The idea is that animals eat slower, imitating grazing to a point and this slows down digestion.
Hay also helps to keep them warm (by fermentation in the gut) and forage buffers gastric acid in the stomach which can cause ulcers.
I still offer some loose hay, especially for Deenah and I always feed loose hay if I think they are especially hungry, i.e. first thing in the morning. I am watching to see if the hay nets are causing frustration and if/ when I see this, as they are still getting used to them, I offer some loose hay beside the net. The donkeys now seem to enjoy the puzzle.
Having a whole bunch of slow feeder hay nets placed here and there, might just be a great thing! When I feed hay, I always have more piles than donkeys (this minimizes squabbling) so having more than 3 hay bags seems like a good idea.
I can pre-fill them and they are ready to go and if I'm not going to be home, I can know that the donkeys have something to nibble!
These new ones are small and I am using them as little stuffed pillows lying on the ground. They are from N.A.G Bags - a BC company that makes many different sizes: www.slowfeeders.com