| More

Impact of thyroid status on the response to ram effect in ewes

Views: 245 Downloads: 208
J. MENEGATOS (Ι. ΜΕΝΕΓΑΤΟΣ), S. CHADIO (Σ. ΧΑΔΙΩ), D. KALOGIANNIS (Δ. ΚΑΛΟΓΙΑΝΝΗΣ), V. BAMBIDIS (Β. ΜΠΑΜΠΙΔΗΣ), I. VALASI (Ε. ΒΑΛΑΣΗ), V. CHRISTODOULOU (Β. ΧΡΙΣΤΟΔΟΥΛΟΥ), D. KANTAS (Δ. ΚΑΝΤΑΣ)
J. MENEGATOS (Ι. ΜΕΝΕΓΑΤΟΣ), S. CHADIO (Σ. ΧΑΔΙΩ), D. KALOGIANNIS (Δ. ΚΑΛΟΓΙΑΝΝΗΣ), V. BAMBIDIS (Β. ΜΠΑΜΠΙΔΗΣ), I. VALASI (Ε. ΒΑΛΑΣΗ), V. CHRISTODOULOU (Β. ΧΡΙΣΤΟΔΟΥΛΟΥ), D. KANTAS (Δ. ΚΑΝΤΑΣ)

Abstract


The role of thyroid hormones on the transition to anestrous has been well established in ewes, but their possible involvement in the induction of reproductive activity remains obscure. The aim of the present study was to investigate the role of thyroid hormones in the induction of the first ovulation in relation to "ram effect" in ewes. Fourty-four ewes of the Greek Zackel mountain type breed were used. The ewes were housed separately from the rams until day 0 (entrance of rams). Blood samples were collected weekly for 4 weeks until 11 weeks after the ram entrance for the determination of thyroxin and progesterone levels. Thirty-five out of 44 ewes (group A) had a silent heat, while the rest 9 ewes (group B) exhibited a delayed estrus. Thyroxin levels rose immediately after ram entrance in animals of group A, but in group Β the increase in thyroid hormone levels was evident only after the first week. The difference in T4 levels between week 0 and 1 for ewes of group A was significantly higher than that observed for animals of group Β (p<005). The pattern of progesterone release was similar between the two groups, but a two week delay in the increase of progesterone concentration was observed in animals of group Β compared to group A. It is concluded that thyroid hormones may act at the beginning of the breeding season to cause a modification in gonadotrophin secretion leading to early ovulation.


Keywords


Thyroxin; ewes; ram effect

Full Text:

PDF

References


Anderson GM, Connors JM, Hardy SL, Valent M and Goodman RL (2002). Thyroid hormones mediate steroids-independent seasonal changes in luteinizing hormone pulsatility in the ewe. Biol Repr; 66: 701-706.

Colavita GP and Malfatti A, (1989). Hematic concentration of thyroid hormones T3 and T4 in goats at the beginning of the seasonal sexual activity. Atti della Società Italiana delle Scienze Veterinarie 43,467-471.

Cushwa WT, Bradford GÈ, Stabenfeldt GH, Berger YM, Daily MR, 1992: Ram influence on ovarian and sexual activity in anestrous ewes: effects of isolation of ewes from rams before

joining and date of ram introduction. J. Anim. Sci. 70 1195-200.

Dahl GE, Evans NP, Moenter SM, Karsch FJ (1994). The thyroid gland is required for reproductive neuroendocrine responses to photoperiod in the ewe. Endocrinology 135,10-15.

Dahl, GE, Evans NP, Thrun LA and Karsch FJ (1995). Thyroxin is permissive to seasonal transition in reproductive neuroendocrine activity in the ewe. Biol Reprod 52, 690-696.

Follet B.K. & Nochols T.J. (1984). Influence of thyroidectomy and thyroxin replacement on photoperiodically controlled reproduction in quail. J. Endocrinology 107: 211-221.

Follett, B. K., and Potts, C. (1990). Hypothyroidism affects reproductive refractoriness and the seasonal oestrous period in Welsh Mountain ewes. Journal of Endocrinology 127:103-109.

Freeman ME., LaRochell FT Jr., Moore RB (1976) Effect of thyroid status on spontaneous and induced surges of luteinizing hormone. Endocrinology 99: 713-719.

Glinoer D, de Nayer P, Bourdoux P, Lemone M, Robyn C, van Steirteghem A, Kinthaert J, Lejeune B, 1990: Regulation of maternal thyroid during pregnancy. J. Clin. Endocrinol Endocrino. Metab. 71 276-87.

Glinoer D, De Nayer P, Robyn C, Lejeune B, Kinthaert J, Meuris S, 1993: Serum levels of intact human chorionic gonadotropin (HCG) and its free alpha and beta subunits, in relation to maternal thyroid stimulation during normal pregnancy. J. Endocrinol. Invest. 16 881-8.

Grun JP, Meuris S, De Nayer P, Glinoer D, 1997: The thyrotrophic role of human chorionic gonadotropin (hCG) in the early stages of twin (versus single) pregnancies. Clin. Endocrinol. (Oxf) 46 719-25.

Harris PE, Dieguez C, Lewis BM, et al (1986). Effects of thyroid status on brain catecholamine biosynthesis in adult rats: assessment by a steady-state method J. Endocrinology 111: 383-389.

Hawken PA, Evans AC, Beard AP, 2007: Prior exposure of maiden ewes to rams enhances their behavioural interactions with rams, but is not a pre-requisite to their endocrine response to the ram effect. Anim Reprod Science (in press).

Hernandez J.A., Hallford D.M., Wells N.H., (2003). Ovarian cyclicity in thyroid-suppressed ewes treated with propylthiouracil immediately before onset of seasonal anestrus. J. Anim. Sci. 81:29-34.

Jallegeas M, Assenmacher I (1979). Further evidence for reciprocal interactions between the annual sexual and thyroid cycles in peking ducks and teal. Gen. Comp. Enndoc; 36: 201-210.

Karsch FJ, Dahl GE, Evans NP, Manning JM, Mayfield KP, Moenter SM, Foster DL, 1993: Seasonal changes in gonadotropinreleasing hormone secretion in the ewe: alteration in response to the negative feedback action of estradiol. Biol. Reprod. 49 1377-83.

Karsch FJ, Dahl GE, Hachigian TM, Thrun LA, 1995: Involvement of thyroid hormones in seasonal reproduction. J. Reprod. Fertil. Suppl. 49 409-22.

Karsch FJ„ Dahl GE, Hachigian TM Thurn LA (1995). Involvement of thyroid hormones in seasonal reproduction. J. Rep. Fert. (sup); 49:409-422.

Kimura M, Amino N, Tamaki H, Mitsuda Ν, Miyai Κ, Tanizawa Ο, (1990). Physiologic thyroid activation in normal early pregnancy is induced by circulating hCG. Obstet. Gynecol. 75 775-8.

Martin GB, Scaramuzzi RJ, 1983: The induction of oestrus and ovulation in seasonally anovular ewes by exposure to rams. J. Steroid Biochem. 19 869-75.

Martin GB, 1984. Factors affecting the secretion of luteinizing hormone in the ewe. Biol. Rev. 59:1-87.

Maruo T., Hayashi M., Matsuo H et al., The role of thyroid hormone as a biological amplifier of the actions of follicle stimulating hormone in the functional differentiation of cultured porcine granulose cells. Endocrinology 1987 121:1233-1241.

Moenter SM, Woodfill CJ, Karsch FJ, 1991: Role of the thyroid gland in seasonal reproduction: thyroidectomy blocks seasonal suppression of reproductive neuroendocrine activity in ewes. Endocrinology 128:1337-44.

O'Callaghan D, Wendung A, Karsch FJ and Roche JF (1993). Effect of exogenous thyroxin on timing of seasonal reproductive transitions in ewes. Biology of Reproduction 49,311-315.

Peeters, R., Buys, N., Pauwels, L, Kuhn, E. R., Decuypere, E., Sian, O., Van Isterdael, J. (1989): Relationhip between the thyroidal and gonadal axes during the estrus cycle of ewes of different breeds and ages. Reprod. Nutr. Develop. 29: 237-245.

Pekary AE, Azukizawa M, Hershman JM, 1983: Thyroidal responses to human chorionic gonadotropin in the chick and rat. Horm. Res. 17 36-42.

Reymond MG, Benotto W., Lemarchand -Beraud T. The secretory activity of the tuberoinfundibular dopaminergic neurons is modulated by the thyroid status in the adult rat: consequences on the prolactin secretion. Neuroendocrinology 1987 46 62-68.

Saleh D.M., Barrell G.K., Bailey C.I., Frampton C.M.A. (1998). Effects of exogenous triiodothyronine (T3) and a goitrogen, methylthiouracil (MTU), on thyroid gland function in sheep. Small Ruminant Research 30,49-56.

Shi ZD, Barrel GK (1992). Thyroid hormones are required for the expression of seasonal changes in red deer stags. Rerod. Fertil Dev 6:187-192.

Tamura K., Hatsuta M., Watanabe G., Taya Κ and KOGO H. (1998). Blockage of gonadotropin induced first ovulation caused by thyroidectomy and its possible mechanisms in rats. Am J Physiol Endocrinol Metab 275: 380-385.

Thrun LA, Dahl GE, Evans NP, Karsch FJ, 1997: A critical period for thyroid hormone action on seasonal changes in reproductive neuroendocrine function in the ewe. Endocrinology 138 3402-9.

Ungerfeld R, Carbajal B, Rubianes E, Forsberg M, 2005: Endocrine and ovarian changes in response to the ram effect in medroxyprogesterone acetate-primed Corriedale ewes during the breeding and non-breeding season. Acta Vet. Scand. 46 33-44.

Ungerfeld R, Dago AL, Rubianes E, Forsberg M, 2004a: Response of anestrous ewes to the ram effect after follicular wave synchronization with a single dose of estradiol-17beta. Reprod. Nutr. Dev. 44 89-98.

Ungerfeld R, Forsberg M, Rubianes E, 2004b: Overview of the response of anoestrous ewes to the ram effect. Reprod. Fertil. Dev 16 479-90.

Velazquez EM., Belabarba Arata G.(Effects of thyroid status on pituitary gonadotropin and testicular reserve in men Arch. Androl 199738:85-92).

Webster JR, Moenter SM, Woodfill CJ and Karsch FJ (1991a). Role of the thyroid gland in seasonal reproduction. II. Thyroxine allows a season-specific suppression of gonadotropin secretion in sheep. Endocrinology, Vol 129,176-183.

Webster JR, Moenter SM, Barrell GK, Lehman MN, Karsch FJ (1991b). Role of the thyroid gland in seasonal reproduction. III. Thyreoidectomy blocks seasonal suppression of gonadotropin - releasing hormone secretion in sheep. Endocrinology 129: 1635-1643.

Wells N.H., Hallford D.M., Hernandez J.A., (2003). Serum thyroid hormones and reproductive characteristics of Rambouillet ewe lambs treated with propylthiouracil before puberty. Theriogenology; 59:1403-1413.

Wilson FE, Reinert BD (1995). The thyroid and photoperiodic control of seasonal reproduction in American tree sparrows (Spizella arborea). J. Comp. Physiol. B; 163: 563-573.


Refbacks

  • There are currently no refbacks.


Copyright (c) 2018 J. MENEGATOS (Ι. ΜΕΝΕΓΑΤΟΣ), S. CHADIO (Σ. ΧΑΔΙΩ), D. KALOGIANNIS (Δ. ΚΑΛΟΓΙΑΝΝΗΣ), V. BAMBIDIS (Β. ΜΠΑΜΠΙΔΗΣ), I. VALASI (Ε. ΒΑΛΑΣΗ), V. CHRISTODOULOU (Β. ΧΡΙΣΤΟΔΟΥΛΟΥ), D. KANTAS (Δ. ΚΑΝΤΑΣ)

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.