Gene expression study of skeletal muscle of pampa rocha pigs fed with different diets

Doctoral thesis abstract

Abstract

In this thesis, the effect of different diets when varying the lipid content on growth performance, meat quality, carcass and gene expression in the skeletal muscle of Pampa Rocha piglets was evaluated. Sixteen pigs were randomly assigned among the treatments: T0 (control diet, 0% of bran rice) and T15 (diet with greater lipid content, 15% of bran rice). In order to study growth performance; daily gain weight, conversion efficiency and feed intake were determined in the totality of the individuals (N = 16), without finding differences in the average during the experimental period. For the analysis of meat quality, the meat and carcass of the males were used (N = 12) to measure some variables: pH, luminosity, index of red and yellow, shear force, content of intramuscular fat and fatty acid profile, body weight and back fat thickness. Differences were found for pH values at 90 minutes and 24 hours (lower in T15), luminosity, content of linoleic acid and of polyunsaturated fatty acids (PUFA) and in the PUFA/SFA (higher in T15). The gene expression analysis was carried out through the sequencing of the RNA extracted from the samples by RNAseq and showed 359 differentially expressed genes. The functional analysis of these genes revealed their participation in different processes and metabolic pathways, highlighting those related with the meat quality (lipid and carbohydrate metabolism, skeletal muscle development and receptor-extracellular matrix interaction). In conclusion, the inclusion of bran rice in the diet of Pampa Rocha piglets could be considered as an alternative for their food intake, however, other factors that could have affected the variables should be considered. The genes and metabolic processes identified can guide future research about the meat quality in pigs as well as in the study of human diseases related to energy metabolism and muscle development.