BLOOD VOLUME CHANGES DURING PREGNANCY AND LACTATION OF SOWS

Abstract

Plasma volume and haematocrit were measured at approximately 20 days intervals in 3 gilts (sows in their first pregnancy and lactation) throughout pregnancy and in 2 of these gilts during lactation. Measurements were made at the beginning and end of pregnancy in a further 9 sows and also at mid‐pregnancy in 4 of these latter sows. In the gilts PV declined during the first 40 days and then increased until parturition. In lactation the PV continued to rise during the first 14 days and then decreased steadily until weaning. Calculated RCV increased linearly during pregnancy and fell immediately after parturition. The results obtained from the sows again showed only a sight rise in PV and RCV until day 70 and then a sharp rise until parturition. There was no relationship between the increase in PV and the weight of the litter born. © 1970 The Physiological Society