Pubertal development of ram lambs: Physical and endocrinological traits in combination as indices of postpubertal reproductive function

1993 ◽  
Vol 40 (4) ◽  
pp. 735-744 ◽  
Author(s):  
T.A. Yarney ◽  
L.M. Sanford
Keyword(s):  
Pubertal Development ◽  
Reproductive Function ◽  
Ram Lambs

PUBERTAL DEVELOPMENT OF RAM LAMBS: BODY WEIGHT AND TESTICULAR SIZE MEASUREMENTS AS INDICES OF POSTPUBERTAL REPRODUCTIVE FUNCTION

1990 ◽  
Vol 70 (1) ◽  
pp. 139-147 ◽  
Author(s):  
T. A. YARNEY ◽  
L. M. SANFORD ◽  
W. M. PALMER
Keyword(s):  
Semen Quality ◽  
Pubertal Development ◽  
Reproductive Function ◽  
Reproductive Traits ◽  
Scrotal Circumference ◽  
Ejaculation Frequency ◽  
Testicular Size ◽  
Ram Lambs ◽  
Sperm Output ◽  
The Relationship

The relationship between the pattern of early testicular growth and postpubertal spermatogenic function and libido was investigated with 14 Suffolk rams born in March. Scrotal circumference and testicular diameter (TD) measurements were taken every 10 d between 30 and 190 d of age, and at 13 and 17 mo. Daily sperm output (DSO, sperm voided in urine) or semen quality, and libido were assessed at approximately 6, 13 and 17 mo of age. At 6 mo of age, rams with the larger testes had a greater DSO (r ≥ 0.77, P < 0.01) and mated estrual ewes more frequently (r ≥ 0.72, P < 0.01). Rams with larger testes at 13 mo had a greater DSO (r ≥ 0.74, P < 0.01), and those with larger testes at 17 mo ejaculated a higher percentage of motile spermatozoa (r ≥ 0.55, P < 0.05) and a greater number of spermatozoa (r = 0.61, P < 0.05; TD only). DSO at 13 mo was related to testicular size (r ≥ 0.54, P < 0.05) between 150 and 190 d of age. There were also correlations between the number of spermatozoa ejaculated at 17 mo and testicular size measurements (r ≥ 0.56, P < 0.05) taken between 170 and 190 d. However, ejaculation frequency (EF) at both 13 and 17 mo was not related to earlier testicular size measurements. Whereas testicular size and spermatogenic function of yearling Suffolk rams relate to testicular size measurements taken at about 6 mo of age, juvenile testicular size measurements correlate with EF only in the immediate postpubertal period. Key words: Sexual maturation, reproductive traits, interrelationships, ram

scholarly journals The neuroendocrine timing of puberty

Reproduction ◽  
2005 ◽  
Vol 129 (6) ◽  
pp. 675-683 ◽  
Author(s):  
Francis J P Ebling
Keyword(s):  
Pubertal Development ◽  
Reproductive Function ◽  
Overweight And Obesity ◽  
Neural Systems ◽  
Large Variability ◽  
Somatic Development ◽  
Gnrh Release ◽  
Gonadotrophin Releasing Hormone ◽  
Timing Of Puberty ◽  
Species Specific

Puberty is the attainment of fertility, a process encompassing morphological, physiological and behavioural development. The increased hypothalamic secretion of the gonadotrophin-releasing hormone decapeptide (GnRH) is essential for the activation of the pituitary–gonadal axis at puberty. The GnRH secretory network initially develops and is temporarily active during species-specific periods of fetal/neonatal development, so puberty is the secondary reactivation of an existing system. From a neurobiological perspective, the timing of puberty is therefore a function of changes in the neural systems controlling GnRH release. The large variability between individuals in the onset and progression of puberty indicates that the timing of puberty is not simply a function of chronological age. Rather, the neurotransmitter and neuromodulatory systems that impact upon the GnRH secretory network convey information about metabolic fuels, energy stores and somatic development and, for many species, information about season and social environment. The clear links demonstrated between metabolic fuel availability and reproductive function in many animal models provides evidence that the earlier onset of pubertal development observed in girls in certain US study populations is likely to relate to the increasing prevalence of overweight and obesity in adolescents.

scholarly journals 141 Reproductive characteristics of post-pubertal lambs after being rendered short scrotum

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 77-77
Author(s):  
Dahlia O’Brien ◽  
Stephan Wildeus ◽  
Susan Schoenian ◽  
Maegan Perdue
Keyword(s):  
Sperm Concentration ◽  
Reproductive Function ◽  
Epididymal Sperm ◽  
Cool Season ◽  
Reproductive Behaviors ◽  
Follow Up Study ◽  
Semen Collection ◽  
Ram Lambs ◽  
Artificial Vagina

Abstract A follow-up study was conducted to validate observations from an earlier trial on reproductive function in ram lambs following short scrotum castration. Again, East Friesian x Lacaune male dairy lambs from a commercial sheep dairy born in February and March were either left intact (IN, n=25), rendered short-scrotum (SS; n=18), or completely banded (WE; n=25) within 10 d of birth. At a mean age of 65 d, lambs were moved to the study site and managed as one group on cool season forages and supplemented with grain at 2–3% BW. At a mean age of 172 d, lambs were tested for libido in a 5 min pen test, and semen was collected from 7 IN and 7 SS lambs. Four estrus-induced teaser ewes were used for libido testing and semen collection by artificial vagina. Lambs were harvested the day after testing/collection, and reproductive tracts were recovered from 5 IN and 5 SS lambs at random. Differences between male lamb types were analyzed using PROC GLM. No statistical differences (P &gt;0.05) in reproductive behaviors were observed between IN and SS, though number of services and kicks were numerically higher in IN than SS (1.3 vs. 0.45; 1.6 vs. 0.73). No reproductive behaviors was observed in WE. Ejaculate volume was not different between IN and SS (0.56 vs. 0.49 ml), but percent motile sperm (45 vs. 6 %; P&lt; 0.01) and sperm concentration (1.52 vs. 0.05 billion/ml; P&lt; 0.05) were higher in IN then SS lambs. Total testis and epididymis weight were also higher (P&lt; 0.01) in IN than SS lambs (291 vs. 109 g; 53.8 g vs. 17.7 g). Additionally, epididymal sperm reserves were higher (P&lt; 0.05) in IN than SS (9.42 vs. 0.89 billion) lambs. Results confirm our earlier findings that reproductive function was greatly reduced, but did not cease in short scrotum ram lambs.

scholarly journals Effects of leptin on secretion of LH and FSH from primary cultured female rat pituitary cells

2001 ◽  
Vol 144 (6) ◽  
pp. 653-658 ◽  
Author(s):  
K Ogura ◽  
M Irahara ◽  
M Kiyokawa ◽  
M Tezuka ◽  
T Matsuzaki ◽  
...  
Keyword(s):  
Body Weight ◽  
Wistar Rats ◽  
Pubertal Development ◽  
Reproductive Function ◽  
Female Rats ◽  
Male Rats ◽  
Pituitary Cells ◽  
Female Rat ◽  
Serum Leptin ◽  
Female Wistar Rats

BACKGROUND: Leptin, which is the product of the obese gene, is believed to play important roles in pubertal development and reproductive function in females. In a study using adult male rats, it was found that leptin stimulated secretion of gonadotropin from the pituitary in a dose-related manner. However, there has been no such study in female rats. OBJECTIVE: To investigate the effects of leptin on the production of LH and FSH from the pituitary in female rats, using primary cultured pituitary cells. METHODS: In this study, we determined body weight, serum leptin concentration and serum estradiol (E(2)) concentration in female Wistar rats at 3, 5, 6, 7, 9 and 11 weeks of age, and cultured pituitary cells from 6-week-old female Wistar rats with leptin (0--10(-7) mol/l) and GnRH (0 or 10(-8) mol/l). Then basal and GnRH-stimulated extra- and intracellular LH and FSH were assayed by RIA. RESULTS: Serum leptin concentration increased with increases in body weight and E(2) concentration. The pubertal serum leptin concentration was about 10(-10) mol/l. At a lower or moderate concentration, leptin produced dose-related increases in both basal and GnRH-stimulated extra- and intracellular LH and FSH in pituitary cells. At a concentration of 10 mol/l, leptin significantly (P<0.05) stimulated both basal and GnRH-stimulated extra- and intracellular LH and FSH. However, at greater concentrations, these effects diminished. CONCLUSIONS: These results indicated that leptin induced pituitary cells to produce and secrete both LH and FSH, with or without GnRH. The concentration of leptin that induced the greatest production of gonadotropins by pituitary cells was 10(-10) mol/l, which was the same as the physiological pubertal concentration. Leptin may be involved in the onset of puberty. It is also conceivable that leptin may be a cause of ovulatory failure, not only in weight loss but also in weight gain.

scholarly journals Neurokinin B Is Critical for Normal Timing of Sexual Maturation but Dispensable for Adult Reproductive Function in Female Mice

Endocrinology ◽  
2015 ◽  
Vol 156 (4) ◽  
pp. 1386-1397 ◽  
Author(s):  
Cadence True ◽  
Sayeda Nasrin Alam ◽  
Kimberly Cox ◽  
Yee-Ming Chan ◽  
Stephanie B. Seminara
Keyword(s):  
Sexual Maturation ◽  
Pubertal Development ◽  
Critical Role ◽  
Reproductive Function ◽  
Wild Type ◽  
Neurokinin B ◽  
Gene Encoding ◽  
Estrous Cycles ◽  
Pubertal Delay ◽  
Deficient Mice

Abstract Humans carrying mutations in neurokinin B (NKB) or the NKB receptor fail to undergo puberty due to decreased secretion of GnRH. Despite this pubertal delay, many of these patients go on to achieve activation of their hypothalamic-pituitary-gonadal axis in adulthood, a phenomenon termed reversal, indicating that NKB signaling may play a more critical role for the timing of pubertal development than adult reproductive function. NKB receptor-deficient mice are hypogonadotropic but have no defects in the timing of sexual maturation. The current study has performed the first phenotypic evaluation of mice bearing mutations in Tac2, the gene encoding the NKB ligand, to determine whether they have impaired sexual development similar to their human counterparts. Male Tac2−/− mice showed no difference in the timing of sexual maturation or fertility compared with wild-type littermates and were fertile. In contrast, Tac2−/− females had profound delays in sexual maturation, with time to vaginal opening and first estrus occurring significantly later than controls, and initial abnormalities in estrous cycles. However, cycling recovered in adulthood and Tac2−/− females were fertile, although they produced fewer pups per litter. Thus, female Tac2−/− mice parallel humans harboring NKB pathway mutations, with delayed sexual maturation and activation of the reproductive cascade later in life. Moreover, direct comparison of NKB ligand and receptor-deficient females confirmed that only NKB ligand-deficient animals have delayed sexual maturation, suggesting that in the absence of the NKB receptor, NKB may regulate the timing of sexual maturation through other tachykinin receptors.

Studies on the reproductive performance of Ethiopian sheep by means of an enzyme immunoassay technique; a review

1992 ◽  
Vol 4 (5) ◽  
pp. 523 ◽  
Author(s):  
E Mukasa-Mugerwa ◽  
ER Mutiga ◽  
A Girma
Keyword(s):  
Post Partum ◽  
Pubertal Development ◽  
Reproductive Function ◽  
Point Of View ◽  
Enzyme Linked Immunosorbent Assay ◽  
Practical Applications ◽  
Immunoassay Technique ◽  
Sheep Production ◽  
Enzyme Immunoassay Technique

Measurement of the concentration of hormones associated with reproductive function in female animals can aid in the evaluation of their reproductive status. In particular, from the point of view of production, determination of the concentration of circulatory progesterone can aid in the correct assessment of ewes. Many investigators have used radioimmunoassay for this purpose, but the enzyme-linked immunosorbent assay (ELISA) is equally reliable, quicker and cheaper. This report reviews the use of the ELISA in Ethiopian Menz sheep. Progesterone profiles in Ethiopian Menz sheep during pubertal development, the oestrous cycle, pregnancy and post-partum anoestrus were similar to those of temperate breeds. The practical applications of progesterone determination to sheep production and the requirement for the correct handling of samples are emphasized.

scholarly journals Neuroanatomical Framework of the Metabolic Control of Reproduction

2018 ◽  
Vol 98 (4) ◽  
pp. 2349-2380 ◽  
Author(s):  
Jennifer W. Hill ◽  
Carol F. Elias
Keyword(s):  
Energy Homeostasis ◽  
Protein Biosynthesis ◽  
Pubertal Development ◽  
Metabolic Stress ◽  
Reproductive Function ◽  
Metabolic Dysfunction ◽  
Physiological Processes ◽  
Extra Energy ◽  
The Brain

A minimum amount of energy is required for basic physiological processes, such as protein biosynthesis, thermoregulation, locomotion, cardiovascular function, and digestion. However, for reproductive function and survival of the species, extra energy stores are necessary. Production of sex hormones and gametes, pubertal development, pregnancy, lactation, and parental care all require energy reserves. Thus the physiological systems that control energy homeostasis and reproductive function coevolved in mammals to support both individual health and species subsistence. In this review, we aim to gather scientific knowledge produced by laboratories around the world on the role of the brain in integrating metabolism and reproduction. We describe essential neuronal networks, highlighting key nodes and potential downstream targets. Novel animal models and genetic tools have produced substantial advances, but critical gaps remain. In times of soaring worldwide obesity and metabolic dysfunction, understanding the mechanisms by which metabolic stress alters reproductive physiology has become crucial for human health.

scholarly journals Congenital hypogonadotropic hypogonadism: from clinical characteristics to genetic aspects

2021 ◽  
Vol 5 (3) ◽  
pp. 97-105
Author(s):  
Ahreum Kwon ◽  
Ho-Seong Kim
Keyword(s):  
Clinical Characteristics ◽  
Pubertal Development ◽  
Hypogonadotropic Hypogonadism ◽  
Reproductive Function ◽  
Delayed Puberty ◽  
Activation Process ◽  
Hpg Axis ◽  
Congenital Hypogonadotropic Hypogonadism ◽  
Sexual Characteristics ◽  
Main Component

Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder caused by a deficiency in gonadotropin-releasing hormone (GnRH). CHH is characterized by delayed puberty and/or infertility; this is because GnRH is the main component of the hypothalamic-pituitary-gonadal (HPG) axis, which is a key factor in pubertal development and reproductive function completion. However, since the development of sexual characteristics and reproduction begins in the prenatal period and is very complex and delicate, the clinical characteristics and involved genes are very diverse. In particular, the HPG axis is activated three times in a lifetime, and the symptoms and biochemical findings of CHH vary by period. In addition, related genes also vary according to the formation and activation process of the HPG axis. In this review, the clinical characteristics and treatment of CHH according to HPG axis activation and different developmental periods are reviewed, and the related genes are summarized according to their pathological mechanisms.

scholarly journals Influences of manganese on pubertal development

2017 ◽  
Vol 235 (1) ◽  
pp. R33-R42 ◽  
Author(s):  
William L Dees ◽  
Jill K Hiney ◽  
Vinod K Srivastava
Keyword(s):  
Luteinizing Hormone ◽  
Developmental Process ◽  
Pubertal Development ◽  
Reproductive Function ◽  
Hypothalamic Region ◽  
Luteinizing Hormone Releasing Hormone ◽  
Physiological Processes ◽  
Timing Of Puberty ◽  
Environmental Element ◽  
The Brain

The onset of puberty is the result of complex neuroendocrine interactions within hypothalamic region of the brain, as well as from genetic and environmental influences. These interactions ultimately result in the increased synthesis and release of luteinizing hormone-releasing hormone (LHRH). Manganese (Mn) is an essential environmental element known for years to be involved in numerous mammalian physiological processes, including growth and reproductive function. Studies in recent years have shown the ability of Mn to cross the blood–brain barrier and act within the hypothalamus to influence the timing of puberty. This review will depict research showing the molecular and physiological actions of Mn in the control of prepubertal LHRH and discuss the potential for the element to cause either helpful or harmful outcomes on the developmental process depending upon the age and accumulation of Mn within the hypothalamus.

scholarly journals Pubertal Development of Intersertoli Cell Junctions in the Testis of Corriedale Ram Lambs

1995 ◽  
Vol 36 (4) ◽  
pp. 543-551
Author(s):  
A. Bielli ◽  
T. Gastel ◽  
A. Castrillejo ◽  
A. Moraña ◽  
H. Rodriguez-Martinez
Keyword(s):  
Pubertal Development ◽  
Cell Junctions ◽  
Ram Lambs
Sign in / Sign up

Export Citation Format

Share Document