Recruitment and selection of ovarian follicles for determination of ovulation rate in the pig
- PMID: 15998504
- DOI: 10.1016/j.domaniend.2005.02.025
Recruitment and selection of ovarian follicles for determination of ovulation rate in the pig
Abstract
Gonadotropins determine the follicle selection and ovulation rate. Follicle growth is independent of gonadotropins until antrum formation, at which time recruitment occurs. Once recruited, follicles will continue to grow or degenerate. In gilts, visible surface follicles are classified as small (<3mm), medium (3-6.9 mm) and large (> or =7.0mm). At estrus (day 0), there are approximately 15 small and medium follicles, and approximately 15 large follicles. By day 3, there may be approximately 30 small, 5 medium and no large follicles. During the remainder of the luteal phase, the pool of follicles increases and peaks at day 11-13 with approximately 50 small, and 30 medium, but with no large follicles observed. By the start of the follicular phase at day 15, numbers of small and medium follicles rapidly decline, while a pool of medium follicles is selected for the ovulation. The size of large follicles at estrus is heterogeneous (6.5-10.0 mm) but their number is reflective of the subsequent number of corpora lutea found following the ovulation. However, the time of medium follicle selection for ovulation is variable during the late luteal and early follicular phases. Suppression of FSH before and at the time of luteolysis reduces medium and large follicles but does not reduce the ovulation rate. In contrast, suppression of FSH for 3 days or unilateral ovariectomy after 3 days of the follicular phase prevents full ovulatory compensation. Therefore, FSH appears to be involved in the maintenance of a pool of medium follicles that can be selected by LH to mature and ovulate.
Similar articles
-
Physiological mechanisms of ovarian follicular growth in pigs--a review.Acta Vet Hung. 2008 Sep;56(3):369-78. doi: 10.1556/AVet.56.2008.3.10. Acta Vet Hung. 2008. PMID: 18828488 Review.
-
Gonadotropin-releasing hormone-induced ovulation and luteinizing hormone release in beef heifers: effect of day of the cycle.J Anim Sci. 2008 Jan;86(1):83-93. doi: 10.2527/jas.2007-0277. Epub 2007 Oct 2. J Anim Sci. 2008. PMID: 17911234 Clinical Trial.
-
The impact of dose of FSH (Folltropin) containing LH (Lutropin) on follicular development, estrus and ovulation responses in prepubertal gilts.Anim Reprod Sci. 2012 Jun;132(3-4):193-200. doi: 10.1016/j.anireprosci.2012.05.013. Epub 2012 May 28. Anim Reprod Sci. 2012. PMID: 22683028 Clinical Trial.
-
Influence of short-term fasting during the luteal phase of the estrous cycle on ovarian follicular development during the ensuing proestrus of ewes.Anim Reprod Sci. 2007 Feb;97(3-4):356-63. doi: 10.1016/j.anireprosci.2006.01.012. Epub 2006 Feb 28. Anim Reprod Sci. 2007. PMID: 16504426
-
Luteinizing hormone pulses, follicle-stimulating hormone and control of follicle selection in sheep.J Reprod Fertil Suppl. 1992;45:5-19. J Reprod Fertil Suppl. 1992. PMID: 1304034 Review.
Cited by
-
Porcine sperm bind to specific 6-sialylated biantennary glycans to form the oviduct reservoir.Biol Reprod. 2012 Dec 27;87(6):147. doi: 10.1095/biolreprod.112.103879. Print 2012 Jun. Biol Reprod. 2012. PMID: 23115267 Free PMC article.
-
Principles and Clinical Uses of Real-Time Ultrasonography in Female Swine Reproduction.Animals (Basel). 2019 Nov 11;9(11):950. doi: 10.3390/ani9110950. Animals (Basel). 2019. PMID: 31717951 Free PMC article. Review.
-
Bone Morphogenetic Protein 15 Knockdown Inhibits Porcine Ovarian Follicular Development and Ovulation.Front Cell Dev Biol. 2019 Nov 19;7:286. doi: 10.3389/fcell.2019.00286. eCollection 2019. Front Cell Dev Biol. 2019. PMID: 31803742 Free PMC article.
-
The relationship between mitochondrial DNA haplotype and the reproductive capacity of domestic pigs (Sus scrofa domesticus).BMC Genet. 2016 May 18;17(1):67. doi: 10.1186/s12863-016-0375-4. BMC Genet. 2016. PMID: 27188709 Free PMC article.
-
Effect of a GnRH analogue (peforelin) on the litter performance of gilts and sows.Porcine Health Manag. 2017 Mar 15;3:6. doi: 10.1186/s40813-017-0054-5. eCollection 2017. Porcine Health Manag. 2017. PMID: 28405462 Free PMC article.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources