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Performance of Broiler Breeder Hens on Wire and Litter Floors1
Performance of Broiler Breeder Hens on Wire and Litter Floors1 R. H. HARMS, S. M. BOOTWALLA, and H. R. WILSON Poultry Science Department, University of Florida, Gainesville, Florida 32611 (Received for publication May 31, 1983) ABSTRACT Two experiments were conducted with broiler breeder hens to study the influence of litter versus wire floor on weight and specific gravity of eggs. In Experiment 1, one group of broiler breeder hens was maintained on litter and the other on wire. Specific gravity was significantly higher for eggs from hens kept on litter floors. When hens on wire floors had access to litter in a feeder, an increase in egg specific gravity was noted within one day. In Experiment 2, broiler .breeder hens, 52 weeks of age, were separated into three treatments: litter floor, wire floor, and wire floor with old litter material in feeder. When hens received 3.22% dietary calcium, the egg specific gravity was highest (P<.05) from hens on the litter floor, intermediate from hens on wire with access to litter, and lowest from hens on wire without access to litter. Hens on wire with access to litter consumed 18.3 g litter/bird/day, corresponding to an additional intake of 352 mg calcium and 93 mg phosphorus. They also received 4700 mg calcium and 790 mg phosphorus from the feed. The specific gravity of eggs from hens with access to litter was higher than for eggs from those hens without access to the litter when hens received diets with 1.0 and .15% calcium. No significant differences were found in egg weight among treatments. The hens on wire with access to litter and fed 1.0 or .25 or 3.22% dietary calcium consumed 24.5, 28.5, and 18.9 gmore of litter, respectively. This resulted in additional intakes of 530 mg calcium, 140 mg phosphorus and 455 mg calcium, 120 mg phosphorus for the low calcium groups, respectively. They also consumed 790 mg phosphorus and 1.46 and .39 g calcium, respectively, from the feed. The additional minerals from the litter were responsible for the improved egg shells. (Key words: broiler breeders, calcium, phosphorus, floor type) 1984 Poultry Science 63:1003-1007 INTRODUCTION D e j o n g ( 1 9 6 3 ) suggested t h a t t h e shells of eggs laid b y birds k e p t in b a t t e r y cages were thinner, and therefore, weaker, t h a n those of eggs laid b y birds h o u s e d o n deep litter. Griminger and Lutz ( 1 9 6 4 ) f o u n d s u p p l e m e n t a l calcium c o n s u m p t i o n was highest for hens in individual cages, intermediate for hens in comm u n i t y cages, a n d lowest for h e n s in litter floor pens. Magruder and Nelson ( 1 9 6 4 ) f o u n d n o difference in egg p r o d u c t i o n , m o r t a l i t y , or feed efficiency b e t w e e n broiler breeders on litter or t o t a l slatted floors. In a later r e p o r t , Magruder and Nelson ( 1 9 6 5 ) f o u n d n o difference in b r o k e n eggs, shell thickness, o r shell strength when comparing slatted floors versus litter as floor. R o w l a n d a n d H a r m s ( 1 9 7 0 ) f o u n d t h a t hens confined t o cages, with restricted activity, had lower b o n e ash and b o n e strength t h a n
hens in litter covered floor pens. Several workers have reported t h a t t h e p h o s p h o r u s r e q u i r e m e n t for h e n s m a i n t a i n e d o n litter floors is less t h a n t h a t for birds k e p t in cages or o n wire floors ( H a r m s et al, 1 9 6 1 ; Singsen et al, 1 9 6 2 ; Crowley et al, 1 9 6 3 ) . F a r m e r et al, ( 1 9 8 3 ) r e p o r t e d t h a t broiler breeders on litter and fed at 1 6 0 0 h r p r o d u c e d eggs with higher specific gravity t h a n hens fed at 0 8 0 0 hr. This finding was confirmed b y Bootwalla et al. ( 1 9 8 3 ) . T h e difference rep o r t e d b y Bootwalla et al. ( 1 9 8 3 ) w i t h hens on litter, however, was smaller t h a n t h a t r e p o r t e d b y F a r m e r et al. ( 1 9 8 3 ) with Leghorn hens in cages. Therefore, t w o e x p e r i m e n t s were designed t o d e t e r m i n e t h e effect of wire a n d litter floor o n egg weight and specific gravity of eggs from broiler b r e e d e r s . MATERIALS AND METHODS Experiment
1
Florida Agricultural Experiment Station Journal Series No. 4734.
1
A 3-week e x p e r i m e n t was c o n d u c t e d from F e b r u a r y 15 t o March 8 w i t h 4 8 C o b b feather-
1003
HARMS ET AL.
1004
sexed broiler breeder females, 45 weeks of age. They had been previously fed at 1600 hr. The concrete floors of four pens were covered with used litter that was collected from the pens where the hens had been housed for 12 weeks. Four pens were equipped with raised wire floors to prevent the hens from having access to the litter or feces. Each treatment consisted of four replicate pens (1.52X 1.83 m) with six hens per pen. At 1100 hr the hens were provided with 146 g of a broiler breeder diet per hen per day (Table 1) containing 3.22% calcium and .54% phosphorus. Daily egg weight and specific gravity were determined. After 17 days, litter from the litter floor pens was placed in separate tube feeders in the wire-floored pens for 4 days. Egg weights were determined by weighing individual eggs on an electronic Mettler balance with .1 g precision. Egg specific gravity was determined using the flotation method. The specific gravity solutions were in increments of .005 units from 1.065 to 1.095. Experiment 2 This experiment was conducted in three consecutive phases with different levels of calcium used in each phase. Broiler breeders were kept in pens with litter, in wire floor pens, or in wire pens with access to old litter in feeders. Egg weight and specific gravity were determined as in Experiment 1. Phase 1, A 2-week experiment was conducted from March 25 to April 8 with 72
broiler breeder hens, 52 weeks of age. The hens were maintained in two floor conditions: either litter floor with used litter from the previous experiment, or raised wire floor without access to litter or feces. A third treatment involved hens on raised wire floors and receiving litter from the previous experiment in feeders. Each treatment was given to four replicate pens (1.52 X 1.83 m) with six females per pen. The feeding regimen was the same as Experiment 1, however, each hen received 145 g feed per day. The feed contained 3.22% calcium and .54% total phosphorus (Table 1). The daily consumption of litter was measured. Phase 2. At the end of Phase 1, the calcium level of the diet was reduced to 1% (Table 1). The feeding schedule, duration, and experimental design were the same as Phase 1. Phase 3. At the end of Phase 2, the calcium level of the diet was reduced to .25% (Table 1). The feeding schedule and experimental design were the same as Phases 1 and 2, except the duration of this phase was 1 week. The litter material was analyzed for calcium and phosphorus content according to procedure of the Association of Official Analytical Chemists (1975). It contained 1.86% calcium and .49% phosphorus. The calcium and phosphorus content of diets were calculated. All data were subjected to an analysis of variance, and differences between specific treatments where appropriate were tested by Duncan's new multiple range test using the method of Steel and Torrie (1980).
TABLE 1. Composition of diets Calcium Ingredients
3.22%
1.00%
Ground yellow corn Soybean meal (48.5%) Ground limestone Dicalcium phosphate (18.5% P, 21% Ca) Salt Microingredients1 DL-Methionine Sand
74.57 16.98 6.90 .95 .30 .24 .06 0
74.58 16.98 2.01 .95 .30 .24 .06 4.88
.25%
\>"> 74.60 16.98 0 .95 .30 .24 .06 6.87
'Vitamin-mineral mix provides the following per kilogram of diet: 6600 IU vitamin A; 2200 ICU vitamin D 3 ; 2.2 mg menadione dimethylprimidinol bisulfite; 4.4 mg riboflavin; 13.2 mg pantothenic acid; 39.6 mg niacin; 499.4 mg choline chloride; 22 ixg vitamin B 1 2 ; 125 mg ethoxyquin; 60 mg manganese; 50 mg iron; 6 mg copper; .198 mg cobalt; 1.1 mg iodine; 35 mg zinc.
BROILER BREEDER HENS ON WIRE AND LITTER Experiment
TABLE 2. Egg weight and specific gravity of eggs from broiler breeder hens maintained on litter or wire floors
Floor type
Egg specific gravity1
weight1
Litter Wire
1.0844 1.0829*
(g) 69.21 70.09
1
Values are the average for all eggs laid for 17 days.
"Indicates control.
significant
difference
(P<.05)
from
RESULTS AND DISCUSSION Experiment
1
When hens were transferred from t h e litter floor t o t h e wire floor pens, specific gravity of eggs was decreased (Table 2). When t h e hens were given access t o litter in t h e wire floor pens t h e specific gravity of eggs was significantly increased (Table 3). This increase in specific gravity of eggs was observed t h e d a y after t h e hens in t h e wire floor pens were given litter. Egg weight was numerically higher for t h e broiler breeder hens k e p t in t h e wire floor pens t h a n for hens on litter (Table 2). After litter was provided in feeders in t h e wire floor pens for 4 days, n o significant difference in t h e egg weight b e t w e e n the t w o types of floors occurred (Table 3).
1005
2
Specific gravity of eggs from t h e broiler breeder hens o n litter floor was significantly higher ( P < . 0 5 ) t h a n t h a t of eggs from hens on wire with or w i t h o u t access t o litter w h e n t h e diet contained 3.22% calcium (Table 4 ) . When dietary calcium was decreased t o 1% (Phase 2), t h e specific gravity of eggs from hens o n t h e litter floor a n d wire floor with access t o litter was significantly higher ( P < . 0 5 ) t h a n t h a t for eggs from hens o n t h e wire floor (Table 4 ) . T h e difference in specific gravity of eggs from hens on litter floor and t h o s e from hens on wire floor w i t h access t o litter was n o t significant. Similar results were o b t a i n e d w h e n t h e dietary calcium was decreased at . 2 5 % (Phase 3). At each level of dietary calcium, egg specific gravity was highest for hens h o u s e d on litter floors a n d lowest o n wire floor w i t h o u t access t o litter. T h e litter c o n s u m p t i o n of hens o n wire floor with access t o litter with 3.22, 1.0, a n d . 2 5 % dietary calcium was 1 8 . 9 , 2 8 . 5 , a n d 2 4 . 5 g per hen per d a y , respectively. Corresponding intakes were 3 5 2 , 5 3 0 , a n d 4 5 5 m g calcium per hen per day a n d 9 3 , 1 4 0 , and 1 2 0 mg p h o s p h o r u s per h e n per d a y , respectively, from t h e litter. T h e y also received 7 9 0 m g p h o s p h o r u s and 4 . 7 , 1.46, a n d .39 g calcium from t h e feed containing 3.22, 1.0, a n d . 2 5 % calcium, respectively. Litter c o n s u m p t i o n was significantly higher w h e n hens were fed diets w i t h 1.0 and .25% calcium t h a n when hens were fed a diet with 3.22% calcium ( P < . 0 5 ) .
TABLE 3. Weight and specific gravity of eggs from broiler breeders on litter and wire floor with access to litter on Days 0 to 4 (Experiment 1) Egg specific gravity2
Egg weiight Wire and litter
Days1
Litter
Wire and litter
Litter
0 1 2 3 4
1.0850* 1.0874 1.0861 1.0838 1.0849
1.0814 1.0860 1.0850 1.0828 1.0855
70.1 68.3 70.0 69.4 70.1
70.2 69.3 71.4 71.4 69.2
Means (Days 1 to 4)
1.0855
1.0850
69.4
69.3
(g)
1
Indicates the days after used litter was provided in feeders in wire floor pens.
2
Values are average for all eggs laid for that day.
"Indicates significant difference (P>.05) from wire and litter.
1006
HARMS ET AL. TABLE 4. Egg weight, egg specific gravity, and litter consumption of broiler breeder hens fed various calcium levels in the diet and kept on either litter floor, wire floor, or access to litter on wire floor (Experiment 2) Daily intake from
Ca of diet
Floor types
Egg specific gravity
(%) 3.22
1.00
.25
Egg weight
Litter consumption
(g)
(g/bird/ day)
Litter Ca
Feed P
Ca
P
( m g)
Litter Wire and litter Wire
1.0834*1 1.0822b 1.0814 c
73.7* 72.7* 72.8*
18.9 B
352
93
4700
790
Litter Wire and litter Wire
1.0782* 1.0776* 1.0750 b
78.4* 72.6* 73.0*
28.5 A
530
140
1460
790
Litter Wire and litter Wire
1.0689* 1.0680* 1.0640 b
71.4* 70.0* 70.5*
24.5A
455
120
390
790
' ' Means within dietary calcium levels followed by the same lower case superscript letter are not significantly different (P<.05) using Duncan's multiple range test. A,B Means followed by the same upper case superscript letter are not significantly different (P<.05). 1
Litter contained 1.86% Ca and .49% P.
Floor type did not significantly affect differences in egg weight (Table 4). A numerical decrease in egg weight accrued when the hens were fed the ,,25% calcium diet. The finding that egg specific gravity was significantly higher from hens on litter than that from hens on the wire floor pens is in agreement with Dejong (1963). Rowland and Harms (1970) also found the egg specific gravity of eggs from hens on litter floor pens to be higher than that from hens kept either on wire floor pens or cages. Singsen et al, (1962) found that litter accumulated phosphorus to a level approximately three times that in the feed. Therefore, litter was a good source of phosphorus. These workers suggested that coprophagy reduced the dietary requirement of phosphorus for birds on litter. Damron et al, (1975) reported fecal calcium varying from 8.1 to 18.9% when diets containing 3.0 to 8.0% were fed to caged laying hens. These data indicate that litter is a good source of calcium and phosphorus. It is suggested that the broiler breeder hens kept on the litter floor had access to fecal calcium, phosphorus, and other nutrients and thus were able to maintain higher egg specific gravity than the birds kept on wire floor. Also, decreasing the dietary calcium resulted in in-
creased litter consumption. These findings indicate that the hens possessed the ability to attempt to meet the dietary calcium requirement by increasing litter consumption. This finding is particularly important for broiler breeders, which are commonly fed only once per day, and therefore, have access to dietary calcium and phosphorus for a short period. During the remainder of the day, they can obtain supplementary calcium and phosphorus through coprophagy. REFERENCES Association of Official Chemists, 1975. Official Methods of Analysis. 12th ed. William Horowitz, ed. Washington, DC. Bootwalla, S. M., H. R. Wilson, and R. H. Harms, 1983. Performance of broiler breeders on different feeding systems. Poultry Sci. 62:2321-2325. Crowley, T. A., A. A. Kurnick, and B. L. Reid, 1963. Dietary phosphorus for laying hens. Poultry Sci. 42:758-765. Damron, B. L., A. R. Eldred, D. A. Roland, Sr., D. B. Underhill, and R. H. Harms, 1975. The dietaryfecal relationship of calcium and phosphorus levels in White Leghorn hens. Poultry Sci. 54: 1716-1718. Dejong, J. J., 1963. The quality of consumption egg. World's Poultry Sci. J. 19:272-282. Farmer, M., D. A. Roland, Sr., and M. K. Eckman,
BROILER BREEDER HENS ON WIRE AND LITTER 1983. Calcium metabolism in broiler breeder hens. 2. The influence of the time of feeding on calcium status of the digestive system and eggshell quality in broiler breeders. Poultry Sci. 62: 465-471. Griminger, P., and H. Lutz, 1964. Observations of the voluntary intake of calcium supplements by laying hens. Poultry Sci. 43:710—716. Harms, R. H., C. R. Douglas, and P. W. Waldroup, 1961. The effects of feeding various levels and sources of phosphorus to laying hens. Florida Agric. Exp. Sta. Bull. 644, Univ. Florida, Gainesville. Magruder, N. D., and J. W. Nelson, 1964. Effect of slatted floor versus litter on laying performance. Poultry Sci. 43:1337. (Abstr.)
1007
Magruder, N. D., and J. W. Nelson, 1965. Long term studies of effect of slatted floor versus litter on laying performance. Poultry Sci. 44:1395. (Abstr.) Rowland, L. O., Jr., and R. H. Harms, 1970. The effect of wire pens, floor pens and cages on bone characteristics of laying hens. Poultry Sci. 49: 1223-1225. Singsen, E. P., A. H. Spandorf, L. D. Matterson, J. A. Serafin, and J. J. Tlustohowciz, 1962. Phosphorus in the nutrition of the adult hen. 1. Minimum phosphorus requirements. Poultry Sci. 4 1 : 1401-1414. 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.
hens in litter covered floor pens. Several workers have reported t h a t t h e p h o s p h o r u s r e q u i r e m e n t for h e n s m a i n t a i n e d o n litter floors is less t h a n t h a t for birds k e p t in cages or o n wire floors ( H a r m s et al, 1 9 6 1 ; Singsen et al, 1 9 6 2 ; Crowley et al, 1 9 6 3 ) . F a r m e r et al, ( 1 9 8 3 ) r e p o r t e d t h a t broiler breeders on litter and fed at 1 6 0 0 h r p r o d u c e d eggs with higher specific gravity t h a n hens fed at 0 8 0 0 hr. This finding was confirmed b y Bootwalla et al. ( 1 9 8 3 ) . T h e difference rep o r t e d b y Bootwalla et al. ( 1 9 8 3 ) w i t h hens on litter, however, was smaller t h a n t h a t r e p o r t e d b y F a r m e r et al. ( 1 9 8 3 ) with Leghorn hens in cages. Therefore, t w o e x p e r i m e n t s were designed t o d e t e r m i n e t h e effect of wire a n d litter floor o n egg weight and specific gravity of eggs from broiler b r e e d e r s . MATERIALS AND METHODS Experiment
1
Florida Agricultural Experiment Station Journal Series No. 4734.
1
A 3-week e x p e r i m e n t was c o n d u c t e d from F e b r u a r y 15 t o March 8 w i t h 4 8 C o b b feather-
1003
HARMS ET AL.
1004
sexed broiler breeder females, 45 weeks of age. They had been previously fed at 1600 hr. The concrete floors of four pens were covered with used litter that was collected from the pens where the hens had been housed for 12 weeks. Four pens were equipped with raised wire floors to prevent the hens from having access to the litter or feces. Each treatment consisted of four replicate pens (1.52X 1.83 m) with six hens per pen. At 1100 hr the hens were provided with 146 g of a broiler breeder diet per hen per day (Table 1) containing 3.22% calcium and .54% phosphorus. Daily egg weight and specific gravity were determined. After 17 days, litter from the litter floor pens was placed in separate tube feeders in the wire-floored pens for 4 days. Egg weights were determined by weighing individual eggs on an electronic Mettler balance with .1 g precision. Egg specific gravity was determined using the flotation method. The specific gravity solutions were in increments of .005 units from 1.065 to 1.095. Experiment 2 This experiment was conducted in three consecutive phases with different levels of calcium used in each phase. Broiler breeders were kept in pens with litter, in wire floor pens, or in wire pens with access to old litter in feeders. Egg weight and specific gravity were determined as in Experiment 1. Phase 1, A 2-week experiment was conducted from March 25 to April 8 with 72
broiler breeder hens, 52 weeks of age. The hens were maintained in two floor conditions: either litter floor with used litter from the previous experiment, or raised wire floor without access to litter or feces. A third treatment involved hens on raised wire floors and receiving litter from the previous experiment in feeders. Each treatment was given to four replicate pens (1.52 X 1.83 m) with six females per pen. The feeding regimen was the same as Experiment 1, however, each hen received 145 g feed per day. The feed contained 3.22% calcium and .54% total phosphorus (Table 1). The daily consumption of litter was measured. Phase 2. At the end of Phase 1, the calcium level of the diet was reduced to 1% (Table 1). The feeding schedule, duration, and experimental design were the same as Phase 1. Phase 3. At the end of Phase 2, the calcium level of the diet was reduced to .25% (Table 1). The feeding schedule and experimental design were the same as Phases 1 and 2, except the duration of this phase was 1 week. The litter material was analyzed for calcium and phosphorus content according to procedure of the Association of Official Analytical Chemists (1975). It contained 1.86% calcium and .49% phosphorus. The calcium and phosphorus content of diets were calculated. All data were subjected to an analysis of variance, and differences between specific treatments where appropriate were tested by Duncan's new multiple range test using the method of Steel and Torrie (1980).
TABLE 1. Composition of diets Calcium Ingredients
3.22%
1.00%
Ground yellow corn Soybean meal (48.5%) Ground limestone Dicalcium phosphate (18.5% P, 21% Ca) Salt Microingredients1 DL-Methionine Sand
74.57 16.98 6.90 .95 .30 .24 .06 0
74.58 16.98 2.01 .95 .30 .24 .06 4.88
.25%
\>"> 74.60 16.98 0 .95 .30 .24 .06 6.87
'Vitamin-mineral mix provides the following per kilogram of diet: 6600 IU vitamin A; 2200 ICU vitamin D 3 ; 2.2 mg menadione dimethylprimidinol bisulfite; 4.4 mg riboflavin; 13.2 mg pantothenic acid; 39.6 mg niacin; 499.4 mg choline chloride; 22 ixg vitamin B 1 2 ; 125 mg ethoxyquin; 60 mg manganese; 50 mg iron; 6 mg copper; .198 mg cobalt; 1.1 mg iodine; 35 mg zinc.
BROILER BREEDER HENS ON WIRE AND LITTER Experiment
TABLE 2. Egg weight and specific gravity of eggs from broiler breeder hens maintained on litter or wire floors
Floor type
Egg specific gravity1
weight1
Litter Wire
1.0844 1.0829*
(g) 69.21 70.09
1
Values are the average for all eggs laid for 17 days.
"Indicates control.
significant
difference
(P<.05)
from
RESULTS AND DISCUSSION Experiment
1
When hens were transferred from t h e litter floor t o t h e wire floor pens, specific gravity of eggs was decreased (Table 2). When t h e hens were given access t o litter in t h e wire floor pens t h e specific gravity of eggs was significantly increased (Table 3). This increase in specific gravity of eggs was observed t h e d a y after t h e hens in t h e wire floor pens were given litter. Egg weight was numerically higher for t h e broiler breeder hens k e p t in t h e wire floor pens t h a n for hens on litter (Table 2). After litter was provided in feeders in t h e wire floor pens for 4 days, n o significant difference in t h e egg weight b e t w e e n the t w o types of floors occurred (Table 3).
1005
2
Specific gravity of eggs from t h e broiler breeder hens o n litter floor was significantly higher ( P < . 0 5 ) t h a n t h a t of eggs from hens on wire with or w i t h o u t access t o litter w h e n t h e diet contained 3.22% calcium (Table 4 ) . When dietary calcium was decreased t o 1% (Phase 2), t h e specific gravity of eggs from hens o n t h e litter floor a n d wire floor with access t o litter was significantly higher ( P < . 0 5 ) t h a n t h a t for eggs from hens o n t h e wire floor (Table 4 ) . T h e difference in specific gravity of eggs from hens on litter floor and t h o s e from hens on wire floor w i t h access t o litter was n o t significant. Similar results were o b t a i n e d w h e n t h e dietary calcium was decreased at . 2 5 % (Phase 3). At each level of dietary calcium, egg specific gravity was highest for hens h o u s e d on litter floors a n d lowest o n wire floor w i t h o u t access t o litter. T h e litter c o n s u m p t i o n of hens o n wire floor with access t o litter with 3.22, 1.0, a n d . 2 5 % dietary calcium was 1 8 . 9 , 2 8 . 5 , a n d 2 4 . 5 g per hen per d a y , respectively. Corresponding intakes were 3 5 2 , 5 3 0 , a n d 4 5 5 m g calcium per hen per day a n d 9 3 , 1 4 0 , and 1 2 0 mg p h o s p h o r u s per h e n per d a y , respectively, from t h e litter. T h e y also received 7 9 0 m g p h o s p h o r u s and 4 . 7 , 1.46, a n d .39 g calcium from t h e feed containing 3.22, 1.0, a n d . 2 5 % calcium, respectively. Litter c o n s u m p t i o n was significantly higher w h e n hens were fed diets w i t h 1.0 and .25% calcium t h a n when hens were fed a diet with 3.22% calcium ( P < . 0 5 ) .
TABLE 3. Weight and specific gravity of eggs from broiler breeders on litter and wire floor with access to litter on Days 0 to 4 (Experiment 1) Egg specific gravity2
Egg weiight Wire and litter
Days1
Litter
Wire and litter
Litter
0 1 2 3 4
1.0850* 1.0874 1.0861 1.0838 1.0849
1.0814 1.0860 1.0850 1.0828 1.0855
70.1 68.3 70.0 69.4 70.1
70.2 69.3 71.4 71.4 69.2
Means (Days 1 to 4)
1.0855
1.0850
69.4
69.3
(g)
1
Indicates the days after used litter was provided in feeders in wire floor pens.
2
Values are average for all eggs laid for that day.
"Indicates significant difference (P>.05) from wire and litter.
1006
HARMS ET AL. TABLE 4. Egg weight, egg specific gravity, and litter consumption of broiler breeder hens fed various calcium levels in the diet and kept on either litter floor, wire floor, or access to litter on wire floor (Experiment 2) Daily intake from
Ca of diet
Floor types
Egg specific gravity
(%) 3.22
1.00
.25
Egg weight
Litter consumption
(g)
(g/bird/ day)
Litter Ca
Feed P
Ca
P
( m g)
Litter Wire and litter Wire
1.0834*1 1.0822b 1.0814 c
73.7* 72.7* 72.8*
18.9 B
352
93
4700
790
Litter Wire and litter Wire
1.0782* 1.0776* 1.0750 b
78.4* 72.6* 73.0*
28.5 A
530
140
1460
790
Litter Wire and litter Wire
1.0689* 1.0680* 1.0640 b
71.4* 70.0* 70.5*
24.5A
455
120
390
790
' ' Means within dietary calcium levels followed by the same lower case superscript letter are not significantly different (P<.05) using Duncan's multiple range test. A,B Means followed by the same upper case superscript letter are not significantly different (P<.05). 1
Litter contained 1.86% Ca and .49% P.
Floor type did not significantly affect differences in egg weight (Table 4). A numerical decrease in egg weight accrued when the hens were fed the ,,25% calcium diet. The finding that egg specific gravity was significantly higher from hens on litter than that from hens on the wire floor pens is in agreement with Dejong (1963). Rowland and Harms (1970) also found the egg specific gravity of eggs from hens on litter floor pens to be higher than that from hens kept either on wire floor pens or cages. Singsen et al, (1962) found that litter accumulated phosphorus to a level approximately three times that in the feed. Therefore, litter was a good source of phosphorus. These workers suggested that coprophagy reduced the dietary requirement of phosphorus for birds on litter. Damron et al, (1975) reported fecal calcium varying from 8.1 to 18.9% when diets containing 3.0 to 8.0% were fed to caged laying hens. These data indicate that litter is a good source of calcium and phosphorus. It is suggested that the broiler breeder hens kept on the litter floor had access to fecal calcium, phosphorus, and other nutrients and thus were able to maintain higher egg specific gravity than the birds kept on wire floor. Also, decreasing the dietary calcium resulted in in-
creased litter consumption. These findings indicate that the hens possessed the ability to attempt to meet the dietary calcium requirement by increasing litter consumption. This finding is particularly important for broiler breeders, which are commonly fed only once per day, and therefore, have access to dietary calcium and phosphorus for a short period. During the remainder of the day, they can obtain supplementary calcium and phosphorus through coprophagy. REFERENCES Association of Official Chemists, 1975. Official Methods of Analysis. 12th ed. William Horowitz, ed. Washington, DC. Bootwalla, S. M., H. R. Wilson, and R. H. Harms, 1983. Performance of broiler breeders on different feeding systems. Poultry Sci. 62:2321-2325. Crowley, T. A., A. A. Kurnick, and B. L. Reid, 1963. Dietary phosphorus for laying hens. Poultry Sci. 42:758-765. Damron, B. L., A. R. Eldred, D. A. Roland, Sr., D. B. Underhill, and R. H. Harms, 1975. The dietaryfecal relationship of calcium and phosphorus levels in White Leghorn hens. Poultry Sci. 54: 1716-1718. Dejong, J. J., 1963. The quality of consumption egg. World's Poultry Sci. J. 19:272-282. Farmer, M., D. A. Roland, Sr., and M. K. Eckman,
BROILER BREEDER HENS ON WIRE AND LITTER 1983. Calcium metabolism in broiler breeder hens. 2. The influence of the time of feeding on calcium status of the digestive system and eggshell quality in broiler breeders. Poultry Sci. 62: 465-471. Griminger, P., and H. Lutz, 1964. Observations of the voluntary intake of calcium supplements by laying hens. Poultry Sci. 43:710—716. Harms, R. H., C. R. Douglas, and P. W. Waldroup, 1961. The effects of feeding various levels and sources of phosphorus to laying hens. Florida Agric. Exp. Sta. Bull. 644, Univ. Florida, Gainesville. Magruder, N. D., and J. W. Nelson, 1964. Effect of slatted floor versus litter on laying performance. Poultry Sci. 43:1337. (Abstr.)
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Magruder, N. D., and J. W. Nelson, 1965. Long term studies of effect of slatted floor versus litter on laying performance. Poultry Sci. 44:1395. (Abstr.) Rowland, L. O., Jr., and R. H. Harms, 1970. The effect of wire pens, floor pens and cages on bone characteristics of laying hens. Poultry Sci. 49: 1223-1225. Singsen, E. P., A. H. Spandorf, L. D. Matterson, J. A. Serafin, and J. J. Tlustohowciz, 1962. Phosphorus in the nutrition of the adult hen. 1. Minimum phosphorus requirements. Poultry Sci. 4 1 : 1401-1414. 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.