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Performance of Broad Breasted Large White Turkey Hens Grown on Restrictive Feeding Programs1
Performance of Broad Breasted Large White Turkey Hens Grown on Restrictive Feeding Programs1 R. A. VOITLE and R. H. HARMS Department of Poultry Science Florida Agricultural Experiment Stations Gainesville, Florida 32611 (Received for publication August 30, 1977)
INTRODUCTION I t has b e c o m e a standard m a n a g e m e n t practice to delay sexual m a t u r i t y in t u r k e y breeder hens in order t o o p t i m i z e r e p r o d u c t i v e performance. Wilson et al. ( 1 9 6 7 ) reviewed t h e literature pertaining t o light restriction during the growing period and r e p o r t e d t h a t it was necessary to delay sexual m a t u r i t y for off season egg p r o d u c t i o n . Leighton ( 1 9 7 0 ) stated t h a t in order to avoid a high incidence of nonlayers and small eggs, s t i m u l a t o r y lighting programs should n o t be initiated before 30 weeks of age with small t y p e t u r k e y s and 32 w e e k s of age for large t y p e s . Certain drugs have been incorporated in t u r k e y grower diets in an a t t e m p t t o delay sexual m a t u r i t y with only limited success (Atkinson et al., 1 9 6 9 , a n d Nixey, 1 9 7 0 ) . A n d e r s o n et al.. ( 1 9 6 3 ) was one of t h e first g r o u p s t o investigate t h e possibility of using feed restriction t o delay sexual m a t u r i t y in t u r k e y breeders. T h e y observed t h a t restricting feed c o n s u m p t i o n to 8 5 % of controls reduced b o d y weights while n o t significantly influencing fertility; however, hatchability of fertile eggs
1
Florida Agr. Exp. Sta. Journal Series No. 675.
1978 Poultry Sci 57:752-756
was significantly improved in t h o s e birds restricted from 12 t o 2 4 weeks of age. T o u c h b u r n et al. ( 1 9 6 8 ) f o u n d t h a t restriction of t u r k e y s t o 7 0 or 80% of their n o r m a l feed c o n s u m p t i o n did n o t improve subsequent overall p e r f o r m a n c e ; perhaps due to a difference in t h e strain of bird used. Voitle and Harms ( 1 9 7 2 ) f o u n d t h a t t h e n u t r i e n t restriction of t u r k e y breeders was an effective m e t h o d of delaying sexual m a t u r i t y in addition t o reducing feed c o n s u m p t i o n in m e d i u m white t u r k e y s . A s u b s e q u e n t s t u d y (Voitle et al., 1973) with this same strain of birds indicated t h a t a feeding p r o g r a m utilizing either physical restriction (skip-a-day) or a l o w protein diet would n o t only delay sexual m a t u r i t y and reduce feed c o n s u m p t i o n b u t would also result in an increase in t o t a l egg p r o d u c t i o n even when t h e initial t w o 28-day periods (while t h e t w o restricted g r o u p s were still on t r e a t m e n t ) were included. Egg weight was n o t affected by t r e a t m e n t ; however, t h e non-restricted group laid a m u c h larger n u m b e r of eggs t h a t were considered t o o small for setting. T h e e x p e r i m e n t s reported herein were c o n d u c t e d t o d e t e r m i n e if these findings were, in fact, applicable t o t h e Broad Breasted Large White varieties.
752
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ABSTRACT Two experiments were conducted to determine the effect of nutrient restriction on Broad Breasted Large White Turkey hens. The birds were subjected to the following feeding regime: control (20.6% protein 10—25 weeks of age), low protein-25 (9-9% protein 11—25 weeks of age), low protein-30 (9.9% protein, 11—30 weeks of age), low lysine (14.6% protein, .37% lysine, 11—30 weeks of age), and skip-a-day (29.6% protein 11—30 weeks of age). Feed consumption was the greatest for the controls followed by the low lysine group with the low protein-30 group consuming the least. Body weights throughout the experimental period were related to feed consumption. Age at sexual maturity was inversely related to feed consumption and body weight. Egg production was significantly reduced by the low protein-30 feed restriction program during the growing period in the floor trial, and it was numerically the lowest for this group in all trials. These data indicate that feed restriction was not as effective a method of delaying sexual maturity or improving production in the Broad Breasted Large White as it was in previous studies with the Medium White varieties. Since a sizeable amount of feed savings results from all of the restrictive programs without any major negative effects, it is felt that nutrient restriction is a very practical method of reducing the cost of producing replacement breeders.
753
RESTRICTED FEEDING TURKEY BREEDERS
EXPERIMENTAL PROCEDURE
TABLE 1.—Composition of diets3-
Ingredient
Starter
Low protein
Grower
Yellow corn SBOM 50% Alfalfa meal 2 0 % G r o u n d limestone ( 3 8 % Ca) Dicalcium phosph;i t e ( 1 8 . 5 % P ; 2 5 % C a ) Iodized salt Microingredients Methionine Hepzideb DDGS C Protein, % Metabolizable energy, kcal/kg Calcium, % Total p h o s p h o r u s , % Sulfur amino acids , % Lysine, % a
Low lysine
Breeder
(.%;
47.15 46.00 2.50 1.3 5 2.00 .30 .50 .10 .10
63.35 30.00 2.00 1.31 2.39 .30 .50 .05 .10
90.48 2.52 3.00 .71 2.39 .30 .50
61.82
.10
.10 30.00
.10
27.1 2826 1.16 .79 .84 1.61
20.6 2969 1.19 .81 .70 1.13
9.9 3797 .91 .72 .22 .32
14.6 3033 1.40 .90 .44 .37
16.3 2936 2.48 .78 .43 .82
5.00 1.78 .40 .40 .50
69.75 19.69 2.50 4.74 2.42 .30 .50
Supplied per kilogram of finished feed: 6600 IU vitamin A, 2200 ICU vitamin D 3 , 11 IU vitamin E, 2.2 mg menadione sodium bisulfite, 4.4 mg riboflavin, 13.2 mg pantothenic acid, 59.6 mg niacin, 998.8 mg choline chloride, 22 meg vitamin B t 2 , 110 meg biotin, .0125% ethoxyquin, 60 mg manganese, 50 mg iron, 6 mg copper, 198 meg cobalt, 1.1 mg iodine, 60 mg zinc, and 55 mg terramycin. Provided .04% nithiazide. Distillers dried grains with solubles.
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Two experiments were conducted utilizing a total of 1740 Broad Breasted Large White Turkeys. Twenty day-old poults were randomly placed in each floor pen (approximately 1.5 X 2.4 m). Peanut hulls were used as litter and infrared heat lamps were used for brooding. The entire house was open-type (pole barn) construction typical of the area. Therefore, no attempt was made to restrict light to these birds. The composition of the diets used is shown in Table 1. All birds were fed a turkey starter diet containing 27.1% protein from 1 day to 10 weeks of age. At 10 weeks of age, one-fifth of the birds were assigned to each of the following feeding regimes: control (20.6% protein, 10—25 weeks of age), low protein-25 (9.9% protein, 11—25 weeks of age), low protein-30 (9.9% protein, 11—30 weeks of age), low lysine (14.6% protein, .37% lysine, 1 1 - 3 0 weeks of age), and skip-a-day (20.6% protein, 11—30 weeks of age). Each treatment was replicated at least 5 times in each experiment. The control group received the 20.6% protein grower ad libitum from 10 to 30 weeks of age.
The skip-a-day group received this same diet in restricted amounts. The feed allotment for the skip-a-day group was based on the amount of feed consumed by the control group during the previous week. The skip-a-day program did not begin until the eleventh week as the control consumption during the tenth week was used as the basis for the initial allotment. As a result, the remainder of the restrictive programs were also initiated at the eleventh week. Feed consumption for all treatments was calculated weekly and the average daily feed consumption for the controls was multiplied by 1.5 to determine the amount to be fed the skip-a-day birds every other day for the subsequent week. Nothing was fed on the alternate days. Water was available at all times. If the weekly feeding program began on a Monday, four feed allotments were weighed (Monday, Wednesday, Friday, and Sunday) but if it began on a Tuesday, there were only three allotments (Tuesday, Thursday, and Saturday). These programs were alternated every throughout the experiment. The result was that the skip-a-day birds received 75% of the control intake for the previous week. At the end of 25 weeks of age
VOITLE AND HARMS
754
TABLE 2.—Feed consumption of Br<
Treatment
10-14
14-18
18-22
Control Low protein-25 Low protein-30 Low lysine Skip-a-day
232 145 145 163 154
259 163 154 172 195
268 185 191 209 200
236 186 191 218 177
236 240 186 209 177
246 184 173 194 181
Control Low protein-25 Low protein-30 Low lysine Skip-a-day
222 150 154 168 168
250 136 136 168 186
245 136 136 192 192
245 160 145 172 192
232 263 168 227 172
239 167 148 185 182
22-26
(grams/bird/day)
—
the multiple range test of Duncan (1955). RESULTS AND DISCUSSION In Experiment 1 feed consumption was the greatest for the control birds followed by the low lysine, low protein-25, skip-a-day, and the low protein-30 groups, respectively (Table 2). In the Experiment 2, the controls again consumed the most feed followed by the low lysine group; however, the skip-a-day group was followed by low-protein-25, with the low protein30 group, again, consuming the least amount of feed. At 26 weeks of age the controls had been changed to the breeder diet; however, this change had no real effect on feed consumption. The low protein-25 birds were also put on the breeder diet at 26 weeks of age and a dramatic increase in feed consumption was observed. The feed consumption for the skip-a-day birds was 25% lower than that of the control group, a result of the skip-a-day allotment being based on the control consumption. The trends were similar for floor-reared and caged birds; therefore, the data have been combined. Body weights throughout both experimental periods tended to be related to feed consumption of the birds (Table 3). This is most dramatically reflected in the low protein-25 group. Again, the trends were similar for floor reared and caged birds; therefore the data were combined. Sexual maturity (Table 4) for the floorreared birds in Experiment 1 appeared to be related to the degree of restriction; however, these differences were not significant. The birds
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for the control and low protein-25 groups and 30 weeks for the remaining groups, the birds were changed to a commercial-type breeder diet ( 1 6 . 3 % protein), which they received ad libitum. At 14 weeks of age the birds were transferred to individual cages in replicate groups of 5 cages each (approximately 46 cm X 61 cm). Each treatment was replicated 8 times. The reassignment of birds left the floor pens replicated with 5 birds each. Body weights were taken and feed consumption calculated every 28 days during the growing period. At 30 weeks of age, all birds were placed on 15 hr of light per day beginning at 6:00 a.m. EST. Fertility of eggs was determined after 1 week of incubation and hatchability data was collected every 2 weeks after the initial hatch. Experiment 1. The first experiment was initiated with 480 female and 100 male Nicholas Large White poults hatched early in November, therefore, they were developing during a period of increasing day length which is highly stimulatory to early sexual maturity. The birds were in production from 7—13 months of age, however, the floor portion of the experiment was terminated at the end of the growing period. Experiment 2. The second experiment was initiated with 951 female and 209 male Nicholas Large White poults hatched early in April. The latter part of the growing period occurred during decreasing day length and initial egg productions began in the late Fall. Data were analyzed by application of the analysis of variance test (Snedecor, 1956) and
26-30
RESTRICTED FEEDING TURKEY BREEDERS
755
TABLE 3.—Body weights of Broad Breasted Large White Turkeys on five grower programs (floor and cage combined)^ Experiment
10 wk
14 wk
18 wk
22 wk
26 wk
30 wk
1
Control Low protein-25 Low protein-30 Low lysine Skip-a-day
3.04 n s 3.04 n s 3.04 n s 3.04 n s 3.04 n s
4.63 a 3.50C 3.45 c 3.63 c 3.95b
6.08a 4.27cd 4.04 d 4.36 c 4.81b
7.22 a 5.04 c 4.77 d 5.36b 5.63b
7.72 a 5.90 c 5.54 d 6.40 b 6.36 b
8.08a 7.17b 5.95 d 6.90C 6.72C
2
Control Low protein-25 Low protein-30 Low lysine Skip-a-day
3.40 n s 3.27 n s 3.18 n s 3.31 n s 3.27 n s
4.95 a 3.72 d 3.78d 4.00C 4.27b
6.31a 4.09 d 4.18 d 4.77C 5.22b
6.99^ 4.13d 4.28 d 5.04 c 5.81&
7.80 a 5.18 d 4.81e 5.86 c 6.58b
8.17a 6.6 7 b 4.99 d 6.36 b 6.04 c
' ' ' Means in the same column with the same superscripts are not significantly different (P<.05) according to Duncan's Multiple Range Test. All birds received identical diets to 10 wk of age.
in the control groups were slow in reaching sexual maturity; therefore, one would not expect much additional delay to result from restriction. The caged birds in Experiment 1 reached sexual maturity earlier than the floorreared birds; the Low Protein-30 and skip-a-day treatments were effective in delaying sexual maturity even though the birds were grown under natural increasing daylength. The delay
in sexual maturity in Experiment 2 was inversely related to feed consumption and 30-week body weight; however, these differences were not significant. Egg production was inversely related to age at sexual maturity with the exception of the control birds in Experiment 1 (Table 4). The data indicated that the low protein-30 program was too severe, and consistently was the
TABLE 4.—Age at 25% production and total eggs from Broad Breasted Large White Turkeys on five grower programs'Age (days) to 25% production Treatment
Floor
Cages
Experiment 1 Control Low protein-25 Low protein-30 Low lysine Skip-a-day
298.8ns 301.6 n s 302.8ns 280.2ns 322.0ns
277.5a 291.4a 313.6 b 276.4a 296.8 a b
Experiment 2 Control Low protein-25 Low protein-30 Low lysine Skip-a-day
237.8 n s 240.0ns 249.3 ns 239.5ns 243.0ns
237.3ns 242.3ns 245.2ns 241.0ns 242.3ns
Total number eggs Floor
Cages
42.7ns 47,4ns 36.9 n s 48.7rrs 51.2"s 65.6b 61.0b 42.4 a 72.2b 62.6 b
64.3ns 50.8ns 48.4ns 50.ins 59.3 n s
a,b,Means within the same environment (floor cages) and parameter with the same superscript are not significantly different (P<.05) according to Duncan's Multiple Range Test. Means within a parameter were analyzed separately for the floor-reared and caged birds.
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Treatment
756
VOITLE AND HARMS
ACKNOWLEDGEMENT T h e a u t h o r s wish to acknowledge t h e partial s u p p o r t of this w o r k by a grant-in-aid from Distillers Feed Research Council, Cincinnati, O h i o , and d o n a t i o n s of p o u l t s from Nicholas T u r k e y F a r m s , S o n o m a , California.
REFERENCES Anderson, D. L., J. R. Smyth, Jr., and R. E. Gleason, 1963. Effect of restricted feeding during the growing period on reproductive performance of large type white turkeys. Poultry Sci. 42:8. Atkinson, R. L., J. W. Bradley, and J. H. Quisenberry, 1969. Delaying sexual maturity of turkey hens by the use of drugs. Poultry Sci. 48:1780. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics 11:1—42. Leighton, A. T., 1970. Year-round lighting program for t u r k e y b r e e d e r f l o c k s . Turkey World 45(2):29-31. Nixey, C , 1970. The use of an anti-fertility drug as an aid to control of sexual maturity in the turkey. Poultry Sci. 49:656-662. Snedecor, G. W., 1956. Statistical methods. 5th ed. Iowa State College Press, Ames, IA. Touchbum, S. P., E. C. Naber, and V. D. Chamberlin, 1968. Effect of growth restriction on reproductive performance of turkeys. Poultry Sci. 47:547—556. Voitle, R. A., and R. H. Harms, 1972. The effect of restrictive feeding progrmas during the growing p e r i o d on t u r k e y b r e e d e r s . Poultry Sci. 51:338-340. Voitle, R. A., J. H. Walter, H. R. Wilson, and R. H. Harms, 1973. The effect of low protein and skip-aday grower diets in the subsequent performance of turkey breeder hens. Poultry Sci. 52:543—548. Wilson, W. O., F. X. Ogasawara, and A. E. Woodard, 1967. Increased egg production in winter hatched turkeys by a light restricted treatment. Poultry Sci. 46:46-52.
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poorest performer. T h e r e were n o significant differences in egg p r o d u c t i o n for t h e caged birds; however, in t h e floor reared birds t h e l o w protein-3p birds p r o d u c e d significantly fewer eggs a n d t h e low-lysine g r o u p had t h e greatest p r o d u c t i o n level of any t r e a t m e n t g r o u p . T h e d a t a on fertility and hatchability of fertile eggs are n o t p r e s e n t e d ; however, n o t r e a t m e n t effects were n o t e d . These d a t a indicate t h a t feed restriction is n o t as efficient a m e t h o d of delaying sexual m a t u r i t y or improving p r o d u c t i o n in t h e Broad Breasted Large White varieties as it is in t h e M e d i u m White varieties (Voitle et al, 1 9 7 3 ) . Since a sizable a m o u n t of feed savings results from all t h e restrictive programs w i t h o u t any major negative effect, it is suggested t h a t n u t r i e n t restriction is a very practical m e t h o d of reducing costs in t h e grower house for t h e Broad Breasted Large White varieties.
INTRODUCTION I t has b e c o m e a standard m a n a g e m e n t practice to delay sexual m a t u r i t y in t u r k e y breeder hens in order t o o p t i m i z e r e p r o d u c t i v e performance. Wilson et al. ( 1 9 6 7 ) reviewed t h e literature pertaining t o light restriction during the growing period and r e p o r t e d t h a t it was necessary to delay sexual m a t u r i t y for off season egg p r o d u c t i o n . Leighton ( 1 9 7 0 ) stated t h a t in order to avoid a high incidence of nonlayers and small eggs, s t i m u l a t o r y lighting programs should n o t be initiated before 30 weeks of age with small t y p e t u r k e y s and 32 w e e k s of age for large t y p e s . Certain drugs have been incorporated in t u r k e y grower diets in an a t t e m p t t o delay sexual m a t u r i t y with only limited success (Atkinson et al., 1 9 6 9 , a n d Nixey, 1 9 7 0 ) . A n d e r s o n et al.. ( 1 9 6 3 ) was one of t h e first g r o u p s t o investigate t h e possibility of using feed restriction t o delay sexual m a t u r i t y in t u r k e y breeders. T h e y observed t h a t restricting feed c o n s u m p t i o n to 8 5 % of controls reduced b o d y weights while n o t significantly influencing fertility; however, hatchability of fertile eggs
1
Florida Agr. Exp. Sta. Journal Series No. 675.
1978 Poultry Sci 57:752-756
was significantly improved in t h o s e birds restricted from 12 t o 2 4 weeks of age. T o u c h b u r n et al. ( 1 9 6 8 ) f o u n d t h a t restriction of t u r k e y s t o 7 0 or 80% of their n o r m a l feed c o n s u m p t i o n did n o t improve subsequent overall p e r f o r m a n c e ; perhaps due to a difference in t h e strain of bird used. Voitle and Harms ( 1 9 7 2 ) f o u n d t h a t t h e n u t r i e n t restriction of t u r k e y breeders was an effective m e t h o d of delaying sexual m a t u r i t y in addition t o reducing feed c o n s u m p t i o n in m e d i u m white t u r k e y s . A s u b s e q u e n t s t u d y (Voitle et al., 1973) with this same strain of birds indicated t h a t a feeding p r o g r a m utilizing either physical restriction (skip-a-day) or a l o w protein diet would n o t only delay sexual m a t u r i t y and reduce feed c o n s u m p t i o n b u t would also result in an increase in t o t a l egg p r o d u c t i o n even when t h e initial t w o 28-day periods (while t h e t w o restricted g r o u p s were still on t r e a t m e n t ) were included. Egg weight was n o t affected by t r e a t m e n t ; however, t h e non-restricted group laid a m u c h larger n u m b e r of eggs t h a t were considered t o o small for setting. T h e e x p e r i m e n t s reported herein were c o n d u c t e d t o d e t e r m i n e if these findings were, in fact, applicable t o t h e Broad Breasted Large White varieties.
752
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ABSTRACT Two experiments were conducted to determine the effect of nutrient restriction on Broad Breasted Large White Turkey hens. The birds were subjected to the following feeding regime: control (20.6% protein 10—25 weeks of age), low protein-25 (9-9% protein 11—25 weeks of age), low protein-30 (9.9% protein, 11—30 weeks of age), low lysine (14.6% protein, .37% lysine, 11—30 weeks of age), and skip-a-day (29.6% protein 11—30 weeks of age). Feed consumption was the greatest for the controls followed by the low lysine group with the low protein-30 group consuming the least. Body weights throughout the experimental period were related to feed consumption. Age at sexual maturity was inversely related to feed consumption and body weight. Egg production was significantly reduced by the low protein-30 feed restriction program during the growing period in the floor trial, and it was numerically the lowest for this group in all trials. These data indicate that feed restriction was not as effective a method of delaying sexual maturity or improving production in the Broad Breasted Large White as it was in previous studies with the Medium White varieties. Since a sizeable amount of feed savings results from all of the restrictive programs without any major negative effects, it is felt that nutrient restriction is a very practical method of reducing the cost of producing replacement breeders.
753
RESTRICTED FEEDING TURKEY BREEDERS
EXPERIMENTAL PROCEDURE
TABLE 1.—Composition of diets3-
Ingredient
Starter
Low protein
Grower
Yellow corn SBOM 50% Alfalfa meal 2 0 % G r o u n d limestone ( 3 8 % Ca) Dicalcium phosph;i t e ( 1 8 . 5 % P ; 2 5 % C a ) Iodized salt Microingredients Methionine Hepzideb DDGS C Protein, % Metabolizable energy, kcal/kg Calcium, % Total p h o s p h o r u s , % Sulfur amino acids , % Lysine, % a
Low lysine
Breeder
(.%;
47.15 46.00 2.50 1.3 5 2.00 .30 .50 .10 .10
63.35 30.00 2.00 1.31 2.39 .30 .50 .05 .10
90.48 2.52 3.00 .71 2.39 .30 .50
61.82
.10
.10 30.00
.10
27.1 2826 1.16 .79 .84 1.61
20.6 2969 1.19 .81 .70 1.13
9.9 3797 .91 .72 .22 .32
14.6 3033 1.40 .90 .44 .37
16.3 2936 2.48 .78 .43 .82
5.00 1.78 .40 .40 .50
69.75 19.69 2.50 4.74 2.42 .30 .50
Supplied per kilogram of finished feed: 6600 IU vitamin A, 2200 ICU vitamin D 3 , 11 IU vitamin E, 2.2 mg menadione sodium bisulfite, 4.4 mg riboflavin, 13.2 mg pantothenic acid, 59.6 mg niacin, 998.8 mg choline chloride, 22 meg vitamin B t 2 , 110 meg biotin, .0125% ethoxyquin, 60 mg manganese, 50 mg iron, 6 mg copper, 198 meg cobalt, 1.1 mg iodine, 60 mg zinc, and 55 mg terramycin. Provided .04% nithiazide. Distillers dried grains with solubles.
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Two experiments were conducted utilizing a total of 1740 Broad Breasted Large White Turkeys. Twenty day-old poults were randomly placed in each floor pen (approximately 1.5 X 2.4 m). Peanut hulls were used as litter and infrared heat lamps were used for brooding. The entire house was open-type (pole barn) construction typical of the area. Therefore, no attempt was made to restrict light to these birds. The composition of the diets used is shown in Table 1. All birds were fed a turkey starter diet containing 27.1% protein from 1 day to 10 weeks of age. At 10 weeks of age, one-fifth of the birds were assigned to each of the following feeding regimes: control (20.6% protein, 10—25 weeks of age), low protein-25 (9.9% protein, 11—25 weeks of age), low protein-30 (9.9% protein, 11—30 weeks of age), low lysine (14.6% protein, .37% lysine, 1 1 - 3 0 weeks of age), and skip-a-day (20.6% protein, 11—30 weeks of age). Each treatment was replicated at least 5 times in each experiment. The control group received the 20.6% protein grower ad libitum from 10 to 30 weeks of age.
The skip-a-day group received this same diet in restricted amounts. The feed allotment for the skip-a-day group was based on the amount of feed consumed by the control group during the previous week. The skip-a-day program did not begin until the eleventh week as the control consumption during the tenth week was used as the basis for the initial allotment. As a result, the remainder of the restrictive programs were also initiated at the eleventh week. Feed consumption for all treatments was calculated weekly and the average daily feed consumption for the controls was multiplied by 1.5 to determine the amount to be fed the skip-a-day birds every other day for the subsequent week. Nothing was fed on the alternate days. Water was available at all times. If the weekly feeding program began on a Monday, four feed allotments were weighed (Monday, Wednesday, Friday, and Sunday) but if it began on a Tuesday, there were only three allotments (Tuesday, Thursday, and Saturday). These programs were alternated every throughout the experiment. The result was that the skip-a-day birds received 75% of the control intake for the previous week. At the end of 25 weeks of age
VOITLE AND HARMS
754
TABLE 2.—Feed consumption of Br<
Treatment
10-14
14-18
18-22
Control Low protein-25 Low protein-30 Low lysine Skip-a-day
232 145 145 163 154
259 163 154 172 195
268 185 191 209 200
236 186 191 218 177
236 240 186 209 177
246 184 173 194 181
Control Low protein-25 Low protein-30 Low lysine Skip-a-day
222 150 154 168 168
250 136 136 168 186
245 136 136 192 192
245 160 145 172 192
232 263 168 227 172
239 167 148 185 182
22-26
(grams/bird/day)
—
the multiple range test of Duncan (1955). RESULTS AND DISCUSSION In Experiment 1 feed consumption was the greatest for the control birds followed by the low lysine, low protein-25, skip-a-day, and the low protein-30 groups, respectively (Table 2). In the Experiment 2, the controls again consumed the most feed followed by the low lysine group; however, the skip-a-day group was followed by low-protein-25, with the low protein30 group, again, consuming the least amount of feed. At 26 weeks of age the controls had been changed to the breeder diet; however, this change had no real effect on feed consumption. The low protein-25 birds were also put on the breeder diet at 26 weeks of age and a dramatic increase in feed consumption was observed. The feed consumption for the skip-a-day birds was 25% lower than that of the control group, a result of the skip-a-day allotment being based on the control consumption. The trends were similar for floor-reared and caged birds; therefore, the data have been combined. Body weights throughout both experimental periods tended to be related to feed consumption of the birds (Table 3). This is most dramatically reflected in the low protein-25 group. Again, the trends were similar for floor reared and caged birds; therefore the data were combined. Sexual maturity (Table 4) for the floorreared birds in Experiment 1 appeared to be related to the degree of restriction; however, these differences were not significant. The birds
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for the control and low protein-25 groups and 30 weeks for the remaining groups, the birds were changed to a commercial-type breeder diet ( 1 6 . 3 % protein), which they received ad libitum. At 14 weeks of age the birds were transferred to individual cages in replicate groups of 5 cages each (approximately 46 cm X 61 cm). Each treatment was replicated 8 times. The reassignment of birds left the floor pens replicated with 5 birds each. Body weights were taken and feed consumption calculated every 28 days during the growing period. At 30 weeks of age, all birds were placed on 15 hr of light per day beginning at 6:00 a.m. EST. Fertility of eggs was determined after 1 week of incubation and hatchability data was collected every 2 weeks after the initial hatch. Experiment 1. The first experiment was initiated with 480 female and 100 male Nicholas Large White poults hatched early in November, therefore, they were developing during a period of increasing day length which is highly stimulatory to early sexual maturity. The birds were in production from 7—13 months of age, however, the floor portion of the experiment was terminated at the end of the growing period. Experiment 2. The second experiment was initiated with 951 female and 209 male Nicholas Large White poults hatched early in April. The latter part of the growing period occurred during decreasing day length and initial egg productions began in the late Fall. Data were analyzed by application of the analysis of variance test (Snedecor, 1956) and
26-30
RESTRICTED FEEDING TURKEY BREEDERS
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TABLE 3.—Body weights of Broad Breasted Large White Turkeys on five grower programs (floor and cage combined)^ Experiment
10 wk
14 wk
18 wk
22 wk
26 wk
30 wk
1
Control Low protein-25 Low protein-30 Low lysine Skip-a-day
3.04 n s 3.04 n s 3.04 n s 3.04 n s 3.04 n s
4.63 a 3.50C 3.45 c 3.63 c 3.95b
6.08a 4.27cd 4.04 d 4.36 c 4.81b
7.22 a 5.04 c 4.77 d 5.36b 5.63b
7.72 a 5.90 c 5.54 d 6.40 b 6.36 b
8.08a 7.17b 5.95 d 6.90C 6.72C
2
Control Low protein-25 Low protein-30 Low lysine Skip-a-day
3.40 n s 3.27 n s 3.18 n s 3.31 n s 3.27 n s
4.95 a 3.72 d 3.78d 4.00C 4.27b
6.31a 4.09 d 4.18 d 4.77C 5.22b
6.99^ 4.13d 4.28 d 5.04 c 5.81&
7.80 a 5.18 d 4.81e 5.86 c 6.58b
8.17a 6.6 7 b 4.99 d 6.36 b 6.04 c
' ' ' Means in the same column with the same superscripts are not significantly different (P<.05) according to Duncan's Multiple Range Test. All birds received identical diets to 10 wk of age.
in the control groups were slow in reaching sexual maturity; therefore, one would not expect much additional delay to result from restriction. The caged birds in Experiment 1 reached sexual maturity earlier than the floorreared birds; the Low Protein-30 and skip-a-day treatments were effective in delaying sexual maturity even though the birds were grown under natural increasing daylength. The delay
in sexual maturity in Experiment 2 was inversely related to feed consumption and 30-week body weight; however, these differences were not significant. Egg production was inversely related to age at sexual maturity with the exception of the control birds in Experiment 1 (Table 4). The data indicated that the low protein-30 program was too severe, and consistently was the
TABLE 4.—Age at 25% production and total eggs from Broad Breasted Large White Turkeys on five grower programs'Age (days) to 25% production Treatment
Floor
Cages
Experiment 1 Control Low protein-25 Low protein-30 Low lysine Skip-a-day
298.8ns 301.6 n s 302.8ns 280.2ns 322.0ns
277.5a 291.4a 313.6 b 276.4a 296.8 a b
Experiment 2 Control Low protein-25 Low protein-30 Low lysine Skip-a-day
237.8 n s 240.0ns 249.3 ns 239.5ns 243.0ns
237.3ns 242.3ns 245.2ns 241.0ns 242.3ns
Total number eggs Floor
Cages
42.7ns 47,4ns 36.9 n s 48.7rrs 51.2"s 65.6b 61.0b 42.4 a 72.2b 62.6 b
64.3ns 50.8ns 48.4ns 50.ins 59.3 n s
a,b,Means within the same environment (floor cages) and parameter with the same superscript are not significantly different (P<.05) according to Duncan's Multiple Range Test. Means within a parameter were analyzed separately for the floor-reared and caged birds.
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Treatment
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VOITLE AND HARMS
ACKNOWLEDGEMENT T h e a u t h o r s wish to acknowledge t h e partial s u p p o r t of this w o r k by a grant-in-aid from Distillers Feed Research Council, Cincinnati, O h i o , and d o n a t i o n s of p o u l t s from Nicholas T u r k e y F a r m s , S o n o m a , California.
REFERENCES Anderson, D. L., J. R. Smyth, Jr., and R. E. Gleason, 1963. Effect of restricted feeding during the growing period on reproductive performance of large type white turkeys. Poultry Sci. 42:8. Atkinson, R. L., J. W. Bradley, and J. H. Quisenberry, 1969. Delaying sexual maturity of turkey hens by the use of drugs. Poultry Sci. 48:1780. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics 11:1—42. Leighton, A. T., 1970. Year-round lighting program for t u r k e y b r e e d e r f l o c k s . Turkey World 45(2):29-31. Nixey, C , 1970. The use of an anti-fertility drug as an aid to control of sexual maturity in the turkey. Poultry Sci. 49:656-662. Snedecor, G. W., 1956. Statistical methods. 5th ed. Iowa State College Press, Ames, IA. Touchbum, S. P., E. C. Naber, and V. D. Chamberlin, 1968. Effect of growth restriction on reproductive performance of turkeys. Poultry Sci. 47:547—556. Voitle, R. A., and R. H. Harms, 1972. The effect of restrictive feeding progrmas during the growing p e r i o d on t u r k e y b r e e d e r s . Poultry Sci. 51:338-340. Voitle, R. A., J. H. Walter, H. R. Wilson, and R. H. Harms, 1973. The effect of low protein and skip-aday grower diets in the subsequent performance of turkey breeder hens. Poultry Sci. 52:543—548. Wilson, W. O., F. X. Ogasawara, and A. E. Woodard, 1967. Increased egg production in winter hatched turkeys by a light restricted treatment. Poultry Sci. 46:46-52.
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poorest performer. T h e r e were n o significant differences in egg p r o d u c t i o n for t h e caged birds; however, in t h e floor reared birds t h e l o w protein-3p birds p r o d u c e d significantly fewer eggs a n d t h e low-lysine g r o u p had t h e greatest p r o d u c t i o n level of any t r e a t m e n t g r o u p . T h e d a t a on fertility and hatchability of fertile eggs are n o t p r e s e n t e d ; however, n o t r e a t m e n t effects were n o t e d . These d a t a indicate t h a t feed restriction is n o t as efficient a m e t h o d of delaying sexual m a t u r i t y or improving p r o d u c t i o n in t h e Broad Breasted Large White varieties as it is in t h e M e d i u m White varieties (Voitle et al, 1 9 7 3 ) . Since a sizable a m o u n t of feed savings results from all t h e restrictive programs w i t h o u t any major negative effect, it is suggested t h a t n u t r i e n t restriction is a very practical m e t h o d of reducing costs in t h e grower house for t h e Broad Breasted Large White varieties.