Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-10T02:41:08.125Z Has data issue: false hasContentIssue false
  • English
  • Français

The Experimental Shortening of the Generation Interval

Published online by Cambridge University Press:  06 May 2016

C. E. Adams
C. E. Adams*
Affiliation:
A.R.C. Unit of Animal Reproduction, Cambridge
Get access

Extract

To those engaged in the improvement of livestock the problem of the generation interval needs virtually no introduction. In mammals, the generation interval consists of two well-defined phases :

  • (a) the interval between birth and sexual maturity and

  • (b) the gestation period.

Whereas the length of gestation within a species is a relatively fixed period subject only to minor variations, the ages at which puberty and sexual maturity are attained are very variable, being influenced both by genetic and environmental factors. Thus, breed, strain, season of birth, plane of nutrition and system of management all contribute to determining the onset of puberty and eventual attainment of sexual maturity.

Type
Research Article
Information
Proceedings of the British Society of Animal Production , Volume 1954 , 1954 , pp. 97 - 108
Copyright
Copyright © The British Society of Animal Production 1954

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adams, C. E., 1953a. Some aspects of ovulation, recovery and transplantation of ova in the immature rabbit. In Mammalian Germ Cells. London: Churchill. Pp. 198–212.Google Scholar
Adams, C. E., 1953b. Studies on growth and reproduction in the female rabbit. Ph.D. Thesis. Cambridge Univ. Google Scholar
Asker, A. A., & Ragab, M. T., 1951. The generation interval in Egyptian livestock. Bull. Fac Agtic. Fouad I Univ. (Cairo), No. 6.Google Scholar
Austin, C. R., 1950. The fecundity of the immature rat following induced superovulation. J. Endocrin, 6 : 293.Google Scholar
Austin, C. R., 1952. The ‘ capacitation ‘ of the mammalian sperm. Nature (Lond.), 170 : 326.Google Scholar
Black, W. G., Ulberg, L. C, Christian, R. E., & Casida, L. E., 1953. Ovulation and fertilization in the hormone-stimulated calf. J. Dairy Sci., 36 : 274.Google Scholar
Casida, L. E., 1935. Prepuberal development of the pig ovary and its relation to stimulation with gonadotropic hormones. Anal. Rec., 61 : 389.Google Scholar
Casida, L. E., Meyer, R. K., Mcshan, W. H., & Wisnicky, W., 1943. Effects of pituitary gonadotropins on the ovaries and the induction of superfecundity in cattle. Amer. J. vet. Res., 4 : 76,Google Scholar
Chang, M. C, 1950. Development and fate of transferred rabbit ova or blastocysts in relation to the ovulation time of recipients. J. exp. Zool., 114: 197.Google Scholar
Chang, M. C., 1951. Fertilizing capacity of spermatozoa deposited in the Fallopian tubes. Nature (Lond.), 168 : 697.Google Scholar
Clauberg, C., 1932. Zbl. f. Gynäk., 56 : 964.Cited by Burrows (1949) Biological Actions of Sex Hormones. Cambridge University Press, 2nd ed., p.85Google Scholar
Cole, H. H., 1936. On the biological properties of mare gonadotropic hormone. Amer. J. Anat., 59 : 299.Google Scholar
Corey, E. L., 1928. Effect of pre-natal and post-natal injections of the pituitary gland in the white rat. Anat. Rec., 41 : 40.Google Scholar
Corey, E. L., 1930. Fetal and early post-natal responses of rat gonads to pituitary injections. Physiol. Zoöl., 3 : 379.CrossRefGoogle Scholar
Dowling, D. F., 1949. Problems of the transplantation of fertilised ova. J. agric. Sci., 39 : 374.CrossRefGoogle Scholar
Hammond, J., 1921. Further observations on the factors controlling fertility and foetal atrophy. J. agric. Sci., 11 : 337.Google Scholar
Hargitt, G. T., 1930. The formation of the sex glands and germ cells of mammals. III. The history of the female germ cells in the albino rat to the time of sexual maturity. J. Morph., 49 : 277.Google Scholar
Hertz, R., & Hisaw, F. L., 1934. Effects of follicle-stimulating and luteinizing pituitary extracts on the ovaries of the infantile and juvenile rabbit. Amer. J.Physiol., 108 : 1.Google Scholar
Johansson, I., 1949. Generationsintervallets längd inom svenska husdjursraser. K. LantbrAkad. Tidskr., 88 : 243.Google Scholar
Lamming, G. E., & Rowson, L. E. A., 1952. Superovulation and ovum transplantation in cattle. Rep. 2nd int. Congr. Physiol. Path. Anim. Reprod. Artif. Insem. (Cph.), 1952, 1 : 144.Google Scholar
Marden, W. G. R., 1951. The hormone control of ovulation in the calf. J. Physiol., 115 : 22 P.Google Scholar
Marden, W. G. R., 1953. The hormone control of ovulation in the calf. J. agric. Sci., 43 : 381.Google Scholar
Parkes, A. S., 1943. Induction of sliperovulation and superfecundation in rabbits. J. Endocrin., 3 : 268.CrossRefGoogle Scholar
Pincus, G., 1940. Superovulation in rabbits. Anat. Rec., 77 : 1.Google Scholar
Runner, R. N., & Palm, J., 1953. Transplantation and survival of unfertilised ova of the mouse in relation to post-ovulatory age. J. exp. Zool., 124 : 303.CrossRefGoogle Scholar
Saunders, F. J., & Cole, H. H., 1936. Age and the qualitative ovarian response of the immature rat to mare gonadotropic hormone. Proc. Soc. exp. Biol. (N. Y.), 33 : 504.Google Scholar
Smith, P. E., Engle, E. T., & Tyndale, H. H., 1934. Gamaetokinetic action of extracts of follicle-stimulating urine. Proc. Soc. exp. Biol. (N. Y), 31 : 745.Google Scholar
Venoe, O., 1950. Studies of the maternal influence on the birth weight in rabbits. Acta. Zool. (Stockh.), 31: 148 pp.Google Scholar
Willett, E. L., Buckner, P. J., & Larson, G. L., 1953. Three successful transplantations of fertilized bovine eggs. J. Dairy Sci., 36 : 520.CrossRefGoogle Scholar
Wishart, J., & Hammond, J., 1933. A statistical analysis of the interrelations of litter size and duration of pregnancy on the birth weight of rabbits. J. agric. Sci., 23 : 463.Google Scholar