Method comparison/correlation

#1
I need to compare blood pressure measurements in rats...to see if the new method collects data that is as reliable as the historical way. 100 rats were used with with data collected every 30 sec for an hour. Both methods were used to collect data simultaneously. Should I do r values for all timepoints to look at correlation across all animals. Or is bland Altman better? I need the best way to visualize this data with so many animals.