Summary
A computer model was developed to simulate the population dynamics involved when selection is for a trait influenced by the presence of a pathogen in addition to quantitative genetic factors. The lymphoid leukosis virus is such a pathogen, when selection is for egg production in chickens. It is transmitted congenitally from dam to offspring and horizontally from one individual to another. For these simulations, individual selection for high performance in the trait influenced by the pathogen was more effective than family selection for removing infected individuals from populations. The resulting reduction in the incidence of infected individuals in following generations made the overall response to individual selection greater than for family selection. However, the virus would remain in most populations due to horizontal transmission to individuals which later transmit the virus to their offspring. These horizontally infected individuals would not be eliminated in the selection process because their egg production was assumed to be less reduced than that of congenitally infected birds. These simulation results seem to mimic certain experimental results which heretofore have been difficult to explain since they were not consistent with quantitative genetic theoretical expectations from selection.
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References
Bennett GL, Dickerson GE, Gowe RS, McAllister AJ, Emsley JAB (1980) Net genetic and temporary epistatic or maternal selection for egg production in chickens. Genetics 99:309–321
Carpenter TE, Miller KF, Gentry RF, Schwarte LD, Mallison ET (1980) An economic analysis of Mycoplasma Gallisepticum control in layer chickens. Proc 29th Western Poultry Disease Conf. University of California, Davis, pp 59–62
Cochran WG (1951) Improvement by means of selection. In: Neyman J (ed) Proc 2nd Berkeley Symp Math Stat Prob, pp 448–470
Crittenden LB (1975) Two levels of genetic resistance to lymphoid leukosis. Avian Dis 19:281–292
Dickerson GE (1963) Experimental evaluation of selection theory in poultry. In: Geerts SJ (ed) Genetics today. Proc 11th Int Congr Genet. Pergamon Press, Oxford 3, pp 747–761
Fairful RW, Gowe RS (1980) Feed consumption and feed efficiency in selected and control strains of egg stocks under long-term selection for a complex of economic traits. In: Robertson A (ed) Selection experiments in laboratory and domestic animals. Commonwealth Agric Bur, Farnham Royal, UK, pp 230–255
Falconer DS (1960) Introduction to quantitative genetics. Longman, New York
Garwood VA, Lowe PC (1979) Comparison of individual, sire family, and index selection for short term rate of egg production in chickens. Poultry Sci 58:751–753
Garwood VA, Okazaki W, Crittenden LB, Lowe PC (1981) Association of lymphoid leukosis virus and performance in a randombred layer population. Poultry Sci 60:2619–2621
Gavora JS, Spencer JL, Gowe RS, Harris DL (1980) Lymphoid leukosis virus infection: effects on production and mortality and consequences in selection for high egg production. Poultry Sci 59:2165–2178
Gavora JS, Spencer JL, Chambers JR (1982) Performance of meat-type chickens test-positive and -negative for lymphoid leukosis virus infection. Avian Path 11:29–38
Gowe RS (1974) Selection for high egg production in the domestic fowl. In: Mackin RJ (ed) Proc Nat Breeders' Roundtable. Poultry Breeders of America, Kansas City, pp 68–111
Gowe RS (1977) Multiple-trait selection in egg stocks. 1. Performance of six selected lines derived from three base populations. 2. Changes in genetic parameters over time in the six selected strains. In: French HL (ed) Proc Nat Poultry Breeders' Roundtable. Poultry Breeders of America, Arlington VA, pp 68–91
Gowe RS, Fairful RW (1980) Performance of six long-term multitrait selected Leghorn strains and three control strains and strain cross evaluations of the selected strains. In: Proc South Pacific Poultry Conv. World's Poultry Sci Assoc. NZ Branch, Auckland, pp 141–162
Griffing B (1960a) Theoretical consequences of truncation selection based on the individual phenotype. Aust J Biol Sci 13:307–343
Griffing B (1960b) Accommodation of linkage in mass selection theory. Aust J Biol Sci 13:501–526
Harris DL, Garwood VA, Lowe PC, Hester PY, Crittenden LB, Fadly AM (1984) Influence of sex-linked feathering phenotypes of parents and progeny upon lymphoid leukosis virus infection status and egg production. Poultry Sci
Kinney TB Jr, Bohren BB, Craig JV, Lowe PC (1970) Responses to individual family or index selection for short-term rate of egg production in chickens. Poultry Sci 49:1052–1064
Lush JL (1947) Family merit and individual merit as bases for selection. Part 1. Am Nat 81:241–261
Lush JL (1947) Family merit and individual merit as bases for selection. Part 2. Am Nat 81:362–379
Lush JL (1948) The genetics of populations. Ames, Iowa (mimeo)
McAllister AJ (1977) Multiple trait selection in egg stocks. 3. Retrospective evaluation involving individual and family selection. Proc Nat Breeders' Roundtable. Poultry Breeders of America, Arlington VA, pp 92–107
Osborne R (1957a) The use of sire and dam family averages in increasing the efficiency of selective breeding under a hierarchal mating system. Heredity 11:93–116
Osborne R (1957b) Family selection in poultry: the use of sire and dam family averages in choosing male parents. Proc R Soc Edinburgh, Sect B 66:374–393
Spencer JL, Crittenden LB, Burmester BR, Okazaki W, Witter RL (1977) Lymphoid leukosis: interrelationships among virus infections in hens, eggs, embryos, and chicks. Avian Dis 21:331–345
Spencer JL, Gavora JS, Gowe RS (1979) Effect of selection for high egg production in chickens on shedding of lymphoid leukosis virus and antigen into eggs. Poultry Sci 58:279–284
Spencer JL, Gavora JS, Gowe RS (1980) Lymphoid leukosis virus: natural transmission and noneoplastic effects. In: Viruses in naturally occurring cancer. Cold Spring Harbor Conf Cell Proliferation 7, pp 553–563
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Communicated by H. Abplanalp
Journal Paper No. 9028 of the Purdue Agricultural Experiment Station
Animal Research Centre Contribution No. 1145
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Harris, D.L., Gavora, J.S. & Spencer, J.L. Genetic selection in presence of pathogens such as the lymphoid leukosis virus: computer simulation. Theoret. Appl. Genetics 68, 397–413 (1984). https://doi.org/10.1007/BF00254807
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DOI: https://doi.org/10.1007/BF00254807