Genomic responses to climatic challenges in beef cattle: A review.

Climate change is a major concern for the near future and for livestock breeding. Cattle breeding, due to its greenhouse gas emissions, is one of the most implicated industries. Consequently, the main future goals are to breed animals resilient to climate change, with the aim of lowering the livestock impact on the environment and selecting animals that will be able to resist different, unsuitable, and changing climates. The aim of this literature review is to compare the most recent studies on the response and adaptation of beef cattle breeds to extreme environments, in terms of genes and pathways involved. Beef breeding is just starting to implement genomics in its selection plans, and shedding light on the genomic responses to extreme climates could speed up and simplify the adaptation of these breeds to climate change. This review discusses the genes involved in climatic stress responses, including those related to extremely cold climates, in beef and dual-purpose cattle breeds. Genes were associated with productive traits, coat and skin structure and development, thermotolerance, cellular physiology and DNA repair mechanisms, immune system, and fertility traits. The knowledge of genes and pathways involved in climate resilience should be taken into consideration for further selection in beef cattle breeding and could promote the valorization of local breeds adapted to extreme environmental conditions. The use of local or resilient breeds could enhance the environmental and social sustainability, animal welfare, and production, compared with the introduction of cosmopolitan breeds with uncertain adaptation in uncontrolled environmental areas.

Population structure and identification of genomic regions associated with productive traits in five Italian beef cattle breeds.

Italy has a long history in beef production, with local breeds such as Marchigiana, Chianina, Romagnola, Maremmana, and Podolica which produce high-quality meat. Selection has improved meat production, precocity, growth ability and muscle development, but the genetic determinism of such traits is mostly unknown. Using 33K SNPs-data from young bulls (N = 4064) belonging to these five Italian breeds, we demonstrated that the Maremmana and Podolica rustic breeds are closely related, while the specialised Marchigiana, Chianina, and Romagnola breeds are more differentiated. A genome-wide association study for growth and muscle development traits (average daily gain during the performance test, weight at 1 year old, muscularity) was conducted in the five Italian breeds. Results indicated a region on chromosome 2, containing the myostatin gene (MSTN), which displayed significant genome-wide associations with muscularity in Marchigiana cattle, a breed in which the muscle hypertrophy phenotype is segregating. Moreover, a significant SNP on chromosome 14 was associated, in the Chianina breed, to muscularity. The identification of diverse genomic regions associated with conformation traits might increase our knowledge about the genomic basis of such traits in Italian beef cattle and, eventually, such information could be used to implement marker-assisted selection of young bulls tested in the performance test.

Exploring the Italian equine gene pool via high-throughput genotyping.

Introduction: The Italian peninsula is in the center of the Mediterranean area, and historically it has been a hub for numerous human populations, cultures, and also animal species that enriched the hosted biodiversity. Horses are no exception to this phenomenon, with the peculiarity that the gene pool has been impacted by warfare and subsequent "colonization". In this study, using a comprehensive dataset for almost the entire Italian equine population, in addition to the most influential cosmopolitan breeds, we describe the current status of the modern Italian gene pool. Materials and Methods: The Italian dataset comprised 1,308 individuals and 22 breeds genotyped at a 70 k density that was merged with publicly available data to facilitate comparison with the global equine diversity. After quality control and supervised subsampling to ensure consistency among breeds, the merged dataset with the global equine diversity contained data for 1,333 individuals from 54 populations. Multidimensional scaling, admixture, gene flow, and effective population size were analyzed. Results and Discussion: The results show that some of the native Italian breeds preserve distinct gene pools, potentially because of adaptation to the different geographical contexts of the peninsula. Nevertheless, the comparison with international breeds highlights the presence of strong gene flow from renowned breeds into several Italian breeds, probably due to historical introgression. Coldblood breeds with stronger genetic identity were indeed well differentiated from warmblood breeds, which are highly admixed. Other breeds showed further peculiarities due to their breeding history. Finally, we observed some breeds that exist more on cultural, traditional, and geographical point of view than due to actual genetic distinctiveness.