Reviewing the low efficiency of protein utilization in heavy preruminant calves – a reductionist approach Joost J. G. C. van den Borne, Johannes M. A. J. Verdonk, Johan W. Schrama and Walter J. J. GerritsReprod. Nutr. Dev., 46 2 (2006) 121-137DOI: https://doi.org/10.1051/rnd:2006011