A growing number of studies have been conducted on this phenomenon. The basic problem/principle being studied is, when food resources are suddenly increased, why don't deer in the population immediately respond by growing bigger? The answer most likely lies in the little understood process of epigenetics. Epigenetics is the process by which life experiences alter the timing of gene expression during development. What it basically comes down to is life stresses can change how you develop as a fetus and as a young person. And because these stress-induced changes are tied to your chromosomes, they can be heritable (passed down from one generation to the next). They do not involve changes to your DNA, but are bits of amino acid chain "stuck" to your DNA that alter when and for how long genes turn on and off during development, which can have life-long ramifications.
In practical terms, what this means is does that have been nutritionally stressed at some point in their lives can later produce offspring that cannot develop to their genetic potential their entire lives. It may take a generation or two to get rid of this epigenetic limiter. In fact, this is most likely why most management programs don't see explosive results once a property's resources are dramatically improved. What is usually seen is a slow progression of better body and antler size over a decade or more. In reality, the entire generation of deer that lived under the poor resource conditions have to die off and be replaced by fawns born under the good conditions, and then THEY produce a set of offspring that no longer have the epigenetic limiter in their system.