Effects of Dietary Energy Density on Growth, Carcass Quality and mRNA Expression of Fatty Acid Synthase and Hormone-sensitive Lipase in Finishing Pigs

Abstract

A single factorial experiment was conducted to test the effects of three dietary levels of energy on mRNA expression of fatty acid synthase (FAS-mRNA) and hormone-sensitive lipase (HSL-mRNA) and their association with intramuscular fat in finishing pigs. 72 crossbred (Large White×Rongchang) barrows with an average initial body weight of 20.71 (s.e. 0.1) kg, were randomly allotted to three dietary treatments (11.75, 13.05 and 14.36 MJ DE/kg) and fed until slaughtered at 100 or 101 kg. The diets were iso-nitrogenous and iso-essential amino acids. The growth performances including the duration of finishing were changed linearly (p<0.05) or quadratically (p<0.05) with increased dietary energy levels. The effects of dietary energy content on the percentage of external fat, intramuscular backfat and the fat thickness were linear (p<0.05). The content of dietary energy increased FAS-mRNA linearly or quadratically, while HSL-mRNA decreased linearly or quadratically in backfat and Longissmus dorsi muscle. Meanwhile, significant positive correlations (p<0.05) were found between energy level and intramuscular fat, FAS-mRNA or the ratio of FAS-mRNA to HSL-mRNA, between the ratio of FAS-mRNA to HSL-mRNA and intramuscular fat. However, the correlations between HSL mRNA and dietary energy or intramuscular fat were negative (p<0.05). The results indicated that dietary energy level regulates lipid accumulation, especially intramuscular fat, possibly by modulating the mRNA of FAS and HSL together rather than individually.

Effects of the standardized ileal digestible lysine to metabolizable energy ratio on performance and carcass characteristics of growing-finishing pigs

“…2. Liu et al [17] reported increased weight gains when the dietary energy increased which is similar to the results of Du et al [18]. Similar to the current study, De La Llata et al [9] found pigs fed high energy levels had a significantly improved weight gain only during the growing stage and not during the finishing stage.…”

The response of gene expression associated with intramuscular fat deposition in the longissimus dorsi muscle of Simmental × Yellow breed cattle to different energy levels of diets

“…The downregulated expression of these lipolysis genes and protein expression means there is an increased capacity of LM for de novo synthesis of FFA, leading to increasing IMF accumulation. Similar results were previously observed by Liu et al (2007) and Peng et al (2012). Liu et al (2007) researched the effects of three dietary energy treatments on mRNA expression of HSL in finishing pigs, results showed that the correlations between HSL mRNA and dietary energy or IMF were negative.…”

“…Liu et al. () researched the effects of three dietary energy treatments on mRNA expression of HSL in finishing pigs, results showed that the correlations between HSL mRNA and dietary energy or IMF were negative. Peng et al.…”

Management and nutritional strategies to improve growth performance and carcass merit in white pigs

“…An increase in the energy content of the diet, results usually in improved FCR (Smith et al, 1999;Quiniou and Noblet, 2012), increased BF depth, and often in an increase in the IMF content of pork meat (King et al, 2004;Liu et al, 2007).…”

“…An increase in energy content of the diet results usually in improved feed efficiency (Smith et al, 1999;Quiniou and Noblet, 2012) and increased BF depth and IMF content of pork meat (King et al, 2004;Liu et al, 2007). However, the beneficial effects of increasing the NE content of the diet on ADG are less consistent (Matthews et al, 2003;Quiniou and Noblet, 2012;Coca et al, 2012).…”