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Restricting Growth of Broiler Breeder Pullets
1121
RESEARCH NOTES
thereby increasing spoilage. However, these points are under further investigation. REFERENCES Baker, J.R., and D.A. Balch, 1962. A study of the organic material of hen's egg shell. Biochem. J. 82: 352-362. Jukes, T.H., 1955. Antibiotics in Nutrition. Medical Encyclopedia Inc., 30 East 60th Street, New York, N.Y. Park, J.T., and L. Strominger, 1957. Mode of action of penicillin. Science, 125: 99-101.
RESTRICTING GROWTH OF BROILER BREEDER PULLETS J. D. SUMMERS, W. F. PEPPER AND E. T. MORAN, JR. Department of Poultry Science, University of Guelph, Guelph, Ontario, Canada {Received for publication April 28, 1969)
Restricting rate of gain and delaying sexual maturity of pullets are important considerations in producing a profitable broiler breeder flock. Most of the existing programs for rearing broiler pullets are based on some type of feed restriction, or the use of diets designed to limit nutrient intake starting around 8 to 10 weeks of age (Singsen et al., 1965; Waldroup et al., 1966; and Wright et al., 1968). Up to this time the birds are usually reared on a good quality starting ration which allows for fairly rapid rate of gain. In effect a stress of rapid growth is placed on the birds during the starting period followed by a stress during the growing period of limited nutrient intake. A more logical approach to growing pullets would seem to be a steady slow rate of growth from day of hatch till around 20 weeks of age. It is conceivable that birds reared on such a program would be subjected to less stress than if they were on many of the growing programs in common use to-day. In order to investigate whether birds grown slower from day of age would per-
form as well as conventionally reared pullets the present study was conducted. EXPERIMENTAL
Day old broiler type female chicks were randomized into 12 litter floor pens, there being 52 chicks per pen. Six replicates were placed on a regular 20% protein (2.91 Kcal.M.E./gm.) chick starter ration and six on a 14% protein (3.02 Kcal. M.E./gm.) ration. Both rations contained only corn and soya as sources of protein and energy, plus the necessary vitamin and mineral supplements. In Table 1 is shown the results of feeding these diets to 8 weeks of age. There was a TABLE 1.—Average results at 8 weeks of age Treatment
(X'nO ' Feed/gain bird per day Mortality*
20% protein 1,318a** 4.3! a 14%protein 1011b 5.34b D.F. 5 5 S.D. of individual 12.74 0.78 values
98.0a 91.0b 5 0.40
0 3
* No. of birds !ost from 6 replicates of 52 birds each started. ** Means having the same subscript do not differ significantly at the 5% level of probability.
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on April 11, 2015
than the control birds. It would appear that the repeated injection of therapeutic doses made the eggs more susceptible to infection and spoilage by P. aeruginosa. It appears that penicillin might have inhibited the synthesis of the membrane structure, thus making it weaker and more susceptible to attack by invading bacteria. Penicillin could have combined with the antibacterial protein in the egg white, thus making them less active and
1122 TABLE
RESEARCH NOTES 2-—A tier age
results at 24 weeks of age 8-24 weeks
Treatment 20% protein 14% protein
Av. feed per Av. wt. Feed/gain bird per day Mortality* (gm.) (gm.) 3,077 a " 2,831b
D.F. 5 S.D. of individual 58.2
6.77 5.90
107.4 a 97.2b
5 0.31
5 2.31
12 5
* Number of birds lost from 6 replicates of 51 birds each started. ** Means having the same subscript do not differ at the 5 % level of probability.
DISCUSSION A substantial amount of work has been done on the rearing of broiler pullets from around 8 to 20 weeks of age, however, little or no attention has been paid to the effect of nutrient intake in the starting period as a means of reducing weight gain and delaying sexual m a t u r i t y of pullets. Any treatment t h a t can be applied during the starting period should be easier to implement since it would be for a shorter period of time and b y and large the birds are usually under better management conditions with respect to ventilation,
TABLE 3.—Average breeder house performance for 6, 28 day periods
Treatment 20% protein 14% protein n.F. S.D. of individual values
Av. prod. H.D.B. (%) 55.7 58.4 5 1.48
* Of 6 reps, of 42 started. '* Of total eggs produced.
Feed per Av. feed per doz. eggs bird per day (kg.) (gm.) 3.32 3.20 5 0.09
154 156 5 1.24
Av. egg wt. (gm.)
Av. wt. gain (%)
61.1 61.0
21.1 29.8
5 0.41
5 1.86
Mortality* Hatchability** No. (%) 24 34
77.6 76.8 5 1.81
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on April 11, 2015
significant decrease in body weight, average daily feed consumption and an increase in feed to gain ratio for the 14 as compared to the 2 0 % protein diet. There was essentially no difference in appearance or mortality for the pullets of the two treatment groups. At 8 weeks of age the pullets were placed on 3 different growing rations and fed ad libitum to 24 weeks of age. All pullets were excessively heavy at 24 weeks thus demonstrating t h a t none of the growing t r e a t m e n t s employed were satisfactory in restricting weight gain. Hence only the results summed across the growing treatments for the two starting diets are shown for the 8 to 24 week period (Table 2). A significant reduction in average body weight was observed for those birds previously fed the 14% protein starting ration as compared to the 2 0 % protein diet. This difference, along with the significant decrease in feed consump-
tion for the 14% protein group, demonstrates t h a t a reduced rate of gain during the starting period will result in smaller birds at 24 weeks of age. Singsen et al. (1965) reported similar findings with their lysine imbalanced starting rations. At 24 weeks of age the pullets were placed on various breeder rations, however, since there was no significant difference in performance of the breeder diets only the effect of the two starting treatments on subsequent hen house performance is shown in Table 3. While it is true t h a t all birds were excessively heavy at the start of the egg production cycle and thus optimum performance m a y not have been obtained, the low protein starting diet was not a factor influencing breeder house performance.
1123
RESEARCH NOTES
broiler type pullets should be fully investigated. ACKNOWLEDGEMENTS T h e authors wish to acknowledge the financial assistance of the Ontario Department of Agriculture and Food in the conduct of the work. REFERENCES Singsen, E.P., J. Nagel, S.G. Patrick and L.D. Matterson, 1965. The effect of a lysine deficiency on growth characteristics, age at sexual maturity and reproductive performance of meat-type pullets. Poultry Sci. 44: 1467-1473. Waldroup, P.W., B.L. Damron and R.H. Harms, 1966. The effect of low protein and high fiber grower diets on the performance of broiler pullets. Poultry Sci. 45:393-402. Wright, C.F., B.L. Damron, P.W. Waldroup and R.H. Harms, 1968. The performance of laying hens fed normal and low protein diets between 8 and 18 weeks of age. Poultry Sci. 47: 635-638.
T H E E F F E C T OF HAKE MEAL I N BROILER RATIONS1 G. H. ARSCOTT AND D A V I D L.
CRAWFORD 2
Departments of Poultry Science and Food Science and Technology, Oregon State University, Corvallis, Oregon 97331 (Received for publication April 28, 1969)
The estimated standing stock of adult pacific hake (Merluccius productus) off the Pacific Coast is 4 to 8 billion pounds (Ahlstrom, 1968) with a maximum sustainable yield of 230 to 540 million pounds (Nelson, 1968). Dyer et al. (1966) reported t h a t pacific hake can be processed 1
Technical paper no. 2667. Oregon Agricultural Experiment Station. Supported in part by Contract No. 14-17-001-1932 from the Bureau of Commercial Fisheries under Section 4(a) of the Commercial Fisheries Research and Development Act, PX. 88-309, and in part by the Fish Commission of Ore gon. 2 Mailing address: Seafood Laboratory, 250 36th Street, Astoria, Oregon 97103.
successfully into fish meal which compared favorably with other fish meals in 21-day chick feeding trials. In view of this potential source of protein, experiments comparing varying amounts of hake and herring meal in broiler rations have been conducted. The trials consisted of either triplicate or quadruplicate lots of 24 day-old crossbred broilers equalized for sex. Care and management of these floor-reared broilers have previously been described (Rose and Arscott, 1962). The composition of the rations is shown in Table 1 and the outline of the experi-
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on April 11, 2015
crowding etc. If the pullets could be held back sufficiently from day of age, by the use of low protein or moderately unbalanced amino acid diets, so t h a t a fullfed feeding program could be utilized from 0 to 20 weeks of age m a n y of the problems encountered during the growing period with the conventional growing programs (e.g. cannibalism, feed medication, etc.) may be reduced or eliminated. Although conditions in our laboratory did not place undue stress on the birds (as evidenced by mortality) there is a limited amount of evidence from the field in favour of the lower protein starting ration judged on number of birds housed at 20 weeks of age. Based on the d a t a presented and further work underway in our laboratory the possibility of concentrating on the starter rather than the growing period as a means of delaying sexual m a t u r i t y in
RESEARCH NOTES
thereby increasing spoilage. However, these points are under further investigation. REFERENCES Baker, J.R., and D.A. Balch, 1962. A study of the organic material of hen's egg shell. Biochem. J. 82: 352-362. Jukes, T.H., 1955. Antibiotics in Nutrition. Medical Encyclopedia Inc., 30 East 60th Street, New York, N.Y. Park, J.T., and L. Strominger, 1957. Mode of action of penicillin. Science, 125: 99-101.
RESTRICTING GROWTH OF BROILER BREEDER PULLETS J. D. SUMMERS, W. F. PEPPER AND E. T. MORAN, JR. Department of Poultry Science, University of Guelph, Guelph, Ontario, Canada {Received for publication April 28, 1969)
Restricting rate of gain and delaying sexual maturity of pullets are important considerations in producing a profitable broiler breeder flock. Most of the existing programs for rearing broiler pullets are based on some type of feed restriction, or the use of diets designed to limit nutrient intake starting around 8 to 10 weeks of age (Singsen et al., 1965; Waldroup et al., 1966; and Wright et al., 1968). Up to this time the birds are usually reared on a good quality starting ration which allows for fairly rapid rate of gain. In effect a stress of rapid growth is placed on the birds during the starting period followed by a stress during the growing period of limited nutrient intake. A more logical approach to growing pullets would seem to be a steady slow rate of growth from day of hatch till around 20 weeks of age. It is conceivable that birds reared on such a program would be subjected to less stress than if they were on many of the growing programs in common use to-day. In order to investigate whether birds grown slower from day of age would per-
form as well as conventionally reared pullets the present study was conducted. EXPERIMENTAL
Day old broiler type female chicks were randomized into 12 litter floor pens, there being 52 chicks per pen. Six replicates were placed on a regular 20% protein (2.91 Kcal.M.E./gm.) chick starter ration and six on a 14% protein (3.02 Kcal. M.E./gm.) ration. Both rations contained only corn and soya as sources of protein and energy, plus the necessary vitamin and mineral supplements. In Table 1 is shown the results of feeding these diets to 8 weeks of age. There was a TABLE 1.—Average results at 8 weeks of age Treatment
(X'nO ' Feed/gain bird per day Mortality*
20% protein 1,318a** 4.3! a 14%protein 1011b 5.34b D.F. 5 5 S.D. of individual 12.74 0.78 values
98.0a 91.0b 5 0.40
0 3
* No. of birds !ost from 6 replicates of 52 birds each started. ** Means having the same subscript do not differ significantly at the 5% level of probability.
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on April 11, 2015
than the control birds. It would appear that the repeated injection of therapeutic doses made the eggs more susceptible to infection and spoilage by P. aeruginosa. It appears that penicillin might have inhibited the synthesis of the membrane structure, thus making it weaker and more susceptible to attack by invading bacteria. Penicillin could have combined with the antibacterial protein in the egg white, thus making them less active and
1122 TABLE
RESEARCH NOTES 2-—A tier age
results at 24 weeks of age 8-24 weeks
Treatment 20% protein 14% protein
Av. feed per Av. wt. Feed/gain bird per day Mortality* (gm.) (gm.) 3,077 a " 2,831b
D.F. 5 S.D. of individual 58.2
6.77 5.90
107.4 a 97.2b
5 0.31
5 2.31
12 5
* Number of birds lost from 6 replicates of 51 birds each started. ** Means having the same subscript do not differ at the 5 % level of probability.
DISCUSSION A substantial amount of work has been done on the rearing of broiler pullets from around 8 to 20 weeks of age, however, little or no attention has been paid to the effect of nutrient intake in the starting period as a means of reducing weight gain and delaying sexual m a t u r i t y of pullets. Any treatment t h a t can be applied during the starting period should be easier to implement since it would be for a shorter period of time and b y and large the birds are usually under better management conditions with respect to ventilation,
TABLE 3.—Average breeder house performance for 6, 28 day periods
Treatment 20% protein 14% protein n.F. S.D. of individual values
Av. prod. H.D.B. (%) 55.7 58.4 5 1.48
* Of 6 reps, of 42 started. '* Of total eggs produced.
Feed per Av. feed per doz. eggs bird per day (kg.) (gm.) 3.32 3.20 5 0.09
154 156 5 1.24
Av. egg wt. (gm.)
Av. wt. gain (%)
61.1 61.0
21.1 29.8
5 0.41
5 1.86
Mortality* Hatchability** No. (%) 24 34
77.6 76.8 5 1.81
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on April 11, 2015
significant decrease in body weight, average daily feed consumption and an increase in feed to gain ratio for the 14 as compared to the 2 0 % protein diet. There was essentially no difference in appearance or mortality for the pullets of the two treatment groups. At 8 weeks of age the pullets were placed on 3 different growing rations and fed ad libitum to 24 weeks of age. All pullets were excessively heavy at 24 weeks thus demonstrating t h a t none of the growing t r e a t m e n t s employed were satisfactory in restricting weight gain. Hence only the results summed across the growing treatments for the two starting diets are shown for the 8 to 24 week period (Table 2). A significant reduction in average body weight was observed for those birds previously fed the 14% protein starting ration as compared to the 2 0 % protein diet. This difference, along with the significant decrease in feed consump-
tion for the 14% protein group, demonstrates t h a t a reduced rate of gain during the starting period will result in smaller birds at 24 weeks of age. Singsen et al. (1965) reported similar findings with their lysine imbalanced starting rations. At 24 weeks of age the pullets were placed on various breeder rations, however, since there was no significant difference in performance of the breeder diets only the effect of the two starting treatments on subsequent hen house performance is shown in Table 3. While it is true t h a t all birds were excessively heavy at the start of the egg production cycle and thus optimum performance m a y not have been obtained, the low protein starting diet was not a factor influencing breeder house performance.
1123
RESEARCH NOTES
broiler type pullets should be fully investigated. ACKNOWLEDGEMENTS T h e authors wish to acknowledge the financial assistance of the Ontario Department of Agriculture and Food in the conduct of the work. REFERENCES Singsen, E.P., J. Nagel, S.G. Patrick and L.D. Matterson, 1965. The effect of a lysine deficiency on growth characteristics, age at sexual maturity and reproductive performance of meat-type pullets. Poultry Sci. 44: 1467-1473. Waldroup, P.W., B.L. Damron and R.H. Harms, 1966. The effect of low protein and high fiber grower diets on the performance of broiler pullets. Poultry Sci. 45:393-402. Wright, C.F., B.L. Damron, P.W. Waldroup and R.H. Harms, 1968. The performance of laying hens fed normal and low protein diets between 8 and 18 weeks of age. Poultry Sci. 47: 635-638.
T H E E F F E C T OF HAKE MEAL I N BROILER RATIONS1 G. H. ARSCOTT AND D A V I D L.
CRAWFORD 2
Departments of Poultry Science and Food Science and Technology, Oregon State University, Corvallis, Oregon 97331 (Received for publication April 28, 1969)
The estimated standing stock of adult pacific hake (Merluccius productus) off the Pacific Coast is 4 to 8 billion pounds (Ahlstrom, 1968) with a maximum sustainable yield of 230 to 540 million pounds (Nelson, 1968). Dyer et al. (1966) reported t h a t pacific hake can be processed 1
Technical paper no. 2667. Oregon Agricultural Experiment Station. Supported in part by Contract No. 14-17-001-1932 from the Bureau of Commercial Fisheries under Section 4(a) of the Commercial Fisheries Research and Development Act, PX. 88-309, and in part by the Fish Commission of Ore gon. 2 Mailing address: Seafood Laboratory, 250 36th Street, Astoria, Oregon 97103.
successfully into fish meal which compared favorably with other fish meals in 21-day chick feeding trials. In view of this potential source of protein, experiments comparing varying amounts of hake and herring meal in broiler rations have been conducted. The trials consisted of either triplicate or quadruplicate lots of 24 day-old crossbred broilers equalized for sex. Care and management of these floor-reared broilers have previously been described (Rose and Arscott, 1962). The composition of the rations is shown in Table 1 and the outline of the experi-
Downloaded from http://ps.oxfordjournals.org/ at Universite de Sherbrooke on April 11, 2015
crowding etc. If the pullets could be held back sufficiently from day of age, by the use of low protein or moderately unbalanced amino acid diets, so t h a t a fullfed feeding program could be utilized from 0 to 20 weeks of age m a n y of the problems encountered during the growing period with the conventional growing programs (e.g. cannibalism, feed medication, etc.) may be reduced or eliminated. Although conditions in our laboratory did not place undue stress on the birds (as evidenced by mortality) there is a limited amount of evidence from the field in favour of the lower protein starting ration judged on number of birds housed at 20 weeks of age. Based on the d a t a presented and further work underway in our laboratory the possibility of concentrating on the starter rather than the growing period as a means of delaying sexual m a t u r i t y in