Fasting initiates a coordinated metabolic response to preserve energy balance. As glycogen stores are depleted, the body transitions to mobilizing fatty acids from adipose tissue and generating ketone bodies in the liver to sustain the function of vital organs. A network of hormonal signals and transcriptional programs coordinate these adaptations. Among these, the hepatokine fibroblast growth factor 21 (FGF21) is strongly upregulated during fasting and has been proposed as a key mediator of the fasting response. To investigate the physiological functions of FGF21, we study mice with hepatocyte-specific deletion of Fgf21. Although the liver is the primary source of circulating FGF21 during fasting, its absence in hepatocytes does not alter typical fasting-induced gene expression or key metabolic pathways such as hepatic gluconeogenesis, adipose tissue lipolysis, or ketone production. Instead, we uncover a distinct role for FGF21 in promoting protein appetite following a fast. These findings challenge the conventional view of hepatocyte-produced FGF21 as a fasting-acting hormone and reveal a more specialized function in guiding nutrient selection after energy depletion.
The emergence of Highly Pathogenic Avian Influenza (HPAI) H5 clade 2.3.4.4b has triggered an unprecedented global panzootic in recent years. As the frequency and scale of HPAI H5 outbreaks continue to rise, understanding how wild birds contribute to shape the global virus spread across regions—affecting poultry, domestic and wild mammals—is increasingly critical. In this review, we examine ecological and evolutionary studies to map the global transmission routes of HPAI H5 viruses, identify key wild bird species involved in viral dissemination, and explore infection patterns, including mortality and survival. We also highlight major remaining knowledge gaps that hinder a full understanding of wild birds’ role in viral dynamics, which must be addressed to enhance surveillance strategies and refine risk assessment models aimed at better predicting future outbreaks in wildlife and mitigating outbreaks in domestic animals to safeguard public health.
Effective management of Bovine Respiratory Disease Complex (BRDC) requires timely, non-invasive diagnostic tools to protect calf health and welfare. Among early clinical signs, coughing stands out as both frequent and informative. To explore its potential for early BRDC detection, we deployed an artificial intelligence (AI)-driven acoustic monitoring system that recorded over 2 730 h of audio during a 30-day period. Four experimental pens, each housing seven calves and stratified by infection status and antibiotic treatment, were equipped with a dedicated microphone to enable targeted acoustic surveillance. This configuration enabled pen-specific detection of cough events, which were subsequently classified using an AI lightweight Hidden-Unit BERT (HuBERT)-based model trained on 1 045 labelled clips. The classifier achieved 92% accuracy. Temporal patterns in cough frequency aligned with infection dynamics, treatment responses, and circadian patterns. Notably, AI-detected coughs consistently preceded clinical scores by 1-2 days, confirming the system's sensitivity to early respiratory disorders. These findings support the use of acoustic surveillance as a valid, scalable, and autonomous tool for continuous monitoring and early warning of respiratory diseases in calves.
La maladie du bas appareil urinaire félin (MBAUF) obstructive constitue une urgence fréquente chez le chat mâle et peut rapidement entraîner des complications métaboliques, cardiovasculaires et rénales engageant le pronostic vital. Malgré une littérature abondante, les recommandations concernant la prise en charge initiale restent hétérogènes. Ce premier consensus du Groupe d’étude urgence – réanimation (GEUR-AFVAC) vise à harmoniser les pratiques lors de l’admission des chats présentant une obstruction urétrale. Les recommandations ont été élaborées selon une méthode Delphi à partir d’une analyse critique de la littérature et validées par un panel de 19 experts. Les principaux facteurs de risque identifiés sont la castration, l’âge, le surpoids, la vie exclusivement en intérieur, l’alimentation sèche et les antécédents de MBAUF. L’absence de signes urinaires ou de globe vésical n’exclut pas une obstruction urétrale. Une attention particulière doit être portée à la fréquence cardiaque et à la température, la bradycardie et l’hypothermie pouvant traduire une hyperkaliémie sévère ou une azotémie importante. Le dosage de la kaliémie, des paramètres rénaux et, si possible, des gaz du sang constitue la base du bilan initial, complété selon le contexte par un électrocardiogramme, une analyse d’urine et un examen d’imagerie.
