Effects of different levels of protein supplementary diet on gene expressions related to intramuscular deposition in early‐weaned yaks

Abstract

This study was conducted to estimate different levels of protein supplementary diet on gene expressions related to intramuscular deposition in early-weaned yaks. Results showed that supplementary dietary protein significantly increased final weight, average daily gain (ADG), intramuscular fat (IMF), serum free fatty acid (FFA), total triglycerides, total cholesterol (Ch), low-density lipoprotein cholesterol (LDL) and high-density lipoprotein cholesterol (HDL) content. There was a quadratic response of ADG, IMF, FFA, Ch, HDL and LDL to dietary crude protein (CP) level. Lipoprotein lipase (LPL), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) enzyme activities were significantly increased by supplementary dietary CP, while hormone-sensitive lipase (HSL) and carnitine palmitoyltransferase-1 (CPT-1) activities were significantly decreased. LPL, ACC and FAS enzyme activities showed quadratic increase as dietary CP increased. Peroxisome proliferator-activated receptor γ (PPARγ), LPL, FAS, sterol regulatory element binding protein 1 (SREBP-1), ACC, stearoyl-CoA desaturase (SCD) and heart fatty-acid binding protein (H-FABP) gene expression were significantly increased by supplementary dietary CP, while HSL and CPT-1 gene expression were significantly decreased. PPARγ, LPL, SREBP-1, ACC and H-FABP gene expression showed quadratic increase as dietary CP increased. These results indicated that supplementary dietary protein increased IMF accumulation mainly to increased intramuscular lipogenic gene expression and decreased lipolytic gene expression.

Impacts of Macronutrients on Gene Expression: Recent Evidence to Understand Productive and Reproductive Performance of Livestock

“…It has been shown that the content of intramuscular fat can be radically increased by low lysine dietary supplementation in finishing gilts (Katsumata et al, 2005). Furthermore, restricted protein content (Teye et al, 2006), manipulation of dietary energy and protein (Zhang et al, 2014) and conjugated linoleic acid (Zhong et al, 2011) were found to have beneficial effects for intramuscular fat deposition in finishing as well as young porcine. At the metabolic level, fat deposition is a complex and coordinated process and as a result of dynamic balance among fatty acid transportation, lipogenesis and lipolysis in tissue (Jurie et al, 2007).…”

Dietary conjugated linoleic acids increase intramuscular fat deposition and decrease subcutaneous fat deposition in Yellow Breed × Simmental cattle

“…; Zhang et al . ). CLAs consist of positional and geometric isomers of linoleic acid, which contain conjugated double‐bond systems.…”

Effects of Starvation on Lipid Metabolism and Gluconeogenesis in Yak

“…About 15 million or more than 90% of the world’s total yak population are currently herded in Chinese territories, which are important for Tibetan herders in providing milk, meat and transport (Zhang et al, 2014). Yak have to survive during inadequate feed supply in the long cold season (October to May) due to herbage deficiency under traditional pure grazing farming system, which is a centuries old grassland yak production cycle, where the yak is expected to satiate in summer, fatten in fall, become thin in winter, and die in spring (Xue et al, 2005).…”