Application of enzyme immunoassay kits for the determination of pig plasma progesterone levels

Enzyme immunoassay kits, Ovucheck Plasma/Serum Progesterone EIA Kit (EIA, Cambridge Veterinary Science Ltd) and Ovucheck Cow Side W (Cow Side W, Cambridge Veterinary Science Ltd), were applied to determination of pigs plasma progesterone (P) levels. We tried to study the modification of EIA assay system for pig P measurement; ie., examined for best dilution methodes with castrated serum/plasma, boar/sow serum and normal saline as dilution solution with 2, 5 and 10 times dilution. All solutions have no effect on the plasma P levels, but castrated serum/plasma and boar serum showed much more suitable for plasma dilution in 2 and 5 times dilution. Porcine plasma P levels assyed by EIA with and without dilution showed significant positive correlation with those by RIA. Cow Side W is used as a qualitative assay system, but it seems to be usable for a semiquantitative assay when using known value solution as standard. Plasma dilution with pigs serum have no effect on Cow Side W assay system too. We demonstrated that modification in assay methods of commercial EIA kits developed for cow were applicable for the determination of pig plasma P levels. Then these system would supply a suitable tool for the diagnosis of pregnancy and ovarian function in pigs.