How fast could a proto-pulsar rotate?
  According to two estimated relations between the initial period and the dynamo-generated magnetic dipole field of pulsars, we calculate the statistical distributions of pulsar initial periods. It is found that proto-pulsars are very likely to have rotation periods between 20 and 30 ms, and that most of the pulsars rotate initially at a period < 60 ms. 
R.X. Xu (PKU), H.G. Wang (PKU), G.J. Qiao (PKU)