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Influence of Sodium Zeolite A with and Without Pullet-Sized Limestone or Oyster Shell on Eggshell Quality1
Influence of Sodium Zeolite A with and Without Pullet-Sized Limestone or Oyster Shell on Eggshell Quality 1 H. W. RABON, JR.,2 D. A. ROLAND, SR.} MARY BRYANT, D. G. BARNES,3 and S. M LAURENT3 Department of Poultry Science, Alabama Agricultural Experiment Station, Auburn University, Alabama 36849 (Received for publication November 5, 1990)
1991 Poultry Science 70:1943-1947 INTRODUCTION
Progress has been made in reduction of eggshell quality problems during die past 15 to 20 yr. One factor responsible for this reduction was the discovery that large particles of CaC03 would improve shell quality. Scott and Mullenhoff (1970) reported that hens fed diets in which two-thirds of the added limestone was replaced with oyster shell improved eggshell quality. Their explanation was that large particles of CaC03 were retained in the gizzard. Calcium was then meted from the gizzard during the night, reducing the degree of severity of calcium deficiency when hens are not eating. In subsequent years, many researchers, as reviewed by Roland (1986), conducted similar research on eggshell quality problems, most of which reported that the inclusion of oyster shell in the diet, at the expense of limestone,
Alabama Agricultural Experiment Station Journal Series Number 12-902581P. Department of Poultry Science. ^thyl Corporation, Baton Rouge, LA 70801.
significantly improved eggshell quality. However, other researchers found that the inclusion of oyster shell in layer diets had no influence on eggshell quality (Roland, 1986). Although there are several reasons for the reported variations in response of hens fed different sources and sizes of CaCC>3 (Roland, 1986), it is generally accepted that feeding large particles of CaCC>3 would be beneficial in most commercial operations (Roland, 1986). Sodium zeolite (ZA) is another dietary supplement that has been reported to improve eggshell quality (Roland et al., 1985; Miles et al, 1986; Ingram and Kling, 1988). However, the mechanism of action of ZA is unknown. It is hypothesized that the mechanism may be related to ZA's high affinity for calcium and its high ion-exchange capability, because ZA can selectively absorb and release calcium with change in pH (Rabo, 1976). Thus, the mechanism for improving eggshell quality may be similar to that of oyster shell. The purpose of the present investigation was to determine whether me beneficial effect of ZA on egg specific gravity is influenced by particle size and source of CaCC>3.
1943
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
ABSTRACT To determine whether particle size oiCaCO^ influences the hen's response to sodium zeolite A (ZA), two experiments were conducted. In Experiment 1, hens were fed 0, .75, and 1.50% ZA for 6 wk with and without a Na correction. At the end of the 4th wk, pullet-sized limestone was substituted for 50% of the added fine granular limestone in the diet containing no ZA. In Experiment 2, hens were fed diets containing 0, .68, and 1.36 ZA for 8 wk with and without one-half of the added fine granular limestone substituted for oyster shell. No correction for Na was made. A dietary calcium concentration of 2.75% was used in Experiment 1 and 3.5% in Experiment 2. Egg specific gravity, egg production, feed consumption, and egg weight were measured. Sodium zeolite A increased egg specific gravity, and the beneficial effects of ZA were maintained during Weeks 5 and 6 when pullet-sized limestone was added to the control diet containing no ZA (Experiment 1). Oyster shell and ZA improved egg specific gravity in Experiment 2 and the effect was additive. Dietary treatments had no effect on egg production or egg weight in Experiments 1 or 2 and there was no effect on feed consumption (Experiment 1). Feed consumption was reduced by ZA, when hens were fed oyster shell, but not when they were fed ZA with fine granular limestone (Experiment 2). It was concluded that the beneficial effect of ZA on egg specific gravity was independent of particle size of CaCX>3 in the diet. (Key wordy, sodium zeolite A, calcium, oyster shell, limestone, particle size)
1944
RABON, JR. ET AL. MATERIALS AND METHODS
RESULTS AND DISCUSSION
The results of Experiment 1 indicated that ZA significantly improved egg specific gravity when hens were fed diets containing fine granular limestone (Weeks 1 to 4, Table 2). Correcting for Na had no influence on the hens response to ZA. When 50% of the fine granular limestone in the control diet (0% ZA) was replaced with an equal quantity of pullet size limestone (Weeks 5 and 6), no influence on the hen's response to ZA was observed. The significant linear response prevailed in egg specific gravity through 5 and 6 wk, regardless of the Na correction status. Sodium zeolite A had no influence on egg production during Weeks 1 to 4 or Weeks 5 and 6 (Table 2). The inclusion of pullet-sized limestone did not affect the hens' response to ZA. Average egg production was 70% for the first 4 wk and 64% for Weeks 5 and 6. Furthermore, ZA with or without pullet-size limestone had no influence on egg weight or feed consumption. In Experiment 2, there was a significant calcium source and ZA effect on egg specific gravity (Table 3). Addition of oyster shell increased egg specific gravity from 1.0787 to 1.0797 and the addition of ZA increased egg specific gravity from 1.0786 to 1.0799. The response obtained from oyster shell and ZA was additive. There was a significant linear effect of ZA on egg specific gravity when birds were fed limestone and when they were fed oyster shell and there were no calcium source by ZA interactions. Calcium source or ZA did not influence average egg production and no ZA by calcium source interaction occurred (Table 3). Average egg production ranged from 70 to 73% for all treatment. Egg weight was not influenced by calcium source or ZA and there were no calcium source by ZA interactions.
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
In Experiment 1, 300 DeKalb XL hens 79 wk of age and housed in individual cages (30.5 x 40.6 cm) were used. Based on 10 days preexperimental egg production and 3 day's preexperimental egg specific gravity measurements, hens were divided into 30 equal groups, with similar egg production and egg specific gravity. Hens were then randomized into treatments (6 replicates of 10 hens per treatment). The pre-experimental egg production for each treatment group was 79%. The pre-experimental egg specific gravity of the different treatment groups ranged from 1.0764 to 1.0768. Starting in March, they were fed commercial corn and soybean meal-based diets containing three levels of ZA (0, .75, and 1.50%) with and without Na correction (Table 1) for 6 wk. In diets corrected for the added Na from ZA, NaCl was removed and HC1 added to replace the CI. At the end of the 4th wk, 50% of the fine granular limestone in the diet containing no Za was replaced with an equal quantity of pullet-sized limestone. No pulletsize limestone was used in any of the other diets. The fine granular limestone had particles ranging from 1.41 mm to 74 u,, with 79.5% of the particles retained by a United States standard mesh screen No. 200 (74 \i). The pullet-sized particles ranged from 4.7 to 2.00 mm, with 99.5% retained by U.S. standard mesh screen No. 10 (2 mm). In Experiment 2, 864 Hy-Line® W36 hens 75 wk of age and housed 3 per cage (30.5 x 40.5 cm) were used. Based on 10 day's preexperimental egg production and 3 days preexperimental egg specific gravity measurements, hens were divided into 36 equal groups, with similar egg production and egg specific gravity. Hens were then randomized in August into treatments (6 replicates of 24 hens per treatment). The pre-experimental egg production for each treatment with 75%. The preexperimental egg specific gravity value ranged from 1.0800 to 1.0804 for the various treatments. Dietary treatments were 0, .68, and 1.36% ZA with and without 50% of the added limestone substituted for an equal quantity of hen-sized oyster shell. All diets (isocaloric and isonitrogenous, Table 1) were fed for 5 wk. Sodium zeolite A was added at the expense of sand. No correction for Na and CI was made. In both experiments, egg production and feed consumption was determined at weekly intervals. Egg specific gravity (Holder and
Bradford, 1979) and egg weight were measured on all eggs laid during a 3-day period at weekly intervals. Data were subjected to analysis of variance using General Linear Models procedure available from the SAS Institute (1986), which uses procedures described by Steel and Torrie (1980). Student Newman-Keuls test (Damon and Harvey, 1987) was used to determine significant differences between means when interactions were observed.
16.00 2,866 .55 2.75 .50 .19
16.00 2,866 55 2.75 .50 .17 16.00 2,866 .55 2.75 .50 .36
Limestone
16.00 2,770 .58 3.50 .40 .25
.68
1.36
16.00 2,770 .58 3.50 .40 .17
1.00 1.64 7.93 .04 .35 .25 .25 .68
66.40 20.77
.68 ZA
1.00 1.64 7.93 .04 .35 .25 .25
66.40 20.77
(%)-
0 ZA
2
1
2
••To partially correct for sodium supplied by sodium zeolite A (ZA), NaCl was removed from the diet of hens fed ZA ZA was added at the expense of sand. No correction for Na was made. 3 Supplied per kilogram of diet: cobalt, 20 mg; iodine, 1.0 mg; iron, 55 mg; copper, 6 mg; and zinc, 55 mg. ^Supplied per kilogram of diet: vitamin A, 8,000 IU; cholecalciferol, 2,200 ICU; vitamin E, 8 IU; menadione (MPB), 2.0 mg; ri mg; choline, 500 mg; vitamin B 1 2 , .02 mg; folic acid, .5 mg; thiamine, 1 mg; and pyridoxine, 2.2 mg. 5 Sodium aluminosilicate (Ethacal®); Ethyl Corp., Baton Rouge, LA 70801.
16.00 2,866 .55 2.75 .50 .27
.35 25 25 1.50
.35 .25 .25 .75
25 25 1.50 .57
.10 25 25 .75 .40
1.00 1.99 5.89
1.00 1.99 5.89
1.00 1.99 5.89
67.20 21.57
1.50 ZA No HC1
1.00 1.99 5.89
67.95 21.57
66.98 21.57
67.80 21.57
Corn 68.70 Soybean meal 21.57 Dehydrated alfalfa meal (17% CP) 1.00 Dicalcium phosphate 1.99 Limestone 5.89 DL-methionine Salt .35 Mineral premix 25 Vitamin premix4 .25 A5 HC1 Sand Oyster shell Calculated analysis Crude protein 16.00 ME, kcal/kg 2,866 TSAA .55 Calcium 2.75 Available phosphorus .50 Na .17
.75 ZA No H a
1.50 ZA HC1
.75 ZA HO
0 ZA No HC1
Ingredients
Experiment 1
TABLE 1. Composition of diets used in Experiments I1 and 2'
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
1946
RABON, JR. EI Ah.
TABLE 2. Influence of sodium zeolite A (ZA) with and without sodium correction (HCl versus no HCl) on egg specific gravity, egg production, egg weight, and feed consumption (Experiment ly Egg production
Egg specific gravity 1 to 4
5 to 6
1 to 4
5 to 6
1 to 4
-(%) ZA + HCl .00 .75 1.50 SEM ZA + no HCl .00 .75 1.50 SEM
*
*
1.0742 1.0764 1.0767 .0007
1.0728 1.0744 1.0762 .0008
**
*
1.0742 1.0767 1.0768 .0007
1.0728 1.0753 1.0766 .0008
Weeks
Weeks
Weeks
Weeks Treatment
Feed consumption
Egg weight 5 to 6
1 to 4
5 to 6
- (g per hen per day) —
firl
\B)
71 71 67 3
63 67 62 5
64.9 63.8 65.6 .7
65.9 63.5 65.2 .9
110 107 108 2
110 107 109 2
71 73 64 4
63 65 64 4
64.9 64.3 64.8 .5
65.9 63.5 65.6 .6
110 108 105 2
110 109 110 2
,
TABLE 3. Influence of sodium zeolite A (ZA) with different calcium sources fed for 8 wk on egg specific gravity, egg production, egg weight, and feed consumption (Experiment 2f
Treatment
Calcium source (CAS) Limestone Oyster shell SEM ZA (%) .00 .68 1.36 SEM CAS x ZA (%) Limestone .00 .68 1.36 Oyster shell .00 .68 1.36 SEM CAS ZA CAS x ZA
Egg production
Egg weight1
Food consumption
(% hen-day)
(g)
(g per hen per day)
1.0787 1.0797 .0002
71 71
105 102
.6
66.4 65.5 .3
1.0786 1.0790 1.0799 .0003
72 72 70
105 103 103
.7
65.9 65.6 65.2 .4
1.0782 1.0784 1.0796
73 72 70
65.9 66.1 64.9
106 105 106
1.0790 1.0797 1.0803 .0004
73 71 71 1.0
65.9 65.1 65.4 .5
105 101 100 1.2
Egg specific gravity
.0075 .009
.7
.9
.005 .07
'There were 864 hens used in the experiment. Egg specific gravity and egg weight was determined on 14,722 eggs.
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
'Hens fed fine granular limestone during Weeks 1 to 4. During Weeks 5 and 6,50% of the fine granular limestone in the diet containing no ZA was replaced with an equal quantity of pullet sized limestone. There were 300 hens used in the experiment Egg specific gravity and egg weight were determined on 2,502 eggs for Weeks 1 to 4 and 1,152 eggs for Weeks 5 and 6. •Significant linear effect (P<05). ••Highly significant linear effect (P<01).
SODIUM ZEOLITE A EFFECT ON SHELL QUALITY
the fine granular limestone in the control diet was substituted for large-particle Ca(X>3. If large-particle CaC03 had been effective and the response was the same as that obtained from ZA, the significant linear response of hens to ZA should have been eliminated and it was not. Thus, this was an indication that hens were not responding to ZA and large-particle CaC03 in the same manner. In Experiment 2 a direct comparison was made. The results demonstrate that ZA and large-particle CaC03 increased egg specific gravity. However, the response was independent and additive. Therefore, it is concluded that the beneficial effect of ZA on egg specific gravity occurred regardless of the particle size of the CaC03 source used. Because ZA increased egg specific gravity in diets containing oyster shell, suggest that the mechanism of ZA action is more complex than simple ionexchange. REFERENCES Damon, R. A., Jr., and W. R. Harvey, 1987. Pages 1-369 in: Experimental Design, ANOVA, and Regression. Harper and Row Publishers, Inc., New York, NY. Holder, D. P., and M. V. Bradford, 1979. Relationship of specific gravity of chicken eggs to number of cracked eggs observed and percent shell. Poultry Sci. 58:250-251. Ingram, D. R., and C. E. Kling, 1988. Influence of Ethacal feed component on production parameters of White leghorn hens during high ambient temperature. Nutr. Rep. Int. 37:811-«18. Miles, R. D., R. H. Harms, and S. M. Laurent, 1986. Influence of sodium zeolite A (Ethacal) on laying hen performance. Nutr. Rep. Int 34:1097-1103. Rabo, J. A., 1976. Pages 285-331 in: Zeolite Chemistry and Catalysis. American Chemical Society. Washington, DC. Roland, D. A., Sr., 1986. Eggshell quality IV. Oystershell versus limestone and the importance of particle size or solubility of calcium source. World's Poult. Sci. J. 42:166-171. Roland, D. A., Sr., S. M. Laurent, and H. D. Orloff, 1985. Shell quality as influenced by zeolite with high ionexchange capability. Poultry Sci. 64:1177-1187. SAS Institute, 1986. SAS® User's Guide: Statistics. Version 6 Editioa SAS Institute, Inc., Cary, NC. Scott, M. L., and P. A. Mullenhoff, 1970. Dietary oystershell and egg shell quality. Pages 24-28 in: Proceedings Cornell Nutrition Conference, Ithaca, NY. Steel, R.G.D., and J. H. Torrie, 1980. Principles and Procedures of Statistics: A Biometrical Approach. 2nd ed. McGraw Hill Book Co., New York, NY.
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
Calcium source and ZA influenced feed consumption (Table 3) and there was a calcium source by ZA interaction on feed consumption for Weeks 3 and 7. Sodium zeolite A had no influence on average feed consumption when hens were fed only limestone; however, there was a significant linear decrease in feed consumption when hens were fed ZA with oyster shell; the reason for that is unknown. There was no significant calcium source by ZA interaction for the average 8-wk data. Oyster shell (large particle CaC03> improves egg specific gravity because largeparticle CaCC>3 is retained in the gizzard and is then slowly metered into the digestive system improving calcium availability (Scott and Mullenhoff, 1970). The mechanism whereby ZA improves egg specific gravity is unknown. However, it has been hypothesized that its ability to exchange cations without major change in structure may be involved in its ability to improve calcium availability (Roland et al., 1985). If large-particle CaCo3 and ZA are effective by increasing calcium availability, then one would expect the beneficial effect of oyster shell to be eliminated or at least reduced when ZA is added to the diet. The opposite should also be true. However, if the mechanisms or degree of shell quality improvement are different, the hen's response in terms of improvement in egg specific gravity may be additive. Because hens respond favorably to largeparticle CaC03 only approximately 50% of the time (Roland, 1986) and ZA is not always effective, it is difficult to compare performance of hens fed these products. To increase the odds of obtaining beneficial effects of oyster shell and ZA, diets used in both experiments contained marginal levels of calcium. Oyster shell (Roland, 1986) and ZA (Roland et al, 1985) have been shown to be most effective when hens are fed marginal levels of calcium. Also two different experimental designs were used. In Experiment 1, ZA improved egg specific gravity when the calcium source was fine granular limestone. It was hypothesized that if the mechanism of action of ZA was similar to large-particle CaC03, the significant beneficial effect of ZA would be masked when 50% of
1947
1991 Poultry Science 70:1943-1947 INTRODUCTION
Progress has been made in reduction of eggshell quality problems during die past 15 to 20 yr. One factor responsible for this reduction was the discovery that large particles of CaC03 would improve shell quality. Scott and Mullenhoff (1970) reported that hens fed diets in which two-thirds of the added limestone was replaced with oyster shell improved eggshell quality. Their explanation was that large particles of CaC03 were retained in the gizzard. Calcium was then meted from the gizzard during the night, reducing the degree of severity of calcium deficiency when hens are not eating. In subsequent years, many researchers, as reviewed by Roland (1986), conducted similar research on eggshell quality problems, most of which reported that the inclusion of oyster shell in the diet, at the expense of limestone,
Alabama Agricultural Experiment Station Journal Series Number 12-902581P. Department of Poultry Science. ^thyl Corporation, Baton Rouge, LA 70801.
significantly improved eggshell quality. However, other researchers found that the inclusion of oyster shell in layer diets had no influence on eggshell quality (Roland, 1986). Although there are several reasons for the reported variations in response of hens fed different sources and sizes of CaCC>3 (Roland, 1986), it is generally accepted that feeding large particles of CaCC>3 would be beneficial in most commercial operations (Roland, 1986). Sodium zeolite (ZA) is another dietary supplement that has been reported to improve eggshell quality (Roland et al., 1985; Miles et al, 1986; Ingram and Kling, 1988). However, the mechanism of action of ZA is unknown. It is hypothesized that the mechanism may be related to ZA's high affinity for calcium and its high ion-exchange capability, because ZA can selectively absorb and release calcium with change in pH (Rabo, 1976). Thus, the mechanism for improving eggshell quality may be similar to that of oyster shell. The purpose of the present investigation was to determine whether me beneficial effect of ZA on egg specific gravity is influenced by particle size and source of CaCC>3.
1943
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
ABSTRACT To determine whether particle size oiCaCO^ influences the hen's response to sodium zeolite A (ZA), two experiments were conducted. In Experiment 1, hens were fed 0, .75, and 1.50% ZA for 6 wk with and without a Na correction. At the end of the 4th wk, pullet-sized limestone was substituted for 50% of the added fine granular limestone in the diet containing no ZA. In Experiment 2, hens were fed diets containing 0, .68, and 1.36 ZA for 8 wk with and without one-half of the added fine granular limestone substituted for oyster shell. No correction for Na was made. A dietary calcium concentration of 2.75% was used in Experiment 1 and 3.5% in Experiment 2. Egg specific gravity, egg production, feed consumption, and egg weight were measured. Sodium zeolite A increased egg specific gravity, and the beneficial effects of ZA were maintained during Weeks 5 and 6 when pullet-sized limestone was added to the control diet containing no ZA (Experiment 1). Oyster shell and ZA improved egg specific gravity in Experiment 2 and the effect was additive. Dietary treatments had no effect on egg production or egg weight in Experiments 1 or 2 and there was no effect on feed consumption (Experiment 1). Feed consumption was reduced by ZA, when hens were fed oyster shell, but not when they were fed ZA with fine granular limestone (Experiment 2). It was concluded that the beneficial effect of ZA on egg specific gravity was independent of particle size of CaCX>3 in the diet. (Key wordy, sodium zeolite A, calcium, oyster shell, limestone, particle size)
1944
RABON, JR. ET AL. MATERIALS AND METHODS
RESULTS AND DISCUSSION
The results of Experiment 1 indicated that ZA significantly improved egg specific gravity when hens were fed diets containing fine granular limestone (Weeks 1 to 4, Table 2). Correcting for Na had no influence on the hens response to ZA. When 50% of the fine granular limestone in the control diet (0% ZA) was replaced with an equal quantity of pullet size limestone (Weeks 5 and 6), no influence on the hen's response to ZA was observed. The significant linear response prevailed in egg specific gravity through 5 and 6 wk, regardless of the Na correction status. Sodium zeolite A had no influence on egg production during Weeks 1 to 4 or Weeks 5 and 6 (Table 2). The inclusion of pullet-sized limestone did not affect the hens' response to ZA. Average egg production was 70% for the first 4 wk and 64% for Weeks 5 and 6. Furthermore, ZA with or without pullet-size limestone had no influence on egg weight or feed consumption. In Experiment 2, there was a significant calcium source and ZA effect on egg specific gravity (Table 3). Addition of oyster shell increased egg specific gravity from 1.0787 to 1.0797 and the addition of ZA increased egg specific gravity from 1.0786 to 1.0799. The response obtained from oyster shell and ZA was additive. There was a significant linear effect of ZA on egg specific gravity when birds were fed limestone and when they were fed oyster shell and there were no calcium source by ZA interactions. Calcium source or ZA did not influence average egg production and no ZA by calcium source interaction occurred (Table 3). Average egg production ranged from 70 to 73% for all treatment. Egg weight was not influenced by calcium source or ZA and there were no calcium source by ZA interactions.
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
In Experiment 1, 300 DeKalb XL hens 79 wk of age and housed in individual cages (30.5 x 40.6 cm) were used. Based on 10 days preexperimental egg production and 3 day's preexperimental egg specific gravity measurements, hens were divided into 30 equal groups, with similar egg production and egg specific gravity. Hens were then randomized into treatments (6 replicates of 10 hens per treatment). The pre-experimental egg production for each treatment group was 79%. The pre-experimental egg specific gravity of the different treatment groups ranged from 1.0764 to 1.0768. Starting in March, they were fed commercial corn and soybean meal-based diets containing three levels of ZA (0, .75, and 1.50%) with and without Na correction (Table 1) for 6 wk. In diets corrected for the added Na from ZA, NaCl was removed and HC1 added to replace the CI. At the end of the 4th wk, 50% of the fine granular limestone in the diet containing no Za was replaced with an equal quantity of pullet-sized limestone. No pulletsize limestone was used in any of the other diets. The fine granular limestone had particles ranging from 1.41 mm to 74 u,, with 79.5% of the particles retained by a United States standard mesh screen No. 200 (74 \i). The pullet-sized particles ranged from 4.7 to 2.00 mm, with 99.5% retained by U.S. standard mesh screen No. 10 (2 mm). In Experiment 2, 864 Hy-Line® W36 hens 75 wk of age and housed 3 per cage (30.5 x 40.5 cm) were used. Based on 10 day's preexperimental egg production and 3 days preexperimental egg specific gravity measurements, hens were divided into 36 equal groups, with similar egg production and egg specific gravity. Hens were then randomized in August into treatments (6 replicates of 24 hens per treatment). The pre-experimental egg production for each treatment with 75%. The preexperimental egg specific gravity value ranged from 1.0800 to 1.0804 for the various treatments. Dietary treatments were 0, .68, and 1.36% ZA with and without 50% of the added limestone substituted for an equal quantity of hen-sized oyster shell. All diets (isocaloric and isonitrogenous, Table 1) were fed for 5 wk. Sodium zeolite A was added at the expense of sand. No correction for Na and CI was made. In both experiments, egg production and feed consumption was determined at weekly intervals. Egg specific gravity (Holder and
Bradford, 1979) and egg weight were measured on all eggs laid during a 3-day period at weekly intervals. Data were subjected to analysis of variance using General Linear Models procedure available from the SAS Institute (1986), which uses procedures described by Steel and Torrie (1980). Student Newman-Keuls test (Damon and Harvey, 1987) was used to determine significant differences between means when interactions were observed.
16.00 2,866 .55 2.75 .50 .19
16.00 2,866 55 2.75 .50 .17 16.00 2,866 .55 2.75 .50 .36
Limestone
16.00 2,770 .58 3.50 .40 .25
.68
1.36
16.00 2,770 .58 3.50 .40 .17
1.00 1.64 7.93 .04 .35 .25 .25 .68
66.40 20.77
.68 ZA
1.00 1.64 7.93 .04 .35 .25 .25
66.40 20.77
(%)-
0 ZA
2
1
2
••To partially correct for sodium supplied by sodium zeolite A (ZA), NaCl was removed from the diet of hens fed ZA ZA was added at the expense of sand. No correction for Na was made. 3 Supplied per kilogram of diet: cobalt, 20 mg; iodine, 1.0 mg; iron, 55 mg; copper, 6 mg; and zinc, 55 mg. ^Supplied per kilogram of diet: vitamin A, 8,000 IU; cholecalciferol, 2,200 ICU; vitamin E, 8 IU; menadione (MPB), 2.0 mg; ri mg; choline, 500 mg; vitamin B 1 2 , .02 mg; folic acid, .5 mg; thiamine, 1 mg; and pyridoxine, 2.2 mg. 5 Sodium aluminosilicate (Ethacal®); Ethyl Corp., Baton Rouge, LA 70801.
16.00 2,866 .55 2.75 .50 .27
.35 25 25 1.50
.35 .25 .25 .75
25 25 1.50 .57
.10 25 25 .75 .40
1.00 1.99 5.89
1.00 1.99 5.89
1.00 1.99 5.89
67.20 21.57
1.50 ZA No HC1
1.00 1.99 5.89
67.95 21.57
66.98 21.57
67.80 21.57
Corn 68.70 Soybean meal 21.57 Dehydrated alfalfa meal (17% CP) 1.00 Dicalcium phosphate 1.99 Limestone 5.89 DL-methionine Salt .35 Mineral premix 25 Vitamin premix4 .25 A5 HC1 Sand Oyster shell Calculated analysis Crude protein 16.00 ME, kcal/kg 2,866 TSAA .55 Calcium 2.75 Available phosphorus .50 Na .17
.75 ZA No H a
1.50 ZA HC1
.75 ZA HO
0 ZA No HC1
Ingredients
Experiment 1
TABLE 1. Composition of diets used in Experiments I1 and 2'
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
1946
RABON, JR. EI Ah.
TABLE 2. Influence of sodium zeolite A (ZA) with and without sodium correction (HCl versus no HCl) on egg specific gravity, egg production, egg weight, and feed consumption (Experiment ly Egg production
Egg specific gravity 1 to 4
5 to 6
1 to 4
5 to 6
1 to 4
-(%) ZA + HCl .00 .75 1.50 SEM ZA + no HCl .00 .75 1.50 SEM
*
*
1.0742 1.0764 1.0767 .0007
1.0728 1.0744 1.0762 .0008
**
*
1.0742 1.0767 1.0768 .0007
1.0728 1.0753 1.0766 .0008
Weeks
Weeks
Weeks
Weeks Treatment
Feed consumption
Egg weight 5 to 6
1 to 4
5 to 6
- (g per hen per day) —
firl
\B)
71 71 67 3
63 67 62 5
64.9 63.8 65.6 .7
65.9 63.5 65.2 .9
110 107 108 2
110 107 109 2
71 73 64 4
63 65 64 4
64.9 64.3 64.8 .5
65.9 63.5 65.6 .6
110 108 105 2
110 109 110 2
,
TABLE 3. Influence of sodium zeolite A (ZA) with different calcium sources fed for 8 wk on egg specific gravity, egg production, egg weight, and feed consumption (Experiment 2f
Treatment
Calcium source (CAS) Limestone Oyster shell SEM ZA (%) .00 .68 1.36 SEM CAS x ZA (%) Limestone .00 .68 1.36 Oyster shell .00 .68 1.36 SEM CAS ZA CAS x ZA
Egg production
Egg weight1
Food consumption
(% hen-day)
(g)
(g per hen per day)
1.0787 1.0797 .0002
71 71
105 102
.6
66.4 65.5 .3
1.0786 1.0790 1.0799 .0003
72 72 70
105 103 103
.7
65.9 65.6 65.2 .4
1.0782 1.0784 1.0796
73 72 70
65.9 66.1 64.9
106 105 106
1.0790 1.0797 1.0803 .0004
73 71 71 1.0
65.9 65.1 65.4 .5
105 101 100 1.2
Egg specific gravity
.0075 .009
.7
.9
.005 .07
'There were 864 hens used in the experiment. Egg specific gravity and egg weight was determined on 14,722 eggs.
Downloaded from http://ps.oxfordjournals.org/ at :: on January 21, 2015
'Hens fed fine granular limestone during Weeks 1 to 4. During Weeks 5 and 6,50% of the fine granular limestone in the diet containing no ZA was replaced with an equal quantity of pullet sized limestone. There were 300 hens used in the experiment Egg specific gravity and egg weight were determined on 2,502 eggs for Weeks 1 to 4 and 1,152 eggs for Weeks 5 and 6. •Significant linear effect (P<05). ••Highly significant linear effect (P<01).
SODIUM ZEOLITE A EFFECT ON SHELL QUALITY
the fine granular limestone in the control diet was substituted for large-particle Ca(X>3. If large-particle CaC03 had been effective and the response was the same as that obtained from ZA, the significant linear response of hens to ZA should have been eliminated and it was not. Thus, this was an indication that hens were not responding to ZA and large-particle CaC03 in the same manner. In Experiment 2 a direct comparison was made. The results demonstrate that ZA and large-particle CaC03 increased egg specific gravity. However, the response was independent and additive. Therefore, it is concluded that the beneficial effect of ZA on egg specific gravity occurred regardless of the particle size of the CaC03 source used. Because ZA increased egg specific gravity in diets containing oyster shell, suggest that the mechanism of ZA action is more complex than simple ionexchange. REFERENCES Damon, R. A., Jr., and W. R. Harvey, 1987. Pages 1-369 in: Experimental Design, ANOVA, and Regression. Harper and Row Publishers, Inc., New York, NY. Holder, D. P., and M. V. Bradford, 1979. Relationship of specific gravity of chicken eggs to number of cracked eggs observed and percent shell. Poultry Sci. 58:250-251. Ingram, D. R., and C. E. Kling, 1988. Influence of Ethacal feed component on production parameters of White leghorn hens during high ambient temperature. Nutr. Rep. Int. 37:811-«18. Miles, R. D., R. H. Harms, and S. M. Laurent, 1986. Influence of sodium zeolite A (Ethacal) on laying hen performance. Nutr. Rep. Int 34:1097-1103. Rabo, J. A., 1976. Pages 285-331 in: Zeolite Chemistry and Catalysis. American Chemical Society. Washington, DC. Roland, D. A., Sr., 1986. Eggshell quality IV. Oystershell versus limestone and the importance of particle size or solubility of calcium source. World's Poult. Sci. J. 42:166-171. Roland, D. A., Sr., S. M. Laurent, and H. D. Orloff, 1985. Shell quality as influenced by zeolite with high ionexchange capability. Poultry Sci. 64:1177-1187. SAS Institute, 1986. SAS® User's Guide: Statistics. Version 6 Editioa SAS Institute, Inc., Cary, NC. Scott, M. L., and P. A. Mullenhoff, 1970. Dietary oystershell and egg shell quality. Pages 24-28 in: Proceedings Cornell Nutrition Conference, Ithaca, NY. Steel, R.G.D., and J. H. Torrie, 1980. Principles and Procedures of Statistics: A Biometrical Approach. 2nd ed. McGraw Hill Book Co., New York, NY.
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Calcium source and ZA influenced feed consumption (Table 3) and there was a calcium source by ZA interaction on feed consumption for Weeks 3 and 7. Sodium zeolite A had no influence on average feed consumption when hens were fed only limestone; however, there was a significant linear decrease in feed consumption when hens were fed ZA with oyster shell; the reason for that is unknown. There was no significant calcium source by ZA interaction for the average 8-wk data. Oyster shell (large particle CaC03> improves egg specific gravity because largeparticle CaCC>3 is retained in the gizzard and is then slowly metered into the digestive system improving calcium availability (Scott and Mullenhoff, 1970). The mechanism whereby ZA improves egg specific gravity is unknown. However, it has been hypothesized that its ability to exchange cations without major change in structure may be involved in its ability to improve calcium availability (Roland et al., 1985). If large-particle CaCo3 and ZA are effective by increasing calcium availability, then one would expect the beneficial effect of oyster shell to be eliminated or at least reduced when ZA is added to the diet. The opposite should also be true. However, if the mechanisms or degree of shell quality improvement are different, the hen's response in terms of improvement in egg specific gravity may be additive. Because hens respond favorably to largeparticle CaC03 only approximately 50% of the time (Roland, 1986) and ZA is not always effective, it is difficult to compare performance of hens fed these products. To increase the odds of obtaining beneficial effects of oyster shell and ZA, diets used in both experiments contained marginal levels of calcium. Oyster shell (Roland, 1986) and ZA (Roland et al, 1985) have been shown to be most effective when hens are fed marginal levels of calcium. Also two different experimental designs were used. In Experiment 1, ZA improved egg specific gravity when the calcium source was fine granular limestone. It was hypothesized that if the mechanism of action of ZA was similar to large-particle CaC03, the significant beneficial effect of ZA would be masked when 50% of
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