An estimate of the nutrients utilized for pregnancy by Merino sheep.

I . Fifty-one pregnant fine-wool Merino ewes were slaughtered at intervals during pregnancy. The gravid uteri were dissected and were separated into uterus, membrane and fluid, and foetus fractions, which were analysed separately for water, nitrogen, ash, fat, calcium, phosphorus, sodium and potassium content. 2. Uteri from twenty-one similar non-pregnant ewes were also analysed for these constituents. 3. A number of relationships between the composition of the gravid uterus minus the composition of the uterus taken from non-pregnant sheep, and time from conception were calculated. 4. The rate of nutrient deposition was calculated from these relationships and estimates were made of the nutrients utilized for pregnancy.