Induced oviposition of precalcified eggs following prostaglandin administration

In order to obtain fertilized ova from White Leghorn chickens in the early cleavage stages, a nonsurgical procedure using prostaglandins (PG) was developed to induce premature oviposition of uncalcified eggs. The experimental design consisted of two 5 x 5 factorial arrangements of treatments using combinations of 0, .5, 1, 2, and 3 micrograms of PGF2 alpha and PGE1 or PGF2 alpha and PGE2. Frequency of PG-induced oviposition was highest (100%) with 1 microgram of PGF2 alpha and 3 micrograms of PGE1 or PGE2. Induced oviposition frequency decreased at the higher (2 and 3 micrograms of each PG) dosages. In general, induction time decreased as PG levels were increased; the minimum induction time was observed with injection of 3 micrograms of PGF2 alpha with 2 or 3 micrograms of PGE1 (1.8 min). There was a significant interaction for frequency of induced oviposition between PGF2 alpha and PGE1 (P less than .05), but not between PGF2 alpha and PGE2. There was also a significant interaction between PGF2 alpha and PGE2 (P less than .01) for induction time, which was not observed with PGF2 alpha and PGE1. Oviposition could not be induced earlier than 5 to 5.5 h after the previous oviposition. Prostaglandin-induced oviposition provides an alternative to euthanasia, surgery, or manual expulsion for collection of precalcified eggs in the early cleavage stages.