That was the feedback from farmers that were involved in the BCS project a few years ago. 
 
Waiting until March to start body condition scoring your herd and identifying the lighter cows limits your options, or compromises calving BCS. 
 
The earlier you identify the lighter heifers and lighter early calving cows the better. It means you have the option to change something (inputs (feed in) or outputs (milk out)) and still get to your desired target with these animals. 
 
Just because you’ve already put the herd on OAD in December doesn’t mean that the lighter cows are going to miraculously start gaining BCS at a faster rate than everyone else in the herd. These high risk animals may still need to be dried off earlier than you would like. They may still may need to be aggressively fed in the dry period. Unfortunately this is the reality. 
 
The cows that ‘managed’ the awful infamous spring of 2017 better were the cows that were in BCS 5 and heifers/second calvers in BCS 5.5. 
 
The time to do something about hitting this target is now.