LH and FSH secretion, follicle development and oestradiol in sows ovulating or failing to ovulate in an intermittent suckling regimen
P. Langendijk A D E , S. J. Dieleman B , C. van Dooremalen A , G. R. Foxcroft C , R. Gerritsen A , W. Hazeleger A , N. M. Soede A and B. Kemp AA Department of Animal Science, Marijkeweg 40, 6709 PG Wageningen, The Netherlands.
B Department of Farm Animal Health, Faculty of Veterinary Medicine, Yalelaan 7, 3584 CL, Utrecht, The Netherlands.
C Swine Research and Technology Centre, University of Alberta, Edmonton, AB T6H2V8, Canada.
D Present address: South Australian Research and Development Institute, Roseworthy Campus, SA 5371, Australia.
E Corresponding author. Email: langendijk.pieter@saugov.sa.gov.au
Reproduction, Fertility and Development 21(2) 313-322 https://doi.org/10.1071/RD06172
Submitted: 21 December 2006 Accepted: 8 September 2008 Published: 27 January 2009
Abstract
The present paper describes LH and FSH secretion, follicle development and ovulation in sows that were subjected to a limited nursing regimen. From Day 14 of lactation, 32 sows were separated from their piglets for 12 h every day (intermittent suckling; IS). Half the sows had boar contact during separation. Nine of 32 sows ovulated spontaneously within 14 days from initiation of IS. The frequency of LH pulses on the first day of IS tended to be higher in anovulatory sows (6.3 v. 4.2 pulses per 12 h; P < 0.10); other characteristics of LH secretion were similar to sows that ovulated. The characteristics of FSH secretion did not differ over the 8-h sampling period. Boar contact did not influence either LH and FSH secretion or the number of sows that ovulated. Up to 58% of anovulatory sows showed an increase in follicle size after initiation of IS and, 4 days after the initiation of IS, one-third still had follicles similar in size to those in ovulatory sows. However, the oestradiol concentration in anovulatory sows did not increase. We conclude that FSH and LH stimulation in anovulatory sows is not limiting for normal follicle development, but that ovarian follicles are not responsive to increased LH secretion.
Additional keywords: lactation, ovulation.
Acknowledgements
The authors gratefully acknowledge A. F. Parlow (Harbor-UCLA Medical Center, Torrance, CA, USA) and NIDDK’s National Hormone and Peptide program for the provision of antisera to IGF-I, antisera to pFSH and purified porcine FSH hormones for iodination and reference standards. The authors also acknowledge the technical contribution of Shirley Shostak (Swine Research and Technology Centre, University of Alberta, Edmonton, AB, Canada) to the FSH and IGF analyses.
Armstrong, J. D. , Kraeling, R. R. , and Britt, J. H. (1988). Effects of naloxone or transient weaning on secretion of LH and prolactin in lactating sows. J. Reprod. Fertil. 83, 301–308.
| PubMed | CAS | CAS |
Dieleman, S. J. , and Bevers, M. M. (1987). Effects of monoclonal antibody against PMSG administered shortly after the preovulatory LH surge on time and number of ovulations in PMSG/PG treated cows. J. Reprod. Fertil. 81, 533–542.
| PubMed | CAS |
Sesti, L. A. , and Britt, J. H. (1993). Agonist-induced release of gonadotropin-releasing hormone, luteinizing hormone, and follicle-stimulating hormone and their associations with basal secretion of luteinizing hormone and follicle-stimulating hormone throughout lactation in sows. Biol. Reprod. 49, 332–339.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS | CAS |
Smith, D. M. (1961). The effect of daily separation of sows from their litters upon milk yield, creep intake and energy efficiency. N.Z. J. Agric. Res. 4, 232–245.
Soede, N. M. , Kemp, B. , and Noordhuizen, J. P. T. M. (1992). The duration of ovulation in pigs, studied by transrectal ultrasonography, is not related to early embryonic diversity. Theriogenology 38, 653–666.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS | CAS |
Stevenson, J. S. , and Davis, D. L. (1984). Influence of reduced litter size and daily litter separation on fertility of sows at 2 to 5 weeks postpartum. J. Anim. Sci. 59, 284–293.
| PubMed | CAS | CAS |
Van den Brand, H. , Dieleman, S. J. , Soede, N. M. , and Kemp, B. (2000). Dietary energy source at two feeding levels during lactation of primiparous sows: I. Effects on glucose, insulin and luteinizing hormone and on follicle development, weaning-to-oestrus-interval and ovulation rate. J. Anim. Sci. 78, 396–404.
| PubMed | CAS | CAS |
Van der Wiel, D. F. M. , and Booman, P. (1993). Post weaning anoestrus in primiparous sows: LH patterns and effects of gonadotropin injection and boar exposure. Vet. Q. 15, 162–166.
| PubMed |
Vandalem, J. L. , Bodart, C. , Pirens, G. , Closset, J. , and Hennen, G. (1979). Development and application of homologous radioimmunoassays for porcine gonadotrophins. J. Endocrinol. 81, 1–10.
| PubMed | CAS | CAS |
Willis, H. J. , Zak, L. J. , and Foxcroft, G. R. (2003). Duration of lactation, endocrine and metabolic state, and fertility of primiparous sows. J. Anim. Sci. 81, 2088–2102.
| PubMed | CAS | CAS |
