I used dry full cream. It was the most convenient form in my situation.
The longer read 
An explanation of how went this way. I wanted to increase the number of hives. This is my first season in this area and, of cause, I choose the worst possible time to do it. I created nuc-sized colonies, but parent colonies were low on pollen stores and I had almost nothing to share without compromising them. As soon as made the splits, nectar and pollen disappeared from nature. Nothing to worry about I said and bought patties from a local supplier. All colonies refused them. I mean they refused even to touch them. Larger colonies just removed the free paper around patties but patties themselves were intact after 2 weeks. 20-frame colonies were good at this stage, but nucs ate through the frames of honey and were on the way to extinction. Sugar was not a problem, but they were in dire need of protein. The last small batch of bees they produced were pitiful dystrophics. Queens almost stopped laying. Now I can skip the worrying and start to panic I said and went to buy some feed. In my current circumstances, the most readily available form of protein bees may consume was milk from supermarkets.
An additional read 
Bees digest cow milk quite well. They absorb 76.5% of matter from it. For comparison, fresh pollen - 79.1%
Is milk a good substitute for pollen? No. But as a supplement food when it is needed works quite well. For example, when 20% of water is replaced with milk in thick sugar syrup, it contains twice as much protein as honey. Bees love such food and take it readily from feeders. What does it give in real terms? Increase in body protein.
Compared to feeding honey only:
Milk in the mix, % |
Increase of body protein, % |
10 |
4.5 |
20 |
6.6 |
40 |
11 |
How did it work for me? Pollen became available again since the beginning of the story. But small starved colonies don’t have resources to scout and bring food, especially if it is in some distance. Nucs recovered in terms of brood but still did not have much pollen in them. At the same time, the 20-frame colony went from “very little pollen left” to stuffing 8 frames with it. This excess is now shared with small colonies. So time in small colonies development was lost, but feeding milk allowed them to survive through the worst until real help became available.
Any form of milk leads to an increase in brood production when compared to pure sugar syrup. But when different forms are compared results are as follows:
Data obtained in the Northern Caucasus area:
Experiment setup: 40 colonies with queens of the same age, the same amount of brood, honey and bees divided into 4 groups of 10 colonies.
Mixes:
1st group: syrup - 1.86 kg of sugar per 1 l of water
2nd Whole - 1.5 kg per 1L of milk
3rd Skimmed milk - 1.5 kg per 1L of milk
4th Dry milk - 875 g of powder + 250 ml of water to prepare 1 l of milk, then mixed with 1.5 kg of sugar.
Method of feeding:
Spring: began to feed on the 3 of April. Duration - 36 days, 18 times (every second day), 200 g of mix every feed through the top feeder.
Autumn (after the end of nectar collection): started on 26 of August, otherwise the same.
Results:
Spring feeding:
Form of milk added |
Increase in brood production, % |
Pure sugar syrup (control) |
100 |
Whole milk |
110.5 |
Dry milk |
108.3 |
Skimmed milk |
106.9 |
Autumn feeding:
Form of milk added |
Increase in brood production, % |
Pure sugar syrup (control) |
100 |
Whole milk |
123 |
Dry milk |
121.6 |
Skimmed milk |
117.6 |