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Effects of Diet and Light During the Pre-Breeder Period, and of Diet During the Breeder Period on Turkey Breeder Performance
Effects of Diet and Light During the Pre-Breeder Period, and of Diet During the Breeder Period on Turkey Breeder Performance L . M . POTTER AND A . T . LEIGHTON, J R .
Department of Poultry Science, Virginia Polytechnic Institute and State University, Virginia 24061
Blacksburg,
(Received for publication January 6, 1973)
POULTRY SCIENCE 52: 1805-1813, 1973
F
EW experiments have been conducted to determine the effects of different energy and vitamin levels in pre-breeder diets of turkeys on subsequent egg production, fertility and hatchability. No nutritional requirements of the turkey between 20 and 32 weeks of age have been established by the National Research Council (1971). In literature reviewed and experiments conducted by Leighton and Potter (1969), turkeys exposed to restricted light treatment prior to sexual maturity were delayed in egg production. In addition, after exposure to days of 15 hours in length, rates of lay were greatly increased over turkeys previously exposed to natural light. One of the experiments presented in the current report provides further information on the effects of restricted light treatment prior to sexual maturity on subsequent reproductive performance of breeder turkeys.
The addition of fish meal to commercial breeder diets for turkeys has been a universal practice during recent years. Some research data are available to support the desirability of adding fish solubles (Ferguson et al., 1956; Feldmen et al, 1957; and Whiteside et al., 1960) and fish meal (Touchburn et al., 1963) to diets of breeder turkeys; however, further research work is needed on the effects of the addition of fish meal to such diets. The two experiments reported in this study were conducted to determine the effects of energy levels and extra vitamin fortification, which also included bacitracin and ethoxyquin, in pre-breeder diets and of light treatments during the pre-breeder period on body weight, feed consumption, subsequent egg production, fertility and hatchability. The same turkeys were utilized during the breeder period to determine the effects of adding fish meal, and of vitamins and trace minerals in
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ABSTRACT Based on two experiments each involving 150 Beltsville or Medium White female turkeys in the pre-breeder period and reduced to 144 in the breeder period, the following results were obtained. When a low energy diet containing 44 percent oat mill feed instead of a currently used high energy diet was fed from 20 to 32 weeks of age, average feed consumption increased 49 percent with only a small decrease in body weight gain. A small reduction in body weight gain was also achieved by feeding the high energy diet on a restricted intake basis saving 10 percent in feed consumption. Fortification of the pre-breeder diet with extra vitamins, and added bacitracin and ethoxyquin failed to influence the results of these measurements, but did tend to increase subsequent egg production (.10 > P > .05). By restricting the amount of light to 6 hours per day during most of the 12-week pre-breeder period of turkey females hatched on October 17, body weights at 32 weeks of age were increased 5.1 percent, feed consumption decreased 12.2 percent, and subsequent egg production was delayed and tended to be increased only slightly (JO > P > .05). The addition of 6 and 12 percent menhaden fish meal to breeder turkey diets increased hatchability of fertile eggs from 72.4 to 78.7 percent (P < .05) and hatchability of all eggs incubated from 57.3 to 64.6 percent (P < .01); and the addition of extra trace minerals increased fertility of eggs incubated from 78.7 to 83.6 percent (P < .05). Egg production, fertility and hatchability from these hens during the 20-week production periods were not significantly influenced by the energy content of the pre-breeder diets or by adding extra vitamins to the breeder diets in these two experiments.
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L. M. POTTER AND A. T. LEIGHTON JR.
excess of those recommended for breeder turkey diets, on egg production, fertility and hatchability. EXPERIMENTAL
Experiment 1. Pre-Breeder Treatments. Twelve pens each containing 12 or 13 Beltsville White female turkeys 20 weeks of age were formed on March 5. A 2 x 2 x 3 factorial design of two levels of energy, two levels
of vitamins and three light treatments was imposed on the 12 pens of turkeys. The compositions of the high energy and low energy pre-breeder diets are presented in Table 1. To form diets containing the extra vitamin fortification, a vitamin premix which contains more nearly those amounts of vitamins added to a breeder diet, plus bacitracin and ethoxyquin, as listed in footnote 4 of Table 1, replaced the regular vitamin premix
TABLE 1.—Basal diets
High energy
Low energy
Breeder diet
g-/kg.
g-/kg.
g-/kg.
440 Oat mill feed — — 375 Standard wheat middlings — — 701.35 76.96 751.96 Ground yellow corn Stabilized animal fat 10 10 10 Dehulled soybean meal 200 25 162.5 Menhaden fish meal 12.5 — — Meat and bone scrap 12.5 25 — Dehydrated alfalfa meal 25 25 — Corn distillers dried solubles 25 — — Defluorinated phosphate 25 10 12.5 30 7.5 7.5 Ground limestone' 4 4 5 Sodium chloride 0.25 0.25 Manganese sulfate2 0.25 Zinc oxide 0.075 0.07 0.07 1.22 1.22 Vitamin premix3-4 — Vitamin and feed additive premix5 3.325 — — Total ,000.000 1,000.00 1,000.00 'The breeder diet for males contained 25 grams of additional ground yellow corn in the place of an2equal amount of ground limestone per kilogram of diet. When extra trace minerals were added as a variable to one-half of the breeder diets, the following additional amounts of trace minerals were added per kilogram of diet: 244 mg. manganese sulfate, 74.7 mg. zinc oxide, 240 mg. ferric citrate, 12.6 mg. anhydrous cupric sulfate, 2.62 mg. potassium iodate and 1.90 mg. cobalt acetate. These additions as a variable provided 60 p.p.m. manganese, 603p.p.m. zinc, 40 p.p.m. iron, 5 p.p.m. copper, 2 p.p.m. iodine and 0.45 p.p.m. cobalt. The vitamin premix supplied the following amounts of vitamins per kg. of diet: 4,410 I.U. vitamin A, 2,205 I.C.U. vitamin D3, 1.1 I.U. vitamin E, 1.65 mg. menadione sodium bisulfite complex, 3.3 mg. riboflavin, 6.6 mg. d-calcium pantothenate, 16.5 mg. niacin, 250 rag. choline chloride and 6.6 meg. vitamin B l2 . No feed additives were included. 4 When extra vitamins were added to the pre-breeder diets as a variable, the following amounts of vitamins and feed additives were added per kg. of diet in place of the above listed regular supplementation: 8,820 I.U. vitamin A, 3,307 I.C.U. vitamin D,, 22 I.U. vitamin E, 6.6 mg. menadione sodium bisulfite complex, 6.6 mg. riboflavin, 16.5 mg. d-calcium pantothenate, 44 mg. niacin, 500 mg. choline chloride, 13.2 meg. vitamin B12, 1.1 mg. folic acid, 11 mg. bacitracin from bacitracin methylene disalicylate and 125 mg. ethoxyquin. This premix contains more nearly those amounts of vitamins and feed additives added to a breeder diet. 5 The vitamin and feed additive premix supplied the following amounts of vitamins and feed additives per kilogram of diet: 8,818 I.U. vitamin A, 3,307 I.C.U. vitamin D3, 33 I.U. vitamin E, 2.2 mg. menadione sodium bisulfite complex, 6.6 mg. riboflavin, 16.5 mg. d-calcium pantothenate, 43.2 mg. niacin, 375 mg. choline chloride, 13.2 meg. vitamin B,2, 1.1 mg. folic acid and 11 mg. procaine penicillin. When the extra vitamins were added as a variable to one-half of the breeder diets, the quantity of vitamin and feed additive premix added to these diets was doubled.
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Pre-breeder diets
Ingredients
TURKEY BREEDER PERFORMANCE
At the end of each two weeks, the turkeys were weighed individually, and feed consumption by pens was determined. These results were summarized and analyzed statistically. Experiment 1. Breeder Treatments. When the turkeys were 32 weeks of age on May 28, one turkey from each of the twelve pens was placed in each of 12 new pens for the 20-week breeder period. Twelve diets varying in amounts of added fish meal, added vitamins and added trace minerals were prepared to form a 3 x 2 x 2 factorial design. The composition of the basal breeder diet containing recommended levels of added vitamins and minerals and no added fish meal is presented in Table 1. Diets with 6 and 12 percent menhaden fish meal were formed by adding increments of 6.00 percent menhaden fish meal with 2.797 percent ground yellow corn and 0.030 percent ground limestone in the place of 7.703 percent dehulled soybean meal and 1.124 percent defluorinated phosphate in an attempt to provide constant levels of protein, calcium and available phosphorus in the diets. From
these diets with 0, 6 and 12 percent menhaden fish meal, three additional diets were formed by doubling the vitamin and feed additive premix, and to each of these, an additional six diets were formed by adding an extra amount of trace minerals as presented in footnote 2 of Table 1. Each diet was assigned at random to one pen of 12 females. The assigned diets, water and insoluble grit, were provided ad libitum. Light from artificial and natural sources was increased to 15 hours per day on May 19, prior to the start of the breeder period, and maintained until October 15 when the turkeys were 52 weeks of age. The hens were trapnested and all eggs were identified by date laid, pen number and bird number if possible. The turkeys were weighed individually at the start of the breeder period and at fourweek intervals throughout the experiment. Hens which became broody were removed from the pen and placed in wire cages for five days. Broody females were fed their respective diets during the broody period. In another pen, 30 Beltsville male turkeys of the same age were maintained on the breeder diet listed in Table 1 except 2.5 percent ground limestone replaced an equal amount of ground yellow corn. Semen was collected from these males, and all females were artificially inseminated at weekly intervals with 0.025 ml. of pooled semen. All setable eggs were incubated every two weeks starting June 9. Egg production records were summarized by two-week periods for each bird and for each pen. Feed consumption records were collected at 28-day intervals, and feed consumption per bird by pens was computed for the five 4-week periods. Number of eggs set, number of fertile eggs, and number of poults were calculated for each female and for each pen of females. Fertility was determined by candling the eggs on the 25th day of incubation. From these data, the percentage fertility, the percentage
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in the high and low energy pre-breeder diets. The turkeys in four pens, representing each dietary treatment, were exposed to one of three light environments designed to be the same as those previously studied (Leighton and Potter, 1969). These light treatments were (1) natural light, (2) six hours of artificial light per day in pens which were light-tight except for natural light entering through cracks about the doors and small holes in the plastic, designated as a "brownout condition," and (3) six hours of artificial light per day in pens completely sealed off from outside light, designated as a "blackout condition." In preparation for the subsequent breeder phase, all turkeys were exposed to 15 hours of natural plus artificial light per day when the turkeys were 30 weeks 5 days of age.
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L. M. POTTER AND A. T. LEIGHTON JR.
hatchability of fertile eggs and the percentage hatchability of all eggs set were calculated for each female and for each pen of females. Analyses of variance were used to determine significant differences among values for egg production, fertility and hatchability associated with the pre-breeder dietary and light treatments, the breeder dietary treatments and the various interactions.
Experiment 2. Breeder Treatments. When the females were 32 weeks of age on August 31, four hens from each of the three prebreeder treatments were assigned to 12 new pens. Each of the 12 breeder diets used in Experiment 1 was randomly assigned to the 12 pens. The day length from artificial and natural sources was increased to 15 hours per day on August 31. Because egg production did not exceed 25 percent during the next six weeks, day length was increased to 24 hours per day on October 14 to further stimulate egg production. Feed consumption and egg production records were cumulated between September 23 and February 10 when the turkeys were between 36 and 56 weeks
RESULTS
Experiment 1. Pre-Breeder Treatments. Results of the dietary and light treatments on body weight, body weight gain and feed consumption of turkeys during the pre-breeder period are presented in Table 2. By feeding the low energy rather than the high energy diet, feed consumption was increased from 10.95 to 17.38 kilograms per bird, or 58.6 percent (P < .001), and body weight gain was significantly decreased from 0.83 to 0.72 kilograms (P < .05). Vitamin fortification, bacitracin and ethoxyquin failed to influence these measurements. By providing only 6 hours of light per day (brownout or blackout) rather than 12 to 14 hours of light per day (natural), body weight was increased by about 0.25 kilograms per bird, or 5.1 percent (P < .01), and feed consumption was decreased by about 1.90 kilograms per bird, or 12.3 percent (P < .001). An attempt was made to determine the effects of the pre-breeder treatments on egg production, fertility and hatchability during the 20-week breeder period. However, 15.0 percent of the eggs were laid on the floor and could not be identified with specific hens
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Experiment 2. Pre-Breeder Treatments. Fifteen pens each containing 10 Medium White female turkeys 20 weeks of age were formed on June 3. For the next 12-weeks, the turkeys in each of five pens were fed (1) the high energy diet (Table 1) ad libitum, (2) the same high energy diet on a restricted basis, and (3) the low energy diet (Table 1) ad libitum. Feed consumption of the restricted turkeys was restricted to 90 percent of the feed consumed by the turkeys receiving the high energy diet on the ad libitum basis during eachprevious week. All turkeys were exposed to natural light during the pre-breeder period. Individual body weights and feed consumption by pens were collected at the end of each two-week period. These results were summarized and analyzed statistically.
of age. Eggs were set at two-week intervals starting on October 19. Thirty male turkeys of the same age and strain were maintained in separate pens, and females were artificially inseminated weekly by methods similar to those used in Experiment 1. Egg production, fertility and hatchability data were also collected in a manner as outlined for the first experiment. Analyses of variance were calculated to determine significant differences among values for egg production, fertility and hatchability associated with the pre-breeder treatments, the breeder treatments and their interactions. The egg production, fertility and hatchability of all eggs laid in each pen of turkeys of the two breeder experiments were also summarized and analyzed statistically.
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TURKEY BREEDER PERFORMANCE
TABLE 2.—Effects of dietary and light treatments n average body weight, average body weight gain and feed consumption of turkeys durir, the pre-breeder period (Experiment I) Body weight gain, 20-32 weeks kg. .83 .72 -.11*
Feed consumed, 20-32 weeks kg. 10.95 17.38 6.43***
Regular vitamin level Extra vitamin level Difference1
4.81 4.80 -0.01
.79 .76 -.03
14.13 14.20 0.07
Natural light Brownout Blackout Difference, average2 'Difference required for significance (P < .05): 72 vs. 72 turkeys 2 Difference required for significance (P < .05): 48 vs. 96 turkeys * Significant 5% level. **Significant 1% level. ***Significant 0.1% level.
4.64 4.90 4.87 0 25**
.67 .81 .84 15**
0.14
0.08
0.74
0.15
0.08
0.79
Treatment High energy Low energy Difference1
by trapnest records. Based upon a summary of eggs that could be identified by hens (Table 3), no significant differences were found among hens on the various pre-breeder treatments for the number of eggs laid, fertility, hatchability of the fertile eggs or hatchability of all eggs set. When analyzed by twoweek periods, egg production was significantly higher during the last six weeks of the 20-week study for hens from the pre-conditioned brownout or blackout treatments than for those from the natural light treatment (Figure 1). A trend for higher egg production (6.4 eggs per hen per 140 days) was observed for hens previously fed diets containing the extra vitamins, bacitracin and ethoxyquin during the pre-breeder period in comparison to those fed diets without these additives (Table 3). Unfortunately, because of the small number of female turkeys involved, large differences between responses associated with treatments are required for
15.43 13.65 13.41 —1 90***
l
BLACK OUT
***
14 28 MAY
II 28 JUNE
B 23 JULY
6 20 AUO
3 IT SEPT
48
tm%
* FLOOR EGGS I44hmt
I
IB 29 OCT
12 26 NOV
10 24 DEC
32
56
60
END OF WEEKLY PERIODS 28
32
36
40
44
48
AGE OF T U R K E Y S (WEEKS)
FIG. 1. Egg production expressed as eggs laid in nests per 100 hens per day plotted against date and age of turkeys at weekly intervals before, during and after the 20-week experiment. Eggs laid on the floor, representing 15.0% of all eggs, expressed per 100 hens (all in the experiment) per day is also plotted on date and age of turkeys. The total egg production, in nests and on the floor, is also plotted for the hens under natural light treatment during a four-week pre-experiment period after egg production was noted.
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Body weight, 32 weeks kg. 4.84 4.76 -0.08
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L. M. POTTER AND A. T. LEIGHTON JR.
TABLE 3.—Effects of dietary and light treatments during the pre-breeder period on subsequent egg production and on fertility and hatchability of eggs (Experiment 1) Percent
Eggs laid per hen per 140 days
Fertility of eggs set
46.8 50.0
Hatchability of all eggs set 63.8 63.8
3.2
-1.5
2.0
0.0
45.2 51.7
83.7 80.6
76.4 77.4
64.5 63.1
Difference2
6.4
-3.1
1.0
-1.4
Natural light Brownout Blackout
44.7 47.7 52.9
82.0 83.5 81.0
74.5 77.8 78.5
61.4 65.5 64.5
5.6
0.2
3.7
3.6
8.5
81.7
75.2
61.4
20.4
15.1
12.9
17.6
Treatment High energy Low energy Difference2 Regular vitamin level Extra vitamin level
Difference, average 3 Floor eggs Standard deviation per hen
'95% of the eggs identified by treatment and 90% of the floor eggs were incubated. 2 Difference required for significance (P < .05): 72 hens vs. 72 hens 6.7 5.0 4.3 'Difference required for significance (P < .05): 48 hens vs. 96 hens 7.1 5.3 4.5
the observed differences to be statistically significant. Experiment 2. Pre-Breeder Treatments. The effects of energy content of the diet on body weight gain and feed consumption during the pre-breeder period in the second experiment are presented in Table 4. Feed in-
TABLE 4.—Effects
5.8 6.2
take of turkeys fed the standard high energy diet on a restricted basis was reduced 1.17 kilograms or to 89.9 percent of the amount of those fed the same diet on a full feed basis. By feeding the low energy diet rather than the high energy diet, feed consumption was increased 4.51 kilograms or 38.9 percent compared to 58.6 percent in Experiment 1.
of level of energy in diet on average body weight, average body weight gain and feed consumption of turkeys during the pre-breeder period (Experiment 2)
Treatment High energy, full feed (1) High energy, restricted (2) Low energy, full feed (3) Difference (2) - (1) Difference (3) - (1) Difference required for significance (P < .05): 48 vs. 48 turkeys "Significant 1% level. ***Significant 0.1% level.
Body weight, 32 weeks
Body weight gain, 20-32 weeks
Feed consumed, 20-32 weeks
kg. 5.38 ± 0.07 5.07 ± 0.05 4.93 ± 0.06 -.31** — 45***
kg. 1.05 ± 0.02 .62 ± 0.03 .55 ± 0.05
kg. 11.58 ± 0.14 10.41 ± 0.05 16.09 ± 0.15
.19
.10
_i
_;50***
17***
4 5j#**
.45
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82.9 81.4
Hatchability of fertile eggs 75.9 77.9
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TURKEY BREEDER PERFORMANCE
TABLE 5.—Effects
of level of energy in diet during the pre-breeder period on subsequent egg production and on fertility and hatchability of eggs (Experiment 2)
Treatment High energy, full feed (1) High energy, restricted (2) Low energy, full feed (3) Difference (2) - (1) Difference (3) - (1)
Percent
Eggs laid per hen per 140 days
Fertility of eggs set
Hatchability of fertile eggs
Hatchability of all eggs set
44.5 45.2 42.3
81.0 82.5 84.0
76.7 77.9 76.0
62.1 64.3 63.9
0.7 -2.2
1.5 3.0
1.2 -0.7
2.2 1.8
Standard deviation per hen
26.5
19.2
21.3
19.9
Floor eggs
10.4
76.5
75.7
57.9
These changes in level of feed intake or in diet formulation resulted in significant reductions in body weights and in body weight gains. The effects of the pre-breeder diet on subsequent egg production and on fertility and hatchability were not significant (Table 5). Of the 150 females in each of the two prebreeder experiments, no mortality occurred between 20 and 32 weeks of age. After reducing the number of females for each breeder experiment to 144, no mortality occurred between 32 and 52 weeks of age in the first experiment and only six died between 36 and 56 weeks of age in the second experiment. Dietary Breeder Treatments (Experiments 1 and 2). The average percentages of egg production, fertility, hatchability of fertile eggs and hatchability of all eggs set from each of the 12 breeder dietary treatments combined for the two 20-week experiments are presented in Table 6. No significant differences in egg production were noted among the dietary treatments. An increase of 4.9 fertile eggs per 100 eggs incubated was observed to be associated with the addition of the extra trace minerals to the breeder diet (P < 0.05). The other differences among percent fertility of eggs as associated with the diets failed to be significant.
7.9
8.1
When 6 or 12 percent fish meal was present in the diets, the hatchability of fertile eggs was increased from 72.4 to 80.3 and to 77.1 percent, respectively, and hatchability of all eggs set was increased from 57.3 to 66.4 and to 62.8 percent, respectively. The added extra vitamins and added extra trace minerals in the breeder diets failed to influence number of poults obtained from fertile eggs or total eggs incubated. DISCUSSION
The increase in egg production for turkeys pre-conditioned under the brownout or blackout treatments over those previously held under the natural light treatment was not as great in this experiment as in experiments previously conducted by Leighton and Potter (1969). Turkeys held under the natural light treatment produced more eggs during the summer months than those on a comparable treatment in Experiment 2 of the above report. In addition, the turkeys exposed to 12 weeks of light restriction did not maintain as high a rate of egg production in the current experiment (Figure 1) as those under comparable treatments in the previously reported study. The turkeys in Experiment 1 of the present study were hatched on October 17, and the benefit from the restricted light treatment
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Difference required for significance (P < .05): 48 vs. 48 turkeys 11.1
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L . M. POTTER AND A . T . LEIGHTON J R .
TABLE 6.—Average 20-week egg production, fertility of eggs incubated, hatchability of fertile eggs and hatchability of all eggs indubated from turkeys fed 12 diets'2 Extra vitamins
Fish meal, %
Extra minerals
0
0 + 0 +
37.7 32.2 45.0 38.2
41.5 45.8 39.1 39.4
41.1 39.0 41.6 43.6
38.3
41.4 3.1
41.3 3.0
0 + Average Difference3
6 Egg production,
12
%
0 + 0 +
+ Average Difference 3
0
39.6
41.0
+
41.2
39.7
1.6
-1.3
0
81.0
78.7
+
81.3
83.6
%
81.6 82.8 75.2 77.3
76.5 87.2 81.1 86.2
77.2 80.8 81.2 87.0
79.2
82.8 3.6
81.4 2.2
0.3
4.9*
Hatchability of fertile eggs,,% 0
0 + 0 +
+ Average Difference 3
71.2 71.0 79.7 67.9
78.6 79.8 83.0 79.8
75.5 78.7 76.4 77.1
72.4
80.3 7.9*
77.1 4.7
0
76.2
77.6
+
77.4
76.0
1.2
-1.6
0
61.8
61.0
+
62.9
63.7
1.1
2.7
Hatchability of eggs incubated, % 0
0 + 0 +
+ Average Difference 3
58.1 58.8 59.9 52.4
60.3 69.7 67.1 68.8
58.3 64.0 62.0 67.1
57.3
66.4
62.8 5.5*
Q
1***
'Data from two experiments combined; 24 hens per dietary treatment. 2 Total of 7727 eggs incubated in the first experiment and 8179 eggs incubated in the second experiment. 3 Difference required for significance (P < .05):
For vitamins or minerals 12 pens vs. 12 pens For fish meal 8 pens vs. 8 pens Standard deviation per pen *Significant at the 5% level. ***Significant at the 0.1% level.
Egg production
Fertility of eggs
Hatchability of fertile eggs
Hatchability of all eggs
4.0
4.2
4.7
3.9
4.9
5.2
5.8
4.7
4.5
4.7
5.2
4.3
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Fertility of eggs incubated, 0
Average by Average by vitamins minerals
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TURKEY BREEDER PERFORMANCE
Results of this study indicate that feeding a high fiber, low energy diet to turkeys during the pre-breeder period provides no advantage, except for controlling body weight gain, and it greatly increases feed consumption and feed cost. The restricted feed intake of a high energy diet does provide advantages through decreased feed consumption as well as controlling body weight gain. The trend toward increased egg production associated with the extra vitamin fortification, including bacitracin and ethoxyquin, in the pre-breeder diet was observed throughout the breeder period and not primarily during the first part of the experiment. Although the observed increase in egg production was 6.4 eggs per hen (.10 > P > .05), further research is needed to confirm or refute this possible effect. The results from the breeder portions of the two experiments indicate that fish meal contains a factor not present in the added vitamins or trace minerals necessary for optimum hatchability of eggs. Biotin and pyridoxine were not included in the vitamin supplement; however, the contributions of these
vitamins by fish meal are not believed to be sufficient to affect hatchability. ACKNOWLEDGMENTS
This research work was supported in part by funds received under contract from the Technological Laboratory, Bureau of Commercial Fisheries, Fish and Wildlife Service, United States Department of the Interior, College Park, Maryland (currently the National Marine Fisheries Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce). The technical assistance of Joel Coleman, Lee Roy Barnett and Larry Melton, Department of Poultry Science, for their part in the care of turkeys, incubation of eggs and preparation of feed is greatly appreciated. REFERENCES
Feldman, G. L., R. L. Atkinson, B. G. Creech, T. M. Ferguson, B. L. Reid and J. R. Couch, 1957. The effect of dehydrated alfalfa meal, dried brewers yeast and condensed fish solubles on the reproductive performance of turkeys. Poultry Sci. 36: 792797. Ferguson, T. M., H. P. Vaught, B. L. Reid and J. R. Couch, 1956. The effect of vitamin E, dehydrated alfalfa meal and condensed fish solubles upon hatchability of eggs from Broad Breasted Bronze hens maintained on litter. Poultry Sci. 35: 872-875. Leighton, A. T., Jr., and L. M. Potter, 1969. Reproductive performance of turkeys subjected to blackout versus brownout restricted light conditions. Poultry Sci. 48: 505-514. National Academy of Sciences, 1971. Nutrient requirements of deomstic animals. Number 1. Nutrient requirements of poultry. Sixth revised edition. Touchburn, S. P., V. D. Chamberlin, M. G. McCartney and E. C. Naber, 1963. Unidentified reproductive and progency growth factor in turkey nutrition. Poultry Sci. 42: 1314. Whiteside, C. H., T. M. Ferguson, B. L. Reid and J. R. Couch, 1960. The effect of dehydrated alfalfa meal, dried brewers yeast, condensed fish solubles and fermentation residue on the reproductive performance of turkeys. Poultry Sci. 39: 77-81.
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was negligible. The females used in Experiments 1 and 2 in the study by Leighton and Potter (1969) were hatched in October 31 and December 18, respectively; marked effects of the restricted light treatment on subsequent egg production were observed in each. The turkeys in the unrestricted light treatments of Experiments 1 and 2 of that study laid at a lower and a much lower rate, respectively, during the summer months than those on the comparable treatment in Experiment 1 of the present study. Especially in the latter experiment of the study by Leighton and Potter (1969), the egg production probably did not increase because the birds were not old enough to respond to the extended periods of lights at the time they were given.
Department of Poultry Science, Virginia Polytechnic Institute and State University, Virginia 24061
Blacksburg,
(Received for publication January 6, 1973)
POULTRY SCIENCE 52: 1805-1813, 1973
F
EW experiments have been conducted to determine the effects of different energy and vitamin levels in pre-breeder diets of turkeys on subsequent egg production, fertility and hatchability. No nutritional requirements of the turkey between 20 and 32 weeks of age have been established by the National Research Council (1971). In literature reviewed and experiments conducted by Leighton and Potter (1969), turkeys exposed to restricted light treatment prior to sexual maturity were delayed in egg production. In addition, after exposure to days of 15 hours in length, rates of lay were greatly increased over turkeys previously exposed to natural light. One of the experiments presented in the current report provides further information on the effects of restricted light treatment prior to sexual maturity on subsequent reproductive performance of breeder turkeys.
The addition of fish meal to commercial breeder diets for turkeys has been a universal practice during recent years. Some research data are available to support the desirability of adding fish solubles (Ferguson et al., 1956; Feldmen et al, 1957; and Whiteside et al., 1960) and fish meal (Touchburn et al., 1963) to diets of breeder turkeys; however, further research work is needed on the effects of the addition of fish meal to such diets. The two experiments reported in this study were conducted to determine the effects of energy levels and extra vitamin fortification, which also included bacitracin and ethoxyquin, in pre-breeder diets and of light treatments during the pre-breeder period on body weight, feed consumption, subsequent egg production, fertility and hatchability. The same turkeys were utilized during the breeder period to determine the effects of adding fish meal, and of vitamins and trace minerals in
1805
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ABSTRACT Based on two experiments each involving 150 Beltsville or Medium White female turkeys in the pre-breeder period and reduced to 144 in the breeder period, the following results were obtained. When a low energy diet containing 44 percent oat mill feed instead of a currently used high energy diet was fed from 20 to 32 weeks of age, average feed consumption increased 49 percent with only a small decrease in body weight gain. A small reduction in body weight gain was also achieved by feeding the high energy diet on a restricted intake basis saving 10 percent in feed consumption. Fortification of the pre-breeder diet with extra vitamins, and added bacitracin and ethoxyquin failed to influence the results of these measurements, but did tend to increase subsequent egg production (.10 > P > .05). By restricting the amount of light to 6 hours per day during most of the 12-week pre-breeder period of turkey females hatched on October 17, body weights at 32 weeks of age were increased 5.1 percent, feed consumption decreased 12.2 percent, and subsequent egg production was delayed and tended to be increased only slightly (JO > P > .05). The addition of 6 and 12 percent menhaden fish meal to breeder turkey diets increased hatchability of fertile eggs from 72.4 to 78.7 percent (P < .05) and hatchability of all eggs incubated from 57.3 to 64.6 percent (P < .01); and the addition of extra trace minerals increased fertility of eggs incubated from 78.7 to 83.6 percent (P < .05). Egg production, fertility and hatchability from these hens during the 20-week production periods were not significantly influenced by the energy content of the pre-breeder diets or by adding extra vitamins to the breeder diets in these two experiments.
1806
L. M. POTTER AND A. T. LEIGHTON JR.
excess of those recommended for breeder turkey diets, on egg production, fertility and hatchability. EXPERIMENTAL
Experiment 1. Pre-Breeder Treatments. Twelve pens each containing 12 or 13 Beltsville White female turkeys 20 weeks of age were formed on March 5. A 2 x 2 x 3 factorial design of two levels of energy, two levels
of vitamins and three light treatments was imposed on the 12 pens of turkeys. The compositions of the high energy and low energy pre-breeder diets are presented in Table 1. To form diets containing the extra vitamin fortification, a vitamin premix which contains more nearly those amounts of vitamins added to a breeder diet, plus bacitracin and ethoxyquin, as listed in footnote 4 of Table 1, replaced the regular vitamin premix
TABLE 1.—Basal diets
High energy
Low energy
Breeder diet
g-/kg.
g-/kg.
g-/kg.
440 Oat mill feed — — 375 Standard wheat middlings — — 701.35 76.96 751.96 Ground yellow corn Stabilized animal fat 10 10 10 Dehulled soybean meal 200 25 162.5 Menhaden fish meal 12.5 — — Meat and bone scrap 12.5 25 — Dehydrated alfalfa meal 25 25 — Corn distillers dried solubles 25 — — Defluorinated phosphate 25 10 12.5 30 7.5 7.5 Ground limestone' 4 4 5 Sodium chloride 0.25 0.25 Manganese sulfate2 0.25 Zinc oxide 0.075 0.07 0.07 1.22 1.22 Vitamin premix3-4 — Vitamin and feed additive premix5 3.325 — — Total ,000.000 1,000.00 1,000.00 'The breeder diet for males contained 25 grams of additional ground yellow corn in the place of an2equal amount of ground limestone per kilogram of diet. When extra trace minerals were added as a variable to one-half of the breeder diets, the following additional amounts of trace minerals were added per kilogram of diet: 244 mg. manganese sulfate, 74.7 mg. zinc oxide, 240 mg. ferric citrate, 12.6 mg. anhydrous cupric sulfate, 2.62 mg. potassium iodate and 1.90 mg. cobalt acetate. These additions as a variable provided 60 p.p.m. manganese, 603p.p.m. zinc, 40 p.p.m. iron, 5 p.p.m. copper, 2 p.p.m. iodine and 0.45 p.p.m. cobalt. The vitamin premix supplied the following amounts of vitamins per kg. of diet: 4,410 I.U. vitamin A, 2,205 I.C.U. vitamin D3, 1.1 I.U. vitamin E, 1.65 mg. menadione sodium bisulfite complex, 3.3 mg. riboflavin, 6.6 mg. d-calcium pantothenate, 16.5 mg. niacin, 250 rag. choline chloride and 6.6 meg. vitamin B l2 . No feed additives were included. 4 When extra vitamins were added to the pre-breeder diets as a variable, the following amounts of vitamins and feed additives were added per kg. of diet in place of the above listed regular supplementation: 8,820 I.U. vitamin A, 3,307 I.C.U. vitamin D,, 22 I.U. vitamin E, 6.6 mg. menadione sodium bisulfite complex, 6.6 mg. riboflavin, 16.5 mg. d-calcium pantothenate, 44 mg. niacin, 500 mg. choline chloride, 13.2 meg. vitamin B12, 1.1 mg. folic acid, 11 mg. bacitracin from bacitracin methylene disalicylate and 125 mg. ethoxyquin. This premix contains more nearly those amounts of vitamins and feed additives added to a breeder diet. 5 The vitamin and feed additive premix supplied the following amounts of vitamins and feed additives per kilogram of diet: 8,818 I.U. vitamin A, 3,307 I.C.U. vitamin D3, 33 I.U. vitamin E, 2.2 mg. menadione sodium bisulfite complex, 6.6 mg. riboflavin, 16.5 mg. d-calcium pantothenate, 43.2 mg. niacin, 375 mg. choline chloride, 13.2 meg. vitamin B,2, 1.1 mg. folic acid and 11 mg. procaine penicillin. When the extra vitamins were added as a variable to one-half of the breeder diets, the quantity of vitamin and feed additive premix added to these diets was doubled.
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Pre-breeder diets
Ingredients
TURKEY BREEDER PERFORMANCE
At the end of each two weeks, the turkeys were weighed individually, and feed consumption by pens was determined. These results were summarized and analyzed statistically. Experiment 1. Breeder Treatments. When the turkeys were 32 weeks of age on May 28, one turkey from each of the twelve pens was placed in each of 12 new pens for the 20-week breeder period. Twelve diets varying in amounts of added fish meal, added vitamins and added trace minerals were prepared to form a 3 x 2 x 2 factorial design. The composition of the basal breeder diet containing recommended levels of added vitamins and minerals and no added fish meal is presented in Table 1. Diets with 6 and 12 percent menhaden fish meal were formed by adding increments of 6.00 percent menhaden fish meal with 2.797 percent ground yellow corn and 0.030 percent ground limestone in the place of 7.703 percent dehulled soybean meal and 1.124 percent defluorinated phosphate in an attempt to provide constant levels of protein, calcium and available phosphorus in the diets. From
these diets with 0, 6 and 12 percent menhaden fish meal, three additional diets were formed by doubling the vitamin and feed additive premix, and to each of these, an additional six diets were formed by adding an extra amount of trace minerals as presented in footnote 2 of Table 1. Each diet was assigned at random to one pen of 12 females. The assigned diets, water and insoluble grit, were provided ad libitum. Light from artificial and natural sources was increased to 15 hours per day on May 19, prior to the start of the breeder period, and maintained until October 15 when the turkeys were 52 weeks of age. The hens were trapnested and all eggs were identified by date laid, pen number and bird number if possible. The turkeys were weighed individually at the start of the breeder period and at fourweek intervals throughout the experiment. Hens which became broody were removed from the pen and placed in wire cages for five days. Broody females were fed their respective diets during the broody period. In another pen, 30 Beltsville male turkeys of the same age were maintained on the breeder diet listed in Table 1 except 2.5 percent ground limestone replaced an equal amount of ground yellow corn. Semen was collected from these males, and all females were artificially inseminated at weekly intervals with 0.025 ml. of pooled semen. All setable eggs were incubated every two weeks starting June 9. Egg production records were summarized by two-week periods for each bird and for each pen. Feed consumption records were collected at 28-day intervals, and feed consumption per bird by pens was computed for the five 4-week periods. Number of eggs set, number of fertile eggs, and number of poults were calculated for each female and for each pen of females. Fertility was determined by candling the eggs on the 25th day of incubation. From these data, the percentage fertility, the percentage
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in the high and low energy pre-breeder diets. The turkeys in four pens, representing each dietary treatment, were exposed to one of three light environments designed to be the same as those previously studied (Leighton and Potter, 1969). These light treatments were (1) natural light, (2) six hours of artificial light per day in pens which were light-tight except for natural light entering through cracks about the doors and small holes in the plastic, designated as a "brownout condition," and (3) six hours of artificial light per day in pens completely sealed off from outside light, designated as a "blackout condition." In preparation for the subsequent breeder phase, all turkeys were exposed to 15 hours of natural plus artificial light per day when the turkeys were 30 weeks 5 days of age.
1807
1808
L. M. POTTER AND A. T. LEIGHTON JR.
hatchability of fertile eggs and the percentage hatchability of all eggs set were calculated for each female and for each pen of females. Analyses of variance were used to determine significant differences among values for egg production, fertility and hatchability associated with the pre-breeder dietary and light treatments, the breeder dietary treatments and the various interactions.
Experiment 2. Breeder Treatments. When the females were 32 weeks of age on August 31, four hens from each of the three prebreeder treatments were assigned to 12 new pens. Each of the 12 breeder diets used in Experiment 1 was randomly assigned to the 12 pens. The day length from artificial and natural sources was increased to 15 hours per day on August 31. Because egg production did not exceed 25 percent during the next six weeks, day length was increased to 24 hours per day on October 14 to further stimulate egg production. Feed consumption and egg production records were cumulated between September 23 and February 10 when the turkeys were between 36 and 56 weeks
RESULTS
Experiment 1. Pre-Breeder Treatments. Results of the dietary and light treatments on body weight, body weight gain and feed consumption of turkeys during the pre-breeder period are presented in Table 2. By feeding the low energy rather than the high energy diet, feed consumption was increased from 10.95 to 17.38 kilograms per bird, or 58.6 percent (P < .001), and body weight gain was significantly decreased from 0.83 to 0.72 kilograms (P < .05). Vitamin fortification, bacitracin and ethoxyquin failed to influence these measurements. By providing only 6 hours of light per day (brownout or blackout) rather than 12 to 14 hours of light per day (natural), body weight was increased by about 0.25 kilograms per bird, or 5.1 percent (P < .01), and feed consumption was decreased by about 1.90 kilograms per bird, or 12.3 percent (P < .001). An attempt was made to determine the effects of the pre-breeder treatments on egg production, fertility and hatchability during the 20-week breeder period. However, 15.0 percent of the eggs were laid on the floor and could not be identified with specific hens
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Experiment 2. Pre-Breeder Treatments. Fifteen pens each containing 10 Medium White female turkeys 20 weeks of age were formed on June 3. For the next 12-weeks, the turkeys in each of five pens were fed (1) the high energy diet (Table 1) ad libitum, (2) the same high energy diet on a restricted basis, and (3) the low energy diet (Table 1) ad libitum. Feed consumption of the restricted turkeys was restricted to 90 percent of the feed consumed by the turkeys receiving the high energy diet on the ad libitum basis during eachprevious week. All turkeys were exposed to natural light during the pre-breeder period. Individual body weights and feed consumption by pens were collected at the end of each two-week period. These results were summarized and analyzed statistically.
of age. Eggs were set at two-week intervals starting on October 19. Thirty male turkeys of the same age and strain were maintained in separate pens, and females were artificially inseminated weekly by methods similar to those used in Experiment 1. Egg production, fertility and hatchability data were also collected in a manner as outlined for the first experiment. Analyses of variance were calculated to determine significant differences among values for egg production, fertility and hatchability associated with the pre-breeder treatments, the breeder treatments and their interactions. The egg production, fertility and hatchability of all eggs laid in each pen of turkeys of the two breeder experiments were also summarized and analyzed statistically.
1809
TURKEY BREEDER PERFORMANCE
TABLE 2.—Effects of dietary and light treatments n average body weight, average body weight gain and feed consumption of turkeys durir, the pre-breeder period (Experiment I) Body weight gain, 20-32 weeks kg. .83 .72 -.11*
Feed consumed, 20-32 weeks kg. 10.95 17.38 6.43***
Regular vitamin level Extra vitamin level Difference1
4.81 4.80 -0.01
.79 .76 -.03
14.13 14.20 0.07
Natural light Brownout Blackout Difference, average2 'Difference required for significance (P < .05): 72 vs. 72 turkeys 2 Difference required for significance (P < .05): 48 vs. 96 turkeys * Significant 5% level. **Significant 1% level. ***Significant 0.1% level.
4.64 4.90 4.87 0 25**
.67 .81 .84 15**
0.14
0.08
0.74
0.15
0.08
0.79
Treatment High energy Low energy Difference1
by trapnest records. Based upon a summary of eggs that could be identified by hens (Table 3), no significant differences were found among hens on the various pre-breeder treatments for the number of eggs laid, fertility, hatchability of the fertile eggs or hatchability of all eggs set. When analyzed by twoweek periods, egg production was significantly higher during the last six weeks of the 20-week study for hens from the pre-conditioned brownout or blackout treatments than for those from the natural light treatment (Figure 1). A trend for higher egg production (6.4 eggs per hen per 140 days) was observed for hens previously fed diets containing the extra vitamins, bacitracin and ethoxyquin during the pre-breeder period in comparison to those fed diets without these additives (Table 3). Unfortunately, because of the small number of female turkeys involved, large differences between responses associated with treatments are required for
15.43 13.65 13.41 —1 90***
l
BLACK OUT
***
14 28 MAY
II 28 JUNE
B 23 JULY
6 20 AUO
3 IT SEPT
48
tm%
* FLOOR EGGS I44hmt
I
IB 29 OCT
12 26 NOV
10 24 DEC
32
56
60
END OF WEEKLY PERIODS 28
32
36
40
44
48
AGE OF T U R K E Y S (WEEKS)
FIG. 1. Egg production expressed as eggs laid in nests per 100 hens per day plotted against date and age of turkeys at weekly intervals before, during and after the 20-week experiment. Eggs laid on the floor, representing 15.0% of all eggs, expressed per 100 hens (all in the experiment) per day is also plotted on date and age of turkeys. The total egg production, in nests and on the floor, is also plotted for the hens under natural light treatment during a four-week pre-experiment period after egg production was noted.
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Body weight, 32 weeks kg. 4.84 4.76 -0.08
1810
L. M. POTTER AND A. T. LEIGHTON JR.
TABLE 3.—Effects of dietary and light treatments during the pre-breeder period on subsequent egg production and on fertility and hatchability of eggs (Experiment 1) Percent
Eggs laid per hen per 140 days
Fertility of eggs set
46.8 50.0
Hatchability of all eggs set 63.8 63.8
3.2
-1.5
2.0
0.0
45.2 51.7
83.7 80.6
76.4 77.4
64.5 63.1
Difference2
6.4
-3.1
1.0
-1.4
Natural light Brownout Blackout
44.7 47.7 52.9
82.0 83.5 81.0
74.5 77.8 78.5
61.4 65.5 64.5
5.6
0.2
3.7
3.6
8.5
81.7
75.2
61.4
20.4
15.1
12.9
17.6
Treatment High energy Low energy Difference2 Regular vitamin level Extra vitamin level
Difference, average 3 Floor eggs Standard deviation per hen
'95% of the eggs identified by treatment and 90% of the floor eggs were incubated. 2 Difference required for significance (P < .05): 72 hens vs. 72 hens 6.7 5.0 4.3 'Difference required for significance (P < .05): 48 hens vs. 96 hens 7.1 5.3 4.5
the observed differences to be statistically significant. Experiment 2. Pre-Breeder Treatments. The effects of energy content of the diet on body weight gain and feed consumption during the pre-breeder period in the second experiment are presented in Table 4. Feed in-
TABLE 4.—Effects
5.8 6.2
take of turkeys fed the standard high energy diet on a restricted basis was reduced 1.17 kilograms or to 89.9 percent of the amount of those fed the same diet on a full feed basis. By feeding the low energy diet rather than the high energy diet, feed consumption was increased 4.51 kilograms or 38.9 percent compared to 58.6 percent in Experiment 1.
of level of energy in diet on average body weight, average body weight gain and feed consumption of turkeys during the pre-breeder period (Experiment 2)
Treatment High energy, full feed (1) High energy, restricted (2) Low energy, full feed (3) Difference (2) - (1) Difference (3) - (1) Difference required for significance (P < .05): 48 vs. 48 turkeys "Significant 1% level. ***Significant 0.1% level.
Body weight, 32 weeks
Body weight gain, 20-32 weeks
Feed consumed, 20-32 weeks
kg. 5.38 ± 0.07 5.07 ± 0.05 4.93 ± 0.06 -.31** — 45***
kg. 1.05 ± 0.02 .62 ± 0.03 .55 ± 0.05
kg. 11.58 ± 0.14 10.41 ± 0.05 16.09 ± 0.15
.19
.10
_i
_;50***
17***
4 5j#**
.45
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82.9 81.4
Hatchability of fertile eggs 75.9 77.9
1811
TURKEY BREEDER PERFORMANCE
TABLE 5.—Effects
of level of energy in diet during the pre-breeder period on subsequent egg production and on fertility and hatchability of eggs (Experiment 2)
Treatment High energy, full feed (1) High energy, restricted (2) Low energy, full feed (3) Difference (2) - (1) Difference (3) - (1)
Percent
Eggs laid per hen per 140 days
Fertility of eggs set
Hatchability of fertile eggs
Hatchability of all eggs set
44.5 45.2 42.3
81.0 82.5 84.0
76.7 77.9 76.0
62.1 64.3 63.9
0.7 -2.2
1.5 3.0
1.2 -0.7
2.2 1.8
Standard deviation per hen
26.5
19.2
21.3
19.9
Floor eggs
10.4
76.5
75.7
57.9
These changes in level of feed intake or in diet formulation resulted in significant reductions in body weights and in body weight gains. The effects of the pre-breeder diet on subsequent egg production and on fertility and hatchability were not significant (Table 5). Of the 150 females in each of the two prebreeder experiments, no mortality occurred between 20 and 32 weeks of age. After reducing the number of females for each breeder experiment to 144, no mortality occurred between 32 and 52 weeks of age in the first experiment and only six died between 36 and 56 weeks of age in the second experiment. Dietary Breeder Treatments (Experiments 1 and 2). The average percentages of egg production, fertility, hatchability of fertile eggs and hatchability of all eggs set from each of the 12 breeder dietary treatments combined for the two 20-week experiments are presented in Table 6. No significant differences in egg production were noted among the dietary treatments. An increase of 4.9 fertile eggs per 100 eggs incubated was observed to be associated with the addition of the extra trace minerals to the breeder diet (P < 0.05). The other differences among percent fertility of eggs as associated with the diets failed to be significant.
7.9
8.1
When 6 or 12 percent fish meal was present in the diets, the hatchability of fertile eggs was increased from 72.4 to 80.3 and to 77.1 percent, respectively, and hatchability of all eggs set was increased from 57.3 to 66.4 and to 62.8 percent, respectively. The added extra vitamins and added extra trace minerals in the breeder diets failed to influence number of poults obtained from fertile eggs or total eggs incubated. DISCUSSION
The increase in egg production for turkeys pre-conditioned under the brownout or blackout treatments over those previously held under the natural light treatment was not as great in this experiment as in experiments previously conducted by Leighton and Potter (1969). Turkeys held under the natural light treatment produced more eggs during the summer months than those on a comparable treatment in Experiment 2 of the above report. In addition, the turkeys exposed to 12 weeks of light restriction did not maintain as high a rate of egg production in the current experiment (Figure 1) as those under comparable treatments in the previously reported study. The turkeys in Experiment 1 of the present study were hatched on October 17, and the benefit from the restricted light treatment
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Difference required for significance (P < .05): 48 vs. 48 turkeys 11.1
1812
L . M. POTTER AND A . T . LEIGHTON J R .
TABLE 6.—Average 20-week egg production, fertility of eggs incubated, hatchability of fertile eggs and hatchability of all eggs indubated from turkeys fed 12 diets'2 Extra vitamins
Fish meal, %
Extra minerals
0
0 + 0 +
37.7 32.2 45.0 38.2
41.5 45.8 39.1 39.4
41.1 39.0 41.6 43.6
38.3
41.4 3.1
41.3 3.0
0 + Average Difference3
6 Egg production,
12
%
0 + 0 +
+ Average Difference 3
0
39.6
41.0
+
41.2
39.7
1.6
-1.3
0
81.0
78.7
+
81.3
83.6
%
81.6 82.8 75.2 77.3
76.5 87.2 81.1 86.2
77.2 80.8 81.2 87.0
79.2
82.8 3.6
81.4 2.2
0.3
4.9*
Hatchability of fertile eggs,,% 0
0 + 0 +
+ Average Difference 3
71.2 71.0 79.7 67.9
78.6 79.8 83.0 79.8
75.5 78.7 76.4 77.1
72.4
80.3 7.9*
77.1 4.7
0
76.2
77.6
+
77.4
76.0
1.2
-1.6
0
61.8
61.0
+
62.9
63.7
1.1
2.7
Hatchability of eggs incubated, % 0
0 + 0 +
+ Average Difference 3
58.1 58.8 59.9 52.4
60.3 69.7 67.1 68.8
58.3 64.0 62.0 67.1
57.3
66.4
62.8 5.5*
Q
1***
'Data from two experiments combined; 24 hens per dietary treatment. 2 Total of 7727 eggs incubated in the first experiment and 8179 eggs incubated in the second experiment. 3 Difference required for significance (P < .05):
For vitamins or minerals 12 pens vs. 12 pens For fish meal 8 pens vs. 8 pens Standard deviation per pen *Significant at the 5% level. ***Significant at the 0.1% level.
Egg production
Fertility of eggs
Hatchability of fertile eggs
Hatchability of all eggs
4.0
4.2
4.7
3.9
4.9
5.2
5.8
4.7
4.5
4.7
5.2
4.3
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Fertility of eggs incubated, 0
Average by Average by vitamins minerals
1813
TURKEY BREEDER PERFORMANCE
Results of this study indicate that feeding a high fiber, low energy diet to turkeys during the pre-breeder period provides no advantage, except for controlling body weight gain, and it greatly increases feed consumption and feed cost. The restricted feed intake of a high energy diet does provide advantages through decreased feed consumption as well as controlling body weight gain. The trend toward increased egg production associated with the extra vitamin fortification, including bacitracin and ethoxyquin, in the pre-breeder diet was observed throughout the breeder period and not primarily during the first part of the experiment. Although the observed increase in egg production was 6.4 eggs per hen (.10 > P > .05), further research is needed to confirm or refute this possible effect. The results from the breeder portions of the two experiments indicate that fish meal contains a factor not present in the added vitamins or trace minerals necessary for optimum hatchability of eggs. Biotin and pyridoxine were not included in the vitamin supplement; however, the contributions of these
vitamins by fish meal are not believed to be sufficient to affect hatchability. ACKNOWLEDGMENTS
This research work was supported in part by funds received under contract from the Technological Laboratory, Bureau of Commercial Fisheries, Fish and Wildlife Service, United States Department of the Interior, College Park, Maryland (currently the National Marine Fisheries Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce). The technical assistance of Joel Coleman, Lee Roy Barnett and Larry Melton, Department of Poultry Science, for their part in the care of turkeys, incubation of eggs and preparation of feed is greatly appreciated. REFERENCES
Feldman, G. L., R. L. Atkinson, B. G. Creech, T. M. Ferguson, B. L. Reid and J. R. Couch, 1957. The effect of dehydrated alfalfa meal, dried brewers yeast and condensed fish solubles on the reproductive performance of turkeys. Poultry Sci. 36: 792797. Ferguson, T. M., H. P. Vaught, B. L. Reid and J. R. Couch, 1956. The effect of vitamin E, dehydrated alfalfa meal and condensed fish solubles upon hatchability of eggs from Broad Breasted Bronze hens maintained on litter. Poultry Sci. 35: 872-875. Leighton, A. T., Jr., and L. M. Potter, 1969. Reproductive performance of turkeys subjected to blackout versus brownout restricted light conditions. Poultry Sci. 48: 505-514. National Academy of Sciences, 1971. Nutrient requirements of deomstic animals. Number 1. Nutrient requirements of poultry. Sixth revised edition. Touchburn, S. P., V. D. Chamberlin, M. G. McCartney and E. C. Naber, 1963. Unidentified reproductive and progency growth factor in turkey nutrition. Poultry Sci. 42: 1314. Whiteside, C. H., T. M. Ferguson, B. L. Reid and J. R. Couch, 1960. The effect of dehydrated alfalfa meal, dried brewers yeast, condensed fish solubles and fermentation residue on the reproductive performance of turkeys. Poultry Sci. 39: 77-81.
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was negligible. The females used in Experiments 1 and 2 in the study by Leighton and Potter (1969) were hatched in October 31 and December 18, respectively; marked effects of the restricted light treatment on subsequent egg production were observed in each. The turkeys in the unrestricted light treatments of Experiments 1 and 2 of that study laid at a lower and a much lower rate, respectively, during the summer months than those on the comparable treatment in Experiment 1 of the present study. Especially in the latter experiment of the study by Leighton and Potter (1969), the egg production probably did not increase because the birds were not old enough to respond to the extended periods of lights at the time they were given.