Dexamethasone administration restored growth in dairy calves exposed to heat stress.

Recent evidence indicates that the heat stress loss on the growth performance of calves is associated with the diversion of nutrients to control enteritis and systemic inflammation. In this study, we investigated the effect of heat stress on markers of inflammation, feed-use efficiency, and growth of dairy calves. We hypothesized that dexamethasone, which is known for its immunosuppressive and anti-inflammatory properties, would reduce inflammation and restore the growth of calves exposed to heat stress.

Heat stress-associated changes in the intestinal barrier, inflammatory signals, and microbiome communities in dairy calves.

Recent studies indicate that heat stress pathophysiology is associated with intestinal barrier dysfunction, local and systemic inflammation, and gut dysbiosis. However, inconclusive results and a poor description of tissue-specific changes must be addressed to identify potential intervention targets against heat stress illness in growing calves. Therefore, the objective of this study was to evaluate components of the intestinal barrier, pro- and anti-inflammatory signals, and microbiota community composition in Holstein bull calves exposed to heat stress.

Heat Stress-Mediated Activation of Immune-Inflammatory Pathways.

Physiological changes in animals exposed to elevated ambient temperature are characterized by the redistribution of blood toward the periphery to dissipate heat, with a consequent decline in blood flow and oxygen and nutrient supply to splanchnic tissues. Metabolic adaptations and gut dysfunction lead to oxidative stress, translocation of lumen contents, and release of proinflammatory mediators, activating a systemic inflammatory response. This review discusses the activation and development of the inflammatory response in heat-stressed models.

Identification of new odorous compounds in Swedish water: mixed haloanisoles and phenolic precursors.

Mixed chlorobromoanisoles have recently been recognized as new potential odorous compounds in tap water. The odour threshold concentrations (OTCs) of these compounds are close to the sub ng/L (ppt) and associated descriptors are "earthy, musty, rubber". During a "swampy, musty" episode in water of the Norrtälje district (Sweden), 2,4,6-mixed chlorobromoanisoles and their phenolic precursors were identified.