My chicken just LOVE blackberries. But I only give them blackberries once in a while so they stay special. Thats what a treat is.... it needs to be special. My chickens also love this snack: (I made it up my self)
1. - Put 2 or 3 scoops of plain yogurt in a plastic container.
2. - I use about 2 'Great value, Made With Whole Grain Slatine Crackers'. Scrape off as much salt as you can, and break them into bight sized pieces. (For chickens)
3. - Add some bread crumbles and stick it in the freezer for a few hours.
4. - Take it out and serve it to the chickens in the container or out.
My chickens REALLY like this treat on hot summer days. Also, you can make it bigger or smaller depending on how many chickens you have.