Exogenous bovine somatotropin and mist-fan cooling synergistically promote the intramammary glucose transport for lactose synthesis in crossbred Holstein cows in the tropics

Background and Aim: Milk synthesis by the mammary gland is negatively influenced in part by high ambient temperature (AT). This study aimed to clarify the pathway of intramammary glucose utilization involved in mediating lactose synthesis during treatment with somatotropin under housing with misters and fans. Materials and Methods: A single subcutaneous injection of 500 mg of recombinant bovine somatotropin (rbST) was administered 3 times once every 14 days to 87.5% crossbred Holstein cattle in early-/mid-/late lactation, under housing in a normal shaded barn and in a shaded barn with a mist-fan cooling system. Results: The milk yields of the cooled cows tended to increase compared with those of uncooled cows and exhibited more potentiated effects in response to rbST treatment, coinciding with increases in mammary plasma flow and glucose uptake, but not in the mammary extraction of glucose. Treatment with rbST in the cooled cows resulted in a greater increase in the milk glucose concentration and a greater decrease in the milk glucose-6-phosphate concentration at all stages of lactation. Conclusion: rbST treatment exerted its galactopoietic action more by local intramammary factors than by other extramammary factors at a low AT and the synergistic effect between rbST treatment and low AT increased the availability of intramammary glucose transport in activating the process of lactose synthesis.

DEPENDENCE OF THE NOISE LEVEL OF DRY FAN COOLING TOWERS ON THE POWER OF THERMAL POWER PLANTS

Сухие вентиляторные градирни тепловых электрических станций могут быть источником превышения санитарных норм на территории станции и в окружающем районе. В статье проведен анализ уровня шума сухих вентиляторных градирен в зависимости от мощности тепловых электрических станций. Получена формула позволяющая определить изменение уровня звука сухих вентиляторных градирен в зависимости от электрической мощности тепловых электрических станций. Dry fan cooling towers of thermal power plants can be a source of exceeding sanitary standards on the territory of the plant and in the surrounding area. The article analyzes the noise level of dry fan cooling towers depending on the power of thermal power plants. A formula has been obtained that makes it possible to determine the change in the sound level of dry fan cooling towers depending on the electrical power of thermal power plants.

Cooling Between Exercise Bouts and Post-exercise With the Fan Cooling Jacket on Thermal Strain in Hot-Humid Environments

This study investigated the effects of cooling between exercise bouts and post-exercise with a commercially available fan cooling jacket on thermal and perceptual responses during and following exercise in hot-humid environments. Ten male athletes completed two 30 min cycling bouts at a constant workload (1.4 watts⋅kg–1 of body mass) with a 5 min recovery period in between. Exercise was followed by a 10 min recovery period. In an environmental chamber (33°C, 65% relative humidity), participants performed two trials with (FCJ) or without (CON) the fan cooling jacket on a T-shirt during the 5 min inter-exercise and 10 min post-exercise recovery periods. Mean, chest and upper arm skin temperatures, and thermal sensation and comfort were lower in FCJ than CON trial during and following exercise (P < 0.05). Thigh and calf skin temperatures, infrared tympanic temperature and heart rate were lower in FCJ than CON trial during the experimental trials (P < 0.05). The rates of fall in mean, chest and upper arm skin temperatures, infrared tympanic temperature and thermal sensation and comfort were faster in FCJ than CON trial during both recovery periods (P < 0.05). There were faster rates of fall in thigh and calf skin temperatures and heart rate in FCJ than CON trial during the post-exercise recovery period (P < 0.05). No difference was observed between trials in the rating of perceived exertion (P > 0.05). This study indicates that cooling between exercise bouts and post-exercise with the fan cooling jacket would effectively mitigate thermal strain and perception/discomfort during and following exercise in hot-humid environments. This garment would reduce whole-body skin temperature quickly while promoting falls in lower-body as well as upper-body skin temperatures.

Post-mortem indications of poor welfare—an hypothesis upon supine broilers: stress and efforts to ameliorate suffering in a low throughput abattoir

Broilers at slaughterhouses are prone to heat stress. They should be checked for panting, which occurs above an ambient temperature of 17°C. Fan cooling, water misting, cooling by evaporation on module roofs, cascading water down the lattice of drawers, and cold drinks all help to reduce heat stress. Drawer opening by 4–6 cm and stocking reduction also facilitate heat escape. Removing live or dead supine, or trapped prone broilers, with broken legs or wings, wedged toes or with rubbed upper wing joints, improves the welfare of the remaining broilers. Indications of stressed broilers, for example, pale soft exudative and dark, firm, dry pectoral muscles, should be sought in untreated dead on arrival birds and in postmortem rejects.

Composite design and thermal comfort evaluation of safety helmet with PCM cooling

Higher temperature and humidity will adversely affect the thermal comfort of helmet users. In order to improve the comfort level of the helmet and obtain an optimal cooling helmet model, four kinds of helmet models were established by using phase-change material (PCM) heat-absorbing cooling technology and fan cooling technology. Through the air conditioning system, the working states of four kinds of helmet models in the thermal environment of 30? were simulated, and the thermal comfort of four kinds of helmet models was evaluated. The results show that: high temperature environment is an important factor affecting the cooling effect of fan helmet (b) fan, Under high temperature environment, the helmet with fan cooling technology has a certain cooling effect in the early stage, but after 30 minutes, the cooling effect becomes worse and worse. Under high temperature environment, PCM safety helmet (c) has a good cooling effect, but poor ventilation results in the excreted sweat clinging to the scalp and hair, resulting in a poor user experience. There are defects in using phase-change material (PCM) heat absorption cooling technology or fan cooling technology alone. The helmet (d) combines PCM heat absorption cooling technology with fan cooling technology, so that the cooling effect and internal thermal environment stability of the helmet are the best, and the thermal sensation of human body is the best. Therefore, the helmet (d) is an optimal design model.