It depends how big your dogs are! Their full days food should be about 2 percent of their body weight if they are adults and between 4 and 6 of their weight if they are puppies (although those figures seem to differ depending on who you talk to). One chicken leg would leave my dog looking for more!!

I don't worry about defrosting too much. I tend to leave it up to my dog to decide whether he wants to wait. If I give him minced meat or minced tripe defrosted, it doesn't touch the sides! Being frozen slows him down which gives his brain time to register he's eaten! Also, he is still teething and seems to quite like the coolness. He prefers bones defrosted. My Mum and kids thought I was really cruel until they saw him yomping his food down, frozen or not. All I can say is I have one happy and healthy dog.

Hope that helps.