Race against time to characterize the world's endangered livestock breeds

Race against time for the preservation of the biodiversity of farmed animals, to avoid serious global environmental and social consequences: Università Cattolica has provided an important contribution, together with other international experts, to elaborate the contents of the FAO Guidelines on their genomic characterization.

As part of FAO's "Global Plan of Action for Animal Genetic Resources," the aim of these guidelines is to address how to use the genetic information of farmed animals to characterize biodiversity and optimize conservation and genetic improvement programs for farmed species, but also to identify genes that increase the resilience of livestock species to climate change.

Part of the effort has been coordinated by Professor Paolo Ajmone Marsan and Dr. Licia Colli of the Faculty of Agricultural, Food and Environmental Sciences at the Università Cattolica, Piacenza.

"Thanks to the exponential reduction in cost and time of genomic sequencing," Professor Ajmone stressed, "it will be possible to carry out a detailed DNA characterization of all existing livestock breeds through the complete sequencing of their genomes. Right now several thousand individuals of more than 100 breeds have been sequenced, but there are more than 8000 breeds yet to be sequenced. The time frame for this enormous "genetic census," is currently thought to be 10 years, but genomics has always gone faster than planned, thanks to continuous technological leaps, so the time frame could be shortened."

Many local breeds of livestock species bred around the world are rapidly disappearing for a variety of reasons, mostly economic, Professor Ajmone Marsan explains, because unfortunately they cannot compete with industrial, more productive breeds; but also because of the abandonment of agriculture in marginal areas of the world, and then again because of bad conservation policies for local breeds, incorrect genetic management, or simply because of social instabilities, caused by wars and famines.

"FAO estimates that 10 percent of breeds have already gone extinct in the last century," Professor Ajmone Marsan highlights, "and another 20 percent are now at risk; finally for another 50 percent there is insufficient information (number of breeding herds, number of males and females of breeding age, etc.) to define their degree of risk. Losing these local breeds might not be a serious economic problem (at least on a large scale, although it could be a cataclysm for rural communities in low- and middle-income countries), but it would be a real disaster for global genetic conservation.

The fact is, the expert continues, "that all livestock species derive from domestication events that occurred several thousand years ago in well-defined centers of domestication, for example, our cattle were domesticated 10,000 years ago in the Fertile Crescent in the Middle East, along with goats, sheep, and pigs; zebu in the Indus Valley a couple of millennia later, The water buffalo (the one of Italian mozzarella) in Northeast India, the swamp buffalo in Southeast Asia, and so on. After domestication these animals followed human fortunes and colonized the planet. Over the following millennia they have adapted to live and reproduce in very different environmental conditions, from the deserts of North Africa, to the tropics, to the cold climates of Scandinavia.

These breeds therefore possess unique gene variants that have enabled their adaptation to extreme conditions, in terms of climate, forage type, disease and pest tolerance. The extinction of these breeds is leading to the loss of these variants, just when DNA analysis methods can begin to identify them" and potentially select for transfer into the breeds that are now being bred on an industrial scale.

In future, temperate countries like Italy will experience more extreme climates, with high temperatures and droughts, these "adaptation genes" could help our breeders as well.   

The contents of the FAO guideline indicate how to use the genetic information of breeds to characterize biodiversity and optimize conservation and genetic improvement programs for livestock species, but also for the identification of genes to exploit in order to create more resilient, efficient and productive animals, with a view to "producing more with less."