So do you think it's in the genes of those chickens?
The food?
They're just for some reason mor happy than the other chickens?What?
Will the chicks of these chickens lay more like their mamas?
I gotta get me come chickens.
I don't know the answers, I can only share my experience.
When we first brought our hens home, I wanted nothing to do with them. My Grandparents lived on a farm when I was a kid and I hated the hen house. Some of those hens were mean. They would stop at nothing to keep you from taking their eggs. Why do I want to fight for my food when I don't have to?
Well, after they were here for a bit I ended up finding them intriguing. I read a little about them and found out that handling them would make them more people friendly.
I started reading more and more. What I read said that happy hens lay more eggs as well as better eggs. So I started doing what I read. I feed them all kinds of stuff. I make oatmeal for them and add things like grated apple, carrots, chopped bananas and yogurt. Foods containing nutrients they need. Like calcium, potassium and so forth. I let them out in my yard at least once a day to go do some scratching for bugs and worms to give them protein.
I keep their coup very clean and change up their environment. Chickens are very curious little creatures and change keeps them from getting bored. I hang a piece of broccoli in their coup for them to play with and eat. This will sound crazy, but I also hang things like an old CD. The sunlight hits it as it spins in the breeze and cause a rainbow of color to move around their coup. They love it and will actually chase the color around.
My son has a huge garden at his farm. I use the stuff I clean out of their coup to add to his compost and I bring a scoop back with me and throw it in the coup. The hens love scratching around it and finding worms. I have also read that the micro organisms are good for their digestive tracts along with the grit a throw in. I know you have a garden now so you could do the same and your hens and garden will both benefit. Also an interesting thing to teach your kids how it all works together.
So from my experience hens that have their nutritional needs met, our given things to keep them intrigued and not bored are happy. And in my opinion, happy hens lay more eggs.