The net result is to elevate blood Ca level to normal. Calcitonin reverses PTH functions, result in lower blood Ca level to normal. Rickets occur only in young growing animals due to normal growth in organic matrix, but insufficient mineralization. Osteomalacia occurs in adult animals on Ca deficient diet. Excessive loss of Ca from bone causes brittle, demineralized bones.
Osteoporosis is the result of loss both mineralization and organic matrix of bone.
Milk fever always hit your high producing dairy cows with first 24 hours after calving. Their body temperature drop, show signs of tetany, and eventually collapse. This is attributed to the lowered blood Ca. Good management practice can prevent this problem. Its metabolism is tightly coupled with Ca.