DEVELOPMENT AND USE OF ROUTINE PLASMAPHER ESIS METHOD TO BOOST PMSG AVAILABILITY FROM MARES

A plasmapheresis procedure was developed for routine use on pregnant m ares. Interest was focused on higher-per-mare PMSG yield, but just as much emphasis was laid on pathophysiological effects on the organism ( blood and serum values, clinical manifestations) as well as on data he lpful in preserving good health and performance of the mares involved. Twenty standard bred mares to which the new method was applied were c ompared to another twenty which had conventional blood-letting techniq ues performed on them. Controls included 15 pregnant mares without PMS G titres and without blood sampling as well as ten non-pregnant animal s (no blood donors). The plasmapheresis method proved helpful in doubl ing the amount of serum obtainable from each of the mares. The PMSG qu antity exceeded by a factor of 2.48 the amount obtainable from convent ional blood-letting. Haematocrit, erythrocyte count and haemoglobin co ncentrations in plasmapheresis mares dropped much less (by about twelv e percent) than comparable parameters in blood-letting mares (by about 37 percent). Serum total protein concentrations were almost identical in the two groups. Four plasmaphereses per week (each for five litres of blood) through a period of six weeks are recommended for the purpo se envisaged.