Non-invasive methods of detecting heat stress magnitude for livestock is gaining momentum in the context of global climate change. Therefore, the objective of this review is to focus on the synthesis information pertaining to recent efforts to develop heat stress detection systems for livestock based on multiple behavioral and physiological responses. There are a number of approaches to quantify farm animal heat stress response, and from an animal welfare point of view, these can be categorized as invasive and non-invasive approaches. The concept of a non-invasive approach to assess heat stress primarily looks into behavioral and physiological responses which can be monitored without any human interference or additional stress on the animal. Bioclimatic thermal indices can be considered as the least invasive approach to assess and/or predict the level of heat stress in livestock. The quantification and identification of the fecal microbiome in heat-stressed farm animals is one of the emerging techniques which could be effectively correlated with animal adaptive responses. Further, tremendous progress has been made in the last decade to quantify the classical heat stress endocrine marker, cortisol, non-invasively in the feces, urine, hair, saliva and milk of farm animals. In addition, advanced technologies applied for the real-time analysis of cardinal signs such as sounds through microphones, behavioral images, videos through cameras, and data stalking body weight and measurements might provide deeper insights towards improving biological metrics in livestock exposed to heat stress. Infrared thermography (IRT) can be considered another non-invasive modern tool to assess the stress response, production, health, and welfare status in farm animals. Various remote sensing technologies such as ear canal sensors, rumen boluses, rectal and vaginal probes, IRT, and implantable microchips can be employed in grazing animals to assess the quantum of heat stress. Behavioral responses and activity alterations to heat stress in farm animals can be monitored using accelerometers, Bluetooth technology, global positioning systems (GPSs) and global navigation satellite systems (GNSSs). Finally, machine learning offers a scalable solution in determining the heat stress response in farm animals by utilizing data from different sources such as hardware sensors, e.g., pressure sensors, thermistors, IRT sensors, facial recognition machine vision sensors, radio frequency identification, accelerometers, and microphones. Thus, the recent advancements in recording behavior and physiological responses offer new scope to quantify farm animals’ heat stress response non-invasively. These approaches could have greater applications in not only determining climate resilience in farm animals but also providing valuable information for defining suitable and accurate amelioration strategies to sustain their production.

The livestock sector, essential for maintaining food supply and security, encounters numerous obstacles as a result of climate change. Rising global populations exacerbate competition for natural resources, affecting feed quality and availability, heightening livestock disease risks, increasing heat stress, and contributing to biodiversity loss. Although various management and dietary interventions exist to alleviate these impacts, they often offer only short-lived solutions. We must take a more comprehensive approach to understanding how animals adapt to and endure their environments. One such approach is quantifying transcriptomes under different environments, which can uncover underlying pathways essential for livestock adaptation. This review explores the progress and techniques in studies that apply gene expression analysis to livestock production systems, focusing on their adaptation to climate change. We also attempt to identify various biomarkers and transcriptomic differences between species and pure/crossbred animals. Looking ahead, integrating emerging technologies such as spatialomics could further accelerate genetic improvements, enabling more thermoresilient and productive livestock in response to future climate fluctuations. Ultimately, insights from these studies will help optimize livestock production systems by identifying thermoresilient/desired animals for use in precise breeding programs to counter climate change.

This review takes a close look at the biology of brown and beige fat, not just as thermogenic tissues, but as active metabolic organs influenced by sex, hormones, age, and even environment. Brown adipose tissue (BAT) and beige adipocytes differ in their origins, gene expression, and regulation. These differences are especially relevant when considering how they behave in males and females. Across both animal and human studies, females show higher BAT volume and more efficient thermogenic activity. Estrogen, acting mainly through estrogen receptor alpha (ERα), increases uncoupling protein 1(UCP1) expression, promotes mitochondrial biogenesis, and supports the formation of beige fat within white adipose tissue. In contrast, testosterone and glucocorticoids tend to reduce thermogenic gene expression and shift fat storage toward visceral depots, which increases metabolic risk, particularly in men. These hormone-driven effects are not limited to adulthood. Puberty, pregnancy, menopause, and andropause all influence thermogenic capacity in sex-specific ways. We also outline the key signaling pathways behind beiging such as PR domain-containing 16 (PRDM16), Peroxisome proliferator activated receptor gamma coactivator 1-alpha (PGC-1α), and β3-adrenergic signaling and how they interact with sex hormones to shape thermogenic responses. Findings from Positron Emission Tomography with Computed Tomography (PET/CT) imaging, genetic models, and molecular profiling show that beige and brown fat are regulated by distinct mechanisms and developmental cues depending on sex. We also review how BAT activity is linked to a lower risk of type 2 diabetes, cardiovascular disease, and inflammation, particularly in women with obesity. Conditions like Polycystic Ovary Syndrome (PCOS), hormone therapy, and exposure to endocrine-disrupting chemicals further influence BAT function in sex dependent ways. Understanding how brown and beige fat respond differently in men and women to internal and external signals, is critical. These differences have clear implications for developing targeted, more effective strategies to treat obesity and metabolic disease.

A study was conducted to assess the efficacy of prebiotic and herbal supplements to relieve transportation stress based on changes in physiological, hematological, and molecular responses in Kenguri sheep. Thirty healthy female sheep were randomly divided into three groups: a control group (CKS) with no supplementation, a prebiotic supplementation group (PKS), and an herbal supplementation group (HKS). The animals were transported 230 km over seven hours during summer conditions, with temperatures ranging from 32.5 °C to 34.9 °C. The groups that received the prebiotic (75.6 breaths/min; 64.8 beats/min) and herbal supplementation (31.0 breaths/min; 66.8 beats/min) had a significantly reduced respiration rate (RR) and pulse rate (PR) compared to those of the control group (38.7 breaths/min; 75.6 beats/min) (p < 0.01 and p < 0.05, respectively), indicating improved physiological stability. The hemoglobin (HGB) and hematocrit (HCT) levels were also significantly lower in the PKS (24.2 g/dL; 24.8%) and HKS (24.7 g/dL; 24.5%) groups than in the CKS (28.1 g/dL; 24.9%) (p < 0.05), highlighting the mitigation of hematological stress. Further, the plasma glucose level was significantly higher (p < 0.01) in the HKS group (80.0 mg/dL) compared to the CKS group (63.5 mg/dL). However, rectal temperature (RT) and skin temperature (ST), red blood cells (RBCs), mean corpuscular volume (MCV), and white blood cells (WBCs) showed no significant differences among the groups. These findings demonstrate that prebiotic and herbal supplementation can effectively reduce transportation-induced stress in Kenguri sheep, offering a practical strategy to improve the welfare and resilience of livestock under challenging environmental conditions.