The Quest for Genes Involved in Adaptation to Climate Change in Ruminant Livestock

Livestock radiated out from domestication centres to most regions of the world, gradually adapting to diverse environments, from very hot to sub-zero temperatures and from wet and humid conditions to deserts. The climate is changing; generally global temperature is increasing, although there are also more extreme cold periods, storms, and higher solar radiation. These changes impact livestock welfare and productivity. This review describes advances in the methodology for studying livestock genomes and the impact of the environment on animal production, giving examples of discoveries made. Sequencing livestock genomes has facilitated genome-wide association studies to localize genes controlling many traits, and population genetics has identified genomic regions under selection or introgressed from one breed into another to improve production or facilitate adaptation. Landscape genomics, which combines global positioning and genomics, has identified genomic features that enable animals to adapt to local environments. Combining the advances in genomics and methods for predicting changes in climate is generating an explosion of data which calls for innovations in the way big data sets are treated. Artificial intelligence and machine learning are now being used to study the interactions between the genome and the environment to identify historic effects on the genome and to model future scenarios

Investigation on genetic contribution to animal stress response

Il benessere degli animali e l'efficienza produttiva sono minacciati dallo stress cronico. Lo stress ha effetti dannosi sulle bovine da latte, tra cui l'immunosoppressione, la diminuzione dell'ingestione, l'alterazione della funzione epatica, l'alterazione del rilascio degli ormoni riproduttivi, che influisce sulla fertilità, e persino l'aumento del tasso di mortalità. A breve termine, è possibile mitigare gli effetti degli stressor ambientali e fisiologici sfruttando i progressi in materia di stabulazione, management e alimentazione del bestiame. Tuttavia, i cambiamenti climatici in corso stanno mettendo ulteriormente a dura prova la salute degli animali e la redditività degli allevamenti, richiedendo interventi sostenibili e a lungo termine per garantire la sicurezza alimentare a livello globale. I bovini da latte sono esposti a fattori di stress derivanti dall'ambiente, dalla fisiologia e dal management, che possono essere mitigati ma non del tutto evitati (Capitolo 1). Allevare bovine capaci di sviluppare una risposta efficace allo stress potrebbe essere una strategia chiave per ottenere sistemi di produzione animale resilienti (Capitolo 2). La risposta allo stress degli animali è un carattere complesso che coinvolge diverse vie biologiche e cambiamenti nella concentrazione di metaboliti specifici. Tali metaboliti sono biomarcatori dell'adattamento degli animali ai fattori di stress e possono essere utilizzati come endofenotipi della risposta allo stress negli studi di associazione genomica (GWAS). Nei capitoli 3 e 4, i biomarcatori plasmatici relativi al metabolismo, all'immunità, all'infiammazione, allo stress ossidativo e alla funzione epatica dei bovini da latte sono stati utilizzati come endofenotipi della risposta allo stress con un approccio GWAS.Animal welfare and production efficiency are threatened by chronic stress. Stress has detrimental effects on dairy cattle, including immune suppression, decreased feed intake, altered liver function, impaired reproductive hormone release, which affects fertility, and even results in an increase in mortality rates. In the short term, mitigating the effects of stress caused by environmental conditions and physiological status is feasible by exploiting advances in livestock housing, management, and feed. However, ongoing climate change is further challenging animal health and farm viability, calling for sustainable and long-term interventions to ensure food security globally. Dairy cattle are exposed to stressors from the environment, physiology, and management, which can be mitigated but not entirely avoided (Chapter 1). Moreover, Breeding individuals that develop an effective stress response could be a key strategy towards resilient animal production systems (Chapter 2). Animal stress response is a complex trait involving several biological pathways and changes in the concentration of specific metabolites. Such metabolites are biomarkers of animal adaptation to stressors and can be used as endophenotypes of stress response in genome-wide association studies (GWAS). In chapter 3 and 4, plasma biomarkers related to dairy cattle metabolism, immunity, inflammation, oxidative stress, and liver function were used as endophenotypes of stress responses with a GWAS approach

The Transition Period Updated: A Review of the New Insights into the Adaptation of Dairy Cows to the New Lactation

Recent research on the transition period (TP) of dairy cows has highlighted the pivotal role of immune function in affecting the severity of metabolic challenges the animals face when approaching calving. This suggests that the immune system may play a role in the etiology of metabolic diseases occurring in early lactation. Several studies have indicated that the roots of immune dysfunctions could sink way before the “classical” TP (e.g., 3 weeks before and 3 weeks after calving), extending the time frame deemed as “risky” for the development of early lactation disorders at the period around the dry-off. Several distressing events occurring during the TP (i.e., dietary changes, heat stress) can boost the severity of pre-existing immune dysfunctions and metabolic changes that physiologically affect this phase of the lactation cycle, further increasing the likelihood of developing diseases. Based on this background, several operational and nutritional strategies could be adopted to minimize the detrimental effects of immune dysfunctions on the adaptation of dairy cows to the new lactation. A suitable environment (i.e., optimal welfare) and a balanced diet (which guarantees optimal nutrient partitioning to improve immune functions in cow and calf) are key aspects to consider when aiming to minimize TP challenges at the herd level. Furthermore, several prognostic behavioral and physiological indicators could help in identifying subjects that are more likely to undergo a “bad transition”, allowing prompt intervention through specific modulatory treatments. Recent genomic advances in understanding the linkage between metabolic disorders and the genotype of dairy cows suggest that genetic breeding programs aimed at improving dairy cows’ adaptation to the new lactation challenges (i.e., through increasing immune system efficiency or resilience against metabolic disorders) could be expected in the future. Despite these encouraging steps forward in understanding the physiological mechanisms driving metabolic responses of dairy cows during their transition to calving, it is evident that these processes still require further investigation, and that the TP—likely extended from dry-off—continues to be “the final frontier” for research in dairy sciences

Emerging Parameters Justifying a Revised Quality Concept for Cow Milk

Milk has become a staple food product globally. Traditionally, milk quality assessment has been primarily focused on hygiene and composition to ensure its safety for consumption and processing. However, in recent years, the concept of milk quality has expanded to encompass a broader range of factors. Consumers now also consider animal welfare, environmental impact, and the presence of additional beneficial components in milk when assessing its quality. This shifting consumer demand has led to increased attention on the overall production and sourcing practices of milk. Reflecting on this trend, this review critically explores such novel quality parameters, offering insights into how such practices meet the modern consumer’s holistic expectations. The multifaceted aspects of milk quality are examined, revealing the intertwined relationship between milk safety, compositional integrity, and the additional health benefits provided by milk’s bioactive properties. By embracing sustainable farming practices, dairy farmers and processors are encouraged not only to fulfill but to anticipate consumer standards for premium milk quality. This comprehensive approach to milk quality underscores the necessity of adapting dairy production to address the evolving nutritional landscape and consumption patterns

The Quest for Genes Involved in Adaptation to Climate Change in Ruminant Livestock

Livestock radiated out from domestication centres to most regions of the world, gradually adapting to diverse environments, from very hot to sub-zero temperatures and from wet and humid conditions to deserts. The climate is changing; generally global temperature is increasing, although there are also more extreme cold periods, storms, and higher solar radiation. These changes impact livestock welfare and productivity. This review describes advances in the methodology for studying livestock genomes and the impact of the environment on animal production, giving examples of discoveries made. Sequencing livestock genomes has facilitated genome-wide association studies to localize genes controlling many traits, and population genetics has identified genomic regions under selection or introgressed from one breed into another to improve production or facilitate adaptation. Landscape genomics, which combines global positioning and genomics, has identified genomic features that enable animals to adapt to local environments. Combining the advances in genomics and methods for predicting changes in climate is generating an explosion of data which calls for innovations in the way big data sets are treated. Artificial intelligence and machine learning are now being used to study the interactions between the genome and the environment to identify historic effects on the genome and to model future scenarios.s