Physiology of reproductive seasonality in sheep – an update

Pampori, Z. A.; Sheikh, Aasif Ahmad; Aarif, Ovais; Hasin, Dilruba; Bhat, Irfan Ahmad

doi:10.1080/09291016.2018.1548112

Cited by 10 publications

(13 citation statements)

References 38 publications

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“…At the same time, it increases the expression of FSH and LH synthesized from the anterior pituitary, thus increasing its level in plasma. These effects increase FSH and LH ovarian increase the cycling activity ( 46 ).…”

Section: Functional Units That Take An Active Role In Reproductionmentioning

confidence: 99%

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A neuroscience-based approach to the assessment of sexual behavior in animals

2023

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Sexual behavior in animals is important in ensuring the continuity of the generation. These behaviors differ in animal species. Sexual behaviors are shaped under the control of the reproductive system. Physiological stimuli produced by the reproductive system find their counterparts in the organism as reproductive activity. Reproductive activity display a critical role by transferring on the genetic heritage of organisms to the next generations. This activity, which is built on delicate balances, is associated with many systems in the organism. Nervous system, hormonal system, and circulatory system are the main ones. The regular formation of the reproductive activity in species is due to the effect of various factors. In domestic mammals, the reproductive activity is regulated by hormones secreted from brain and endocrine glands. Many hormones have duties in terms of the sustainability of reproductive activity. GnRH is the main hormone responsible for initiating this reproductive activity. Gonadotropin-releasing hormone (GnRH), which is a small molecule peptide from certain nerve cells in the nucleus infundibularis region of the hypothalamus and consists of different amino acids, is secreted under the influence of smell, temperature, light, and physical stimulation. Besides, GnRH release is controlled by various neurotransmitters (adrenaline, noradrenaline, dopamine, acetylcholine, serotonin). On the other hand, various genetic factors in secretory glands, gonadal cells, reproductive tissues can lead to significant changes on reproductive activity through specific molecular pathways and mechanisms.

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Section: Functional Units That Take An Active Role In Reproductionmentioning

confidence: 99%

“…This, in turn, suppresses GnRH secretion. Thanks to this effect, sheep pass into the anoestrus period ( 46 ).…”

Section: Functional Units That Take An Active Role In Reproductionmentioning

confidence: 99%

A neuroscience-based approach to the assessment of sexual behavior in animals

2023

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“…The pineal gland plays an important role as a functional neuroendocrine transducer of photoperiodic changes that occur in environmental or seasonal events by activating N-acetyl transferase transfer [30]. Norepinephrine is the most important transmitter in the postganglionic sympathetic nerve endings in this gland.…”

Section: Synthesis Of Melatoninmentioning

confidence: 99%

“…Norepinephrine then binds to β-adrenergic receptors on the pinealocyte membrane and causes an increase in intracellular cAMP. As a result, it increases the activity of the N-acetyltransferase enzyme, which is a rate-limiting enzyme in melatonin synthesis in increasing intracellular cAMP and melatonin synthesis increases from serotonin [30,32]. Melatonin synthesis begins with the uptake of tryptophan from the circulatory system by pinealocytes [33].…”

Section: Synthesis Of Melatoninmentioning

confidence: 99%

Biochemistry and Antioxidant Effects of Melatonin

Merhan¹

2022

Melatonin - Recent Updates

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Melatonin (N-acetyl-5-methoxy-tryptamine) is a hormone taking place in many biological and physiological processes, such as reproduction, sleep, antioxidant effect, and circadian rhythm (biological clock), and is a multifunctional indolamine compound synthesized mainly from the metabolism of tryptophan via serotonin in the pineal gland. Melatonin, which is a hormone synthesized from the essential amino acid tryptophan, is substantially secreted from the pineal gland between the cerebral hemispheres found in the mammalian brain. In addition to this, it is also produced in the cells and tissues, such as the gastrointestinal system, gall, epithelial hair follicles, skin, retina, spleen, testis, salivary glands, bone marrow, leukocytes, placenta, and thrombocytes. It plays a role in many physiological events, such as synchronizing circadian rhythms, reproduction, fattening, molting, hibernation, and change of pigment granules, preserving the integrity of the gastrointestinal system with an anti-ulcerative effect in tissues and organs from which it is produced. Melatonin is also a powerful antioxidant and anti-apoptotic agent that prevents oxidative and nitrosative damage to all macromolecules due to its ability to form in metabolic activities, directly excrete toxic oxygen derivatives, and reduce the formation of reactive oxygen and nitrogen species. In this book chapter, we will explain the structure, synthesis, metabolism, and antioxidant effects of the melatonin hormone.

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“…Kafi, Safdarian, and Hashemi (2004) reported that the Karakul ram has the capability to be used for mating all year round. Several protocols have been developed to induce the reproductive function of ewes during the non-breeding season (Abecia, Forcada, & González-Bulnes, 2011;Ahmad Pampori, Ahmad Sheikh, Aarif, Hasin, & Ahmad Bhat, 2020;Rosa & Bryant, 2003).…”

Section: Introductionmentioning

confidence: 99%

The effect of prostaglandin and gonadotrophins (GnRH and hCG) injection combined with the ram effect on progesterone concentrations and reproductive performance of Karakul ewes during the non‐breeding season

Ayaseh

Mirzaei

Boostani

et al. 2020

Veterinary Medicine & Sci

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The effect of prostaglandin and gonadotrophins (GnRH and hCG) combined with the ram effect on the progesterone (P4) concentrations and reproductive performance of Karakul ewes was investigated during non‐breeding season. Ewes (n = 93) received a male effect and were divided into two treatment groups including GnRH ‐ hCG (hCG, n = 32), GnRH ‐ GnRH (GnRH, n = 30) and a control (n = 31) group. This study was carried out from April (hormonal injection) to October (lambing). The first doses of GnRH (4.2 μg, Buserelin) were injected at the beginning of the study in treatment groups. These ewes were treated with hCG (250 IU) or the second GnRH dose five days later. All animals received two injections (ten days apart) of 150 μg PGF2α five days after the hCG or the second GnRH injection. Mating was initiated two days after the second prostaglandin injection and lasted for 34 days. Blood samples were collected by jugular venipuncture on days −10, −5, 0 (first PGF2α injection), 17 and 30 during the study. Pregnancy diagnosis was performed through transabdominal ultrasonography on day 40 after the removing of ram. Conception rate was 93.8, 90 and 87.1% in the hCG, GnRH and control groups, respectively. Lambing rate tended to increase in the hCG group compared with the control group (87.1 versus 58.1%; p < .1). There was no significant difference in P4 concentrations among studied groups in identical sampling times (p > .05). In conclusion, the administration of prostaglandin and hCG in combination with the ram effect tended to decrease lambing period. In other words this protocol tended to increase lambing rate at the first cycle. Treatment with hCG or GnRH did not increase serum P4 concentrations of treated Karakul ewes during the non‐breeding season.

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Physiology of reproductive seasonality in sheep – an update

Cited by 10 publications

References 38 publications

A neuroscience-based approach to the assessment of sexual behavior in animals

A neuroscience-based approach to the assessment of sexual behavior in animals

Biochemistry and Antioxidant Effects of Melatonin

The effect of prostaglandin and gonadotrophins (GnRH and hCG) injection combined with the ram effect on progesterone concentrations and reproductive performance of Karakul ewes during the non‐breeding season

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