I suggest you research making organic chicken feed rations. Many companies sell the various ingredients needed to mix a balanced ration/diet. You will need a number of ingredients, a feed mill/grinder and a lot of work and dedication. Various ingredients can be substituted for each other, with care, to balance the proper ratio of nutrients. Sprouts protein content varies considerably, and being a fresh item, spoils rapidly. Feeding them as a snack could be good, if the chickens don't neglect the food containing the other requirements too much(don't give them too much)! They need fat, carbohydrates, vitamins and minerals not supplied sufficiently in any one plant food source. Fatty liver syndrome (too many snacks/high energy/protein feeds), malnutrition, poor laying or weak egg shells , premature/excessive moulting and more , may result from poor feeding practices. Most of the low producing and short lived birds, in other flocks, otherwise well cared for, I have seen, were caused by feed issues. Table scraps, homemade feed rations, "chicken treats" and too much "scratch grains/corn" are the typical sources of problems. When large healthy looking and "correctly"behaving birds suddenly drop dead, it is often fatty liver syndrome from feeding them too many snacks, table scraps or too much high protein/energy diets (meat bird rations for old hens.) Mixing feeding organic rations in smaller batches, I could manage, increased my per egg and chicken dinner cost, way too much and was a lot of extra work. Good luck and best wishes for you and your birds.