Genetic correlations and expected response for intramuscular fat content in a Duroc pig line

Genetic parameters between slaughter pig efficiency and growth rate of different body tissues estimated by computed tomography in live boars of Landrace and Duroc

“…All studies calculated an LMP based on a cutting procedure and the weight of lean meat for different premium cuts expressed as a percentage of the half carcass weight. Traits associated with fatness generally have high heritability and estimated heritabilities for ultrasonic backfat ranged from 0.35 to 0.72 in some studies by Ducos et al (1993), Hoque et al (2007) and Solanes et al (2009).…”

Hepatic lipogenic enzyme expression in pigs is affected by selection for decreased backfat thickness at constant intramuscular fat content

“…The groups differed in backfat thickness, but not in IMF content (Reixach, Tor, Díaz, & Estany, 2008;). The genetically selected and the control groups were constituted according to the mid-parent (litter) breeding values for backfat thickness at 180 days of age and for IMF content in the gluteus medius muscle adjusted for carcass weight, which were predicted using the model described in Solanes et al (2009). Litters in the selected group were selected against backfat thickness while maintaining IMF content to the values most similar to those in the control group.…”

“…During the last decades IMF content in pigs has been continuously decreasing as a result of selection towards leaner genotypes which compromised eating quality of pork (Hermesch, 2004;Merks, 2000). Although it is known that there is a positive relationship between IMF and subcutaneous backfat (Solanes, Reixach, Tor, Tibau, & Estany, 2009), there is evidence that genetic correlation between these two fat depots is not always strong and that it is possible to manipulate IMF and subcutaneous fat independently by dietary or genetic means Solanes et al, 2009). Manipulation of IMF and subcutaneous fat deposition is associated with regulation of expression of lipogenic enzymes in these tissues (Cánovas, Estany, Tor, Pena, & Doran, 2009;Doran et al, 2006;Ntawubizi, Raes, Buys, & De Smet, 2009).…”

Relationship between blood lipid indicators and fat content and composition in Duroc pigs

“…It is known that intramuscular fat (IMF) has a favorable effect on pork sensorial quality (Fernandez et al, 1999) and that some specific fatty acids (FA), as the oleic FA, may have beneficial cardiovascular properties (Williams, 2000). However, the continuous selection for lean meat content that happened in the last decades, due to the positive genetic correlation among backfat thickness (BT), IMF, and oleic FA content (Reixach and Estany, 2010;Solanes et al, 2009), has not only led to reduce BT but also IMF and oleic content. Therefore, for increasing meat quality, particularly for dry-cured products, there is a need to find selection criteria allowing for an independent manipulation of lean and IMF content.…”