1. Introduction
The growth rates of pigs are modulated by the
endocrine system. The somatotrophic axis, including
the growth hormone (GH) and insulin-like growth
factor (IGF)-I found in animals [1], contributed to
animal growth [2].
Somatostatin (SS) is the major inhibitory peptide
modulating GH secretion. SS antagonists have recently
been synthesized successfully and shown to induce GH
release [3]. The SS antagonists may be a good
candidate as feed additive to promote GH release and