Associations between Feed Efficiency, Body Growth and Serum Insulin-like Growth Factor-I Level for Korean Native Ogol Chickens

W K Kim,Y O Suk,Y Ko,M H Kim,D S Seo,C Y Lee

doi:10.5713/ajas.2005.532

Abstract

Increasing of body weight has been one of the important economic factors in the poultry industry. Insulin-like growth factor (IGF)-I is a polypeptide that serves to regulate muscle development and body growth. Moreover, IGF-I is related to feed efficiency. However, there are few studies regarding the regulatory roles of chicken IGF-I/-II compared with that of mammals. Especially, the Korean Native Ogol Chicken (KNOC) has a lean body growth and its body weight is generally lighter than the broiler chicken. Therefore, this study was conducted to investigate associations among serum IGF-I/-II concentration, feed efficiency, and body growth in KNOC. The body weight and feed intake of KNOC were recorded from 20 to 36 weeks at 2 weeks intervals, and blood was taken every 2 weeks. Serum IGF-I/-II were measured by RIA. Chickens were divided into two groups, high and low serum IGF-I concentration. Generally, feed efficiency and growth performance (body weight and weight gain) in the high serum IGF-I group were higher than those of the low group during the experimental period. In particular, the body weight of the IGF-I high group were significantly different from those of the IGF-I low group at 34 and 36 weeks, respectively (p<0.05). Moreover, body weight, weight gain, and feed efficiency had a significant correlation with serum IGF-I at several weeks (p<0.05 and p<0.01). These results show that IGF-I plays an important role in body growth and suggests a possibility that serum IGF-I could be used as a selection marker for body growth in KNOC. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 4 : 532-537)

Highlights

Korean Native Ogol Chicken (KNOC) is a protected species by the Korean government (Protected Species ActNo 265), which is a dual purpose chicken with lean body growth
A total of 50 female KNOC were kept in individual cages (40 cm high, 25 cm wide and 35 Serum insulin-like growth factor (IGF)-I/-II concentrations cm deep), and fed a commercial boiler diet
Recorded biweekly and blood was taken from the wing vein In general, serum IGF-I concentrations progressively from 20 to 36 wks every 2 wks

Summary

INTRODUCTION

Korean Native Ogol Chicken (KNOC) is a protected species by the Korean government There are few studies regarding the regulatory roles of chicken IGFs in body growth. There were reports regarding a negative correlation between chicken IGF-I and body growth (Pym et al, 1991; Bacon et al, 1993). Recent studies have shown that circulating IGF-I concentrations have a positive correlation with muscle growth rate and decreased fatness (Guernec et al, 2003; Tesseraud et al, 2003; Yun et al, 2003b). Due to such contradictory findings, studies are required to clarify regulatory roles of IGF-I in avian growth physiology.

RESULTS

MATERIALS AND METHODS

DISCUSSION