RESUMO
Farm animals are sources of meat, milk and eggs for the humans, and animal health ensures the quality and security of these agricultural and sideline products. The animal raising conditions in livestock stations and poultry houses play vital roles in both animal health and production. One of the major factors affecting raising conditions, relative humidity, has not received much attention even though it is important for animal husbandry. In this review, we summarize the impacts of relative humidity on animal health and welfare to draw attention for its importance in the improvement of animal raising conditions in the future.
RESUMO
A number of emerging studies suggest that air pollutants such as hydrogen sulfide (H2S) and ammonia (NH3) may cause a decline in spermatozoa motility. The impact and underlying mechanisms are currently unknown. Boar spermatozoa (in vitro) and peripubertal male mice (in vivo) were exposed to H2S and/or NH3 to evaluate the impact on spermatozoa motility. Na2S and/or NH4Cl reduced the motility of boar spermatozoa in vitro. Na2S and/or NH4Cl disrupted multiple signaling pathways including decreasing Na+/K+ ATPase activity and protein kinase B (AKT) levels, activating Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and phosphatase and tensin homolog deleted on chromosome ten (PTEN), and increasing reactive oxygen species (ROS) to diminish boar spermatozoa motility. The increase in ROS might have activated PTEN, which in turn diminished AKT activation. The ATP deficiency (indicated by reduction in Na+/K+ ATPase activity), transforming growth factor (TGFß) activated kinase-1 (TAK1) activation, and AKT deactivation stimulated AMPK, which caused a decline in boar spermatozoa motility. Simultaneously, the deactivation of AKT might play some role in the reduction of boar spermatozoa motility. Furthermore, Na2S and/or NH4Cl declined the motility of mouse spermatozoa without affecting mouse body weight gain in vivo. Findings of the present study suggest that H2S and/or NH3 are adversely associated with spermatozoa motility.
RESUMO
Most small homotherms display low leptin level in response to chronic cold exposure. Cold-induced hypoleptinemia was proved to induce hyperphagia. However, it is still not clear whether hypoleptinemia regulates energy expenditure in cold condition. We try to answer this question in chronic cold-acclimated rats. Results showed that 5-day intracerebroventricular(ICV) infusion of leptin (5 µg/day) had no effects on basal and adaptive thermogenesis and uncoupling protein 1 expression. Physical activity was increased by leptin treatment. We further determined whether ghrelin could reverse the increasing effect of leptin on physical activity. Coadministration of ghrelin (1.2 µg/day) completely reversed the effect of leptin on physical activity. Collectively, this study indicated the regulation of leptin on energy expenditure during cold acclimation may be mainly mediated by physical activity but not by thermogenesis. Our study outlined behavioral role of leptin during the adaptation to cold, which adds some new knowledge to promote our understanding of cold-induced metabolic adaptation.
