title: Cystic ovaries in intermittently-suckled sows: follicle growth and endocrine profiles.
abstract: This paper presents follicle development and hormone profiles for sows with normal ovulation or cystic follicles during an intermittent-suckling (IS) regime that started at Day 14 of lactation. Sows were subjected to separation from their piglets during blocks of 6h or 12h. In total, 8 out of 52 sows developed cystic follicles; either full cystic ovaries (n=6) or partial ovulation (n=2). Increase in follicle size of these sows was similar to that of normal ovulating sows until pre-ovulatory size at Day 5 after the start of separation, but from then on became larger (P<0.05). LH surge was smaller or absent in sows that developed (partially) cystic ovaries (0.4 ± 0.1 vs 3.6 ± 0.3 ngmL(-1); P<0.01). Peak levels of oestradiol (E2) were similar but high E2 levels persisted in sows that developed (partly) cystic ovaries and duration of oestrus tended to be longer. The risk of developing (partly) cystic ovaries was higher when IS occurred in blocks of 6h versus 12h (33 vs 10%). In conclusion, the appearance of cystic ovaries at approximately Day 20 of ongoing lactation was related to an insufficient LH surge, as is also the case in non-lactating sows.
authors.affiliation: Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Gerritsen
authors.affiliation: Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: B F A
authors.initials: BF
authors.lastname: Laurenssen
authors.affiliation: Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: Hazeleger
authors.affiliation: Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Langendijk
authors.affiliation: Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Kemp
authors.affiliation: Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: N M
authors.initials: NM
authors.lastname: Soede
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004958:Estradiol / Q000378:metabolism; D005260:Female; D007774:Lactation / Q000502:physiology*; D007986:Luteinizing Hormone / Q000378:metabolism; D010048:Ovarian Cysts / Q000378:metabolism* / Q000503:physiopathology*; D006080:Ovarian Follicle / Q000254:growth & development*; D013552:Swine / Q000502:physiology*; D013997:Time Factors
chemical_list: D004958:Estradiol; D007986:Luteinizing Hormone