Growth of the pig: changes in red cell and plasma volumes

In the pig, plasma volume increased from 58.0 +/- 2.53 ml/kg on day 1 to 66.7 +/- 3.35 (P less than 0.05) on day 2, and decreased between days 7 and 9 to 56.4 +/- 1.16 (P less than 0.02). The next significant change in volume occurred at weaning: from 53.1 +/- 1.24 ml/kg at week 4 to 44.16 +/- 2.2 at week 5. It then increased to 56.1 +/- 1.41 ml/kg by week 7 and decreased to 48.5 +/- 1.44 by week 9; then between weeks 10 and 11 it increased to 59.33 +/- 3.01 (P less than 0.005). Red cell volume on day 1 was 32.3 +/- 1.25 ml/kg and decreased to 20.2 +/- 1.37 (P less than 0.01) on day 2. The only other change of significance in red cell volume over the 12-week growth period was a small increasan 0.05) at week 6. The mean for BVRcells was 0.88 +/- 0.01 for the growth period. The pattern of changes in plasma and red cell volumes differed from those for the beagle.