Liquid Chromatography–Mass Spectrometry Based Metabolomics Study of Cloned versus Normal Pigs Fed Either Restricted or Ad Libitum High-Energy Diets

Abstract

Genetically identical cloned pigs should in principle eliminate biological variation and provide more pronounced effects when subjected to, e.g., dietary interventions, but little is known about how phenotype and phenotypic variation is affected by cloning. Therefore, an investigation of the metabolome of cloned pigs compared to normal control pigs was performed to elucidate the variation and possible differences in the metabolic phenotypes during a dietary intervention. A total of 19 control pigs and 17 cloned pigs were given the same high-energy dense diet either ad libitum or in a restricted manner (60% of ad libitum) for ∼6 months, and plasma was subjected to liquid chromatography-mass spectrometry nontargeted metabolomics and biochemical analyses. Low systemic levels of IGF-1 could indicate altered growth conditions and energy metabolism in cloned pigs. In response to ad libitum feeding, clones had a decreased energy intake and lower weight gain compared to controls, and plasma lipid profiles were changed accordingly. Elevated lactate and decreased creatine levels implied an increased anaerobic metabolism in ad libitum fed clones. Less interindividual variation between cloned pigs was however not established, suggesting a strong role for epigenetics and/or the gut microbiota to develop variation.

The effect of high-fat diet on the composition of the gut microbiota in cloned and non-cloned pigs of lean and obese phenotype

“…After weaning all the pigs received a standard pig diet with an energy distribution of 18.5% protein, 7.9% fat, 72.4% carbohydrate and 1.2% fiber, until the cloned pigs were 22 weeks old and the non-cloned pigs were 19 weeks old. After this period, the pigs were housed individually and fed a wheat-based high-fat-high-energy (HF/HE) experimental diet consisting of 19.5% protein, 27% fat, 53% carbohydrates and 0.5% fiber, 28 in restricted amounts for approximately 21 weeks. The lean group of pigs received the same diet as the pigs in the obese group (ad libitum) but restricted to 60% of the feed consumed by the ad libitum group.…”

Expression of Innate Immune Response Genes in Liver and Three Types of Adipose Tissue in Cloned Pigs

“…Surviving cloned pigs are generally found to be healthy and production and reproduction properties in adult cloned pigs are generally normal; however, there are several reports of cloned pigs having deviant phenotypes. These include pulmonary hypertension and other hemodynamic disorders, contracted foreleg tendons, and respiratory problems (Whyte et al, 2011), changes in metabolic phenotype (Christensen et al, 2012;Clausen et al, 2011), and a higher incidence of mild atelectasis (Park et al, 2011). Lower body weight is a common finding in cloned pigs, both at birth and later (Archer et al, 2003;Jiang et al, 2007;Park et al, 2011;Tian et al, 2008), although it is not always observed (Carter et al, 2002).…”

Orosomucoid expression profiles in liver, adipose tissues and serum of lean and obese domestic pigs, Göttingen minipigs and Ossabaw minipigs

“…Previous studies (Lee et al, 2009) have shown a high number of significant differences in blood parameters of obese Ossabaw pigs compared to lean pigs with significantly elevated levels of total cholesterol (p = 0.03) and triglycerides (p = 0.02) (and insulin, though not significantly, p = 0.10). According to Christensen et al (2012) the only obesity feature affected in domestic pig is total cholesterol (p = 0.01) and in the Göttingen minipigs the only obesity feature affected by obesity was fasting insulin (Moesgaard et al, in preparation). Fig.…”

“…They were all female and reared and housed in the same experimental stables of Aarhus University (Tjele, Denmark). At three months of age the pigs were fed a high-energy diet (containing 10% sugar and 10% soy oil, as described by Christensen et al (2012)) ad libitum (obese, n = 10) or at 60% intake (lean, n = 9). At 8-9 months the pigs were euthanized and tissue samples from liver, abdominal s.c. adipose tissue (SAT) (a combination of deep and superficial SAT), mesenteric fat surrounding the appendix (VAT) and s.c. fat from the neck (neck SAT) were obtained and snap frozen in liquid nitrogen, and blood was collected for serum preparation.…”