  A mixed spin-$(1/2, S)$ system with arbitrary spin $S$ and interactions
satisfying the U(1) axial symmetry is considered. Compact explicit forms of the
local quantum uncertainty (LQU) and local quantum Fisher information (LQFI) are
obtained directly through the entries and eigenvalues of the density matrix.
Using these forms, we perform a comparative study of discord-type quantum
correlations LQU and LQFI for the system at thermal equilibrium. An increase in
quantum correlations with increasing spin length $S$ is discovered. Moreover,
we find that as the system cools, quantum correlations can undergo one or more
abrupt transitions while the temperature changes smoothly.
