Fatty and lean piglets establish early differentiation in DNA, RNA and Protein retain: comparative trial on Alentejano breed vs. crossbred piglets.

Abstract

The aim of this trial was to compare protein, DNA and RNA concentrations in muscle samples from Alentejano piglets (AL) versus Large-White Landrace crossbred piglets (C), since DNA-RNA interrelations and the relations of each parameter with the protein, can serve as indicators for the number of muscle cells and the ability to synthesize protein. The Alentejano swine breed carcasses are characterized by offering a high fat/muscle ratio, consequently it is important to determine the reasons of the relatively small proportion of muscle in the carcass. Samples were taken from longissimus dorsi muscle (LD) of 6 Alentejano piglets (AL) and 6 crossbred piglets (C) slaughtered at 21 days of age. DNA, RNA and protein concentrations were determined. The LD samples from AL piglets showed lower concentration in the DNA compared with C piglets (131.87 ± 10.50 mg/100 g vs. 169.38 ± 10.50 mg/100 g; P < 0.05). However, the LD from AL piglets presented greater concentration of RNA (180.50 ± 11.25 mg/100 g vs. 134.00 ± 11.25 mg/100 g; P ≤ 0.01) and protein (22.41 ± 0.83 vs. 18.91 ± 0.83 g/100g; P ≤ 0.01) when compared to the LD from C piglets. The RNA/ADN and Protein/DNA relations were also significantly higher (P < 0.01) in samples of muscle from AL piglets. These results indicate a lower number of muscle cells in the LD of AL piglets however, the situation reversed when capacity for synthesis was considered.