There is a need for a safe, effective and practical method of oestrus suppression in the mare. The aim of this study was to monitor ovarian activity in mares exposed to either 9.4 or 28.2 mg deslorelin acetate, a GnRH agonist, in the form of a sustained-release implant. Following oestrus synchronisation, mares were randomly assigned to one of three groups (n = 4 per group) and administered either one (Des1 group; 9.4 mg) or three (Des3 group; 28.2 mg) implants of deslorelin acetate (Suprelorin-12, Virbac Australia) or one blank implant (Control group; Virbac Australia). Mares underwent weekly blood sampling for 12 weeks following implant placement (Day 0-Day 84), with transrectal palpation and ultrasonography of the reproductive tract at all sampling timepoints except Days 56, 70 and 77. All mares showed baseline serum progesterone concentrations (SPC; ≤1.3 nmol/L or 0.4 ng/ml) on Day 0. Cycling Control mares showed typical oestrous cyclicity characterised by peaks and troughs in SPC over time. Four of eight treated mares demonstrated a sustained elevation in SPC after the initial ovulation after implant placement; SPC declined to baseline levels (Des1 group; 2 mares) or remained elevated (Des3 group; 2 mares) at the final sampling timepoint on Day 84. Oestrous cyclicity was erratic in three of the remaining four treated mares. In total, 87.5% (7 of 8) of treated mares showed atypical oestrous cyclicity after implant placement. These results suggest that deslorelin acetate disrupts oestrous cyclicity in the mare, which warrants further research.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/avj.13244 | DOI Listing |
Management of reproduction that relies on naturally based solutions is extremely important to counter the negative perception around hormone-based interventions. In Mediterranean latitudes and wider regions of non-tropical drylands, sheep do not normally ovulate during spring but exposure to a ram can induce oestrus and ovulation. This study assesses the response of maiden Barbarine ewes in drylands to the 'ram effect' during springtime and estimates the genetic parameters of this response.
View Article and Find Full Text PDFReprod Domest Anim
October 2024
Department of Animal Pathology, Universidad de Zaragoza, Zaragoza, Spain.
Reprod Domest Anim
August 2024
Department of Veterinary Anatomy, Guru Angad Dev Veterinary and Animal Science University, Ludhiana, India.
The reproductive efficiency in buffalo is highly influenced by seasonal variability. Angiogenesis in the reproductive cycle is important for optimal physiological functioning of uterus. Estrogen receptor-α (ERα), vascular endothelial growth factor (VEGF) and reduced nicotinamide adenine dinucleotide phosphatase diaphorase (NADPH-d) are vital indicators for the uterine angiogenic process.
View Article and Find Full Text PDFTheriogenology
October 2024
UMR 1253, iBrain, INSERM, Université de Tours, 37000, Tours, France. Electronic address:
Successful reproductive management of domestic mammals depends primarily upon timely identification of oestrous cycle stages. There is a need to develop an alternative non-invasive, welfare-friendly, accurate and reliable method to identify reproductive cycle stages. This is of particular interest for horse breeders, because horses are high-value farm animals that require careful management and individual monitoring.
View Article and Find Full Text PDFReprod Domest Anim
June 2024
Faculdade de Veterinária, Universidade Federal Fluminense, Rio de Janeiro, Brazil.
The efficiency of combining oestrous induction via a light program (16 h of light and 8 h of darkness for 60 days, ending on Day 0 - D0) with cloprostenol administration, followed by the male effect or not, was tested in acyclic Saanen goats during the non-breeding season (June/2019 to January/2020). Initially, all animals (males and females) were submitted to the described light program; 60 days after its ending (D60), the females were divided into two groups, with (G1; n = 67) or without (G2; n = 61) a male effect from D60 to D75 after the light program. At D75, both groups received two cloprostenol doses (120 μg; intramuscular) 7.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!