RT Journal Article
T1 Artificial long days in addition to exogenous melatonin and daily contact with bucks stimulate the ovarian and oestrous activity in Mediterranean goat females
A1 Zarazaga Garcés, Luis Ángel
A1 Gatica Jorquera, María Carolina
A1 Celi Mariátegui, Irma del Rosario
A1 Guzmán Guerrero, José Luis
A1 Malpaux, B.
AB One experiment was conducted to determine whether the treatment with artificial long days and exogenous melatonin can inducereproductive activity during spring (seasonal anoestrus) in Mediterranean goats that are in daily contact with bucks and whetherthis treatment causes a variation in the reactivation of the reproductive activity in the normal breeding season. The experimentstarted on 4 November 2005 and finished on 27 October 2006. Thirty-four adult and barren does were used, distributed into twogroups balanced according to their live weight (LW) and body condition score (BCS). Seventeen females were exposed to longdays (16 h of light/day) from 14 November 2005 to 20 February 2006. On 20 February, they received one s.c. melatonin implant(LD-M group) and were exposed to natural photoperiodic changes in an open shed. The other females during the experiment wereplaced in an open shed under natural photoperiod and remained as the control group (C group). The C and LD-M groups werekeeping in contact with males during the whole experiment. During the experiment, the LW, BCS and plasma progesteroneconcentrations were measured weekly, oestrous activity was tested daily using entire aproned bucks, and ovulation rate wasevaluated by laparoscopy 7 days after positive identification of the oestrus. A clear treatment–time interaction was observed forplasma progesterone concentrations ( P,0.001), with a period of high progesterone concentrations during the natural seasonalanoestrus in the LD-M group. Although 94.1% of females in the LD-M group presented ovarian activity during this period, nofemale in group C did. Resumption of ovarian activity in the subsequent natural breeding season was 2 weeks later in the LD-Mgroup in comparison with group C ( P,0.05). We can conclude that in Mediterranean goat breeding systems, when females arein daily contact with bucks, the treatment with 3 months of long days and melatonin implant at the end of the light photoperiodictreatment can induce ovarian and oestrous activity during the seasonal anoestrus. Finally, this treatment causes a short delayin the subsequent reactivation of ovarian activity in the natural breeding season.
PB Cambridge University Press
SN 1751-7311
SN 1751-732X (online)
YR 2011
FD 2011
LK http://hdl.handle.net/10272/6391
UL http://hdl.handle.net/10272/6391
LA eng
NO Zarazaga Garcés, L.A., Gatica Jorquera, M.C., Celi Mariátegui, I.R., Guzmán Guerrero, J.L., Malpaux, B.: "Artificial long days in addition to exogenous melatonin and daily contact with bucks stimulate the ovarian and oestrous activity in Mediterranean goat females". Animal. Vol. 5, n. 9, pág. 1414-1419 (2011). ISSN 1751-7311
DS Repositorio Institucional de la Universidad de Huelva
RD 30 may 2026