In vivo computed tomography evaluation of the composition of the carcass and main cuts of growing pigs of three commercial crossbreeds

Non-destructive evaluation of carcass and ham traits and meat quality assessment applied to early and late immunocastrated Iberian pigs

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 in vivo and postmortem. The aims of the present work were (a) to determine the relationship between ham composition measured with computed tomography (CT) and in vivo 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 14 months of age (EIP or LIP; respectively; n = 10 each) and slaughtered at 17 months of age. Fat depots were evaluated in vivo 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 14.9 kg 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.

On-line Ham Grading using pattern recognition models based on available data in commercial pig slaughterhouses

The thickness of the subcutaneous fat in hams is one of the most important factors for the dry-curing process and largely determines its final quality. This parameter is usually measured in slaughterhouses by a manual metrical measure to classify hams. The aim of the present study was to propose an automatic classification method based on data obtained from a carcass automatic classification equipment (AutoFom) and intrinsic data of the pigs (sex, breed, and weight) to simulate the manual classification system. The evaluated classification algorithms were decision tree, support vector machines (SVM), k-nearest neighbour and discriminant analysis. A total of 4000 hams selected by breed and sex were classified as thin (0-10 mm), standard (11-15 mm), semi-fat (16-20 mm) and fat (>20 mm). The most reliable model, with a percentage of success of 73%, was SVM with Gaussian kernel, including all data available. These results suggest that the proposed classification method can be a useful online tool in slaughterhouses to classify hams.

Evolution of testes characteristics in entire and immunocastrated male pigs from 30 to 120 kg live weight as assessed by computed tomography with perspective on boar taint

The present study addressed (1) the levels of boar taint compounds in entire (EM) and immunocastrated (IM) male pigs during their growth, (2) the evolution of testes volume and density and (3) the relationship between physical characteristics of the testes and boar taint compounds. For that purpose 24 EM and 20 IM pigs were CT scanned at several body weights (TBW). After each scanning a subsample of pigs was slaughtered, and subcutaneous fat was collected to determine androstenone and skatole concentration. Additional subsample (n=4/sex) was CT scanned 13 days after the second vaccination (V2). Testes density changes with growth, is different in EM and IM, but is not a reliable marker of the level of boar taint compounds. On the other hand, testes to body volume ratio is a better predictor for androstenone and could provide a good tool at slaughter plants to detect immunocastrated pigs with high boar taint compounds.