Acknowledgments
The authors thank Hybrid Turkeys Inc., Kitchner, Ontario, Canada N2K 3S2 and Nicholas turkey Breeding Farms, Sonoma, CA 95476 for graciously providing the hatching eggs from their sire lines. Financial support for this project was also provided by British United Turkeys of America, Lewisburg, WV 14901 and Hybrid Turkeys Inc.
References
Asmundson, V.S. 1942. Crossbreeding and heterosis in turkeys. Poultry Sci. 21:311-316.
Asmundson, V.S. 1948. Inherited differences in weight and conformation of bronze turkeys. Poultry Sci. 27:695-708.
Asmundson, V.S., and C.F. Pun. 1954. Inheritance of rate of growth in bronze turkeys. Poultry Sci. 33:411-416.
Barbour, G.W., and M.S. Lilburn. 1995. Characterization of carcass development from 14 to 145 days of age in turkey hens from two strains. Poultry Sci. 74:1650-1658.
Barbour, G.W., and M.S. Lilburn. 1996. Comparative growth and development of Nicholas and Hybrid toms from 16 to 82 days and effects of protein restriction from 0 to 59 days on growth of Hybrid toms through 125 days of age. Poultry Sci. 75:790-796.
Clark, T.B. 1961. Crossbreeding in turkeys. II. Summary of studies on hatchability, growth and body characteristics. West Virginia Agric. Exp. Stat. Bull. 455T. Morgantown, WV.
Emmerson, D.A., N.B. Anthony, and K.E. Nestor. 1991. Genetics of growth and reproduction in the turkey. 11. Evidence of nonadditive genetic variation. Poultry Sci. 70:1084-1091.
Friars, G.W., F.N. Jerome, L.T. Weeden, and G.C. Ashton. 1963. Body weights and reproduction traits of two strains and reciprocal crosses of Broad Breasted Bronze turkeys. Poultry Sci. 42:935-940.
Jerome, F.N., G.W. Friars, and L.T. Weeden. 1960. Heterosis for growth in turkeys. Poultry Sci. 39:1225-1226.
Hill, W.G. 1982. Dominance and epistasis as components of heterosis. Z. Tier. Zuchtungbiol. 99:161-167.
Knox, C.W., and S.J. Marsden. 1944. The inheritance of some quantitative characteristics in turkeys. J. Hered. 35:89-96.
Kondra, P.A., and R.N. Shoffner. 1955. Crossing strains and breeds of turkeys. Poultry Sci. 34:1268-1274.
Kuhnlein, U., D. Zadworny, Y. Dawe, R.W. Fairfull, and J.S. Gavora. 1990. Assessment of inbreeding by DNA fingerprinting: Development of a calibration curve using defined strains of chickens. Genetics 125:161-165.
Lilburn, M.S., and D. Emmerson. 1993. The influence of differences of dietary amino acids during the early growing period on growth and development of Nicholas and British United Turkey toms. Poultry Sci. 72:1722-1730.
Lilburn, M.S., P.A. Renner, and N.B. Anthony. 1992. Interaction between step-up versus step-down lighting from four to sixteen weeks on growth and development in turkey hens from two commercial strains. Poultry Sci. 71:419-426.
McCartney, M.G., and V.D. Chamberlin. 1961. Crossbreeding turkeys. 2. Effect of mating system on body weight and conformation. Poultry Sci. 40:224-231.
McCartney, M.G., K.E. Nestor, and W.R. Harvey. 1968. Genetics of growth and reproduction in the turkey. 2. Selection for increased body weight and egg production. Poultry Sci. 47:717-721.
Naber, E.C., and S.P. Touchburn. 1970. Ohio poultry rations. Ohio Cooperative Extension Service Bulletin 343, The Ohio State University, Columbus, OH.
Nestor, K.E. 1971. Genetics of growth and reproduction in the turkey. 4. Strain crossing for improvement of growth and reproduction. Poultry Sci. 50:1683-1689.
Nestor, K.E. 1977a. The use of a paired mating system for the maintenance of experimental populations of turkeys. Poultry Sci. 56:60-65.
Nestor, K. E. 1977b. Genetics of growth and reproduction in the turkey. 5. Selection for increased body weight alone and in combination with increased egg production. Poultry Sci. 56:337-347.
Nestor, K.E. 1984. Genetics of growth and reproduction in the turkey. 9. Long-term selection for increased 16-week body weight. Poultry Sci. 63:2114-2122.
Nestor, K.E., and J.W. Anderson. 1998. Effect of crossing a line selected for increased shank width and two commercial sire lines on performance and walking ability. Poultry Sci. 77:1601-1607.
Nestor, K.E., J.W. Anderson, and R.A. Patterson. 2000. Genetics of growth and reproduction in the turkey. 14. Changes in genetic parameters over thirty generations of selection for increased body weight. Poultry Sci. 79:445-452.
Nestor, K.E., W.L. Bacon, Y.M. Saif, and P.A. Renner. 1985. The influence of genetic increases in shank width on body weight, walking ability, and reproduction in turkeys. Poultry Sci. 64:2248-2255.
Nestor, K.E., M.G. McCartney, and N. Bachev. 1969. Relative contributions of genetics and environment to turkey improvement. Poultry Sci. 48:1944-1949.
Nestor, K.E., D.O. Noble, and D.A. Emmerson. 1997. Genetics of growth and reproduction in the turkey. 13. Effects of repeated backcrossing of an egg line to two sire lines. Poultry Sci. 76:227-235.
Nestor, K.E., D.O. Noble, J. Zhu, and Y. Moritsu. 1996. Direct and correlated responses to long-term selection for increased body weight and egg production in turkeys. Poultry Sci. 75:1180-1191.
SAS Institute. 1988. SAS/STATÒ User's Guide. 6.03 Edition. SAS Institute Inc., Cary, NC.
Wilhelm, R.L., and E. Pollak. 1985. Theory of heterosis. J. Dairy Sci. 68:2411-2417.
Ye, X., J.W. Anderson, D.O. Noble, J. Zhu, and K.E. Nestor. 1997. Influence of crossing a line selected for increased shank width and a commercial sire line on performance and walking ability of turkeys. Poultry Sci. 76:1327-1331.
Ye, X., J. Zhu, S.G. Velleman, and K.E. Nestor. 1998. Genetic diversity of commercial primary breeding lines as estimated by DNA fingerprinting. Poultry Sci. 77:802-807.
Zhu, J., K.E. Nestor, and S.J. Lamont. 1995. Survey of major histocompatibility complex Class II haplotypes in four turkey lines using restriction fragment length polymorphism analysis with nonradioactive DNA detection. Poultry Sci. 74:1067-1073.
Zhu, J., K.E. Nestor, and Y. Moritsu. 1996a. Relationship between band sharing levels of DNA fingerprints and inbreeding coefficients and estimation of true inbreeding in turkey lines. Poultry Sci. Poultry Sci. 75:25-28.
Zhu, J., K.E. Nestor, and Y. Tang. 1996b. Frequencies and genetic diversity of major histocompatibility complex Class II haplotypes in commercial turkey lines. Poultry Sci. 75:954-958.