The GARDENA gardening expert
The new shoots are perfectly healthy so I do not think they fell because of a nutrient deficiency. On closer inspection of the shoots lying on the ground, it would seem that rather than having fallen off, they have been bitten off. In addition, the shoots come from the top part of the tree. However, as always, it is hard to give a precise assessment of plant or tree damage without seeing it close up.
This said, I can suggest the following: the damage may have been caused by squirrels. They don't just eat tender spruce shoots when there is new growth — they also like the protein-rich male flower buds on spruce branches. The severed shoots are then dropped on the ground. The cones on the ground show that your spruces are already producing fruit. This means that there are also male flowers on the trees. So in your case, the main culprit is likely to be plump with a bushy tail.