JA Abecia

article

Extended day length in late winter/early spring, with a return to natural day length of shorter duration, increased plasma testosterone and sexual performance in rams with or without melatonin implants

JA Abecia, P Chemineau, M Keller, JA Delgadillo

Reproduction in Domestic Animals > 52 > 5 > 851 - 856

Sixteen rams were used to quantify the effects of long days, imposed during late winter/early spring, with or without exogenous melatonin, on plasma testosterone concentrations and ram serving capacity. Rams were assigned to two groups: photoperiod‐treated rams (Artificial Photoperiod, AP; n = 8), exposed to 2 months of long days (16 hr of light/day) between 22 December and 22 February, and control...

article

Presence of photoperiod-melatonin-induced, sexually-activated rams in spring advances puberty in autumn-born ewe lambs

J.A. Abecia, P. Chemineau, A. Gómez, M. Keller, more

Animal Reproduction Science > 2016 > 170 > C > 114-120

The objective of this study was to determine the effect of sexually activated (by specific photoperiodic treatments) vasectomized rams on the onset of puberty in autumn-born ewe lambs in spring. Photoperiodic-treated rams were assigned to one of three groups, which were sequentially exposed to two months of long days (16h light/d) and given three melatonin implants at the end of the long days (sexually-activated-rams;...

article

Evidence of melatonin synthesis in the ram reproductive tract

M. Gonzalez‐Arto, T. R dos S. Hamilton, M. Gallego, E. Gaspar‐Torrubia, more

Andrology > 4 > 1 > 163 - 171

Melatonin is a ubiquitous molecule found in a wide range of fluids, one of them being ram seminal plasma, in which it can reach higher concentrations than those found in blood, suggesting an extrapineal secretion by the reproductive tract. In order to identify the source of the melatonin found in ram seminal plasma, we first tried to determine whether the melatonin levels were maintained during the...

article

Continuous exposure to sexually active rams extends estrous activity in ewes in spring

J.A. Abecia, P. Chemineau, J.A. Flores, M. Keller, more

Theriogenology > 2015 > 84 > 9 > 1549-1555

Sexual activity in sheep is under photoperiodic control, which is the main environmental factor responsible for the seasonality of reproduction. However, other natural environmental factors such as presence of conspecifics can slightly influence the timing of onset and offset of the breeding season. In goats, we have found that the continuous presence of bucks that were rendered sexually active out...

article

The effect of melatonin and season on in vivo embryo production of Dohne Merino ewes

A. Buffoni, P.A. Vozzi, D.M. Gonzalez, G. Rios, more

Small Ruminant Research > 2014 > 120 > 1 > 121-124

To determine the effect of melatonin on embryo production in superovulated donor Dohne Merino ewes, two experiments were carried out at Trelew, Argentina (43°S 65°W), during the breeding and the anestrous seasons. Twenty-two ewes were used in experiment 1 (breeding season). Animals were divided into two groups: group M (melatonin, n=11) received a melatonin implant 48 days before superovulatory treatment,...

article

Effect of exogenous melatonin on embryo viability and uterine environment in undernourished ewes

M.I. Vázquez, F. Forcada, C. Sosa, A. Casao, more

Animal Reproduction Science > 2013 > 141 > 1-2 > 52-61

The effect of exogenous melatonin on embryo viability in undernourished ewes was investigated. At lambing, 24 ewes were treated (+MEL) or not (−MEL) with a melatonin implant. After 45 days, both groups were fed to provide 1.5 (Control, C) or 0.5 (Low, L) times daily maintenance requirements, so that experimental groups were: C−MEL, C+MEL, L−MEL and L+MEL. Ewes were mated (Day 0) and on Day 5 embryos...

article

Hormonal control of reproduction in small ruminants

J.A. Abecia, F. Forcada, A. González-Bulnes

Animal Reproduction Science > 2012 > 130 > 3-4 > 173-179

Reproduction of small ruminants can be controlled by several methods developed in recent decades. Some of these involve administration of hormones that modify the physiological chain of events involved in the sexual cycle. Methods which utilise progesterone or its analogues are based on their effects in the luteal phase of the cycle, simulating the action of natural progesterone produced by the corpus...

article

Repeated superovulation using a simplified FSH/eCG treatment for in vivo embryo production in sheep

F. Forcada, M. Ait Amer-Meziane, J.A. Abecia, M.C. Maurel, more

Theriogenology > 2011 > 75 > 4 > 769-776

This study investigated the efficacy of a simplified repeated superovulation treatment (eCG plus FSH in a single dose, rather than the usual protocol of six decreasing doses of FSH) in the in vivo embryo production in Ojalada donor ewes during the breeding season. In vitro viability after vitrification and warming of embryos recovered from both treatments was also assessed. In addition, the study...

article

Short‐Term Undernutrition Affects Final Development of Ovulatory Follicles in Sheep Synchronized for Ovulation

C Sosa, A Gonzalez‐Bulnes, JA Abecia, F Forcada, more

Reproduction in Domestic Animals > 45 > 6 > 1033 - 1038

The objective of this study was to determine, in sheep, the effect of a short‐term undernutrition on growth dynamics and competence of pre‐ovulatory follicles. Synchronization of sexual cycles and induction of ovulation were performed, with progestagens and gonadotrophins, in 14 adult female sheep. Morphological characteristics and developmental competence of ovarian follicles to achieve ovulation...

article

Effects of exogenous melatonin on in vivo embryo viability and oocyte competence of undernourished ewes after weaning during the seasonal anestrus

M.I. Vázquez, J.A. Abecia, F. Forcada, A. Casao

Theriogenology > 2010 > 74 > 4 > 618-626

This study investigated the effects of exogenous melatonin on embryo viability and oocyte competence in post-partum undernourished ewes during the seasonal anestrus. At parturition (mid-Feb), 36 adult Rasa Aragonesa ewes were assigned to one of two groups: treated (+MEL) or not treated (−MEL) with a subcutaneous implant of melatonin (Melovine®, CEVA) on the day of lambing. After 45 d of suckling,...

article

Undernutrition and Exogenous Melatonin Can Affect the In Vitro Developmental Competence of Ovine Oocytes on a Seasonal Basis

MI Vázquez, F Forcada, A Casao, JA Abecia, more

Reproduction in Domestic Animals > 45 > 4 > 677 - 684

This study evaluated the effects of exogenous melatonin and level of nutrition on oocyte competence, in vitro fertilization (IVF), and early embryonic development in sheep during seasonal anoestrus (SA) and the reproductive season (RS). Adult Rasa Aragonesa ewes were assigned randomly to one of four treatment groups in two experiments based on a 2 × 2 × 2 factorial design. Individuals were treated...

article

Effects of Melatonin Implants During Non‐Breeding Season on Sperm Motility and Reproductive Parameters in Rasa Aragonesa Rams

A Casao, S Vega, I Palacín, R Pérez‐Pe, more

Reproduction in Domestic Animals > 45 > 3 > 425 - 432

The effect of melatonin implants administered during non‐breeding season in Rasa Aragonesa rams on sperm motility parameters and other reproductive traits was assessed. In a first experiment, two Rasa Aragonesa rams were implanted (with melatonin group M), remaining other two males as control group (C). Semen of each group was collected from 1 May to 23 June, twice or three times a week, and motility...

article

Effects of melatonin and undernutrition on the viability of ovine embryos during anestrus and the breeding season

M.I. Vázquez, F. Forcada, A. Casao, C. Sosa, more

Animal Reproduction Science > 2009 > 112 > 1-2 > 83-94

This study examined the effects of melatonin and level of nutrition on embryo yield during anestrous and breeding season. Adult Rasa Aragonesa ewes were assigned randomly to one of the four treatment groups in two experiments using a 2×2×2 factorial design. Individuals were treated (+MEL) or not treated (−MEL) with a subcutaneous implant of melatonin for 42d (Melovine ^® , CEVA) and fed 1.5...

article

Changes in calmodulin immunocytochemical localization associated with capacitation and acrosomal exocytosis of ram spermatozoa

C. Colás, P. Grasa, A. Casao, M. Gallego, more

Theriogenology > 2009 > 71 > 5 > 789-800

The aim of this study was to determine the localization of calmodulin (CaM) in ram sperm and the possible changes during in vitro capacitation (CA) and the ionophore-induced acrosome reaction (AR). Likewise, changes in intracellular calcium levels ([Ca ²⁺ ] _i ) were also analysed by using flow cytometry. CA was induced in vitro in a medium containing BSA, CaCl ₂ , NaHCO ...

article

Early pregnancy alters the metabolic responses to restricted nutrition in sheep

C. Sosa, J.A. Abecia, M. Carriquiry, F. Forcada, more

Domestic Animal Endocrinology > 2009 > 36 > 1 > 13-23

This study investigated whether a 27-day period of nutrition at half-maintenance during early pregnancy (up to Day 14) could alter maternal endocrine responses. Forty-six ewes were fed all or half of their maintenance requirements and slaughtered on Day 14 of the oestrous cycle or pregnancy. We used real time RT-PCR to study gene expression of growth hormone receptor (GHR) and leptin in adipose tissue...

article

Simplified superovulatory treatments in Corriedale ewes

L. Simonetti, F. Forcada, O.E. Rivera, N. Carou, more

Animal Reproduction Science > 2008 > 104 > 2-4 > 227-237

Two experiments were designed to evaluate the possibility of simplifying superovulatory treatments in Corriedale ewes with use of ovine FSH (oFSH). Ewes received intravaginal progestogen sponges for 14 days. In Experiment 1, several simplified schedules were tested. Ewes were treated with 176 NIH-FSH-S1 units’ oFSH given as a single injection in saline, along with 500IU eCG 48h before sponge removal...

article

Undernutrition reduces the oviductal mRNA expression of progesterone and oestrogen receptors in sheep

C. Sosa, J.A. Abecia, F. Forcada, A. Meikle

The Veterinary Journal > 2008 > 175 > 3 > 413-415

The effect of undernutrition on the oviductal mRNA expression of oestrogen and progesterone receptors (ERα and PR) determined by a solution hybridisation assay in sheep was investigated. Adult ewes were fed either 1.5 (C) or 0.5 (L) times their maintenance requirements and were slaughtered on day 5 or 14 of a synchronised oestrous cycle (day 0=oestrus). In the oviduct ipsilateral to the corpus luteum,...

article

The effect of melatonin on the reproductive performance of three sheep breeds in Spain

J.A. Abecia, J.A. Valares, F. Forcada, I. Palacín, more

Small Ruminant Research > 2007 > 69 > 1-3 > 10-16

In order to determine the efficacy of melatonin implants in initiating the lambing season and improving reproductive efficiency in sheep, ewes (n=1932) from three breeds (Rasa Aragonesa, Assaf and Merino) received melatonin implants (Group M) every 45 days from the winter solstice (1 January and 15 February—winter; 1 April and 15 May—spring) on 12 commercial farms. The other group of ewes (n=1715)...

article

Effects of ageing and exogenous melatonin on pituitary responsiveness to GnRH in ewes during anestrus and the reproductive season

F. Forcada, J.A. Abecia, A. Casao, J.A. Cebrián-Pérez, more

Theriogenology > 2007 > 67 > 4 > 855-862

The study examined the effect of melatonin implants on in vivo pituitary responsiveness to GnRH in control, fully productive (5.7±0.4 years old, n=17) and aged (10.7±0.3 years old, n=14) ovariectomized, estradiol-treated Rasa Aragonesa ewes. On 27 February, eight ewes in each age group received a single implant containing 18mg melatonin. On 10 April, blood samples to be assayed for LH were collected...

article

The effect of melatonin treatment on the ovarian response of ewes to the ram effect

J.A. Abecia, I. Palacín, F. Forcada, J.A. Valares

Domestic Animal Endocrinology > 2006 > 31 > 1 > 52-62

To determine the ovarian response to the ram effect after treatment with melatonin, on 8 March, 71 Rasa Aragonesa ewes were randomly assigned to either the treatment group and given an 18mg melatonin implant or the untreated group. On 19 April (day 0), rams were introduced into the flock. Melatonin treatment produced a significantly higher percentage of cyclic ewes at ram introduction (P<0.05)...

INFONA - science communication portal

Search results for: JA Abecia

Extended day length in late winter/early spring, with a return to natural day length of shorter duration, increased plasma testosterone and sexual performance in rams with or without melatonin implants

Presence of photoperiod-melatonin-induced, sexually-activated rams in spring advances puberty in autumn-born ewe lambs

Evidence of melatonin synthesis in the ram reproductive tract

Continuous exposure to sexually active rams extends estrous activity in ewes in spring

The effect of melatonin and season on in vivo embryo production of Dohne Merino ewes

Effect of exogenous melatonin on embryo viability and uterine environment in undernourished ewes

Hormonal control of reproduction in small ruminants

Repeated superovulation using a simplified FSH/eCG treatment for in vivo embryo production in sheep

Short‐Term Undernutrition Affects Final Development of Ovulatory Follicles in Sheep Synchronized for Ovulation

Effects of exogenous melatonin on in vivo embryo viability and oocyte competence of undernourished ewes after weaning during the seasonal anestrus

Undernutrition and Exogenous Melatonin Can Affect the In Vitro Developmental Competence of Ovine Oocytes on a Seasonal Basis

Effects of Melatonin Implants During Non‐Breeding Season on Sperm Motility and Reproductive Parameters in Rasa Aragonesa Rams

Effects of melatonin and undernutrition on the viability of ovine embryos during anestrus and the breeding season

Changes in calmodulin immunocytochemical localization associated with capacitation and acrosomal exocytosis of ram spermatozoa

Early pregnancy alters the metabolic responses to restricted nutrition in sheep

Simplified superovulatory treatments in Corriedale ewes

Undernutrition reduces the oviductal mRNA expression of progesterone and oestrogen receptors in sheep

The effect of melatonin on the reproductive performance of three sheep breeds in Spain

Effects of ageing and exogenous melatonin on pituitary responsiveness to GnRH in ewes during anestrus and the reproductive season

The effect of melatonin treatment on the ovarian response of ewes to the ram effect

Filter options

Publication date

Content availability

Keywords

Data set

Journal

INFONA - science communication portal

Search results for: JA Abecia

Add recipient

Sending message cancelled

Are you sure you want to cancel sending this message?

Send message

Filter options

Publication date

Date range setting

Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.

Content availability

Keywords

Data set

Journal

Reporting an error / abuse

Sending the report failed

Accessibility options