Plasma Luteinizing Hormone (LH) and Testosterone Levels during Sexual Maturation in Beef Bull Calves1

Rawlings, N.C.; Fletcher, Paul W.; Henricks, D. M.; Hill, J. R.

doi:10.1095/biolreprod19.5.1108

Cited by 63 publications

(33 citation statements)

References 20 publications

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“…The relationship between reduced FSH and delayed postnatal activation of the reproductive axis observed in the pubertal and postpubertal LPeri cohort concurs with previous research: FSH levels, along with LH, rise transiently between 1 and 4 months of age in the prepubertal bull (Rawlings et al 1978;Evans et al 1996;Moura and Erickson 1997;Kaneko et al 2001;Bagu et al 2006), a rise reported to be associated with the initiation of rapid testis growth (Moura and Erickson 1997). FSH levels then fall, remaining low during peri-puberty and puberty (Moura and Erickson 1997;Kaneko et al 2001;Brito et al 2007cBrito et al , 2007d.…”

Section: Postnatal Developmentsupporting

confidence: 90%

Peri-conception and first trimester diet modifies reproductive development in bulls

Copping

Ruiz-Diaz

Mongan

et al. 2018

Reprod. Fertil. Dev.

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Abstract. Nutritional perturbation during gestation alters male reproductive development in rodents and sheep. In cattle both the developmental trajectory of the feto-placental unit and its response to dietary perturbations is dissimilar to that of these species. This study examined the effects of dietary protein perturbation during the peri-conception and first trimester periods upon reproductive development in bulls. Nulliparous heifers (n ¼ 360) were individually fed a high-or low-protein diet (HPeri and LPeri) from 60 days before conception. From 24 until 98 days post conception, half of each treatment group changed to the alternative post-conception high-or low-protein diet (HPost and LPost) yielding four treatment groups in a 2 Â 2 factorial design. A subset of male fetuses (n ¼ 25) was excised at 98 days post conception and fetal testis development was assessed. Reproductive development of singleton male progeny (n ¼ 40) was assessed until slaughter at 598 days of age, when adult testicular cytology was evaluated. Low peri-conception diet delayed reproductive development: sperm quality was lowered during pubertal development with a concomitant delay in reaching puberty. These effects were subsequent to lower FSH concentrations at 330 and 438 days of age. In the fetus, the low periconception diet increased the proportion of seminiferous tubules and decreased blood vessel area in the testis, whereas low first trimester diet increased blood vessel number in the adult testis. We conclude that maternal dietary protein perturbation during conception and early gestation may alter male testis development and delay puberty in bulls.

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Section: Postnatal Developmentsupporting

confidence: 90%

Peri-conception and first trimester diet modifies reproductive development in bulls

Copping

Ruiz-Diaz

Mongan

et al. 2018

Reprod. Fertil. Dev.

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“…In bull calves, blood concentrations of gonadotropins increase long before the animal reaches puberty. It has been shown that LH starts to rise from 6 weeks of age reaching peak values between 12 to 16 weeks and subsequently drops to basal concentrations at week 25 of life remaining low until attainment of puberty (Amann and Walker, 1983;Aravindakshan et al, 2000;Bagu et al, 2006;Evans et al, 1996;Lacroix and Pelletier, 1979;McCarthy et al, 1979;Rawlings and Evans, 1995;Rawlings et al, 1978Rawlings et al, , 2008Rodriguez and Wise, 1989). The early rise in gonadotropin secretion seems to be essential for normal testicular development and reproductive maturation in bull calves Rawlings et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Effect of vaccination against gonadotropin-releasing factor (GnRF) with Bopriva® in the prepubertal bull calf

Janett

Gerig

Tschuor³

et al. 2012

Animal Reproduction Science

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“…The steroidogenic capacity of bull testes is low during the first few months of postnatal life (Karg et al, 1976;Rawlings & Cook, 1986), serum concentrations of androstenedione and individ¬ ual 5a-reduced androgens (androsterone, DHT, 5a-androstane-3a,17ß-diol and 5a-androstane-3ß,17ß-diol) do not exceed that of serum at any time from birth to 28 weeks of age (Rawlings & Cook, 1986) and serum increases to adult concentrations by 10 months of age (Lunstra et al, 1978;Rawlings et al, 1978;Amann & Schanbacher, 1983;Amann & Walker, 1983;Rawlings & Cook, 1986). Thus, administration of exogenous steroids to bulls during the first few months of life would markedly increase the amount of steroid reaching the brain and may modify subsequent sexual behaviour.…”

Section: Introductionmentioning

confidence: 99%

Effect of implanting bull calves with testosterone propionate, dihydrotestosterone propionate or oestradiol-17 prepubertally on the pituitary-testicular axis and on postpubertal social and sexual behaviour

Godfrey

Lunstra²,

Schanbacher³

1992

Reproduction

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Twelve non-implanted crossbred bull calves served as controls and 30 crossbred bull calves (10/treatment) were implanted for 82 days, beginning at 34 days of age, to determine the influence of testosterone propionate (TP), dihydrotestosterone propionate (DHTP) and oestradiol-17 beta (E2) on prepubertal and pubertal pituitary-testicular function and on postpubertal social and sexual behaviour. Compared with control bulls, concentrations of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and inhibin concentrations were suppressed (P less than 0.01) in all implanted bulls. Testosterone (T) concentration increased (P less than 0.001) in TP-implanted, but decreased (P less than 0.01) in DHTP and E2 bulls during the implant period. LH response to gonadotrophin-releasing hormone (GnRH) challenge during the implant period (2.5 months of age) was less (P less than 0.01) in TP, E2 and DHTP bulls than in controls. A small but significant T response to GnRH occurred in control bulls at 2.5 months of age. LH and T responses to GnRH challenge at 7 months of age (100 days after implant removal) was similar (P greater than 0.20) in control and implanted bulls. Steroid implants administered prepubertally had no effect (P greater than 0.10) on postpubertal social and sexual behaviours, including number of flehmen responses, abortive mounts, services and competitive order score. Body weight did not differ (P greater than 0.10) between treatment groups, but testis size was reduced (P less than 0.01) during the implant period and up to 10 months of age in treated bulls compared with controls. Testes remained smaller in E2-treated bulls up to the end of the study (23 months of age), but daily sperm production and epididymal weight did not differ (P greater than 0.10) between treatment groups at slaughter. Control bulls reached puberty earlier (P less than 0.01; 270 +/- 11 days of age) than did TP (302 +/- 11 days), DHTP (309 +/- 11 days) or E2 (327 +/- 11 days) bulls. Although puberty was delayed in all implant groups, there was no difference in scrotal circumference at puberty (average 28.4 +/- 0.4 cm) between treatment groups. Our findings indicate that TP, DHTP and E2 implants administered prepubertally result in acute suppression of serum LH, FSH and inhibin during the implant period and in post-implant suppression of testis size and delayed puberty in bulls. The lack of treatment effect on behaviour suggests that steroidal programming of sexual behaviour occurs before 1 month of age in bulls.

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Plasma Luteinizing Hormone (LH) and Testosterone Levels during Sexual Maturation in Beef Bull Calves1

Abstract: Blood samples were taken by jugular venipuncture from bull calves every other week from I to

Cited by 63 publications

References 20 publications

Peri-conception and first trimester diet modifies reproductive development in bulls

Peri-conception and first trimester diet modifies reproductive development in bulls

Effect of vaccination against gonadotropin-releasing factor (GnRF) with Bopriva® in the prepubertal bull calf

Effect of implanting bull calves with testosterone propionate, dihydrotestosterone propionate or oestradiol-17 prepubertally on the pituitary-testicular axis and on postpubertal social and sexual behaviour

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