Experiment aimed to determine dietary adaptability to transition from hay to silage based TMR during the post weaning period. Other objectives were to determine effects of dietary hay inclusion in TMR on sorting behavior, intake, growth performance, and feed efficiency (FE). Eighteen (Friesian × Jersey) weaned calves were randomly assigned to 3 TMR treatments (n = 6 calves/treatment): RG13, RG26 and RG39 containing 13%, 26%, and 39% chopped rhodes grass (RG) hay on DM basis. Total duration of experiment was 8 wk including 2 phases (4 wk each). During 1st phase (1–4 wk), weaned calves were fed on TMR diets (RG13, RG26 and RG39); thereafter, during 2nd phase (5–8 wk), all calves were shifted to a corn silage based TMR. Calves were housed in individual pens and were given free choice access to water and feed. Samples of diets fed and orts were collected twice weekly to calculate sorting % using Penn state particle separator. Data for ADG, daily DMI, feed sorting and blood metabolites were analyzed using repeated measures ANOVA; whereas, BW and FE were analyzed using one way ANOVA. To determine effect of increasing hay level in TMR diet polynomial orthogonal contrasts were used. Results were declared significant at P < 0.05. During 1st phase, calves sorted for short and fine particles (P < 0.05) with increasing level of RG hay. However, during 2nd phase, sorting behavior was not affected (P > 0.05) by hay level during 1st phase. Overall, daily DMI and ADG was not affected (P > 0.05) by dietary treatments. However, FE was higher (P > 0.05) in the RG26 compared with the RG13 and RG39 calves. Glucose concentration decreased linearly (P < 0.05) by increasing hay level in the diets. Although calves sorted for fine particles when chopped hay inclusion was increased in post weaning TMR; however, higher ADG, FE and lower blood glucose level in RG26 suggest positive impact of hay inclusion on transition to silage based TMR.