The Hankel determinant appears in the representation of solutions to several integrable systems. Asymptotic expansion of the Hankel determinant thus plays a key role for investigating asymptotic analysis of such integrable system. In this paper, an asymptotic expansion formula of a certain Casorati determinant is presented as an extension of the Hankel case. It is also shown that an application of it to an asymptotic analysis of the discrete hungry Lotka-Volterra system, which is one of basic models in mathematical biology.