
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UWAYJANETAL. TABLE 6. Effect of dietary level of sunflower seed on egg quality characteristics (Experiment 2)*
Dietary treatment
Shell thickness
Haugh units
.336 .339 .339
80.3 78.6 79.3
9.50 a 8.73 b 8.73 b
22.64 a 23.70 b 23.77 b
.339
78.6
8.74 b
23.74 b
(mm) SBM control 30% sunflower seed 30% sunflower seed + . 1 % lysine 30% sunflower seed + . 1 % lysine + .01% methionine
Egg yolk cholesterol
Yolk color score2
(mg/g)
' Within each column, means without a common superscript differ significantly (P<.01). 1
Average data for eight 28-day periods.
2
Using the Hoffman La-Roche yolk color fan with a scale of 1 to 15.
metation agree with the findings of Rose et al. (1972) who reported that lysine supplementation to layer diets containing 50 and 100% replacement levels of SSM did not improve hen performance. Mortality, as in the first experiment, was also normal, ranging between 3 and 9%, and was not influenced by either dietary treatment or amino acid supplementation. All hens in the four treatments of this experiment gained weight, and their gain was appreciably more than those of the first experiment (Table 5). This difference, however, is explained by the fact that the first experiment was started when pullets were already 42 weeks of age, at which time physiological maturity was reached, whereas pullets of the second experiment were only 28 weeks of age and they were still adding weight. Results on egg quality studies are shown in Table 6. Statistical analyses of the data did not show any significant differences in shell thickness or Haugh Units among the four treatments. Yolk color and egg yolk cholesterol content, however, showed significant differences between the control and the sunflower diets (P<.01). All sunflower diets yielded eggs whose yolk color was lighter than those of the SBMcontrol diet. This result was expected, because the SBM-control diet included 28.6% more corn than any of the sunflower diets. Also, all sunflower diets resulted in eggs whose yolks gave higher cholesterol values. The magnitude of increase in cholesterol content of yolks from sunflower diets seemed small (about 1.1 mg/g,
amounting to 4.86% increase); nevertheless, it was highly significant. There is reason to believe that such an increase could be due to the high level of unsaturated fat in the sunflower diets, because Combs and Helbacka (1960) have observed that egg yolk cholesterol increased with an increase of unsaturated oil in the diet. This increase was observed upon feeding diets containing 10% corn oil. The figures on egg yolk cholesterol reported in our study, including those obtained from the SBM-control diet, were found to be relatively high, ranging between 22.64 and 23.77 mg cholesterol/g egg yolk, as compared to most values reported in the literature. Miller and Denton (1962) found 15.5 to 17.5 mg cholesterol/g yolk, whereas Harris and Wilcox (1963) reported values from 22 to 26. Rangachar et al. (1970) reported a mean value of 12.9 mg and Feeley et al. (1972) a mean value of 14.8 mg. More recently, Cotterill et al. (1977), Washburn and Marks (1977), and Bair and Marion (1978) reported mean values of 14.3, 16.9, and 14.0 mg, respectively. Thus, our values on egg yolk cholesterol are not within the range of previously reported data with the exception of these reported by Harris and Wilcox (1963). Because we have used the same method of cholesterol extraction and determination as that used by Harris and Wilcox, it is possible that the high values obtained are the result of the direct method employed. A comparative study on the methods used for cholesterol determination in egg yolk is further needed to verify the above.
SUNFLOWER SEED FOR LAYERS REFERENCES Bair, C. W., and W. W. Marion, 1978. Yolk cholesterol in eggs from various avian species. Poultry Sci. 57:1260-1265. Carpenter, K. J., and K. M. Clegg, 1956. The metabolizable energy of poultry feedingstuffs in relation to their composition. J. Sci. Food Agric. 7: 45-51. Combs, G. F., and N. V. Helbacka, 1960. Studies with laying hens. 1. Effect of dietary fat, protein levels and other variables in practical rations. Poultry Sci. 39:271-279. Cotterill, O. J., W. W. Marion, and E. C. Naber, 1977. A nutrient reevaluation of shell eggs. Poultry Sci. 56:1927-1934. Daghir, N. J., M. A. Raz, and M. Uwayjan, 1980. Studies on the utilization of full fat sunflower seed in broiler rations. Poultry Sci. 59:2273— 2278. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics 11:1—42. Feeley, R., P. C. Criner, and B. K. Watt, 1972. Cholesterol content of foods. J. Am. Diet. Assoc. 6 1 : 134. Hale, R. W., and W. O. Brown, 1957. Sunflower meal as a protein concentrate for laying hens. J. Agric. Sci. 48:336-372. Harris, P. C , and F. H. Wilcox, 1963. Studies on egg yolk cholesterol. 1. Genetic variation and some phenotypic correlations in a random bred population. Poultry Sci. 42:178-182. Miller, E. C , and C. A. Denton, 1962. Serum and egg yolk cholesterol of hens fed dried egg yolk. Poultry Sci. 41:335-337.
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National Research Council, 1977. Nutrient Requirements of Domestic Animals. 1. Nutrient Requirements of Poultry. 7th ed. Natl. Acad. Sci., Washington, DC. Pettit, J. H., S. J. Slinger, E. V. Evans, and F. N. Marcellus, 1944. The utilization of sunflower seed oil meal in poultry rations. Can. J. Agric. Sci. 24:201-213. Rangachar, T.R.S., S.V.S. Setty, and R. Hedge, 1970. Cholesterol content in eggs of chicken and duck. Mysore J. Agric. Sci. 4:146. Rose, R. J., R. N. Coit, and J. L. Sell, 1972. Sunflower seed meal as a replacement for soybean meal protein in laying hen rations. Poultry Sci. 51:960-967. Scott, M. L., M. C. Nesheim, and R. J. Young, 1976. Nutrition of the Chicken. 2nd ed. M. L. Scott Assoc, Ithaca, NY. Snedecor, G. W., and W. G. Cochran, 1967. Statistical Methods. 6th ed. Iowa State Univ. Press, Ames, IA. Titus, H. W., and J. C. Fritz, 1971. The Scientific Feeding of Chickens. 4th ed. Interstate Printers and Publ. Inc., Danville, IL. Vaughan, J. G., 1970. The structure and utilization of oil seeds. Chapman and Hall Ltd., London, England. Walter, E. D., G. S. Lindblad, and J. R. Aitken, 1959. The value of sunflower seed oil meal as a protein supplement for laying hens. Can. J. Anim. Sci. 39:45-49. Washburn, K. W., and H. L. Marks, 1977. Relationship of yolk and plasma cholesterol levels to position of egg in clutch. Poultry Sci. 56:1676— 1678.
INTRODUCTION
Sunflowers are a highly adaptable plant to many parts of Lebanon. They have been recently introduced as a substitute for certain cash crops in some areas of the country. Although the present production remains too low to warrant oil extraction on a commercial scale, enough of the seed is being annually produced to justify investigating the possibility of its use in poultry rations. Almost all the work on sunflowers in poultry rations has been done with the meal. A number of studies have been conducted to determine the nutritional value of sunflower seed meal (SSM) in poultry rations. We have recently reviewed (Daghir et al., 1980) work on the use of this meal for growing chickens. Few studies have dealt with the value of SSM for laying hens. Pettit et al. (1944) observed satisfactory laying hen performance when a low level (6%) of sunflower seed meal was used in mash-grain rations. Also using mash-grain rations, Hale and Brown (1957) concluded that sunflower seed meal was satis-
1 Contribution from the Faculty of Agricultural and Food Sciences, American University of Beirut, as Journal No. 564B.
factory for egg production, but they realized that rations high in sunflower seed meal were also high in fiber and low in energy. In all-mash rations for laying hens, Walter et al. (1959) completely replaced meat meal or soybean meal with sunflower meal. They observed no influence on egg production, egg weight, or maintenance of body weight when those diets included 2.0 or 2.5% fish meal. However, feed consumption seemed to be increased when the diets contained 9.5 or 13% sunflower seed meal. Trying to evaluate SSM obtained from two different processing methods as a protein replacement for soybean meal in rations for laying hens, Rose et al. (1972) reported that 50% replacement of the soybean protein by SSM protein did not adversely affect hen performance. However, 100% replacement of SBM protein with SSM resulted in decreased egg production and feed efficiency. The same authors also observed that although the two SSM's generally produced similar effects, the SSM of highest fiber content resulted in increased feed consumption only at the 100% replacement level in mash rations, and lysine supplementation did not consistently improve utilization of the diets used. Sunflower seed contains a widely variable oil content (25 to 32%) depending on variety, soil, and climatic conditions (Vaughan, 1970).
1247
1248
UWAYJAN ET AL.
The protein content of the unhulled seed is about 16%. Its crude fiber content varies from as low as 13% to as high as 28%, depending on the variety and the extent to which the seed was cleaned prior to its analysis. Because of the increased need to utilize unprocessed sunflower crops, justified by the scarcity of both energy and protein sources in Lebanon, the present study was initiated to evaluate whole sunflower seed as a partial replacement of soybean meal and corn in laying hen rations. Also, part of the objective was to establish the highest possible replacement level within the physical and nutritional limitations of the seed and to attempt improving the feeding value of such rations by methionine and/or lysine supplementation.
MATERIALS AND METHODS
Two experiments were conducted for seven and eight 28-day periods between November 1978 and July 1980. In both experiments, commercial Single Comb White Leghorn pullets of the Shaver strain were housed in floor pens at the rate of 25 birds per pen for the first experiment and 32 birds per pen for the second study and were provided with 14 hr of light daily. The first experiment was initiated during November when the birds were 42 weeks of age whereas the second experiment was initiated during December of the following year when the birds were 28 weeks of age. Egg production and mortality data were recorded daily for each pen whereas feed consumption for each pen was determined at the end of each 28-day period. Feed and water were provided ad libitum in both experiments. The criteria of response were egg production, feed consumption, feed efficiency, egg weight, and average body weight change. All forementioned criteria except body weight change were summarized at 28-day intervals. In addition, the second experiment included various egg quality measurements such as shell thickness, albumen quality, yolk color, and egg yolk cholesterol. Data on egg weight were collected during the last 3 days of every 28-day period in both experiments. Data on egg quality studies in the second experiment were collected in a manner similar to that in the first experiment except that eggs for the cholesterol study were collected at the end of every other period. All eggs collected from each pen during the 3-day collection period were pooled together, and aver-
age egg weight was recorded for every pen. Eggs for egg yolk cholesterol determination were collected randomly, 3 eggs from each pen daily, in the same manner and were hard boiled for 12 min. The yolks were then separated from their whites, pooled, sealed in plastic bags, and frozen at —20 C until analyzed. Yolk cholesterol determinations were made using the method employed by Harris and Wilcox (1963). Albumen and shell thickness were measured by an Ames Albumen Thickness Measure Gauge Model S-6428 and Ames Paper Thickness Measure Model 25, respectively. Egg yolk color was scored using the Hoffman La Roche yolk color fan. In both experiments, average hen weights for birds in each pen were taken at the start of the experiment and when the experiment was terminated. All data were subjected to standard analysis of variance according to Snedecor and Cochran (1967). Duncan's (1955) multiple range test was applied when treatment effects were found to be significant. Sunflower seed grown in Lebanon was obtained from the local market and was used in both experiments in its crude state without cleaning. It had about 10.4% impurities, which came mainly from the head and stem of the
TABLE 1. Composition of sunflower seed used Composition Moisture Crude protein Ether extract Crude fiber Nitrogen free extract Ash Calcium Phosphorus (total) Methionine 1 Methionine and cystine 1 Lysine1 Metabolizable energy, kcal/kg2 Linoleic acid3
(%) 6.81 15.80 16.73 14.20 43.03 3.43 .50 .35 .25 .50 .59 3882 9.7
1 Methionine, sulfur amino acids, and lysine were calculated on the basis of protein content with reference to dehulled sunflower meal (45.4%) as reported in National Research Council (1977) feed composition tables. 2 Calculated from chemical composition using the equation of Carpenter and Clegg (1956). 3 Calculated from oil content of sunflower seed as reported by Scott et al. (1976).
SUNFLOWER SEED FOR LAYERS sunflower plant. The composition of the seed in its crude form (Table 1) does not differ greatly from the clean seed, which normally contains an average of 5.9% moisture, 17.5% oil, 14.8% crude fiber, and 16.5% crude protein. Experiment 1. Four hundred hens were randomly distributed among four ration treatments with four replicates of 25 hens per treatment. Levels of 10, 20, and 30% sunflower seed replaced 15, 30, and 45% of the total SBM and 9.5, 19, and 28.6% of the corn in a practical, corn-soybean basal diet (Table 2). The rations for this experiment were formulated to be within 1% difference in protein content and a maximum difference of 75 kcal metabolizable energy (ME)/kg. The sunflower seed was ground, mixed with the other ration ingredients, and fed in mash form. Experiment 2. To investigate if the highest level of replacement of sunflower seed used in the first experiment could be improved by supplementation with . 1 % lysine or with . 1 % lysine plus .01% methionine, we conducted Experiment 2. Supplemental amino acid levels were chosen to equalize the experimental diets in those amino acids with that of the control. The study involved 512 hens distributed among four ration treatments with four replications of 32
1249
hens per treatment. The rations for Experiment 2 (Table 3) were similar to those in Experiment 1 and were fed in mash form.
RESULTS AND DISCUSSION
The sunflower seed used in both experiments was of the low oil variety. Values for crude protein and ash (Table 1) are similar to those reported by Titus and Fritz (1971), whereas ether extract, crude fiber, and phosphorus values are considerably lower. The calcium value, however, was a little higher and this may be due to the calcareous soil of the area in which the seed was grown. The lower phosphorus value may be also explained by the soil as well as the climatic conditions as suggested by Vaughan (1970). The difference in the crude fiber content is not explained by the rather thorough cleaning of the seeds as suggested by Daghir et al. (1980), because the analysis reported herein, performed on both crude and cleaned seeds, did not account for such a difference. However, it may be interpreted as a possible varietal difference. Experiment 1. The results of this experiment are summarized on the basis of the replacement level of sunflower seed used (Table
TABLE 2. Composition of diets used in Experiment 1 Diets (%) Ingredients Ground yellow corn Soybean meal (44%) Sunflower seed Soybean oil Constant ingredients1 Calculated analysis ME, kcal/kg Protein, % Ca, % P (total), % Methionine, % Lysine, % Linoleic acid, %
IV
I
II
III
63.00 20.00
51.00 14.00 20.00 1.00 14.00
45.00 11.00 30.00
3.00 14.00
57.00 17.00 10.00 2.00 14.00
2997 16.42 3.30 .70 .29 .90 2.87
3030 16.00 3.32 .74 .28 .85 3.25
3062 15.77 3.34 .78 .28 .80 3.57
3072 15.63 3.36 .82 .28 .76 3.88
14.00
'Constant ingredients were the following as percent of the diet: alfalfa meal (17%), 2.00; fish meal (70%), 2.00; limestone, 6.Off; steamed bone meal, 3.00; salt, .50; and vitamin and trace mineral premix, .50. The premix supplied the following per kilogram of diet: vitamin A, 10,000 IU: vitamin D 3 , 1000 ICU; vitamin E, 7.5 IU; menadione sodium bisulfite, 2.5 mg; thiamine, 2.5 mg; riboflavin, 4 mg; pantothenic acid, 7.5 mg; niacin, 30 mg; pyridoxine, 4.5 mg; biotin, .2 mg; folic acid, .4 mg; vitamin B 1 2 , 8 Mg; antioxidant, 150 mg; iron, 40 mg; copper, 10 mg; iodine, .35 mg; manganese, 60 mg; zinc, 70 mg; selenium, .15 mg; and choline chloride, 625 mg.
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UWAYJAN ET AL.
4). Hen-day egg production was slightly depressed in all sunflower diets, but this depression was not statistically significant for any treatment. Egg production was reduced equally at the 10 and 20% replacement levels. However, the largest reduction occurred with the 30% level. Feed consumption (g/hen/day) revealed an unexpected but definite drop with increasing sunflower levels. The most significant drop in consumption (P<.01) was noticed at 10
and 30% but not at 20%. This drop in feed consumption could be partially explained on the basis of differences in energy content. The largest drop in feed consumption occurred at the 30% level. The use of sunflower seed in the experimental diets did not seem to increase feed consumption as would have been expected, because those 'diets had their fiber content increased due to the relatively high fiber content of the
TABLE 3. Composition of diets used in Experiment 2 Diets (%) 1
11
III
63.00 20.00
45.00 11.00 30.00
44.90 11.00 30.00
44.89 11.00 30.00
.10
Ingredients G r o u n d yellow corn S o y b e a n meal (44%) Sunflower seed Soybean oil L-Lysine HC1 DL-Methionine Constant ingredients 1 Calculated analysis ME, kcal/kg Protein, % Ca, % P (total), % Methionine, %
Lysine, % Linoleic acid, %
IV
3.00
14.00
14.00
14.00
.10 .01 14.00
2961 16.04 2.78 .66 .28 .87 2.87
3037 15.25 2.85 .79 .27 .73 3.88
3033 15.24 2.85 .79 .27 .83 3.88
3033 15.24 2.85 .79 .28 .83 3.88
'Constant ingredients were the following as percent of the diet: alfalfa meal (17%), 2.00; fish meal (70%), 2.00; limestone, 7.00; polyphos (a product containing 17% phosphorus from phosphoric acid, obtained from Division of Rhone Poulene Industries, 25, Quai Paul Doumer, 92408 Courberole, France), 2.00; salt, .50; and vitamin and trace mineral premix, .50. For composition of vitamin and trace mineral premix refer to footnote of Table 2.
TABLE 4. Effect of dietary level of sunflower seed on laying hen performance (Experiment 1)'
Dietary sunflower seed
Hen-day production
(">) 0 10 20 30
74.8 72.1 72.3 70.6
Feed consumed
Feed efficiency
(g/hen/day)
(kg feed/ doz eggs)
a
117 112b H4ab lllb
1.88 1.87 1.91 1.88
Average body weight change
Egg weight
(%)
(g) 64 64 65 66
+ 102 + 32 -13 +68
a' b Within the column, means without a common superscript differ significantly (P<.01). 1
Average data for seven, 28-day periods.
Mortality
5 6 9 4
SUNFLOWER SEED FOR LAYERS seed. Actually, feed consumption was least with the ration highest in fiber content. However, looking at the diets' composition, as the fiber of the diet was elevated due to increased sunflower seed incorporation there was a simultaneous increase in the energy content (Table 2). This energy increment seemed to have accounted for the reduced feed consumption observed. Feed efficiency (kilograms of feed per dozen eggs) and egg weight were not affected by any of the sunflower seed replacement levels, but there was a noticeable tendency toward an egg weight increase as the sunflower level increased. This may be due to the reduced production rates of those birds. Feed efficiency reflected a parallel effect of feed consumption on egg production. Again this was most evident at the 10 and 30% levels. Mortality seemed to be normal, ranging between 4 and 9%, and was not influenced by dietary treatment. All hens gained weight except those on the 20% sunflower diet for which there was no justifiable explanation. The SBM-control group had the highest weight gain (Table 4). Experiment 2. Results are summarized on the basis of 30% sunflower replacement level with a) no amino acid supplementation, b) . 1 % lysine, and c) . 1 % lysine plus .01% methionine supplementation (Table 5). Statistical analysis of the data on egg production, feed efficiency, feed consumption, and egg weight did not show significant differences among any of the above treatments. However, the . 1 % lysine-supplemented diet appeared to have produced a slightly inferior result reflected mainly in egg production, feed efficiency, and egg weight. Overall egg production in this experiment was lower than that in the previous experiment although birds were placed on the experimental diets at 28 weeks of age rather than 42 weeks as in the first experiment. Experiment 2 was started on December 15 whereas Experiment 1 was started on November 15. The start of this Experiment 2 corresponded with severe winter conditions, which prevented birds from reaching their peak of performance and contributed to reduced overall production. The results produced by the 30% sunflower diet, with no amino acid supplementation, indicated that a 30% sunflower seed substitution was a good practice and that no amino acid supplementation was necessary under the conditions of this study. Our results concerning lysine supple-
1251
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UWAYJANETAL. TABLE 6. Effect of dietary level of sunflower seed on egg quality characteristics (Experiment 2)*
Dietary treatment
Shell thickness
Haugh units
.336 .339 .339
80.3 78.6 79.3
9.50 a 8.73 b 8.73 b
22.64 a 23.70 b 23.77 b
.339
78.6
8.74 b
23.74 b
(mm) SBM control 30% sunflower seed 30% sunflower seed + . 1 % lysine 30% sunflower seed + . 1 % lysine + .01% methionine
Egg yolk cholesterol
Yolk color score2
(mg/g)
' Within each column, means without a common superscript differ significantly (P<.01). 1
Average data for eight 28-day periods.
2
Using the Hoffman La-Roche yolk color fan with a scale of 1 to 15.
metation agree with the findings of Rose et al. (1972) who reported that lysine supplementation to layer diets containing 50 and 100% replacement levels of SSM did not improve hen performance. Mortality, as in the first experiment, was also normal, ranging between 3 and 9%, and was not influenced by either dietary treatment or amino acid supplementation. All hens in the four treatments of this experiment gained weight, and their gain was appreciably more than those of the first experiment (Table 5). This difference, however, is explained by the fact that the first experiment was started when pullets were already 42 weeks of age, at which time physiological maturity was reached, whereas pullets of the second experiment were only 28 weeks of age and they were still adding weight. Results on egg quality studies are shown in Table 6. Statistical analyses of the data did not show any significant differences in shell thickness or Haugh Units among the four treatments. Yolk color and egg yolk cholesterol content, however, showed significant differences between the control and the sunflower diets (P<.01). All sunflower diets yielded eggs whose yolk color was lighter than those of the SBMcontrol diet. This result was expected, because the SBM-control diet included 28.6% more corn than any of the sunflower diets. Also, all sunflower diets resulted in eggs whose yolks gave higher cholesterol values. The magnitude of increase in cholesterol content of yolks from sunflower diets seemed small (about 1.1 mg/g,
amounting to 4.86% increase); nevertheless, it was highly significant. There is reason to believe that such an increase could be due to the high level of unsaturated fat in the sunflower diets, because Combs and Helbacka (1960) have observed that egg yolk cholesterol increased with an increase of unsaturated oil in the diet. This increase was observed upon feeding diets containing 10% corn oil. The figures on egg yolk cholesterol reported in our study, including those obtained from the SBM-control diet, were found to be relatively high, ranging between 22.64 and 23.77 mg cholesterol/g egg yolk, as compared to most values reported in the literature. Miller and Denton (1962) found 15.5 to 17.5 mg cholesterol/g yolk, whereas Harris and Wilcox (1963) reported values from 22 to 26. Rangachar et al. (1970) reported a mean value of 12.9 mg and Feeley et al. (1972) a mean value of 14.8 mg. More recently, Cotterill et al. (1977), Washburn and Marks (1977), and Bair and Marion (1978) reported mean values of 14.3, 16.9, and 14.0 mg, respectively. Thus, our values on egg yolk cholesterol are not within the range of previously reported data with the exception of these reported by Harris and Wilcox (1963). Because we have used the same method of cholesterol extraction and determination as that used by Harris and Wilcox, it is possible that the high values obtained are the result of the direct method employed. A comparative study on the methods used for cholesterol determination in egg yolk is further needed to verify the above.
SUNFLOWER SEED FOR LAYERS REFERENCES Bair, C. W., and W. W. Marion, 1978. Yolk cholesterol in eggs from various avian species. Poultry Sci. 57:1260-1265. Carpenter, K. J., and K. M. Clegg, 1956. The metabolizable energy of poultry feedingstuffs in relation to their composition. J. Sci. Food Agric. 7: 45-51. Combs, G. F., and N. V. Helbacka, 1960. Studies with laying hens. 1. Effect of dietary fat, protein levels and other variables in practical rations. Poultry Sci. 39:271-279. Cotterill, O. J., W. W. Marion, and E. C. Naber, 1977. A nutrient reevaluation of shell eggs. Poultry Sci. 56:1927-1934. Daghir, N. J., M. A. Raz, and M. Uwayjan, 1980. Studies on the utilization of full fat sunflower seed in broiler rations. Poultry Sci. 59:2273— 2278. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics 11:1—42. Feeley, R., P. C. Criner, and B. K. Watt, 1972. Cholesterol content of foods. J. Am. Diet. Assoc. 6 1 : 134. Hale, R. W., and W. O. Brown, 1957. Sunflower meal as a protein concentrate for laying hens. J. Agric. Sci. 48:336-372. Harris, P. C , and F. H. Wilcox, 1963. Studies on egg yolk cholesterol. 1. Genetic variation and some phenotypic correlations in a random bred population. Poultry Sci. 42:178-182. Miller, E. C , and C. A. Denton, 1962. Serum and egg yolk cholesterol of hens fed dried egg yolk. Poultry Sci. 41:335-337.
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National Research Council, 1977. Nutrient Requirements of Domestic Animals. 1. Nutrient Requirements of Poultry. 7th ed. Natl. Acad. Sci., Washington, DC. Pettit, J. H., S. J. Slinger, E. V. Evans, and F. N. Marcellus, 1944. The utilization of sunflower seed oil meal in poultry rations. Can. J. Agric. Sci. 24:201-213. Rangachar, T.R.S., S.V.S. Setty, and R. Hedge, 1970. Cholesterol content in eggs of chicken and duck. Mysore J. Agric. Sci. 4:146. Rose, R. J., R. N. Coit, and J. L. Sell, 1972. Sunflower seed meal as a replacement for soybean meal protein in laying hen rations. Poultry Sci. 51:960-967. Scott, M. L., M. C. Nesheim, and R. J. Young, 1976. Nutrition of the Chicken. 2nd ed. M. L. Scott Assoc, Ithaca, NY. Snedecor, G. W., and W. G. Cochran, 1967. Statistical Methods. 6th ed. Iowa State Univ. Press, Ames, IA. Titus, H. W., and J. C. Fritz, 1971. The Scientific Feeding of Chickens. 4th ed. Interstate Printers and Publ. Inc., Danville, IL. Vaughan, J. G., 1970. The structure and utilization of oil seeds. Chapman and Hall Ltd., London, England. Walter, E. D., G. S. Lindblad, and J. R. Aitken, 1959. The value of sunflower seed oil meal as a protein supplement for laying hens. Can. J. Anim. Sci. 39:45-49. Washburn, K. W., and H. L. Marks, 1977. Relationship of yolk and plasma cholesterol levels to position of egg in clutch. Poultry Sci. 56:1676— 1678.