That's a decent protein value. It could very well be these specific girls.
I don't understand why scratch is viewed as being a candy to chickens. Prepared chicken feed is made from grain. It's tested to ensure it's safe and meets protein values etc.of course, but scratch is not that much different unless it contains a lot of corn. Wheat, millet, rye (my chickens don't like rye) are good grains. With a 20% protein prepared feed...a bit of scratch is fairly negligible. Layer isn't as high of a protein...but good feed wheat can be 14%-15% protein. That's still just plant protein..but meal worms are being given so that helps the animal protein aspect. The fat content could be an issue, agreed.
Most scratch grains are around 8% protein. Many folks tend to give scratch often, and in fairly large amounts. Formulated feeds are balanced, and provide balanced amino acids, as well as other nutrients. Layer feed at 16% is formulated to provide the minimal needs of a layer hen, assuming that is ALL SHE EATS. If her flock master gives that hen a fist full of scratch in the morning, and again in the evening, and then gives her a couple of bread crusts, and other kitchen (non-meat) scraps, that hen is going to be seriously deficient in her diet. Many flocks live their existence confined to coop and bare soil run, which also limits their ability to forage for nutritional supplements to the diet provided by the flock master.
