Effects of Colostrum Ingestion by calves on their own Lactation Performance as Cows
A research paper from USA showing the difference in adult milk yield due to the amount of colostrum given at birth.
Basically 2L versus 4 Litres, the higher amount giving you:-
230g extra live weight gain per day,
less illness & vet costs,
550kg extra milk over the first 2 lactations.
The actual paper is in the document section.