It's true that non-organic milk replacer commonly contains spray-dried blood plasma and blood serum from cattle and hogs. Non-organic milk replacer cannot be fed to organic calves according to the National Organic Program (NOP). Section 205.237(b)(5) of the NOP regulation prohibits the feeding of mammalian or poultry slaughter by-products to organic mammals or poultry. Numerous inputs and feed ingredients, allowed by the USDA and/or FDA for non-organic production, are not allowed in organic production.

Most organic calves are fed organic whole milk. For more information, please see eXtension.org article, “Feed and Feed Additives Regulations for Organic Dairy and Livestock in the United States” at http://www.extension.org/article/18563.