Effect of Removing Salt, Sodium, or Chloride from the Diet of Commercial Layers1 R. H. HARMS
(Received for publication April 19, 1990) ABSTRACT Two experiments were conducted with Hy-Line® W-36 hens. The hens were 45 and 65 wk old at the start of Experiments 1 and 2, respectively. A corn-soybean meal basal diet was used. Four diets were fed for 19 days: 1) control; 2) no added NaCl; 3) no added NaCl withNa supplied as NaHCCfy and 4) no added Na with CI supplied as CaC^- All hens were fed the control diet from Day 20 to Day 84. Hens fed a diet without NaCl reached zero production in 9.8 and 13.3 days in Experiments 1 and 2, respectively. Hens fed the diet without Na reached zero production in 10.3 and 13.1 days in Experiments 1 and 2, respectively. Only a few of the hens fed the diets with no CI reached zero production. Time required for all hens to return to production after returning to control diets were 16.0,15.7, and 6.0 days for hens receiving no added NaCl, Na, or CI, respectively in Experiment 1, and 13.2,15.0, and .6 days in Experiment 2. Molting occurred in 92.7,77.8, and 24.2% of the hens receiving the no NaCl, Naor CI, respectively, in Experiment 1, and 80.0,723, 30% in Experiment 2. Mortality rates were 7.5, 12.5, 20.0, and 5.0% for die hens receiving diets with no NaCl, Na, CI, or control, respectively, in Experiment 1, and 25, 10.0, 20.0, and 0% in Experiment 2. (Key words: laying hen, forced rest, molt, egg production, sodium chloride) 1991 Poultry Science 70:333-336 INTRODUCTION
A number of reports have been published on the response of the laying hen to removal of salt from the diet (Whitehead and Shannon, 1974; Nesbeth et al., 1976a,b; Begin and Johnson, 1976; Monsi and Enos, 1977; Ross and Herrick, 1981; Naber et al, 1984). The major effect was a sharp drop in egg production to near zero, which was reversible with the addition of salt to the diet. It has been generally assumed that the reduction of egg production was due to the removal of the Na. However, the removal of only CI from the diet has not been studied. Nesbeth et al. (1976b), Begin and Johnson (1976), Compos and Baiao (1979), and Naber et al. (1984) concluded that resting the hen by feeding a diet with no added salt was as effective in inducing a rest as using a forced molt. However, Ross and Herrick (1981) obtained poorer performance from hens rested on a low-salt diet than from using a conventional forced molt.
Florida Agricultural Experiment Station Journal Series Number R-00630. 2 Hy-Line International, Dallas Center, IA 50063.
Most of those workers did not measure the incidence or severity of the molt when hens were fed the diet with no added salt However, Naber et al. (1984) noted feather loss that increased as duration of the experiment was increased. Therefore, the present experiments were conducted to determine whether the removal of Na or CI was the cause of the cessation of egg production. Also the incidence and severity of the molt were measured. MATERIALS AND METHODS
Two experiments were conducted with HyLine® W36 hens.2 Hens were 45 wk old in Experiment 1 and 65 wk old in Experiment 2. A corn-soybean meal basal diet (Table 1) was used that contained .03% sodium and .03% chloride by analysis. The water contained 10 and 33 ppm Na and CI, respectively. Four experimental diets were fed for 19 days: 1) control, containing .4% NaCl; 2) unsupplemented basal (no Na or CI); 3) no CI with Na supplied as NaHCC^; and 4) no Na with CI supplied as CaC^. The Na and CI in Diets 3 and 4 were equal to the amount supplied by the .4% NaCl. All hens were fed the control (added NaCl) from Day 20 to 84.
333
Downloaded from http://ps.oxfordjournals.org/ at Ernst Mayr Library of the Museum Comp Zoology, Harvard University on April 25, 2015
Institute of Food and Agricultural Sciences, Department of Poultry Science, University of Florida, Gainesville, Florida 32611
334
HARMS TABLE 1. Composition of basal diet
(%)
Ground yellow com Soybean meal (48% protein) DL-methionine Ground limestone Dicalcium phosphate (18.5% P + 21% Ca) Microingredients1 Variable2
74.33 1557
Calculated analyses Calcium Phosphorus Sodium Chloride Chemical analyses Corn Sodium Chloride Soybean meal Sodium Chloride Dicalcium phosphate Sodium Chloride
.06 8.12
.96 .48 .78 3.35
.48 .03 .03
RESULTS AND DISCUSSION
Removal of the NaCl from the diet resulted in hens reaching zero production in 9.8 and 13.3 days in Experiments 1 and 2, respectively .030 (Table 2). When Na was removed from the .021 diet, hens reached zero production in 10.3 and 13.8 days, respectively, in Experiments 1 and .08 2. Only a few of the hens ceased egg . . . production when the CI was removed from the Supplied per kilogram of diet: vitamin A, 6,600 IU; diet A sharp decrease in egg production vitamin D3, 2,200 ICU; menadione dimethylpyrimidinol occurred when NaCl was removed from the bisulfite, 2.2 mg; riboflavin, 4.14 mg; pantothenic acid, 135 mg; niacin, 39.6 mg; vitamin Bj2, .022 mg; diet, which agrees with previous reports 1976a,b; Whitehead and ethoxyquin, 125 mg; manganese, 60 mg; iron, 50 mg; (Nesbeth et at, Shannon, 1974; Monsi and Enos, 1977; Ross copper, 6 mg; iodine, 1.1 mg; zinc, 35 mg; selenium, .1 mg. and Herrick, 1981). The data in the present 2 Included NaCl, NaHC03, CaCl2, or builder's sand. study indicate that hens reached zero production because of the removal of the Na and not the removal of the CI. When the NaCl was returned to the diet, all Four replicates of 10 individually caged hens returned to egg production within an hens verified to be in production were fed each average of 16.0 and 13.2 days in Experiments of the four experimental diets. Daily egg 1 and 2, respectively (Table 2). All hens production records were kept for each hen. The continued egg production when CI was retime required for each hen to reach zero moved from the diet; therefore, only an production was recorded and the average time average of 6.0 and .6 days was required for the was calculated. Also the time required for each hens to return to full production when the CI hen to return to egg production after the hen was restored to the diet. reached zero production was recorded. The When the NaCl was removed from the diet, number of hens molting was measured by the the hens molted an average of 2.2 and 1.8 loss of primary feathers as described by Harms primary feathers in Experiments 1 (Table 1) (1983). Also the average number of primaries and 2 (Table 2), respectively. The hens lost was calculated. Mortality rates were receiving the diet without added Na molted 1.6 obtained for 84 days. The hens were allowed and 1.9 primaries in Experiments 1 and 2, 16 h of light daily throughout each experiment. respectively. Significantly fewer of the Egg production was measured for 1 to 32 primaries were molted when the hens received days and 33 to 84 days. The first 32 days were the diet without added CI. The molting of considered the resting period and the subse- feathers when NaCl or Na was removed from quent days to 84 as the postrest period. All the diet agrees with previous observations by eggs produced on the last day of each week Naber et al. (1984). during the postrest period were weighed, and Significantly more deaths were observed specific gravity was determined. Feed con- when the hens received the diet without added sumption was measured in Experiment 2 for Q (Table 2). The removal of the NaCl or Na each pen for Days 1 to 20 and 33 to 84. did not significantly affect deaths. .028 .023
Downloaded from http://ps.oxfordjournals.org/ at Ernst Mayr Library of the Museum Comp Zoology, Harvard University on April 25, 2015
Ingredient and analysis
Data were analyzed for dietary treatment effects, with the hen as the experimental unit for time to zero production, time to return to lay, number of primaries molted, egg weight, and specific gravity. The residual means square was used as the error term. Replicate data were used as the experimental unit for deaths, egg production, and feed consumption and the replicate x treatment was used as the error. Significant differences were determined according to Duncan's (1955) multiple range test
2
.2 .6
.8 .9 .5
.8
(days) — —
.3 16.0 ± 4 6.0 ± .4 15.7 ± .4 13.2 ± 4 .6 ± .4 15.0 ±
(n) 12 ± .2 0 (40) .7 ± 2 1.6 ± .4 1.8 ± .2 0 (40) .3 ± .1 1.9 ± .2
molted2 7.5 ± 2.5b 5.0 ± 2.5*b 20.0 ± 4.1 a 10.0 ± 4.1 b 2.5 ± 2.5b 5.0 ± 2.5b 20.0 ± 4.1 a 10 ± 4.4 b
^Production did not stop.
Control hens; therefore, production did not stop.
Coded LOxxx.
3
Numbers in parentheses indicate numbers of hens not molting.
2
(28) (11)
(22) (5) (8)
(3)
Mortality 48.8 67.4 59.6 49.0 48.9 74.7 65.6 48.5
± ± ± ± ± ± ± ±
(%) .9° l.la .6 b .9° 1.8° 1.2* 2.5 b 1.9"
0 to 32 72.5 76.6 75.2 72.7 65.9 71.2 71.1 61.9
± ± ± ± ± ± ± ±
1.6a 1.7a 1.7* 1.6* 1.3b 3.7* 2.3* 3.4b
33 to 84
Production days
60.4 59.7 60.5 59.7 64.1 63.7 62.6 63.5
(g) ± .8* ± 1.0* ± 1.5* ± 1.0* ± 1.0* ± .7* ± .9* ± .8 b
Egg weight
Means within experiment and variable with no common superscripts are significantly (P
(Received for publication April 19, 1990) ABSTRACT Two experiments were conducted with Hy-Line® W-36 hens. The hens were 45 and 65 wk old at the start of Experiments 1 and 2, respectively. A corn-soybean meal basal diet was used. Four diets were fed for 19 days: 1) control; 2) no added NaCl; 3) no added NaCl withNa supplied as NaHCCfy and 4) no added Na with CI supplied as CaC^- All hens were fed the control diet from Day 20 to Day 84. Hens fed a diet without NaCl reached zero production in 9.8 and 13.3 days in Experiments 1 and 2, respectively. Hens fed the diet without Na reached zero production in 10.3 and 13.1 days in Experiments 1 and 2, respectively. Only a few of the hens fed the diets with no CI reached zero production. Time required for all hens to return to production after returning to control diets were 16.0,15.7, and 6.0 days for hens receiving no added NaCl, Na, or CI, respectively in Experiment 1, and 13.2,15.0, and .6 days in Experiment 2. Molting occurred in 92.7,77.8, and 24.2% of the hens receiving the no NaCl, Naor CI, respectively, in Experiment 1, and 80.0,723, 30% in Experiment 2. Mortality rates were 7.5, 12.5, 20.0, and 5.0% for die hens receiving diets with no NaCl, Na, CI, or control, respectively, in Experiment 1, and 25, 10.0, 20.0, and 0% in Experiment 2. (Key words: laying hen, forced rest, molt, egg production, sodium chloride) 1991 Poultry Science 70:333-336 INTRODUCTION
A number of reports have been published on the response of the laying hen to removal of salt from the diet (Whitehead and Shannon, 1974; Nesbeth et al., 1976a,b; Begin and Johnson, 1976; Monsi and Enos, 1977; Ross and Herrick, 1981; Naber et al, 1984). The major effect was a sharp drop in egg production to near zero, which was reversible with the addition of salt to the diet. It has been generally assumed that the reduction of egg production was due to the removal of the Na. However, the removal of only CI from the diet has not been studied. Nesbeth et al. (1976b), Begin and Johnson (1976), Compos and Baiao (1979), and Naber et al. (1984) concluded that resting the hen by feeding a diet with no added salt was as effective in inducing a rest as using a forced molt. However, Ross and Herrick (1981) obtained poorer performance from hens rested on a low-salt diet than from using a conventional forced molt.
Florida Agricultural Experiment Station Journal Series Number R-00630. 2 Hy-Line International, Dallas Center, IA 50063.
Most of those workers did not measure the incidence or severity of the molt when hens were fed the diet with no added salt However, Naber et al. (1984) noted feather loss that increased as duration of the experiment was increased. Therefore, the present experiments were conducted to determine whether the removal of Na or CI was the cause of the cessation of egg production. Also the incidence and severity of the molt were measured. MATERIALS AND METHODS
Two experiments were conducted with HyLine® W36 hens.2 Hens were 45 wk old in Experiment 1 and 65 wk old in Experiment 2. A corn-soybean meal basal diet (Table 1) was used that contained .03% sodium and .03% chloride by analysis. The water contained 10 and 33 ppm Na and CI, respectively. Four experimental diets were fed for 19 days: 1) control, containing .4% NaCl; 2) unsupplemented basal (no Na or CI); 3) no CI with Na supplied as NaHCC^; and 4) no Na with CI supplied as CaC^. The Na and CI in Diets 3 and 4 were equal to the amount supplied by the .4% NaCl. All hens were fed the control (added NaCl) from Day 20 to 84.
333
Downloaded from http://ps.oxfordjournals.org/ at Ernst Mayr Library of the Museum Comp Zoology, Harvard University on April 25, 2015
Institute of Food and Agricultural Sciences, Department of Poultry Science, University of Florida, Gainesville, Florida 32611
334
HARMS TABLE 1. Composition of basal diet
(%)
Ground yellow com Soybean meal (48% protein) DL-methionine Ground limestone Dicalcium phosphate (18.5% P + 21% Ca) Microingredients1 Variable2
74.33 1557
Calculated analyses Calcium Phosphorus Sodium Chloride Chemical analyses Corn Sodium Chloride Soybean meal Sodium Chloride Dicalcium phosphate Sodium Chloride
.06 8.12
.96 .48 .78 3.35
.48 .03 .03
RESULTS AND DISCUSSION
Removal of the NaCl from the diet resulted in hens reaching zero production in 9.8 and 13.3 days in Experiments 1 and 2, respectively .030 (Table 2). When Na was removed from the .021 diet, hens reached zero production in 10.3 and 13.8 days, respectively, in Experiments 1 and .08 2. Only a few of the hens ceased egg . . . production when the CI was removed from the Supplied per kilogram of diet: vitamin A, 6,600 IU; diet A sharp decrease in egg production vitamin D3, 2,200 ICU; menadione dimethylpyrimidinol occurred when NaCl was removed from the bisulfite, 2.2 mg; riboflavin, 4.14 mg; pantothenic acid, 135 mg; niacin, 39.6 mg; vitamin Bj2, .022 mg; diet, which agrees with previous reports 1976a,b; Whitehead and ethoxyquin, 125 mg; manganese, 60 mg; iron, 50 mg; (Nesbeth et at, Shannon, 1974; Monsi and Enos, 1977; Ross copper, 6 mg; iodine, 1.1 mg; zinc, 35 mg; selenium, .1 mg. and Herrick, 1981). The data in the present 2 Included NaCl, NaHC03, CaCl2, or builder's sand. study indicate that hens reached zero production because of the removal of the Na and not the removal of the CI. When the NaCl was returned to the diet, all Four replicates of 10 individually caged hens returned to egg production within an hens verified to be in production were fed each average of 16.0 and 13.2 days in Experiments of the four experimental diets. Daily egg 1 and 2, respectively (Table 2). All hens production records were kept for each hen. The continued egg production when CI was retime required for each hen to reach zero moved from the diet; therefore, only an production was recorded and the average time average of 6.0 and .6 days was required for the was calculated. Also the time required for each hens to return to full production when the CI hen to return to egg production after the hen was restored to the diet. reached zero production was recorded. The When the NaCl was removed from the diet, number of hens molting was measured by the the hens molted an average of 2.2 and 1.8 loss of primary feathers as described by Harms primary feathers in Experiments 1 (Table 1) (1983). Also the average number of primaries and 2 (Table 2), respectively. The hens lost was calculated. Mortality rates were receiving the diet without added Na molted 1.6 obtained for 84 days. The hens were allowed and 1.9 primaries in Experiments 1 and 2, 16 h of light daily throughout each experiment. respectively. Significantly fewer of the Egg production was measured for 1 to 32 primaries were molted when the hens received days and 33 to 84 days. The first 32 days were the diet without added CI. The molting of considered the resting period and the subse- feathers when NaCl or Na was removed from quent days to 84 as the postrest period. All the diet agrees with previous observations by eggs produced on the last day of each week Naber et al. (1984). during the postrest period were weighed, and Significantly more deaths were observed specific gravity was determined. Feed con- when the hens received the diet without added sumption was measured in Experiment 2 for Q (Table 2). The removal of the NaCl or Na each pen for Days 1 to 20 and 33 to 84. did not significantly affect deaths. .028 .023
Downloaded from http://ps.oxfordjournals.org/ at Ernst Mayr Library of the Museum Comp Zoology, Harvard University on April 25, 2015
Ingredient and analysis
Data were analyzed for dietary treatment effects, with the hen as the experimental unit for time to zero production, time to return to lay, number of primaries molted, egg weight, and specific gravity. The residual means square was used as the error term. Replicate data were used as the experimental unit for deaths, egg production, and feed consumption and the replicate x treatment was used as the error. Significant differences were determined according to Duncan's (1955) multiple range test
2
.2 .6
.8 .9 .5
.8
(days) — —
.3 16.0 ± 4 6.0 ± .4 15.7 ± .4 13.2 ± 4 .6 ± .4 15.0 ±
(n) 12 ± .2 0 (40) .7 ± 2 1.6 ± .4 1.8 ± .2 0 (40) .3 ± .1 1.9 ± .2
molted2 7.5 ± 2.5b 5.0 ± 2.5*b 20.0 ± 4.1 a 10.0 ± 4.1 b 2.5 ± 2.5b 5.0 ± 2.5b 20.0 ± 4.1 a 10 ± 4.4 b
^Production did not stop.
Control hens; therefore, production did not stop.
Coded LOxxx.
3
Numbers in parentheses indicate numbers of hens not molting.
2
(28) (11)
(22) (5) (8)
(3)
Mortality 48.8 67.4 59.6 49.0 48.9 74.7 65.6 48.5
± ± ± ± ± ± ± ±
(%) .9° l.la .6 b .9° 1.8° 1.2* 2.5 b 1.9"
0 to 32 72.5 76.6 75.2 72.7 65.9 71.2 71.1 61.9
± ± ± ± ± ± ± ±
1.6a 1.7a 1.7* 1.6* 1.3b 3.7* 2.3* 3.4b
33 to 84
Production days
60.4 59.7 60.5 59.7 64.1 63.7 62.6 63.5
(g) ± .8* ± 1.0* ± 1.5* ± 1.0* ± 1.0* ± .7* ± .9* ± .8 b
Egg weight
Means within experiment and variable with no common superscripts are significantly (P
