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The Effects of Dietary Phosphorus, Vitamin D3, and 25-Hydroxy Vitamin D3 Levels on Feed Intake, Productive Performance, and Egg and Shell Quality in Two Strains of Force-Molted White Leghorns1
The Effects of Dietary Phosphorus, Vitamin D 3 , and 25-Hydroxy Vitamin D 3 Levels on Feed Intake, Productive Performance, and Egg and Shell Quality in Two Strains of Force-Molted White Leghorns1 R.M.G. HAMILTON Animal Research Institute, Research Branch, Agriculture Canada, Central Experimental Farm, Ottawa, Canada K1A 0C6 (Received for publication May 7, 1979)
1980 Poultry Science 59:598-604 INTRODUCTION In t h e laying hen, a vitamin D 3 ( D 3 ) depend e n t calcium binding protein (CaBP) is involved in t h e transfer of calcium across t h e intestinal mucosa (Wasserman and Taylor, 1 9 6 8 ) and possibly across t h e uterine mucosa (Corradino et al., 1 9 6 8 ; Bar and Hurwitz, 1973). Since 1 9 6 5 it has been shown t h a t a h o r m o n a l l y active m e t a b o l i t e , 1,25-dihydroxy vitamin D 3 (1,25 ( O H ) 2 D 3 ) , controls t h e biosynthesis of intestinal CaBP (DeLuca, 1 9 7 7 ; N o r m a n and Henry, 1 9 7 9 ) . In t h e p r o d u c t i o n of 1,25 ( O H ) 2 D 3 , dietary and e n d o g e n o u s D 3 is t h e first h y d r o x y l a t e d at position 25 of t h e D 3 molecule in t h e liver t o p r o d u c e 2 5 - h y d r o x y vitamin D 3 (25 O H - D 3 ) which is t h e main circulating D 3 m e t a b o l i t e in t h e b l o o d (DeLuca, 1 9 7 7 ) . This hepatic h y d r o x y l a t i o n step is regulated b y p r o d u c t inhibition ( O m d a h l and DeLuca, 1973). T h e circulating 25 O H - D 3 is further h y d r o x y l a t e d in position 1 of t h e molecule in t h e kidney t o p r o d u c e 1,25 ( O H ) 2 D 3 (DeLuca, 1977). T h e r e is evidence t h a t t h e conversion of
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Animal
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25 O H - D 3 t o 1, 25 ( O H ) 2 D 3 is regulated b y p r o d u c t inhibition via a short feedback system and by b l o o d calcium and p h o s p h o r u s levels t h r o u g h a long feedback system ( N o r m a n and Henry, 1 9 7 9 ) . These findings explain t h e biochemical and physiological bases of t h e nutritional interrelationships b e t w e e n calcium, p h o s p h o r u s , and vitamin D t h a t have been k n o w n for m a n y years ( S c o t t et al, 1 9 7 6 ) . Substitution of 25 O H - D 3 for D 3 in laying hen diets has s h o w n little consistent effect on egg shell quality. Marrett et al. ( 1 9 7 5 ) fed diets containing either 2 5 O H - D 3 or D 3 for 336 days t o sexually m a t u r e hens. Irrespective of t h e dietary calcium level, thicker shelled eggs were p r o d u c e d b y t h e hens given t h e 25 O H - D 3 diet. Polin and Ringer ( 1 9 7 7 ) also r e p o r t e d t h a t 25 O H - D 3 p r o d u c e d an improvem e n t in shell strength c o m p a r e d t o D 3 , particularly at a l o w dietary p h o s p h o r u s level (.28% available), over a 364-day laying period. Charles and Ernst ( 1 9 7 4 ) and McLoughlin and Soares ( 1 9 7 6 ) f o u n d t h a t 25 O H - D 3 c o m p a r e d t o D 3 improved t h e shell strength of eggs laid b y old hens (144 and 7 4 weeks of age, respectively) b u t n o t t h a t of eggs from y o u n g hens (28 and 4 2 weeks, respectively). Roland and Harms ( 1 9 7 6 ) , however, found t h a t shell quality was
598
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ABSTRACT A total of 576 force-molted hens were used to investigate the effect of dietary phosphorus level, and the source and level of vitamin D 3 on egg production and shell quality. The experiment was a 2 X 2 X 2 X 3 factorial design with two strains of hens, two levels of available phosphorus (.34 and .60%), and two sources of D 3 (25-hydroxy vitamin D 3 and vitamin D 3 ) at three levels (8, 16, 24 Mg/kg); the diets were provided ad libitum for 84 days (from 646 to 730 days of age). Egg and shell quality measurements were taken on eggs laid over a 4-day period when the hens were 727 days of age. Dietary phosphorus level, and D 3 source and level had no significant (P>.05) effect on 730-day body weight, feed intake and efficiency, egg production and yield, shell weight, percent shell, shell weight per unit surface area, Haugh units, blood spots, egg specific gravity, nondestructive deformation, compression fracture force, and shell thickness. There were significant differences among strains for the aforementioned variables except feed intake, egg weight, Haugh units, and blood spot incidence. Few interactions were found between the main effects. Results indicate that no improvement in shell quality of eggs from force-molted hens was obtained by decreasing the level of phosphorus or substituting 25-hydroxy vitamin D 3 for vitamin D3 in the diet.
VITAMIN D SOURCE AND LEVEL AND EGG QUALITY
MATERIALS AND METHODS
The experiment was of a randomized complete block design with 4 blocks, each containing a 2 x 2 x 2 x 3 factorial arrangement of two strains of force-molted hens (1 and 4) which have been previously described by Gowe (1977) and Gowe et al. (1973), respectively. The dietary treatments were two levels of available phosphorus (.34 and .60%), two sources of vitamin D (D 3 and 25 OH-D 3 ), and three levels of each source of vitamin D (8, 16, and 24 jug/kg); there were 6 hens per strain x diet group. After completion of their first laying cycle at 497 days of age, the hens were force-molted according to Washington State University method described by Swanson and Bell (1974). The experimental diets were prepared by mixing a D 3 or 25 OH-D3 premix with the low or high phosphorus basal diets (Table 1). The D 3 and 25 OH-D 3 premixes were prepared by first making "premix concentrates" that contained the calculated quantity of D activity for 320 kg of experimental diet in 600 g of ground corn. Subsequently, " D 3 and 25 OH-D3 premixes" were obtained by diluting 600 g of premix concentrate to 40 kg with ground corn. Both the premix concentrates and premixes were stored at —20 C until needed. Experimental diets were prepared twice weekly by mixing 5 kg of the appropriate D 3 or 25 OH-D 3 premix with 35 kg of the low or high phosphorus-containing basal diet. These diets were kept at room temperature and were consumed within 4 days of preparation. The basal diets were analyzed for Kjeldahl nitrogen, calcium, and total phosphorus according to the methods described by AOAC (1975). Phytate
phosphorus content was determined as described by Hamilton and Sibbald (1977). Five hundred and seventy-six Single Comb White Leghorns hens were housed individually in wire cages (20.3 X 40.6 cm). The hens received the experimental diets and water ad libitum and were provided with 16 hr (0100 to 1700 hr) of light daily. Individual body weights were obtained at 646 and 730 days of age. Egg production, quantity of feed given per strain X diet group, and mortality were recorded. A feed weighback was done at the completion (730 days) of the experiment. Egg mass was determined on the eggs laid Monday and Thursday of each week. Egg shell strength measurements and interior quality measurements were taken on eggs laid during a 4-day period starting when the hens were 727 days of age. Shell strength was estimated by specific gravity according to the flotation procedure (Voisey and Hamilton, 1977), by non-destructive deformation between applied forces of .1 and 1.1 kg, and by compression factor force at 20 mm/min. Details of the nondestructive deformation and compression fracture force measurements have been discussed elsewhere (Voisey and MacDonald, 1978; Hamilton et al, 1979). All eggs were weighed, the contents removed, and the shells carefully washed with warm tap water, dried, and weighed. Shell weight per unit surface area (SW/SA) and percent shell was calculated as described by Hamilton (1978). Shell thickness was measured with a dial gauge comparator (Voisey and Hunt, 1974). Albumen height and blood spots were other egg quality variables measured. The means of the data for the eggs from up to 6 hens per strain X diet group were used for the statistical analyses. Strain X diet group means were also used to analyze the body weight, feed intake and efficiency, egg production, and shell quality data.
RESULTS AND DISCUSSION
The data shown in Tables 2 and 3 are presented according to strain, phosphorus level, D 3 source, and D 3 level because there were few interactions between these main effects. Initial body weight (646 days) differences for phosphorus level and D 3 source and level were not significant (P>.05) indicating the effectiveness of the randomization procedure. Significant differences (P<.001) in 646- and 730-day body weight were found among strains and agree
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the same for young (320 days of age) and old (507 days) hens receiving diets that contained either 25 OH-D 3 or D 3 . Cohen et al. (1978) also observed that replacing dietary D 3 with 25 OH-D3 had no effect on shell strength in 15-month-old hens. Previously, Hamilton and Sibbald (1977) found that decreasing the level of dietary phosphorus produced a significant increase in egg specific gravity, a criterion of shell quality. Therefore, the purpose of the experiment being reported was to determine the effects of dietary phosphorus, vitamin D 3 , and 25-hydroxy vitamin D 3 levels on the productive performance and egg shell quality of force-molted Single Comb White Leghorn (SCWL) hens from two strains.
599
,600
HAMILTON TABLE 1. Composition of basal diets
Ingredient
High phosphorus
315.5 125.0 100.0 100.0 100.0 30.0 15.0 10.0 72.0
310.0 125.0 100.0 100.0 100.0 30.0 15.0 10.0 65.0 12.5
2.5 5.0
2.5 5.0
875.0
875.0
91.0 17.8 3.52
90.7 18.4 3.54
.49
.79
Supplied per kilogram feed: vitamin A, 5500 IU; vitamin E, 3.3 IU; vitamin K, 1.1 mg; riboflavin, 4.4 mg; niacin, 22.0; calcium pantothenate, 5.5 mg; folacin, 1.1 mg; choline chloride, 220 mg; vitamin B 1 2 , 5.5 Mg; manganese, 55.0 mg; zinc, 44.0 mg; copper, 5.5 mg; and iodine, 1.1 mg.
with the results of Gowe et al. (1973) and Hamilton and Thompson (1980). Dietary phosphorus level and D 3 source and level had no effect (P>.05) on 730-day body weight, feed intake and efficiency, and egg production and yield. Mortality was numerically but not statistically higher for the hens receiving the .34% phosphorus diet than for those given the .60% diet. There were significant strain X D3 source interactions for kg feed/dozen and egg production which were primarily attributable to variation among phosphorus levels. Hamilton and Sibbald (1977) also found that dietary phosphorus level did not affect feed intake while Antillon et al. (1977) observed that feed intake was lower when total phosphorus level was decreased from .55 to .26% of the diet. The feed efficiency results (Table 2) are similar to those reported by Hamilton and Sibbald (1977). The egg production data disagree with those of Antillon et al. (1977) who found that egg production was improved when phosphorus level was reduced. However, Hamilton and Sibbald (1977) observed that dietary phosphorus level had no effect on egg production. The effect of D 3 source on feed intake does not agree with Cohen et al. (1978) who reported that feed intake was higher for 15-month-old
laying hens (White Leghorn X Rhode Island Red) given 25 OH-D 3 than for those receiving a D 3 -containing diet. Hens given D 3 diets had higher egg production (P>.05) than those receiving 25 OH-D 3 diets (70.2 vs. 68.5 HD %) and utilized less feed to produce eggs (1.88 vs. 1.91 kg feed/dozen and 2.46 vs. 2.52 kg feed/kg egg). These egg production results (Table 2) were similar to those of Charles and Ernst (1974) but the feed efficiency results differ. Marrett et al. (1975) and Polin and Ringer (1977), however, obtained higher egg production from hens given diets containing 25 OH-D3 than those receiving D 3 , whereas production was the same in the present experiment. Roland and Harms (1976) found no difference in egg production of young or old hens given 25 OH-D3 or D 3 in their diets. The results for shell and interior quality variables of the eggs laid over a 4-day period, starting after the hens had received the diets for 81 days, are presented in Table 3. There were no differences (P>.05) among strains for egg weight, Haugh units, and blood spots but shell weight, percent shell, shell weight per unit surface area (SW/SA), specific gravity, and compression fracture force were lower (P <.001) and non-destructive deformation was
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Wheat Corn Oats Barley Soybean meal (48%) Fishmeal (63%) Dehydrated alfalfa Stabilized tallow Pulverized limestone Dicalcium phosphate Iodized salt Vitamin-mineral premix a Total Composition (by analysis) Dry matter (%) Crude protein (N X 6.25) Calcium (%) Total phosphorus (%)
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VITAMIN D SOURCE AND LEVEL AND EGG QUALITY
Dietary D 3 source a n d level had n o effect on shell or interior quality (Table 3). There were strain X p h o s p h o r u s interactions (P<.05) for b l o o d spots, strain X D 3 source for shell weight and b l o o d spots, p h o s p h o r u s x D 3 source for egg weight a n d Haugh units, and D 3 source X D 3 level for egg weight. T h e interactions involving egg and shell weight were mainly a t t r i b u t a b l e t o variation a m o n g strains while t h o s e for b l o o d spots and Haugh units m a y have been r a n d o m occurrences. Both Roland and Harms ( 1 9 7 6 ) and Cohen et al. ( 1 9 7 8 ) f o u n d t h a t substituting 25 O H - D 3 for D 3 in laying hen diets had no effect on specific gravity, egg and shell weight, and SW/SA, whereas Charles and Ernst ( 1 9 7 4 ) , Marrett et al. ( 1 9 7 5 ) , and McLoughlin and Soares ( 1 9 7 6 ) r e p o r t e d t h a t c o m p a r e d t o D 3 , 25 O H - D 3 improved specific gravity, shell thickness, and compression fracture force. Charles and Ernst ( 1 9 7 4 ) also found t h a t D 3 source did n o t influence shell d e f o r m a t i o n . Antillon et al. ( 1 9 7 7 ) observed t h a t D 3 level had n o influence o n shell fracture force which agrees with t h e results in Table 3. T h e results from this e x p e r i m e n t indicate t h a t i m p r o v e m e n t in egg p r o d u c t i o n and shell quality of eggs from force m o l t e d hens was n o t o b t a i n e d b y decreasing t h e level of dietary p h o s p h o r u s or substituting 2 5 - h y d r o x y vitamin D 3 for vitamin D 3 in t h e diets.
ACKNOWLEDGMENTS T h e a u t h o r wishes t o t h a n k R. T. Poirier for his technical assistance, K. G. Hilson for his assistance with t h e data files, J.A.B. Emsley
for his advice and assistance with t h e statistical analyses, and M. J. DeGeeter, T h e U p j o h n C o m p a n y , Kalamazoo, MI for t h e generous supply of 2 5 - h y d r o x y vitamin D 3 . T h e chemical analyses of t h e e x p e r i m e n t a l diets were performed b y t h e staff of t h e Chemistry and Biology Research Institute, Agriculture Canada.
REFERENCES Antillon, A., M. L. Scott, L. Krook, and R. H. Wasserman, 1977. Metabolic response of laying hens to different dietary levels of calcium, phosphorus and vitamin D 3 . Cornell Vet. 67:413—444. Association of Official Analytical Chemists, 1975. Official methods of analysis. 12th ed. AOAC, Washington, DC. Bar, A., and S. Hurwitz, 1973. Uterine calcium-binding protein in the laying fowl. Comp. Biochem. Physiol. 45A:579-586. Charles, O. W., and R. A. Ernst, 1974. Effect of age, calcium level and vitamin D metabolites on egg shell quality of SCWL. Poultry Sci. 5 3:1908. Cohen, A., A. Bar, U. Eisner, and S. Hurwitz, 1978. Calcium absorption, calcium-binding protein, and egg shell quality in laying hens fed hydroxylated vitamin D derivatives. Poultry Sci. 57:1646— 1651. Corradino, R. A., R. H. Wasserman, M. H. Pubols, and S. I. Chang, 1968. Vitamin D 3 induction of a calcium-binding protein in the uterus of the laying hen. Arch. Biochem. Biophys. 125:378— 380. DeLuca, H. F., 1977. Vitamin D endocrine system. Adv. Clinical Chem. 19:125-174. Gowe, R. S., 1977. Multiple-trait selection in egg stocks: 1. Performance of six selected lines derived from three base populations; 2. Changes in genetic parameters over time in six selected strains. Page 68—91 in Proc. 26th Ann. Poultry Breeders' Roundtable, Kansas City, MO. Gowe, R. S., W. E. Lentz, and J. H. Strain, 1973. Long-term selection for egg production in several strains of White Leghorns: Performance of selected and control strains including genetic parameters of two control strains. Page 225—245 in 4th Europ. Poultry Conf., London. Hamilton, R.M.G., 1978. Observations on the changes in physical characteristics that influence egg shell quality in ten strains of White Leghorns. Poultry Sci. 57:1192-1197. Hamilton, R.M.G., and I. R. Sibbald, 1977. The effects of dietary phosphorus on production performance and egg quality of ten strains of White Leghorns. Poultry Sci. 56:1221-1228. Hamilton, R.M.G., and B. K. Thompson, 1980. Effects of sodium plus potassium to chloride ratio in practical-type diets on blood gas levels in three strains of White Leghorn hens and the relationship between acid-base balance and egg shell strength. Poultry Sci. (In press). Hamilton, R.M.G., B. K. Thompson, and P. W. Voisey, 1979. The effects of age and strain on the relationships between destructive and non-destructive
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higher ( P < . 0 0 1 ) for strain 4 t h a n 1. Although t h e egg weight was n o t different b e t w e e n strains, as e x p e c t e d (Gowe, 1 9 7 7 ) , specific gravity and t h e o t h e r shell variables agreed with t h e results of G o w e ( 1 9 7 7 ) a n d H a m i l t o n and T h o m p s o n ( 1 9 8 0 ) . E x c e p t for egg weight, p h o s p h o r u s level had n o effect on shell a n d interior quality. T h e specific gravity and fracture force results d o n o t agree with those of Hamilton and Sibbald ( 1 9 7 7 ) and Antillon et al. ( 1 9 7 7 ) , respectively, b o t h of w h o m r e p o r t e d t h a t there were significant increases in shell quality w h e n t h e level of p h o s p h o r u s was decreased in t h e laying diets. A l t h o u g h t h e SW/SA results agree with those of Polin and Ringer ( 1 9 7 7 ) , it m a y be n o t e d t h a t in their diets, as t h e p h o s p h o r u s levels increased t h e calcium levels also increased.
603
604
HAMILTON shell quality or other criteria in laying hens. Poultry Sci. 55:1982-1985. Scott, M. L., M. C. Nesheim, and R. J. Young, 1976. Nutrition of the chicken. M. L. Scott and Ass., Ithaca, NY. Swanson, M. H., and D. D. Bell, 1974. Force molting of chickens. II. Methods. University of California, Berkley, CA, Pub. AXT-411. Voisey, P. W., and R.M.G. Hamilton, 1977. Sources of error in egg specific gravity measurements by the flotation method. Poultry Sci. 56:1457-1462. Voisey, P. W., and J. R. Hunt, 1974. Measurement of eggshell strength. J. Texture Stud. 5:135-182. Voisey, P. W., and D. C. MacDonald, 1978. Laboratory measurement of egg shell strength. 1. An instrument for measuring shell strength by quasi-static compression, puncture, and non-destructive deformation. Poultry Sci. 57:860-869. Wasserman, R. H., and A. N. Taylor, 1968. Vitamin D-dependent calcium-binding protein. Response to some physiological and nutritional variables. J. Biol. Chem. 243:3987-3993.
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measurements of egg shell strength for White Leghorn hens. Poultry Sci. 58:1125-1132. Marrett, L. E., F. R. Frank, and R. G. Zimbelman, 1975. 25-hydroxycholecalciferol as a dietary replacement of D 3 to improve egg shell calcification. Poultry Sci. 54:1788. McLoughlin, C. P., and J. H. Soares, Jr., 1976. A study of the effects of 25-hydroxycholecalciferol and calcium source on egg shell quality. Poultry Sci. 55:1400-1410. Norman, A. W., and H. L. Henry, 1979. Vitamin D to 1,25-dihydroxycholecalciferol: Evolution of a steroid hormone. Trends Biochem. Sci. 4:14—18. Omdahl, J. L., and H. F. DeLuca, 1973. Regulation of vitamin D metabolism and function. Physiol. Rev. 53:327-372. Polin, D., and R. K. Ringer, 1977. 25-hydroxy-D,, vitamin D3 and graded levels of phosphorus: Effect on egg production and shell quality. Feedstuffs 49(44):40-41, 47. Roland, D. A., Sr., and R. H. Harms, 1976. The lack of response of 25-hydroxy-vitamin D 3 on egg
1980 Poultry Science 59:598-604 INTRODUCTION In t h e laying hen, a vitamin D 3 ( D 3 ) depend e n t calcium binding protein (CaBP) is involved in t h e transfer of calcium across t h e intestinal mucosa (Wasserman and Taylor, 1 9 6 8 ) and possibly across t h e uterine mucosa (Corradino et al., 1 9 6 8 ; Bar and Hurwitz, 1973). Since 1 9 6 5 it has been shown t h a t a h o r m o n a l l y active m e t a b o l i t e , 1,25-dihydroxy vitamin D 3 (1,25 ( O H ) 2 D 3 ) , controls t h e biosynthesis of intestinal CaBP (DeLuca, 1 9 7 7 ; N o r m a n and Henry, 1 9 7 9 ) . In t h e p r o d u c t i o n of 1,25 ( O H ) 2 D 3 , dietary and e n d o g e n o u s D 3 is t h e first h y d r o x y l a t e d at position 25 of t h e D 3 molecule in t h e liver t o p r o d u c e 2 5 - h y d r o x y vitamin D 3 (25 O H - D 3 ) which is t h e main circulating D 3 m e t a b o l i t e in t h e b l o o d (DeLuca, 1 9 7 7 ) . This hepatic h y d r o x y l a t i o n step is regulated b y p r o d u c t inhibition ( O m d a h l and DeLuca, 1973). T h e circulating 25 O H - D 3 is further h y d r o x y l a t e d in position 1 of t h e molecule in t h e kidney t o p r o d u c e 1,25 ( O H ) 2 D 3 (DeLuca, 1977). T h e r e is evidence t h a t t h e conversion of
'Contribution Institute.
number:
845
Animal
Research
25 O H - D 3 t o 1, 25 ( O H ) 2 D 3 is regulated b y p r o d u c t inhibition via a short feedback system and by b l o o d calcium and p h o s p h o r u s levels t h r o u g h a long feedback system ( N o r m a n and Henry, 1 9 7 9 ) . These findings explain t h e biochemical and physiological bases of t h e nutritional interrelationships b e t w e e n calcium, p h o s p h o r u s , and vitamin D t h a t have been k n o w n for m a n y years ( S c o t t et al, 1 9 7 6 ) . Substitution of 25 O H - D 3 for D 3 in laying hen diets has s h o w n little consistent effect on egg shell quality. Marrett et al. ( 1 9 7 5 ) fed diets containing either 2 5 O H - D 3 or D 3 for 336 days t o sexually m a t u r e hens. Irrespective of t h e dietary calcium level, thicker shelled eggs were p r o d u c e d b y t h e hens given t h e 25 O H - D 3 diet. Polin and Ringer ( 1 9 7 7 ) also r e p o r t e d t h a t 25 O H - D 3 p r o d u c e d an improvem e n t in shell strength c o m p a r e d t o D 3 , particularly at a l o w dietary p h o s p h o r u s level (.28% available), over a 364-day laying period. Charles and Ernst ( 1 9 7 4 ) and McLoughlin and Soares ( 1 9 7 6 ) f o u n d t h a t 25 O H - D 3 c o m p a r e d t o D 3 improved t h e shell strength of eggs laid b y old hens (144 and 7 4 weeks of age, respectively) b u t n o t t h a t of eggs from y o u n g hens (28 and 4 2 weeks, respectively). Roland and Harms ( 1 9 7 6 ) , however, found t h a t shell quality was
598
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ABSTRACT A total of 576 force-molted hens were used to investigate the effect of dietary phosphorus level, and the source and level of vitamin D 3 on egg production and shell quality. The experiment was a 2 X 2 X 2 X 3 factorial design with two strains of hens, two levels of available phosphorus (.34 and .60%), and two sources of D 3 (25-hydroxy vitamin D 3 and vitamin D 3 ) at three levels (8, 16, 24 Mg/kg); the diets were provided ad libitum for 84 days (from 646 to 730 days of age). Egg and shell quality measurements were taken on eggs laid over a 4-day period when the hens were 727 days of age. Dietary phosphorus level, and D 3 source and level had no significant (P>.05) effect on 730-day body weight, feed intake and efficiency, egg production and yield, shell weight, percent shell, shell weight per unit surface area, Haugh units, blood spots, egg specific gravity, nondestructive deformation, compression fracture force, and shell thickness. There were significant differences among strains for the aforementioned variables except feed intake, egg weight, Haugh units, and blood spot incidence. Few interactions were found between the main effects. Results indicate that no improvement in shell quality of eggs from force-molted hens was obtained by decreasing the level of phosphorus or substituting 25-hydroxy vitamin D 3 for vitamin D3 in the diet.
VITAMIN D SOURCE AND LEVEL AND EGG QUALITY
MATERIALS AND METHODS
The experiment was of a randomized complete block design with 4 blocks, each containing a 2 x 2 x 2 x 3 factorial arrangement of two strains of force-molted hens (1 and 4) which have been previously described by Gowe (1977) and Gowe et al. (1973), respectively. The dietary treatments were two levels of available phosphorus (.34 and .60%), two sources of vitamin D (D 3 and 25 OH-D 3 ), and three levels of each source of vitamin D (8, 16, and 24 jug/kg); there were 6 hens per strain x diet group. After completion of their first laying cycle at 497 days of age, the hens were force-molted according to Washington State University method described by Swanson and Bell (1974). The experimental diets were prepared by mixing a D 3 or 25 OH-D3 premix with the low or high phosphorus basal diets (Table 1). The D 3 and 25 OH-D 3 premixes were prepared by first making "premix concentrates" that contained the calculated quantity of D activity for 320 kg of experimental diet in 600 g of ground corn. Subsequently, " D 3 and 25 OH-D3 premixes" were obtained by diluting 600 g of premix concentrate to 40 kg with ground corn. Both the premix concentrates and premixes were stored at —20 C until needed. Experimental diets were prepared twice weekly by mixing 5 kg of the appropriate D 3 or 25 OH-D 3 premix with 35 kg of the low or high phosphorus-containing basal diet. These diets were kept at room temperature and were consumed within 4 days of preparation. The basal diets were analyzed for Kjeldahl nitrogen, calcium, and total phosphorus according to the methods described by AOAC (1975). Phytate
phosphorus content was determined as described by Hamilton and Sibbald (1977). Five hundred and seventy-six Single Comb White Leghorns hens were housed individually in wire cages (20.3 X 40.6 cm). The hens received the experimental diets and water ad libitum and were provided with 16 hr (0100 to 1700 hr) of light daily. Individual body weights were obtained at 646 and 730 days of age. Egg production, quantity of feed given per strain X diet group, and mortality were recorded. A feed weighback was done at the completion (730 days) of the experiment. Egg mass was determined on the eggs laid Monday and Thursday of each week. Egg shell strength measurements and interior quality measurements were taken on eggs laid during a 4-day period starting when the hens were 727 days of age. Shell strength was estimated by specific gravity according to the flotation procedure (Voisey and Hamilton, 1977), by non-destructive deformation between applied forces of .1 and 1.1 kg, and by compression factor force at 20 mm/min. Details of the nondestructive deformation and compression fracture force measurements have been discussed elsewhere (Voisey and MacDonald, 1978; Hamilton et al, 1979). All eggs were weighed, the contents removed, and the shells carefully washed with warm tap water, dried, and weighed. Shell weight per unit surface area (SW/SA) and percent shell was calculated as described by Hamilton (1978). Shell thickness was measured with a dial gauge comparator (Voisey and Hunt, 1974). Albumen height and blood spots were other egg quality variables measured. The means of the data for the eggs from up to 6 hens per strain X diet group were used for the statistical analyses. Strain X diet group means were also used to analyze the body weight, feed intake and efficiency, egg production, and shell quality data.
RESULTS AND DISCUSSION
The data shown in Tables 2 and 3 are presented according to strain, phosphorus level, D 3 source, and D 3 level because there were few interactions between these main effects. Initial body weight (646 days) differences for phosphorus level and D 3 source and level were not significant (P>.05) indicating the effectiveness of the randomization procedure. Significant differences (P<.001) in 646- and 730-day body weight were found among strains and agree
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the same for young (320 days of age) and old (507 days) hens receiving diets that contained either 25 OH-D 3 or D 3 . Cohen et al. (1978) also observed that replacing dietary D 3 with 25 OH-D3 had no effect on shell strength in 15-month-old hens. Previously, Hamilton and Sibbald (1977) found that decreasing the level of dietary phosphorus produced a significant increase in egg specific gravity, a criterion of shell quality. Therefore, the purpose of the experiment being reported was to determine the effects of dietary phosphorus, vitamin D 3 , and 25-hydroxy vitamin D 3 levels on the productive performance and egg shell quality of force-molted Single Comb White Leghorn (SCWL) hens from two strains.
599
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HAMILTON TABLE 1. Composition of basal diets
Ingredient
High phosphorus
315.5 125.0 100.0 100.0 100.0 30.0 15.0 10.0 72.0
310.0 125.0 100.0 100.0 100.0 30.0 15.0 10.0 65.0 12.5
2.5 5.0
2.5 5.0
875.0
875.0
91.0 17.8 3.52
90.7 18.4 3.54
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.79
Supplied per kilogram feed: vitamin A, 5500 IU; vitamin E, 3.3 IU; vitamin K, 1.1 mg; riboflavin, 4.4 mg; niacin, 22.0; calcium pantothenate, 5.5 mg; folacin, 1.1 mg; choline chloride, 220 mg; vitamin B 1 2 , 5.5 Mg; manganese, 55.0 mg; zinc, 44.0 mg; copper, 5.5 mg; and iodine, 1.1 mg.
with the results of Gowe et al. (1973) and Hamilton and Thompson (1980). Dietary phosphorus level and D 3 source and level had no effect (P>.05) on 730-day body weight, feed intake and efficiency, and egg production and yield. Mortality was numerically but not statistically higher for the hens receiving the .34% phosphorus diet than for those given the .60% diet. There were significant strain X D3 source interactions for kg feed/dozen and egg production which were primarily attributable to variation among phosphorus levels. Hamilton and Sibbald (1977) also found that dietary phosphorus level did not affect feed intake while Antillon et al. (1977) observed that feed intake was lower when total phosphorus level was decreased from .55 to .26% of the diet. The feed efficiency results (Table 2) are similar to those reported by Hamilton and Sibbald (1977). The egg production data disagree with those of Antillon et al. (1977) who found that egg production was improved when phosphorus level was reduced. However, Hamilton and Sibbald (1977) observed that dietary phosphorus level had no effect on egg production. The effect of D 3 source on feed intake does not agree with Cohen et al. (1978) who reported that feed intake was higher for 15-month-old
laying hens (White Leghorn X Rhode Island Red) given 25 OH-D 3 than for those receiving a D 3 -containing diet. Hens given D 3 diets had higher egg production (P>.05) than those receiving 25 OH-D 3 diets (70.2 vs. 68.5 HD %) and utilized less feed to produce eggs (1.88 vs. 1.91 kg feed/dozen and 2.46 vs. 2.52 kg feed/kg egg). These egg production results (Table 2) were similar to those of Charles and Ernst (1974) but the feed efficiency results differ. Marrett et al. (1975) and Polin and Ringer (1977), however, obtained higher egg production from hens given diets containing 25 OH-D3 than those receiving D 3 , whereas production was the same in the present experiment. Roland and Harms (1976) found no difference in egg production of young or old hens given 25 OH-D3 or D 3 in their diets. The results for shell and interior quality variables of the eggs laid over a 4-day period, starting after the hens had received the diets for 81 days, are presented in Table 3. There were no differences (P>.05) among strains for egg weight, Haugh units, and blood spots but shell weight, percent shell, shell weight per unit surface area (SW/SA), specific gravity, and compression fracture force were lower (P <.001) and non-destructive deformation was
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VITAMIN D SOURCE AND LEVEL AND EGG QUALITY
Dietary D 3 source a n d level had n o effect on shell or interior quality (Table 3). There were strain X p h o s p h o r u s interactions (P<.05) for b l o o d spots, strain X D 3 source for shell weight and b l o o d spots, p h o s p h o r u s x D 3 source for egg weight a n d Haugh units, and D 3 source X D 3 level for egg weight. T h e interactions involving egg and shell weight were mainly a t t r i b u t a b l e t o variation a m o n g strains while t h o s e for b l o o d spots and Haugh units m a y have been r a n d o m occurrences. Both Roland and Harms ( 1 9 7 6 ) and Cohen et al. ( 1 9 7 8 ) f o u n d t h a t substituting 25 O H - D 3 for D 3 in laying hen diets had no effect on specific gravity, egg and shell weight, and SW/SA, whereas Charles and Ernst ( 1 9 7 4 ) , Marrett et al. ( 1 9 7 5 ) , and McLoughlin and Soares ( 1 9 7 6 ) r e p o r t e d t h a t c o m p a r e d t o D 3 , 25 O H - D 3 improved specific gravity, shell thickness, and compression fracture force. Charles and Ernst ( 1 9 7 4 ) also found t h a t D 3 source did n o t influence shell d e f o r m a t i o n . Antillon et al. ( 1 9 7 7 ) observed t h a t D 3 level had n o influence o n shell fracture force which agrees with t h e results in Table 3. T h e results from this e x p e r i m e n t indicate t h a t i m p r o v e m e n t in egg p r o d u c t i o n and shell quality of eggs from force m o l t e d hens was n o t o b t a i n e d b y decreasing t h e level of dietary p h o s p h o r u s or substituting 2 5 - h y d r o x y vitamin D 3 for vitamin D 3 in t h e diets.
ACKNOWLEDGMENTS T h e a u t h o r wishes t o t h a n k R. T. Poirier for his technical assistance, K. G. Hilson for his assistance with t h e data files, J.A.B. Emsley
for his advice and assistance with t h e statistical analyses, and M. J. DeGeeter, T h e U p j o h n C o m p a n y , Kalamazoo, MI for t h e generous supply of 2 5 - h y d r o x y vitamin D 3 . T h e chemical analyses of t h e e x p e r i m e n t a l diets were performed b y t h e staff of t h e Chemistry and Biology Research Institute, Agriculture Canada.
REFERENCES Antillon, A., M. L. Scott, L. Krook, and R. H. Wasserman, 1977. Metabolic response of laying hens to different dietary levels of calcium, phosphorus and vitamin D 3 . Cornell Vet. 67:413—444. Association of Official Analytical Chemists, 1975. Official methods of analysis. 12th ed. AOAC, Washington, DC. Bar, A., and S. Hurwitz, 1973. Uterine calcium-binding protein in the laying fowl. Comp. Biochem. Physiol. 45A:579-586. Charles, O. W., and R. A. Ernst, 1974. Effect of age, calcium level and vitamin D metabolites on egg shell quality of SCWL. Poultry Sci. 5 3:1908. Cohen, A., A. Bar, U. Eisner, and S. Hurwitz, 1978. Calcium absorption, calcium-binding protein, and egg shell quality in laying hens fed hydroxylated vitamin D derivatives. Poultry Sci. 57:1646— 1651. Corradino, R. A., R. H. Wasserman, M. H. Pubols, and S. I. Chang, 1968. Vitamin D 3 induction of a calcium-binding protein in the uterus of the laying hen. Arch. Biochem. Biophys. 125:378— 380. DeLuca, H. F., 1977. Vitamin D endocrine system. Adv. Clinical Chem. 19:125-174. Gowe, R. S., 1977. Multiple-trait selection in egg stocks: 1. Performance of six selected lines derived from three base populations; 2. Changes in genetic parameters over time in six selected strains. Page 68—91 in Proc. 26th Ann. Poultry Breeders' Roundtable, Kansas City, MO. Gowe, R. S., W. E. Lentz, and J. H. Strain, 1973. Long-term selection for egg production in several strains of White Leghorns: Performance of selected and control strains including genetic parameters of two control strains. Page 225—245 in 4th Europ. Poultry Conf., London. Hamilton, R.M.G., 1978. Observations on the changes in physical characteristics that influence egg shell quality in ten strains of White Leghorns. Poultry Sci. 57:1192-1197. Hamilton, R.M.G., and I. R. Sibbald, 1977. The effects of dietary phosphorus on production performance and egg quality of ten strains of White Leghorns. Poultry Sci. 56:1221-1228. Hamilton, R.M.G., and B. K. Thompson, 1980. Effects of sodium plus potassium to chloride ratio in practical-type diets on blood gas levels in three strains of White Leghorn hens and the relationship between acid-base balance and egg shell strength. Poultry Sci. (In press). Hamilton, R.M.G., B. K. Thompson, and P. W. Voisey, 1979. The effects of age and strain on the relationships between destructive and non-destructive
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higher ( P < . 0 0 1 ) for strain 4 t h a n 1. Although t h e egg weight was n o t different b e t w e e n strains, as e x p e c t e d (Gowe, 1 9 7 7 ) , specific gravity and t h e o t h e r shell variables agreed with t h e results of G o w e ( 1 9 7 7 ) a n d H a m i l t o n and T h o m p s o n ( 1 9 8 0 ) . E x c e p t for egg weight, p h o s p h o r u s level had n o effect on shell a n d interior quality. T h e specific gravity and fracture force results d o n o t agree with those of Hamilton and Sibbald ( 1 9 7 7 ) and Antillon et al. ( 1 9 7 7 ) , respectively, b o t h of w h o m r e p o r t e d t h a t there were significant increases in shell quality w h e n t h e level of p h o s p h o r u s was decreased in t h e laying diets. A l t h o u g h t h e SW/SA results agree with those of Polin and Ringer ( 1 9 7 7 ) , it m a y be n o t e d t h a t in their diets, as t h e p h o s p h o r u s levels increased t h e calcium levels also increased.
603
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HAMILTON shell quality or other criteria in laying hens. Poultry Sci. 55:1982-1985. Scott, M. L., M. C. Nesheim, and R. J. Young, 1976. Nutrition of the chicken. M. L. Scott and Ass., Ithaca, NY. Swanson, M. H., and D. D. Bell, 1974. Force molting of chickens. II. Methods. University of California, Berkley, CA, Pub. AXT-411. Voisey, P. W., and R.M.G. Hamilton, 1977. Sources of error in egg specific gravity measurements by the flotation method. Poultry Sci. 56:1457-1462. Voisey, P. W., and J. R. Hunt, 1974. Measurement of eggshell strength. J. Texture Stud. 5:135-182. Voisey, P. W., and D. C. MacDonald, 1978. Laboratory measurement of egg shell strength. 1. An instrument for measuring shell strength by quasi-static compression, puncture, and non-destructive deformation. Poultry Sci. 57:860-869. Wasserman, R. H., and A. N. Taylor, 1968. Vitamin D-dependent calcium-binding protein. Response to some physiological and nutritional variables. J. Biol. Chem. 243:3987-3993.
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measurements of egg shell strength for White Leghorn hens. Poultry Sci. 58:1125-1132. Marrett, L. E., F. R. Frank, and R. G. Zimbelman, 1975. 25-hydroxycholecalciferol as a dietary replacement of D 3 to improve egg shell calcification. Poultry Sci. 54:1788. McLoughlin, C. P., and J. H. Soares, Jr., 1976. A study of the effects of 25-hydroxycholecalciferol and calcium source on egg shell quality. Poultry Sci. 55:1400-1410. Norman, A. W., and H. L. Henry, 1979. Vitamin D to 1,25-dihydroxycholecalciferol: Evolution of a steroid hormone. Trends Biochem. Sci. 4:14—18. Omdahl, J. L., and H. F. DeLuca, 1973. Regulation of vitamin D metabolism and function. Physiol. Rev. 53:327-372. Polin, D., and R. K. Ringer, 1977. 25-hydroxy-D,, vitamin D3 and graded levels of phosphorus: Effect on egg production and shell quality. Feedstuffs 49(44):40-41, 47. Roland, D. A., Sr., and R. H. Harms, 1976. The lack of response of 25-hydroxy-vitamin D 3 on egg