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Periconception and first trimester diet modifies reproductive development in bulls
Nutritional perturbation during early gestation alters male reproductive development in rodents and sheep. In the bovine, both the developmental trajectory of the fetoplacental 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 periconception and first trimester periods upon reproductive development in male bovine progeny. Nulliparous heifers (n = 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 x 2 factorial design. A subset of male fetuses (n = 25) was excised at 98 days post-conception, and fetal testis development assessed. Reproductive development of singleton male progeny (n = 40) was assessed until slaughter at 598 days of age, when adult testicular cytology was evaluated. The low periconception 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 both 330 and 438 days of age in this cohort. In the fetus, the low periconception diet increased the proportion of seminiferous tubules and decreased blood vessel area in the testis and within the parenchyma, 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 this species.
RD17102 Accepted 19 September 2017
© CSIRO 2017