  We investigate the effects of spin on entanglement arising in Dirac field in
an expanding spacetime characterized by the Robertson-Walker metric. We present
a general approach that allows us to treat the case where only charge
conservation is required, as well as the case where also angular momentum
conservation is required. We fiend that in both situations entanglement,
quantified by subsystem entropy, behaves the same and does not qualitatively
deviates from the spinless case. Differences only arise when particles and/or
antiparticles are present in the input state.
