Thesis (M.S., Animal and Veterinary Science) -- University of Idaho, 2016 | Twelve newborn Holstein bull calves were divided into cohort groups and fed (1. PUFA-2:1 flaxseed oil:CLA or 2. SFA – palm oil) in 2L milk twice daily for 50 d to determine the effect on preadipocyte development in pre-ruminating cattle. Fatty acid profiles, cell growth, morphological differentiation, and adipose tissue gene expression were measured. In PUFA fed calves, CLA was greater in SC (P<0.01), PR (P<0.001), calf serum (P<0.0002) and trended in IM (P<0.06). No significant level of ALA was present in any tissue samples; however, serum from the PUFA treatment had 20-fold higher ALA. No treatment effect was seen on relative gene abundance. Subcutaneous clonal preadipocytes grew faster with PUFA treatment calf serum (P=0.03), and isolated PUFA treatment SC S-V cells differentiated more than intramuscular preadipocytes (P=0.01). Feeding specific FAs affects tissue and serum FA profiles and aspects of adipocyte development.