The experiment was discontinued in the late 70's because the crop yields in the organic half of the farm never really stabilised, but it still measured a statistical difference in herd health between the organic and conventional cows. The economic lifespan (number of lactations) of the organic cows was far longer than the conventional cows. The output of the organic cows was similar to that of the conventional cows even when they were fed less. Incidences of intestinal and reproductive cancers were much lower in the organic cows as well.
Anecdotally, the cows would knock down the fence to get to the organic pasture even when visually, the chemical pasture was more lush.