The advent of genomic selection has accentuated interest in procuring saleable semen from young genetically elite bulls, as early in life as possible. However, the timing of availability of semen, for commercial use, will be determined by the age at which these young animals reach puberty and subsequent sexual maturity. Enhancing early life nutrition stimulates the functionality of the hypothalamic-pituitary-testicular (HPT) axis, mediated through a complex biochemical interplay between metabolic and neuro endocrine signals and culminating in enhanced testicular growth, steroidogenesis, spermatogenesis and ultimately earlier onset of sexual maturation. Indeed, recent evidence suggests that the timing of sexual precocity in the bull is determined by prevailing metabolic status during calfhood and is not compensable following nutritional augmentation, once calves reach 6 mo of age. However, despite this, the precise neuronal mechanisms regulating these developmental processes remain to be elucidated for the bull. While early life nutrition clearly affects the sexual maturation process, there is little evidence for latent effects on post pubertal semen characteristics. Equally, post pubertal fertility measured as in vitro fertilisation and early embryogenesis is not influenced by nutritional status during early life. Current efforts employing high throughput nucleic acid and proteomic sequencing and targeted immunofluoresence and couple with systems biology based gene network analyses, are providing further insight on how nutrition may mediate the biochemical interaction between neuroendocrine and testicular processes. Such information can be harnessed to identify potential genomic targets as part of genomically assisted breeding programmes as well as facilitating development of nutritional regimens to optimize sexual maturation and subsequent semen availability from genetically elite young bulls.