Olanzapine Administration Shortened the Laying Interval in Pigeon (Columba livia)

About 120 pairs of American king pigeon were used to investigate the effect of olanzapine on laying interval. Olanzapine was added to the basal diet of 720 days old pigeon breeders at the level of 0, 0.5, 0.75 and 1.25 mg kg-1, respectively. During 60 days of treatment, laying interval of 0.75 and 1.25% group decreased significantly by 37.46 and 29.83% (p<0.05), respectively. This change was accompanied by significantly elevated plasma FSH and progesterone levels whereas declined PRL levels and diminished Prolactin Receptor (PRLR) mRNA expression in liver of olanzapine-treated pigeons. The results provided evidence that olanzapine shorten the laying intervals accompanying with changes in the secretion of hormones and expression of PRLR gene.