Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-26T19:14:50.329Z Has data issue: false hasContentIssue false

The induction of pregnancy during lactation in the sow: the effects of a treatment imposed at 21 days of lactation

Published online by Cambridge University Press:  02 September 2010

D. B. Crighton
Affiliation:
University of Nottingham, School of Agriculture, Sutton Bonington, Loughborough, Leicestershire
Get access

Summary

1. Experiments carried out in two herds to examine the effects of a treatment designed to induce oestrus and ovulation during the lactational anoestrus of the sow and to allow the establishment of pregnancy during lactation are described. Two aspects are examined: (a) the effects on the reproductive performance of the sow of repetition of the treatment in successive lactations and (b) the effects of the treatment on the suckled young.

2. The treatment involved the separation of each sow and litter for 12 hr on days 21, 22 and 23 of lactation followed by an injection of 1500 IU pregnant mare serum gonadotrophin (PMSG) at the end of the third period of separation.

3. It is concluded that oestrus and ovulation can be induced with some consistency in the fourth week of lactation, that lactation is not incompatible with the first two to three weeks of pregnancy, and that the establishment of pregnancy during the fourth week of lactation is not detrimental to the growth of the suckled young when supplementary food is provided.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1970

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

REFERENCES

Allen, A. D., Lasley, J. F. and Uren, A. W. 1957. The effects of gonadotrophic hormone injections on induction of estrus in lactating sows. J. Anim. Sci. 16: 1097.Google Scholar
Barber, R. S., Braude, R. and Mitchell, K. G. 1955. Studies on milk production of Large White pigs. J. agric. Sci., Camb. 46: 97118.CrossRefGoogle Scholar
Cole, H. H. and Hughes, E. H. 1946. Induction of estrus in lactating sows with equine gonadotrophin. J. Anim. Sci. 5: 2529.CrossRefGoogle Scholar
Crighton, D. B. 1968. The induction of oestrus and ovulation during the lactational anoestrus of the sow. Vie Congrès de Reproduction et Insámination Artificielle, Paris, 1968. Résumés p. 266.Google Scholar
Crighton, D. B. 1970. The induction of pregnancy during lactation in the sow. J. Reprod. Fert. 22: 223231.CrossRefGoogle ScholarPubMed
Crighton, D. B. and Lamming, G. E. 1969. The lactational anoestrus of the sow: The status of the anterior pituitary-ovarian system during lactation and after weaning. J. Endocr. 43: 507519.CrossRefGoogle ScholarPubMed
Garcia, T. P. and Carrasco, L. C. 1968. PMSG antigenic capacity and its relations with heat synchronization and twin induction in sheep. Vie Congrès de Reproduction et Insémination Artificielle, Paris, 1968. Résumés, p. 293.Google Scholar
Heitman, H. Jr, and Cole, H. H. 1956. Further studies in the induction of estrus in lactating sows with equine gonadotrophin. J. Anim. Sci. 15: 970977.CrossRefGoogle Scholar
Smith, D. M. 1952. Yield and composition of milk of New Zealand Berkshire sows. N.Z. Jl. Sci. Technol. A34: 6575.Google Scholar
Smith, D. M. 1961. The effect of daily separation of sows from their litters upon milk yield, creep intake and energetic efficiency. N.Z. Jl. agric. Res. 4: 232245.CrossRefGoogle Scholar