Epigenomics of metabolic organs from in vitro or in vivo-produced dairy male calves

In cattle, two of the most common technologies for embryo production are “in vivo”, after multiple ovulation and embryo transfer (MOET), or “in vitro” (IVP). IVP can sometimes impact fetal growth, resulting in large offspring, although most IVP calves are born apparently healthy. However, gene regulation changes in the organs involved in the developmental process in phenotypically normal postnatal calves are unknown and could indicate physiological programming. The objective was to compare the epigenomic and transcriptomic modifications in the liver, muscle, and organs of the hypothalamus-pituitary-gonadal and adrenal (HPGA) axes between IVP and MOET male calves of three months of age. Pregnancies were monitored until delivery. Male calves were maintained in similar conditions during the postnatal period until euthanasia at around 100 days of age. There were no differences regarding body weight at birth and growth rate among the animals in both groups at this age. Samples were obtained from the liver, muscle, hypothalamus, pituitary, testicle and adrenal from three-month-old IVP calves (n=4) and control MOET calves (n=4).