Basic neuroendocrine events before puberty in cattle, sheep and pigs.

Area of Science:

• Comparative animal physiology
• Reproductive endocrinology
• Neuroendocrinology

Background:

• Puberty onset is a critical developmental stage influenced by neuroendocrine factors.
• Understanding prepubertal neuroendocrine events is crucial for reproductive success in domestic animals.
• Existing knowledge on the transition to puberty in livestock species remains incomplete.

Purpose of the Study:

• To compare pre-pubertal neuroendocrine events in male and female cattle, sheep, and pigs.
• To investigate the maturity of the hypothalamic-pituitary axis before puberty.
• To identify gaps in the understanding of prepubertal development.

Main Methods:

• Analysis of gonadotropin secretion patterns.
• Assessment of luteinizing hormone (LH) responses to castration and gonadotropin-releasing hormone (GnRH) administration.
• Evaluation of prolonged steroid treatment effects.
• Measurement of plasma LH levels and pulses.
• Examination of pituitary cytosol receptor variations.

Main Results:

• Neuroendocrine mechanisms regulating puberty appear to be progressive, not abrupt, across the studied species.
• Age-related changes in LH secretion were observed in gilts.
• Variations in pituitary cytosol receptors for androgens and estrogens were noted in male lambs.

Conclusions:

• The expression of puberty in cattle, sheep, and pigs is a gradual process.
• Specific findings support the progressive nature of pubertal development.
• Significant gaps remain in our comprehension of pre-pubertal neuroendocrine regulation in these species.