Abstract
Thirty-six gilts which had not shown oestrus at about 8 months of age or more were transported from the pig research station to the clinic, a journey of 12 km. The gilts were examined by laparoscopy and those which had only small follicles in the ovaries were catheterized and placed in pens, with sexually mature boars kept in adjacent pens. Oestrus detection was done twice daily and blood was sampled three times a day. After 7 days the laparoscopy was repeated and gilts which still had only small follicles in their ovaries were given 250 μg GnRH intravenously the following day. Blood samples were taken frequently before and after GnRH treatment. One week. after administration of GnRH the ovaries were inspected by laparoscopy once more.
The first laparoscopic examination showed that 42 % of the gilts were sexually mature. One gilt had no uterus or ovaries. Twenty gilts had only small follicles in the ovaries and fourteen of these gilts showed ovulatory oestrus 5.5 days (4-7.5 days) after arrival. In these fourteen gilts a rise in the oestradiol-17B level (>30 pmol/1) was seen at an average time of 1.9 days and a rise in LH (preovulatory peak) was seen at an averaged 4.5 days after the start of blood sampling. Six gilts were given 250 ug GnRH. An immediate rise in LH could be seen in all the gilts (mean peak level was 6.18 μg/l) and the elevated levels had a duration of 4 hours. None of the GnRH-treated gilts responded with oestrus symptoms or increased ovarian activity.
Keywords: transport, oestradiol-17B, LH, GnRH-treatment
Sammanfattning
Trettiosex gyltor som inte hade visat brunst vid ca 8 månaders ålder transporterades 12 km från en försöksstation till kliniken. Gyltorna undersöktes med laparoskopi. På gyltor som bara hade små folliklar i äggstockarne opererades en kateter in för blodprovstagning och därefter placerades gyltorna i boxar med könsmogna galtar i närheten. Brunstkontroll utfördes 2 gånger och blodprov togs 3 gånger per dag. Efter 7 dagar upprepades laparoskopi-undersökningen och gyltor som fortfarande bara hade små folliklar i äggstockarna behandlades med 250 μg GnRH i.v. följande dag. Frekvent blodprovstagning utfördes i anslutning till GnRH-behandlingen och 5 ggr per dag därefter. En vecka efter GnRH-behandlingen undersöktes gyltorna på nytt med laparoskopi. Den första laparoskopi-undersökningen visade att 42 % av gyltorna var könsmogna. En gylta saknade livmoder och äggstockar. Tjugo gyltor hade små folliklar i äggstockarna och av dessa visade 14 brunst 5,5 dagar (4–7,5 dagar) efter ankomsten till kliniken. Hos dessa 14 gyltor sågs en östradiol-17ß stegring (>30 pmol/1) efter i medeltal 1.9 dagar och en stegring av LH (preovulatorisk stegring) efter i medeltal 4.5 dagar från blodprovstagningens början. Hos de 6 gyltorna som behandlades med GnRH sågs omedelbart en LH-stegring. Medelvärdet för maximumnivåen var 6.18 μg/l och LH-stegringen hade en duration på 4 timmar. Ingen av gyltorna svarade med brunst eller ökad äggstocksaktivitet efter GnRH-behandlingen.
Full Text
The Full Text of this article is available as a PDF (747.3 KB).
Acknowledgment
This investigation was supported by grants from the Swedish Council for Forestry and Agricultural Research. The Department of Animal Breeding and Genetics is gratefully acknowledged for supplying the gilts. Thanks are also due to Prof. Stig Einarsson for valuable advice and to Marianne Carlsson, Eva Hedberg, Mari Wallbring and Carina Ahlstedt for their excellent technical assistance.
Antiserum to ovine LH was kindly donated by Dr. G. D. Niswender, Colorado State University, Fort Collins, USA. The authors are indebted to Dr. L. E. Reichert for supplying porcine LH for iodination and as standard.
References
- Andersson Α-M, Einarsson S, Karlbom I. A study of the occurrence of silent and/or anovulatory heats in peripubertal gilts. Mexico: International Pig Veterinary Society Congress; 1982. p. 236. [Google Scholar]
- Andersson Α-M, Einarsson S, Edqvist L-E. Prepubertal LH, oestradiol-17β and progesterone pattern in gilts. Zbl. Vet. Med. A. 1983;30:438–446. doi: 10.1111/j.1439-0442.1983.tb01003.x. [DOI] [PubMed] [Google Scholar]
- Andersson Α-M, Einarsson S, Edqvist L-E. Treatment with gonadotropin releasing hormone in prepubertal gilts at two different ages. Acta vet. scand. 1983;24:446–455. doi: 10.1186/BF03546717. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Boilert B, Edqvist L-E, Johansson EDB, Lind-berg P, Martinsson K. The influence of conjugated estrogens in radioimmunoassays using different antibodies against estradiol-17β. Steroids. 1973;22:891–894. doi: 10.1016/0039-128X(73)90060-3. [DOI] [PubMed] [Google Scholar]
- Bosu WTK, Edqvist L-E, Lindberg P, Martins-son K, Johansson EDB. The effect of various dosages of lynestrenol on plasma levels of oestrogen and progesterone during the menstrual cycle in rhesus monkey. Contraception. 1976;13:677–684. doi: 10.1016/0010-7824(76)90119-0. [DOI] [PubMed] [Google Scholar]
- Carpenter LS, Anderson LL. Pulsatile infusion of luteinizing hormone-releasing hormone: Effects on luteinizing hormone secretion and ovarian function in prepubertal gilts. Anim. Repr. Sci. 1985;9:261–272. doi: 10.1016/0378-4320(85)90009-0. [DOI] [Google Scholar]
- Du Mesnil D, Boisson F, Signoret JP. Influences de facteurs externes sur le déclechement de la puberté chez la truie. (Influence of external factors on the onset of puberty in the gilt) Ann. Zootech. 1962;11:53–59. doi: 10.1051/animres:19620103. [DOI] [Google Scholar]
- Edqvist L-E, Johansson EDB. Radioimmunoassay of oestrone and oestradiol in human and bovine peripheral plasma. Acta Endocrinol. (Kbh.) 1972;77:716–730. doi: 10.1530/acta.0.0710716. [DOI] [PubMed] [Google Scholar]
- Edqvist L-E, Einarsson S, Karlbom I, Viring S. The hormonal and clinical response of gilts with delayed puberty to GnRH. A preliminary study. Theriogenology. 1978;9:401–407. doi: 10.1016/0093-691X(78)90096-1. [DOI] [Google Scholar]
- Einarsson S, Linde C, Settergren I. Studies of the genital organs of gilts culled for anoe-strus. Theriogenology. 1974;2:109–113. doi: 10.1016/0093-691X(74)90033-8. [DOI] [PubMed] [Google Scholar]
- Einarsson S, Gustafsson B. Developmental abnormalities of female sexual organs in swine. A post-mortem examination of the genital tract in 1 000 gilts. Acta vet. scand. 1970;11:427–442. doi: 10.1186/BF03547969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ehnvall R, Blomqvist, Einarsson S, Karlberg K. Culling of gilts with special reference to reproductive failure. Nord. Vet.-Med. 1981;33:167–171. [PubMed] [Google Scholar]
- Karlbom I, Einarsson S, Edqvist L-E. Attainment of puberty in female pigs. Clinical appearance and patterns of progesterone, oestradiol-17B and LH. Anim. reprod. Sci. 1982;4:301–312. doi: 10.1016/0378-4320(82)90044-6. [DOI] [Google Scholar]
- Lutz JB, Rampacele GB, Kraeling RR. Induction of ovulation in the prepuberal gilt by pulsatile administration of gonadotropin-releasing hormone. Domest. Anim. Endocrinol. 1985;2:61–65. doi: 10.1016/0739-7240(85)90027-X. [DOI] [Google Scholar]
- Niswender GD, Reichert L-E, Jr, Midgley AR, Jr, Nalbandov AV. Radioimmunoassay for bovine and ovine luteinizing hormone. Endocrinology. 1969;54:1166–1173. doi: 10.1210/endo-84-5-1166. [DOI] [PubMed] [Google Scholar]
- Niswender GD, Reichert L-E, Jr, Zimmermann DR. Radioimmunoassay of serum levels of luteinizing hormone throughout the estrus cycle in pigs. Endocrinology. 1970;87:576–580. doi: 10.1210/endo-87-3-576. [DOI] [PubMed] [Google Scholar]
- Paredis F: Onderzoekingen over vruchtbaarheid en kunstmatige inseminatie bij het varken. (Studies on reproduction and artificial insemination in pigs). PhD Thesis, Gent 1961.
- Rodriguez H, Kunavongkrit A. Chronical venous catheterization for frequent blood sampling in unrestrained pigs. Acta vet. scand. 1983;24:318–320. doi: 10.1186/BF03546736. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wildt DE, Fujimoto S, Spencer JL, Dukelow WR. Direct ovarian observation in pigs by means of laparoscopy. J. Reprod. Fert. 1973;35:541–543. doi: 10.1530/jrf.0.0350541. [DOI] [PubMed] [Google Scholar]