Twenty-four extensively reared Iberian pigs were used to study the influence of fattening period length (30, 60 or 90 days) on the fatty acid profiles of intramuscular and subcutaneous fat and the relationships between both profiles. Regarding fatty acid (FA) percentage, PUFA was greater in backfat and MUFA was greater in intramuscular fat (IMF), regardless of fattening period length. The longer fattening period increased MUFA content in backfat (which had a more marked change in oleic acid) and decreased PUFA content in backfat and IMF, but it did not affect SFA content. Within the three-layer subcutaneous backfat, SFA content was greater in the inner layer, MUFA was greater in the outer layer and PUFA was greater in both of these layers. The few differences in FA composition between both adipose tissues suggest that the changes due to the feeding regime are slow and, therefore, although the length of the fattening phase was increased, the fatty acid profile did not change substantially. The strong relationship between the FA profiles of IMF and backfat might be used to predict one profile from the other one when the latter is more readily available for sampling or analytical reasons.

Autochthonous pig breeds provide products of differentiated quality, among which quality control is difficult to perform and insufficient for current market requirements. The present research evaluates the predictive ability of near-infrared (NIR) spectroscopy, combined with chemometric methods as a rapid and affordable tool to assure traceability and quality control. Thus, NIR technology was assessed for intact and minced muscle Longissimus thoracis et lumborum samples collected from 12 European autochthonous pig breeds for the quantification of lipid content and fatty acid composition. Different tests were performed using different numbers of samples for calibration and validation. The best predictive ability was found using minced presentation and set with 80% of the samples for the calibration and the remaining 20% for the external validation test for the following traits: lipid content and saturated and polyunsaturated fatty acids, which attained both the highest determination coefficients (0.89, 0.61, and 0.65, respectively) and the lowest root mean square errors in external validation (0.62, 1.82, and 1.36, respectively). Lower predictive ability was observed for intact muscles. These results could contribute to improve the management of autochthonous breeds and to ensure quality of their products by traditional meat industry chains.

Castration is a common practice in Iberian pigs due to their advanced age and high weight at slaughter. Immunocastration (IC) is an alternative to surgical castration that influences carcass and cut fatness. These traits need to be evaluated invivo and postmortem. The aims of the present work were (a)to determine the relationship between ham composition measured with computed tomography (CT) and invivo ultrasound (US) and carcass fat thickness measurements, (b)to apply these technologies to early (EIP) and late (LIP) immunocastrated Iberian pigs in order to evaluate carcass fatness and ham tissue composition and (c)to assess meat quality on these animals and to find the relationships between meat quality traits (namely, intramuscular fat (IMF)) and fat depot thicknesses. For this purpose, 20 purebred Iberian pigs were immunocastrated with three doses of Improvac ®, at either 4.5, 5.5 and 9 or 11, 12 and 14months of age (EIP or LIP; respectively; n=10 each) and slaughtered at 17months of age. Fat depots were evaluated invivo by US, in carcass with a ruler and in hams by CT. Carcass and cut yields, loin meat quality and loin acceptability by consumers were determined. Also, IMF was determined in the loin and three muscles of the ham. Carcass weight was 14.9kg heavier in EIP vs LIP, and loin backfat thickness (US- and ruler-measured) was also greater in EIP. Similarly, CT-evaluated ham bone and fat contents were greater and smaller for EIP vs LIP, respectively. Loin and ham IMF were also greater in EIP, but the other meat quality parameters were similar. The acceptability of meat by consumers was high and it did not differ between IC protocols. Correlations between several fat depots measured with the different technologies were high. In conclusion, all these technologies allowed fat depot measurements, which were highly correlated despite being obtained at different anatomical locations.

The Iberian pig breed includes several well-differentiated strains. The present study evaluated carcass traits, fat deposition and muscle expression of important lipogenic genes (SCD, ME1, ACACA, FASN, EGR1, ACOX and ACLY) using 65 male pigs of 3 Iberian strains (20 Lampiño, 23 Torbiscal, and 22 Retinto) finished either in a conventional, concentrate-based system (CF) or in montanera (MF), a traditional free-range system with acorn feeding. Torbiscal had the highest ham, Longissimus thoracis and prime cuts yields, and the thinnest subcutaneous adipose tissue (SAT). Retinto had the highest monounsaturated fatty acids (MUFA) and percentage of intramuscular fat (IMF), while Lampiño had the greatest content of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), atherogenic (AI) and thrombogenic (TI) indexes in SAT. Conventionally finished pigs had the highest ham, L. thoracis and prime cuts yields, and SFA. Montanera-finished animals had the highest PUFA and MUFA contents, and the lowest AI, TI and n6/n3 ratio in SAT. In relation to gene expression, Retinto had the greatest SCD, FASN and ACLY levels. Most studied genes were overexpressed in CF pigs. In conclusion, MF pigs had healthier fat than CF pigs, and Retinto had the healthiest fat and the greatest lipogenic trend in muscle, supported by IMF and lipogenic gene expression.

The replacement of soybean meal with sweet white lupin (Lupinus albus L.) seeds was investigated in the diets of Iberian pigs during the growing and fattening phases, evaluating its effects on growth performance, carcass traits, and meat quality. Iberian pigs (n = 50) were divided into two dietary groups (n = 25 per group), receiving either a lupin-based concentrate or a soybean meal-based concentrate. The data were analysed using one-way analysis of variance (ANOVA), with a significance level of p < 0.05. The results showed that lupin substitution had no adverse effect on body weight, average daily gain, or carcass characteristics. No significant differences were observed in meat quality parameters such as pH, colour, and texture. However, significantly (p = 0.007) lower levels of saturated fatty acids (SFA) content were found in the intramuscular fat of pre-finishing (primor) pigs fed lupin-based diets. In addition, these pigs had lower plasma triglyceride levels at the end of the growing phase. Overall, the results suggest that sweet white lupin is a viable alternative protein source in Iberian pig production, offering potential health benefits in line with consumer preferences for sustainably produced, healthier meat products, without compromising production efficiency or product quality.