- Email: [email protected]
Selecting for Age at First Egg: Effects on Social dominance1,2
RESEARCH
and 1.47 ± 0.11 p.p.m. Cu for eight eggs from hens receiving the highest level of supplementation. This is within the range reported by Pennington and Calloway (1973) and indicates that the ingested supplemental copper was not deposited in the eggs. ACKNOWLEDGMENTS The author thanks Mrs. O. Donis, Miss D. Robert and Miss E. Griminger for their technical assistance.
Bubien, Z., M. Morand, J. Gastellu and A. Magat, 1971. Intoxication experimentale du poulet par le
sulfate de cuivre. Revue Med. Vet. 122: 511-520. Davis, G. K., 1974. High-level copper feeding of swine and poultry and the ecology. Fed. Proc. 33: 119411%. Fisher, C , A. P. Laursen-Jones, K. J. Hill and W. S. Hardy, 1973. The effect of copper sulphate on performance and the structure of the gizzard in broilers. Br. Poultry Sci. 14: 55-68. King, J. O. L., 1975. The feeding of copper sulphate to ducklings. Br. Poultry Sci. 16: 409-411. Maynard, L. A., and J. K. Loosli, 1969. Animal Nutrition, 6th ed., McGraw-Hill Book Co., New York. Nutrient Requirements of Poultry, 1971. National Research Council, 6th ed., Natl. Academy of Science, Washington, D.C. Pennington, J. T., and D. H. Calloway, 1973. Copper content of foods. J. Am. Diet. Assoc. 63: 143-153.
SELECTING FOR AGE AT FIRST EGG:: EFFECTS ON SOCIAL DOMINANCE' 2 A. L. BHAGWATANDJ. V. CRAIG
Department of Dairy and Poultry Sciences, Kansas State University, Manhattan,
Kansas 66506
(Received for publication July 19, 1976)
ABSTRACT Pullets of strains selected for early and late age at first egg were compared, along with unselected control strains, for relative social dominance ability in flocks assembled at 21 and 36 weeks of age. An apparent correlated response was found at 21, but not at 36 weeks. Early-strain pullets dominated nearly twice as many other-strain females as did late-strain pullets (P = 0.08) in flocks assembled at 21 weeks of age. Relative social dominance potential appeared to vary with age. POULTRY SCIENCE 56: 361-363, 1977
B
IDIRECTIONAL selection for social dominance potential, based on results from initial pair contests between mature males, produced strains within each of 2 breeds differing in the selected trait (Craig et al., 1965) and in age at sexual maturity as well (Craig, 1968; Craig and Toth, 1969). Increased social dominance was associated with earlier maturity. A later study (Biswas and Craig, 1970) involving selected strains of the White Leghorn breed only, indicated
1. This investigation is part of the Kansas contribution to the NC-89 Regional Poultry Breeding Project. 2. Contribution No. 937-J, Department of Dairy and Poultry Sciences, Kansas Agricultural Experiment Station, Manhattan, Kansas 66506.
a genotype x environmental interaction; the socially dominant strain was earlier maturing when kept in cages, but the difference tended to disappear when the strains were kept separately in floor flocks. Evidence presented favored the hypothesis that increased social stress reduced reproductive performance of the socially dominant strain when it was kept in floor pens. Recently, Craig et al. (1975) compared age at maturity, social dominance, and aggressiveness of the Ottawa Randombred Control and strains derived from it by selecting for early egg production (see Gowe et al., 1973; and Frankham and Weiss, 1969). We found that pullets of the selected strains began laying earlier and showed increased aggressi-
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 8, 2015
REFERENCES
361
NOTES
RESEARCH NOTES
362
Random samples of pullets were drawn from separated-strain flocks at 21 weeks (before any were laying) and again at 36 weeks (when nearly all were laying) to form intermingled-strain flocks. At 21 weeks, 3 flocks of 27 each (3 per strain), and at 36 weeks, TABLE 1.—Effects
6 flocks of 18 each (2 per strain), were formed. Each pullet received a numbered plastic badge on each wing for easy identification during observation. Pullets assembled in flocks at 21 and 36 weeks were watched from 21 to 26 and from 36 to 39 weeks, respectively, to determine their peck-order status. About 70% of all possible pair relationships were determined within each flock. The average number of other-strain females dominated by pullets of each strain was calculated and used for analysis. Mean age at 50% hen-day production was determined for each separated-strain flock of pullets as an estimate of age at sexual maturity. Means for strains designated as unselected, early, and late were 27, 25, and 27 weeks, respectively. The difference of 2 weeks between early and late maturing strains approached significance (P = 0.08); this difference in age was only about one-half that reported for age at first egg by Garwood et al. (1975) for pullets of early and late strains kept in individual cages. Table 1 indicates the effects of selecting for early or late sexual maturity on ability to dominate other-strain pullets at each of two ages. Results indicated that the strains selected for early first egg differed from strains selected for late first egg (P = 0.08) in flocks assembled at 21 weeks of age. There was no overlapping of means for strains selected for early and late maturity, and early-strain pullets dominated nearly twice
of selection for early or late sexual maturity on ability to dominate other-strain pullets at each of 2 ages Other-strain pullets dominated Mean
Age at flock assembly, wks.
Selection for age at 1st egg
No. of strains
(By strains)
21
Early None Late
3 3 3
(12.4,9.1,8.8) (14.0, 7.4, 6.5) (5.3, 6.4, 4.7)
10.1* 9.3 5.5
36
Early None Late
3 3 3
(7.2, 4.5, 5.5) (3.5, 5.3, 6.5) (7.9, 8.2, 4.7)
5.7 5.1 6.9
*P = 0.08 that strains selected for early first egg differed from strains selected for late first in flocks assembled at 21 weeks of age only.
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 8, 2015
veness and dominance relative to the control during adolescence, but not when fully mature. In fact, the strain developed by Gowe et al. reversed its dominance rank relative to the control when fully mature and was then dominanted by the control. To explore further the apparent genetic relationship between agonistic behavior and age at sexual maturity, we have now compared strains selected solely for early or late age at first egg with each other and with unselected strains derived from the same foundation stock (Regional Cornell Randombred). Nine strains developed and described by Garwood et al. (1975) were used; 3 were unselected, 3 had been selected for early age, and 3 for late age at first egg. Chicks of all strains were hatched together. They were then vaccinated against Marek's disease and combs were removed. All strains were reared together in 3 brooding-rearing pens. Fifty-six to 72 pullets and 25 cockerels of each strain were retained. During the fourth week, chicks were vaccinated against fowl pox and onethird of the upper beak was removed. At 16 weeks, pullets were separed by strain and housed in randomly assigned pens.
363
RESEARCH NOTES
as many other-strain pullets per flock as did late-strain pullets. There were no indications that selection for age at maturity affected relative dominance at 36 weeks of age. ACKNOWLEDGMENT We thank V. A. Garwood and P. C. Lowe for suggesting this study and for supplying samples of the various genetic strains. REFERENCES
A TEST OF THE ADDITIVITY OF TRUE METABOLIZABLE ENERGY VALUES OF FEEDINGSTUFFS1 I. R. SIBBALD
Animal Research Institute, Agriculture Canada, Central Experimental Farm, Ottawa, Ontario K1A 0C6 (Received for publication July 19, 1976)
ABSTRACT The true metabolizable energy (T.M.E.) values of 5 feedingstuffs and of 10 diets prepared therefrom were measured with adult S.C.W.L. roosters. The observed T.M.E. values of the diets were similar to those calculated from the observed T.M.E. values of the energy-contributing dietary ingredients. Statistical analysis of the data confirmed the absence of meaningful differences. It is concluded that the T.M.E. values of the feedingstuffs used were additive. POULTRY SCIENCE 56: 363-366, 1977
INTRODUCTION
C
URRENT methods of feed formulation are based on the assumption that the amount of a nutrient in a mixed feed is equal to the sum of the amounts contributed by each dietary component. Therefore it is important to determine if the nutrient values 1. Contribution number 646, Animal Research Institute.
obtained by applying an assay are additive. An assay has been developed which measures the true metabolizable energy (T.M.E.) values of poultry feedingstuffs (Sibbald, 1976) but little is known about the additivity of the values which it yields. Simple mixtures of wheat with fish meal and of corn with soybean meal had T.M.E. values similar to those calculated from the T.M.E. values of the component parts (Sibbald, 1976); however, interactions which make T.M.E.
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 8, 2015
Biswas, D. K., and J. V. Craig, 1970. Genotype-environment interactions in chickens selected for high and low social dominance. Poultry Sci. 49: 681-692. Craig, J. V., 1968. Correlated responses in body weight and egg production traits in chickens selected for social dominance. Poultry Sci. 47: 1033-1035. Craig, J. V., M. L. Jan, C. R. Polley, A. L. Bhagwat and A. D. Dayton, 1975. Changes in relative aggressiveness and social dominance associated with
selection for early egg production in chickens. Poultry Sci. 54: 1647-1658. Craig, J. V., L. L. Ortman and A. M. Guhl, 1965. Genetic selection for social dominance ability in chickens. Animal Behav. 13: 114-131. Craig, J. V., and A. Toth, 1969. Productivity of pullets influenced by genetic selection for social dominance ability and by stability of flock membership. Poultry Sci. 48: 1729-1736. Frankham, R., and G. M. Weiss, 1969. Changes in relative aggressiveness of lines selected for part-record egg production under floor housing. Poultry Sci. 48: 1691-1694. Garwood, V. A., P. C. Lowe and B. B. Bohren, 1975. Response in egg weight and rate of lay to bidirectional selection for age at maturity. Poultry Sci. 54: 1765. Gowe, R. S., W. E. Lentz and J. H. Strain, 1973. Long-term selection for egg production in several strains of White Leghorns: Performance of selected and control strains including genetic parameters of two control strains. Fourth Europ. Poultry Conf., London: 225-245.
and 1.47 ± 0.11 p.p.m. Cu for eight eggs from hens receiving the highest level of supplementation. This is within the range reported by Pennington and Calloway (1973) and indicates that the ingested supplemental copper was not deposited in the eggs. ACKNOWLEDGMENTS The author thanks Mrs. O. Donis, Miss D. Robert and Miss E. Griminger for their technical assistance.
Bubien, Z., M. Morand, J. Gastellu and A. Magat, 1971. Intoxication experimentale du poulet par le
sulfate de cuivre. Revue Med. Vet. 122: 511-520. Davis, G. K., 1974. High-level copper feeding of swine and poultry and the ecology. Fed. Proc. 33: 119411%. Fisher, C , A. P. Laursen-Jones, K. J. Hill and W. S. Hardy, 1973. The effect of copper sulphate on performance and the structure of the gizzard in broilers. Br. Poultry Sci. 14: 55-68. King, J. O. L., 1975. The feeding of copper sulphate to ducklings. Br. Poultry Sci. 16: 409-411. Maynard, L. A., and J. K. Loosli, 1969. Animal Nutrition, 6th ed., McGraw-Hill Book Co., New York. Nutrient Requirements of Poultry, 1971. National Research Council, 6th ed., Natl. Academy of Science, Washington, D.C. Pennington, J. T., and D. H. Calloway, 1973. Copper content of foods. J. Am. Diet. Assoc. 63: 143-153.
SELECTING FOR AGE AT FIRST EGG:: EFFECTS ON SOCIAL DOMINANCE' 2 A. L. BHAGWATANDJ. V. CRAIG
Department of Dairy and Poultry Sciences, Kansas State University, Manhattan,
Kansas 66506
(Received for publication July 19, 1976)
ABSTRACT Pullets of strains selected for early and late age at first egg were compared, along with unselected control strains, for relative social dominance ability in flocks assembled at 21 and 36 weeks of age. An apparent correlated response was found at 21, but not at 36 weeks. Early-strain pullets dominated nearly twice as many other-strain females as did late-strain pullets (P = 0.08) in flocks assembled at 21 weeks of age. Relative social dominance potential appeared to vary with age. POULTRY SCIENCE 56: 361-363, 1977
B
IDIRECTIONAL selection for social dominance potential, based on results from initial pair contests between mature males, produced strains within each of 2 breeds differing in the selected trait (Craig et al., 1965) and in age at sexual maturity as well (Craig, 1968; Craig and Toth, 1969). Increased social dominance was associated with earlier maturity. A later study (Biswas and Craig, 1970) involving selected strains of the White Leghorn breed only, indicated
1. This investigation is part of the Kansas contribution to the NC-89 Regional Poultry Breeding Project. 2. Contribution No. 937-J, Department of Dairy and Poultry Sciences, Kansas Agricultural Experiment Station, Manhattan, Kansas 66506.
a genotype x environmental interaction; the socially dominant strain was earlier maturing when kept in cages, but the difference tended to disappear when the strains were kept separately in floor flocks. Evidence presented favored the hypothesis that increased social stress reduced reproductive performance of the socially dominant strain when it was kept in floor pens. Recently, Craig et al. (1975) compared age at maturity, social dominance, and aggressiveness of the Ottawa Randombred Control and strains derived from it by selecting for early egg production (see Gowe et al., 1973; and Frankham and Weiss, 1969). We found that pullets of the selected strains began laying earlier and showed increased aggressi-
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 8, 2015
REFERENCES
361
NOTES
RESEARCH NOTES
362
Random samples of pullets were drawn from separated-strain flocks at 21 weeks (before any were laying) and again at 36 weeks (when nearly all were laying) to form intermingled-strain flocks. At 21 weeks, 3 flocks of 27 each (3 per strain), and at 36 weeks, TABLE 1.—Effects
6 flocks of 18 each (2 per strain), were formed. Each pullet received a numbered plastic badge on each wing for easy identification during observation. Pullets assembled in flocks at 21 and 36 weeks were watched from 21 to 26 and from 36 to 39 weeks, respectively, to determine their peck-order status. About 70% of all possible pair relationships were determined within each flock. The average number of other-strain females dominated by pullets of each strain was calculated and used for analysis. Mean age at 50% hen-day production was determined for each separated-strain flock of pullets as an estimate of age at sexual maturity. Means for strains designated as unselected, early, and late were 27, 25, and 27 weeks, respectively. The difference of 2 weeks between early and late maturing strains approached significance (P = 0.08); this difference in age was only about one-half that reported for age at first egg by Garwood et al. (1975) for pullets of early and late strains kept in individual cages. Table 1 indicates the effects of selecting for early or late sexual maturity on ability to dominate other-strain pullets at each of two ages. Results indicated that the strains selected for early first egg differed from strains selected for late first egg (P = 0.08) in flocks assembled at 21 weeks of age. There was no overlapping of means for strains selected for early and late maturity, and early-strain pullets dominated nearly twice
of selection for early or late sexual maturity on ability to dominate other-strain pullets at each of 2 ages Other-strain pullets dominated Mean
Age at flock assembly, wks.
Selection for age at 1st egg
No. of strains
(By strains)
21
Early None Late
3 3 3
(12.4,9.1,8.8) (14.0, 7.4, 6.5) (5.3, 6.4, 4.7)
10.1* 9.3 5.5
36
Early None Late
3 3 3
(7.2, 4.5, 5.5) (3.5, 5.3, 6.5) (7.9, 8.2, 4.7)
5.7 5.1 6.9
*P = 0.08 that strains selected for early first egg differed from strains selected for late first in flocks assembled at 21 weeks of age only.
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 8, 2015
veness and dominance relative to the control during adolescence, but not when fully mature. In fact, the strain developed by Gowe et al. reversed its dominance rank relative to the control when fully mature and was then dominanted by the control. To explore further the apparent genetic relationship between agonistic behavior and age at sexual maturity, we have now compared strains selected solely for early or late age at first egg with each other and with unselected strains derived from the same foundation stock (Regional Cornell Randombred). Nine strains developed and described by Garwood et al. (1975) were used; 3 were unselected, 3 had been selected for early age, and 3 for late age at first egg. Chicks of all strains were hatched together. They were then vaccinated against Marek's disease and combs were removed. All strains were reared together in 3 brooding-rearing pens. Fifty-six to 72 pullets and 25 cockerels of each strain were retained. During the fourth week, chicks were vaccinated against fowl pox and onethird of the upper beak was removed. At 16 weeks, pullets were separed by strain and housed in randomly assigned pens.
363
RESEARCH NOTES
as many other-strain pullets per flock as did late-strain pullets. There were no indications that selection for age at maturity affected relative dominance at 36 weeks of age. ACKNOWLEDGMENT We thank V. A. Garwood and P. C. Lowe for suggesting this study and for supplying samples of the various genetic strains. REFERENCES
A TEST OF THE ADDITIVITY OF TRUE METABOLIZABLE ENERGY VALUES OF FEEDINGSTUFFS1 I. R. SIBBALD
Animal Research Institute, Agriculture Canada, Central Experimental Farm, Ottawa, Ontario K1A 0C6 (Received for publication July 19, 1976)
ABSTRACT The true metabolizable energy (T.M.E.) values of 5 feedingstuffs and of 10 diets prepared therefrom were measured with adult S.C.W.L. roosters. The observed T.M.E. values of the diets were similar to those calculated from the observed T.M.E. values of the energy-contributing dietary ingredients. Statistical analysis of the data confirmed the absence of meaningful differences. It is concluded that the T.M.E. values of the feedingstuffs used were additive. POULTRY SCIENCE 56: 363-366, 1977
INTRODUCTION
C
URRENT methods of feed formulation are based on the assumption that the amount of a nutrient in a mixed feed is equal to the sum of the amounts contributed by each dietary component. Therefore it is important to determine if the nutrient values 1. Contribution number 646, Animal Research Institute.
obtained by applying an assay are additive. An assay has been developed which measures the true metabolizable energy (T.M.E.) values of poultry feedingstuffs (Sibbald, 1976) but little is known about the additivity of the values which it yields. Simple mixtures of wheat with fish meal and of corn with soybean meal had T.M.E. values similar to those calculated from the T.M.E. values of the component parts (Sibbald, 1976); however, interactions which make T.M.E.
Downloaded from http://ps.oxfordjournals.org/ at University of Georgia on June 8, 2015
Biswas, D. K., and J. V. Craig, 1970. Genotype-environment interactions in chickens selected for high and low social dominance. Poultry Sci. 49: 681-692. Craig, J. V., 1968. Correlated responses in body weight and egg production traits in chickens selected for social dominance. Poultry Sci. 47: 1033-1035. Craig, J. V., M. L. Jan, C. R. Polley, A. L. Bhagwat and A. D. Dayton, 1975. Changes in relative aggressiveness and social dominance associated with
selection for early egg production in chickens. Poultry Sci. 54: 1647-1658. Craig, J. V., L. L. Ortman and A. M. Guhl, 1965. Genetic selection for social dominance ability in chickens. Animal Behav. 13: 114-131. Craig, J. V., and A. Toth, 1969. Productivity of pullets influenced by genetic selection for social dominance ability and by stability of flock membership. Poultry Sci. 48: 1729-1736. Frankham, R., and G. M. Weiss, 1969. Changes in relative aggressiveness of lines selected for part-record egg production under floor housing. Poultry Sci. 48: 1691-1694. Garwood, V. A., P. C. Lowe and B. B. Bohren, 1975. Response in egg weight and rate of lay to bidirectional selection for age at maturity. Poultry Sci. 54: 1765. Gowe, R. S., W. E. Lentz and J. H. Strain, 1973. Long-term selection for egg production in several strains of White Leghorns: Performance of selected and control strains including genetic parameters of two control strains. Fourth Europ. Poultry Conf., London: 225-245.