Genetic parameters of meat quality traits in two pig breeds measured by rapid methods

Abstract

To study genetic variation in meat quality traits measured by rapid methods, data were recorded between 2005 and 2008 on samples of M. longissimus dorsi (LD) in Landrace (n 5 3838) and Duroc (n 5 2250) pigs included in the Norwegian pig breeding scheme. In addition, ultimate pH levels in the glycolytic LD (loin muscle) and M. gluteus medius (GM, ham muscle), and in the oxidative m. gluteus profundus (GP, ham muscle) were recorded as an extended data set (n 5 16 732 and n 5 7456 for Landrace and Duroc, respectively) from 1998 to 2008. Data were analysed with a multi-trait animal model using AI-REML methodology. Meat from Duroc had considerably more intramuscular fat (IMF), less moisture and protein, appeared darker with higher colour intensity and had lower drip loss than meat from Landrace. The heritability estimates (s. in LD all demonstrated moderate-to-high genetic variation for these traits in both breeds. Near infrared spectroscopy and EZ-DripLoss are modern technologies used in this study for the determination of chemical components and drip loss in meat. These methods gave higher heritabilities than more traditional methods used to measure these traits. The estimated genetic correlations between moisture and IMF in Duroc, and pH and drip loss in Duroc were both 20.89. Interesting differences between the two breeds in numerical value of some genetic correlations were observed, probably reflecting the differences in physiology and selection history between Landrace and Duroc. The estimated genetic correlation between drip loss and pH was much stronger in Duroc than in Landrace (20.89 and 20.63, respectively). This might be due to the high pH in Duroc, whereas Landrace had a lower pH closer to the iso-electric point for muscle proteins. The positive genetic correlation between the L* value in meat and IMF in Duroc (0.50) was an effect of differences in visible marbling, rather than meat colour. For Landrace, this correlation was negative (20.20). IMF content showed favourable genetic correlations to drip loss (20.36 and 20.35 for Landrace and Duroc, respectively).

Prediction of fat quality in pig carcasses by near-infrared spectroscopy

“…This allows for a legitimate question to be asked as to whether the NIRS method is more accurate than the reference method. In a similar study on meat quality, the FoodScan instrument gave a better estimated heritability than the reference method (Bü chi Caviezel) in determining the fat percentage of meat (Gjerlaug-Enger et al, 2010). The heritability is as much of a corresponding parameter as the repeatability; the difference is that a permanent environment is left out of the model, and therefore only a genetic covariance between animals remains.…”

“…The carcass records made available for these analyses came from half-sib tested females and castrated males from two different test stations. The pigs were fed conventional concentrates ad libitum during the test period (30 to 113 kg live weight), and more detailed information about the test and slaughtering is described by Gjerlaug-Enger et al (2010).…”

Genetic trends of conformation traits and genetic correlations to osteochondrosis in boars

“…The animals scored were half-sibs of boars in a boar test described by Gjerlaug-Enger et al (2010). The phenotypes acquired were used for an estimation of an OC breeding value, and the trait was included in the breeding goal.…”

Genetic parameters of fat quality in pigs measured by near-infrared spectroscopy

“…This study is an expansion of an earlier work on meat quality traits presented by Gjerlaug-Enger et al (2010b). Fat quality data were recorded between 2005 and 2008 in Norwegian Landrace (n 5 3230 for fat quality, n 5 4797 for lean meat percentage (LMP)) and Duroc (n 5 1769 for fat quality, n 5 2819 for LMP) pigs, with all animals included in the national pig breeding scheme.…”

“…The pigs were slaughtered at two different abattoirs and all carcasses were transported to a partial dissection line at the Norwegian Meat and Poultry Research Centre (Animalia). More detailed information about the tests and slaughtering has been described by Gjerlaug-Enger et al (2010b).…”