MATERIALS AND METHODS
Animals and sampling
Forty three entire males pigs, Pietrain x (Landrace x Large White), were randomly assigned to
one of five dietary fat treatments with the individual animal as the experimental unit. All the
diets contained the same proportions of raw materials (barley grain, wheat grain and soybean
meal 44 % CP), except the proportion of corn grain that was different depending on the
percentage of added fat. The five diets differed in their fat sources: 1) Control diet (without
added fat); 2) Animal fat (tallow-lard mix) at 1% (AF1); 3) Animal fat at 3% (AF3); 4)
Soyabean oil at 1% (SBO1); and 5) Calcium soaps of palm oil fatty acids at 1% (CaSPO1). All
the concentrates were isoproteic (17 % crude protein). The pigs were stunned using carbon
dioxide and slaughtered at an abattoir at approximately 83.8 ± 6.3 kg carcass weight.
The M. Longissimus thoracis et lumborum (LTL) was removed from each carcass 48 h after
slaughter. After 24 h at 4 ± 1 °C, the M. LTL was divided in half and the portion more caudal
was sectioned into 2 cm-thick steaks for lipid oxidation, fatty acid composition, drip loss and
muscle colour measurements. All samples (except those for colour and drip loss) and the
portion more cranial of M. LTL were placed in vacuum bags and frozen at -20 °C until meat
quality analysis. Two years later, the portion more cranial of M. LTL was thawed and sectioned
into 2 cm-thick steaks for lipid oxidation, fatty acid composition, drip loss and muscle colour
measurements.