See link on cattle dealing with copper toxity with very limited research.
http://www.saltinstitute.org/wp-content/uploads/2013/05/STM-3rd-2011.pdf
Sometimes selection pressure and introduction of new blood needs to consider more than just color, gain and efficiency.
http://www.saltinstitute.org/wp-content/uploads/2013/05/STM-3rd-2011.pdf
Sometimes selection pressure and introduction of new blood needs to consider more than just color, gain and efficiency.