Association of growth rate with hormone levels and myogenic gene expression profile in broilers

Yingping Xiao,Hua Yang,Guolong Zhang,Choufei Wu,Kaifeng Li,Guohong Gui

doi:10.1186/s40104-017-0170-8

Abstract

BackgroundThe growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormone levels and myogenic gene expression profile in broilers, a feeding trial was conducted with 10,000 newly hatched Ross 308 chicks in a commercial production facility under standard management. At 38 d of age, 30 fast-, 30 medium-, and 30 slow-growing broilers were selected among 600 healthy male individuals. The levels of insulin-like growth factor-1 (IGF-1), triiodothyronine (T3), thyroxine (T4), and growth hormone in the serum or breast muscle were assayed by ELISA or RIA kits, and the expression levels of several representative pro- and anti-myogenic genes in the breast muscle were also measured by real-time PCR.ResultsResults showed that both absolute and relative weights of the breast muscle were in linear positive correlations with the body weight of broilers (P < 0.001). Fast-growing broilers had higher concentrations of IGF-1 than slow-growing broilers (P < 0.05) in both the serum and breast muscle. The serum concentration of T3 was significantly higher in fast-growing birds than in slow-growing birds (P < 0.05). However, no difference was observed in growth hormone or T4 concentration among three groups of birds. Additionally, a decreased expression of an anti-myogenic gene (myostatin) and increased expressions of pro-myogenic genes such as myogenic differentiation factor 1, myogenin, muscle regulatory factor 4, myogenic factor 5, IGF-1, and myocyte enhancer factor 2B, C, and D were observed in fast-growing broilers (P < 0.05), relative to slow-growing broilers.ConclusionsCollectively, these findings suggested that the growth rate is linked to the hormone and myogenic gene expression levels in broiler chickens. Some of these parameters such as serum concentrations of IGF-1 and T3 could be employed to breed for enhanced growth.

Highlights

The growth rate often varies among individual broilers of the same breed under a common management condition
Myogenic regulatory factors (MRF) and myocyte enhancer factor 2 (MEF2) proteins are key transcription factors that are positively involved in the regulation of skeletal muscle development [1]
The MRF family of transcription factors is comprised of a group of basic helix-loop-helic proteins such as myogenic differentiation factor 1 (MyoD1), myogenic factor 5 (Myf5), myogenin, and MRF4, whereas the

Summary

Introduction

The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormone levels and myogenic gene expression profile in broilers, a feeding trial was conducted with 10,000 newly hatched Ross 308 chicks in a commercial production facility under standard management. Myogenic regulatory factors (MRF) and myocyte enhancer factor 2 (MEF2) proteins are key transcription factors that are positively involved in the regulation of skeletal muscle development [1]. Myostatin (MSTN), a member of the transforming growth factor β (TGF-β) superfamily secreted from skeletal muscle, acts as a potent negative regulator of muscle differentiation and growth [2]. Inhibition of MSTN causes myofibre hypertrophy [4], while MSTN over-expression decreases the skeletal muscle mass and fiber size [5]

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