Observations on the maturity of stillborn calves

: Organ weight and trace element analyses were performed on 75 stillborn calves from the same dairy cow herd. The elements Fe, Mn, Zn and Cu were measured in the livers of 66 of the calves. The calves ranged in age from 259 to 299 days of gestation, and in weight from 18 to 58 kg. Based on the quotients of organ and other body parts, stage of growth of the humerus and age, the animals were grouped as either preterm (P), term but light (TL), and term with appropriate weight (TA) calves. In P group calves the heart, lungs, liver, kidneys, thymus, spleen and thyroid glands were relatively heavy. In the TL group calves the brain, heart, lungs and thyroid glands were relatively heavy whereas the spleen and thymus were comparatively light. The liver Fe and Zn values were lower in this group than in the other 2 groups.