Can I feed the chickens with calcium carbonate or limestone?

Yes, yes, but if you feed a full-price feed, enough calcium has been added to the feed. If calcium is supplemented additionally, high calcium will cause phosphorus deficiency, and excess calcium and phosphorus will combine to form calcium phosphate and be excreted, which will reduce the absorption rate of phosphorus. The decrease of phosphorus increases the level of urinary calcium, which puts pressure on the kidneys. A diet high in calcium and low in phosphorus is easy to cause kidney and ureteral stones. High calcium feed affects the absorption of manganese. The high content of calcium and phosphorus in feed will reduce the utilization rate of manganese. High calcium and high phosphorus form calcium phosphate precipitation in the intestine, and the manganese adsorbed by the precipitation is excreted, resulting in manganese deficiency in the body. When laying hens and breeders are deficient in manganese, they often show a decrease in egg production, low hatching rate and poor embryo development after hatching. High calcium feed can cause diarrhea in breeders. When broiler breeders first change the laying diet, if the calcium content is high, it is easy to cause diarrhea, because stone powder is added to the feed to stimulate intestinal peristalsis.