The effect of high and low planes of nutrition on the haematology of monozygous twin calves

Abstract

1. In an experiment conducted with eight pairs of monozygous twin heifer calves aged from 7 to 9 months, it was shown that the mean haemoglobin concentration of those reared on a high plane of nutrition was higher than the corresponding value of those reared on low-plane rations.2. The relative anaemia of the low-plane animals was microcytic but normochromic in type. Its cause must await further investigation, but these features would not be inconsistent with a deficiency of iron.3. For this type of haematological study, monozygous twins proved more efficient than unrelated animals, as shown by the smaller variability within than between pairs.4. Day-to-day variation in the same animal must be considered an important possible source of sampling error.