Effects of stress on reproduction in ewes

Dobson, H.; Fergani, Chrysanthi; Routly, J.E.; Smith, Robert F.

doi:10.1016/j.anireprosci.2012.01.006

Cited by 76 publications

(58 citation statements)

References 31 publications

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“…Gonadotrophin releasing hormone is a decapeptide synthesised in specialised neurons within the hypothalamus and is responsible for initiating the synthesis and secretion of gonadotrophins, LH and follicle stimulating hormone (FSH), from the anterior pituitary (Nestor 2012). Follicle-stimulating hormone and LH synthesis and secretion are mediated by the amplitude and frequency of GnRH pulses and feedback interactions from gonadal hormones (Dobson et al 2012). In female animals, gonadotrophin action is dependent upon the target structure on the ovary during the reproductive cycle, being either the corpus luteum or the dominant follicle (Nestor 2012).…”

Section: Functional Interactions Between the Hpa And Hpg Axesmentioning

confidence: 99%

“…Gonadotrophin-releasing hormone axons project from the arcuate nucleus and POA to the median eminence, which constitutes a diffuse neural network that forms the GnRH pulse generator (Li et al 2010). The pulsatile neuropeptide secretion from GnRH neurons is dependent on intracellular signalling mechanisms that lead to the pulsatile release of GnRH from the hypothalamus (Dobson et al 2012). The GnRH pulse generator also constitutes the pulsatile release of LH from the anterior pituitary (Li et al 2010).…”

Section: Hpa-hpg Axes Interplay On Gnrhmentioning

confidence: 99%

“…In ewes, the cells that synthesise GnRH are located in the POA and the arcuate nucleus of the hypothalamus (Dobson et al 2012). Gonadotrophin-releasing hormone axons project from the arcuate nucleus and POA to the median eminence, which constitutes a diffuse neural network that forms the GnRH pulse generator (Li et al 2010).…”

Section: Hpa-hpg Axes Interplay On Gnrhmentioning

confidence: 99%

“…The three structures that comprise the HPG axis are the hypothalamus, the anterior pituitary and the gonads (Dismukes 2013). The most important function of the HPG axis is to regulate reproduction in females by controlling the ovarian or oestrous cycle to prepare the follicle in the ovary for ovulation (Dobson et al 2012). Gonadotrophin releasing hormone is a decapeptide synthesised in specialised neurons within the hypothalamus and is responsible for initiating the synthesis and secretion of gonadotrophins, LH and follicle stimulating hormone (FSH), from the anterior pituitary (Nestor 2012).…”

Section: Functional Interactions Between the Hpa And Hpg Axesmentioning

confidence: 99%

“…Although production animals (e.g. sheep) tend to be well adapted to aspects such as environmental conditions, feed availability and disease (Qureshi 2012), studies have demonstrated that stressors associated with animal production negatively affect reproductive physiology (Dobson et al 2012). Sheep are prey animals and their natural response to stress is to mask any obvious behavioural signs to avoid predation (Stubsjøen et al 2015).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Influences of the stress endocrine system on the reproductive endocrine axis in sheep (Ovis aries)

Narayan

Parisella

2017

Italian Journal of Animal Science

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The hypothalamic-pituitary-adrenal (HPA) axis and the hypothalamic-pituitary-gonadal (HPG) axis systems are inversely related in humans and animals. Although livestock animals, such as sheep (Ovis aries), tend to be well adapted to their environment, it is known that the livestock production processes subject animals to a multitude of physical and psychological stressful stimuli that have the potential to elevate the HPA axis activity. Chronic stress is one of the major challenges in sheep production, as it is difficult to detect and can result in prolonged dysfunction of the HPA axis, causing downstream negative physiological effects such as immunosuppression, increased susceptibility to disease and reproductive dysfunction. The elevation of HPA axis activity during chronic stress has been suggested as the primary neuroendocrine mechanism underlying the aetiology of reproductive dysfunction in sheep. Research in sheep has demonstrated that glucocorticoids act on the HPG axis at the level of the hypothalamus and hypophyseal portal system to decrease gonadotrophin secretion and at the level of the pituitary gland to reduce responsiveness and sensitivity of gonadotroph cells and their receptors to GnRH. Sheep farming enterprises rely on the breeding efficacy of ewes to optimise lambing percentage and reproductive success in order to ensure a profitable business. This review discusses the influences of the HPA axis on the HPG axis and defines any significant reproductive function consequences caused by stress in ewes and places them into perspective for sheep management and productivity.ARTICLE HISTORY

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Section: Functional Interactions Between the Hpa And Hpg Axesmentioning

confidence: 99%