Genomics in heavy pigs unravels a dry-cured ham tale of quality and tradition
The animal article of the month for September is ‘Genome wide association studies for seven production traits highlight genomic regions useful to dissect dry-cured ham quality and production traits in Duroc heavy pigs‘
Heavy pig production chains are very important sources of niche pork products, particularly in several European countries with long traditions in processed products. In Italy about 70% of the pigs are raised for the production of Protected Designation of Origin (PDO) products, like Parma and San Daniele dry-cured hams, that, together with many other minor productions, reach a total economic value of more than 3 billion € per year. PDO dry-cured hams are obtained from pigs that are slaughtered at about 160 kg of live weight when animals are at least 9 months old, according to dry-cured ham Consortia rules. Seasoning of the legs lasts at least 12 months during which the only addition of salt and the combined effects of controlled temperature and humidity in the processing plants act together to obtain the right dryness of the hams. This simple production technology cannot adjust intrinsic characteristics of the green (fresh) legs. Thus, it is fundamental that suitable raw materials (e.g. green legs) are supplied starting from a breeding program able to produce animals with the requested characteristics of the meat and legs.
Selection of the most suitable animals for this peculiar production is driven by the objective of the whole production chain. Therefore, two traits linked to the final quality of the dry-cured hams (ham weight loss at first salting and visible intermuscular fat), in addition to other traits that define the right carcass characteristics (backfat thickness, ham weight and lean cuts: indicators of the overall fat/lean content of the animals) and efficiency traits (average daily gain and feed/gain ratio) are used to obtain the right mix of genetic gain to satisfy this high-quality production system.
The article reports the results of the first genome wide association study applied in a Duroc heavy pig population (the male terminal line) to identify the most important genetic variability affecting all the traits that are used in the selection program of this breed. This study identified novel genomic regions and candidate genes that might be involved in the biological mechanisms that affect seasoning, helping to clarify the genetic bases of dry-cured ham quality parameters and other important production traits in a breed that is specifically selected for the heavy pig production chain. This study highlights how genomics can be used to investigate complex traits that are important to fulfil the needs of traditional and high-quality products to design sustainable breeding programs.
This article is freely available for one month: ‘Genome wide association studies for seven production traits highlight genomic regions useful to dissect dry-cured ham quality and production traits in Duroc heavy pigs‘.
Author: Luca Fontanesi et al.