To investigate the regulatory relationship between kisspepti…
To investigate the regulatory relationship between kisspeptin and leptin as gatekeepers of puberty in beef heifers, evaluating their roles in hypothalamic pathways across developmental stages and production cycles. Objective 1: To elucidate the mechanisms by which leptin regulates Kiss1 expression in the hypothalamus. Hypothesis 1: Leptin acts as a Kiss1 regulator in the arcuate nucleus, influencing pulsatile GnRH frequency and subsequent reproductive processes. Objective 2: To determine if significant post-pubertal body weight fluctuations alter the neuroendocrine pathways involving NPY, POMC, and kisspeptin. Hypothesis 2: Significant weight fluctuations will impact neuroendocrine pathway function, potentially impairing reproductive efficiency in mature cows, but pathway structure will remain unaffected if fully developed prepuberty. Objective 3: To assess whether underdeveloped kisspeptin pathways can recover structurally and functionally with increased energy intake post-puberty. Hypothesis 3: Increased energy intake post-puberty can restore kisspeptin pathway efficiency, enhancing reproductive performance. References: Amstalden, M., et al. (2014). Hypothalamic Neuropeptides and Nutritional Programming of Puberty in Heifers. Journal of Animal Science, 92(8), 3211–3222. Cardoso, R.C., et al. (2018). Neuroendocrine Signaling Pathways and Nutritional Control of Puberty in Heifers. Animal Reproduction.