Expression of Growth Hormone Gene in the Pituitary of Piglets Born to Gilts Injected with Pregnant Mare Serum Gonadotropin and human Chorionic Gonadotropin Prior to Mating

Abstract

Injection of pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) are expected to improve endogenous secretions of pregnant hormones that will improve gestation quality that will be expressed in the improved growth performance of the piglets born. Growth and development are controlled by growth hormone (GH) gene. This research was conducted to study the expression of GH gene in the piglets born to gilts injected with gonadotropin prior to mating. The experimental gilts used were Landrace that were divided into two groups: 1) gilts injected with physiological NaCl 0.90% solution as control, and 2) gilts injected with PMSG and hCG to increase endogenous secretions of pregnant hormones. The experimental gilts were maintained during pregnancy until parturition.

At the age of 100 days postpartum, 8 piglets (4 piglets born to gilts injected with NaCl 0.90% as control and 4 piglets born to gilts injected with PMSG and hCG) were selected from the experimental piglets born in the same litter size of 8 and were euthanized for measurement of GH gene expression in the pituitary. Messenger ribonucleic acid (mRNA) was extracted from pituitary tissue to observe differences in GH gene expression of piglets using real time quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR), with ?-actin as a housekeeping gene. The results showed that piglets born to gilts injected with PMSG and hCG prior to mating had higher GH gene expression in the pituitary even though the increase was not statistically significant in the t-test analysis (P>0.05). It is concluded that the improved prenatal growth and postnatal growth of piglets born to gilts injected with gonadotropin was associated with the increased expression of growth hormone gene.