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Effects of weather variables on thermoregulation of calves during periods of extreme heat
2014
Theurer, Miles E. | Anderson, Daivd E. | White, Brad J. | Miesner, Matt D. | Larson, Robert L.
Objective-To determine effects of ambient temperature, relative humidity, wind speed, relative barometric pressure, and temperature-humidity index (THI) on nasal submucosal and rectal temperatures in cattle during extreme summer conditions. Animals-20 black crossbred beef heifers (mean body weight, 217.8 kg). Procedures-Nasal submucosal and rectal temperatures were monitored every 2 hours for 24 hours on 3 nonconsecutive days when ambient temperature was forecasted to exceed 32.2°C. Ambient temperature, relative humidity, wind speed, and relative barometric pressure were continuously monitored at a remote weather station located at the research facility. The THI was calculated and used in the livestock weather safety index (LWSI). Relationships between nasal submucosal or rectal temperature and weather variables were evaluated. Results-Nasal submucosal and rectal temperatures were related to all weather variables monitored. A positive relationship was determined for ambient temperature and THI with both nasal submucosal and rectal temperatures. A negative relationship was evident for nasal submucosal and rectal temperature with relative humidity, wind speed, and relative barometric pressure. Nasal submucosal and rectal temperatures increased with increasing severity of LWSI category. Conclusions and Clinical Relevance-Effects of environmental conditions on thermoregulation in calves exposed to extreme heat were detected. The positive relationship between nasal submucosal temperature and ambient temperature and THI raised concerns about the efficacy of intranasal administration of temperature-sensitive modified-live virus vaccines during periods of extreme heat. Environmental conditions must be considered when rectal temperature is used as a diagnostic tool for identifying morbid cattle.
Mostrar más [+] Menos [-]Relationship between estimated finishing-pig space allowance and in-transit loss in a retrospective survey of 3 packing plants in Ontario in 2003
2010
Haley, Charles | Dewey, Catherine E. | Widowski, Tina | Friendship, Robert
The objective of this study was to determine the association between space allowance and in-transit loss of finishing pigs going to select abattoirs in Ontario during summer weather conditions. The study included data from 2- or 3-tiered trailers transporting >or= 130 pigs in June, July, and August 2003 to 3 packers that processed 76% of Ontario market pigs. Daily in-transit loss data were merged with packer data to determine the number of pigs on each trailer. Space allowance (in square meters per pig) was estimated from the percentage of each trailer’s capacity that was filled by the load size. Actual pig weights were not available. Hourly temperature and relative humidity were obtained from 2 local Ontario weather stations. In-transit loss increased with environmental temperature, by 6.6 times at temperatures between 28°C and 34.2°C compared with < 17°C. At space allowances between 0.44 and 0.43 m2/pig compared with >or= 0.515 m2/pig, in-transit losses increased 2.12 times when environmental temperatures were < 21°C. Temperature is likely a more important determinant of in-transit loss than space allowance. However, in-transit losses in hot weather are likely to be reduced by increasing space allowance or by adding a cooling device.
Mostrar más [+] Menos [-]Quantitation of house dust mites and house dust mite allergens in the microenvironment of dogs
2003
Randall, Amy | Hillier, Andrew | Cole, Lynette K. | Kwochka, Kenneth W. | Needham, Glen | Wassom, Donald L.
Objective-To quantitate the density of Dermatophagoides farinae and D pteronyssinus and concentrations of house dust mite (HDM) allergens (Der f 1, Der p 1, and Group 2 allergens) in the indoor microenvironment of dogs. Sample Population-50 homes in Columbus, Ohio. Procedure-In each home, samples of dust were collected from 3 locations in which dogs spent most time. Whenever possible, the species of mites collected was identified. Mite density (mites/g of dust) was assessed, and allergen concentrations were assayed by standardized ELISAs. Relative humidity and temperature in each home were monitored during a 5-day period. Characteristics of homes and sample sources were evaluated. Results-Dust samples from all 50 homes contained greater than 1 HDM allergen; Der f 1 and Der p 1 were detected in 100 and 74% of homes, respectively. Fifteen homes had HDMs; compared with D pteronyssinus, D farinae was found more commonly (14/15 homes) and at a higher density. Basements, homes without central air-conditioning, and dog beds that were greater than 1 year old had high HDM allergen concentrations. Homes with greater than 2 micrograms of Der f 1 or Group 2 allergens/g of dust or greater than 100 mites/g of dust were significantly more likely to have a maximum relative humidity greater than 75%. Conclusions and Clinical Relevance-Results indicated the presence of HDMs and HDM allergens in the specific microenvironment of dogs in homes. Factors associated with high levels of exposure were identified, which may be associated with increased risk for sensitization and development of atopic diseases.
Mostrar más [+] Menos [-]Effect of building ventilation design on environment and performance of turkeys
1994
DeBey, M.C. | Trampel, D.W. | Richard, J.L. | Bundy, D.S. | Hoffman, L.J. | Meyer, V.M. | Cox, D.F.
Environmental variables in 10 commercial turkey confinement buildings, representing 2 natural ventilation designs, were measured during summer and the following winter. Sliding doors spaced at intervals along the walls of 5 of the buildings provided about 35% opening, and continuous wall curtains provided 60 to 80% opening in the other 5 buildings. Environmental variables assessed included airspeed; temperature; relative humidity; gases; particle number, size, and mass per cubic meter of air; and colonies of bacteria, yeasts, and other fungi per cubic meter of air. Colonies of yeasts and other fungi were quantitated in feed and litter. For most of the variables evaluated, significant differences were not attributable to building ventilation design; however, in winter, the total mass of particulate matter per cubic meter of air was higher in the curtain-type houses, compared with sliding door-type houses. Ammonia concentration in the air of sliding door-type houses progressively increased during summer and winter sampling periods. A significant effect of building ventilation design on turkey performance was not detected when using mortality, average daily gain, feed conversion, condemnations at slaughter, or average individual bird weight as measures of production.
Mostrar más [+] Menos [-]Effect of humidification on the airways of cats during high-frequency ventilation
1991
Whitfield, J.B. | Bjorling, D.E. | Munnell, J.F.
The effect of humidity on the histologic lesions induced by high-frequency jet ventilation was investigated in 12 healthy cats. After 16 hours of ventilation, the appearance of the tracheal epithelium ranged from normal to necrotic. The damage was considerably more severe in the trachea of cats of the group ventilated without added humidity. Increasing the relative humidity to 63% at 24 C had a protective effect, but further increasing the relative humidity to 92% at 35 degrees C did not appear to provide significantly more protection. The bronchi and distal airways had minimal, if any, damage in all groups.
Mostrar más [+] Menos [-]Effect of pneumoperitoneum with warmed humidified or standard-temperature carbon dioxide during laparoscopy on core body temperature, cardiorespiratory and thromboelastography variables, systemic inflammation, peritoneal response, and signs of postoperative pain in healthy mature dogs
2018
Scott, Jacqueline E. | Singh, Ameet | Valverde, Alex | Blois, Shauna L. | Foster, Robert A. | Kilkenny, Jessica J. | zur Linden, Alex
OBJECTIVE To evaluate effects of pneumoperitoneum created with warmed humidified CO2 (WHCO2) during laparoscopy on core body temperature, cardiorespiratory and thromboelastography variables, systemic inflammation, peritoneal response, and signs of postoperative pain in healthy mature dogs. ANIMALS 6 mature purpose-bred dogs. PROCEDURES In a randomized crossover study, each dog was anesthetized twice, and pneumoperitoneum was created with standard-temperature CO2 (STCO2; 22°C and 0% relative humidity) and WHCO2 (37°C and 98% relative humidity). Data were collected during each procedure, including core body temperature, cardiorespiratory and thromboelastography variables, and inflammatory biomarkers. Peritoneal biopsy specimens were collected and evaluated with scanning electron microscopy. Dogs were assessed for signs of postoperative pain. RESULTS Mean core body temperature was significantly lower (35.2°C; 95% confidence interval, 34.5° to 35.8°C) with WHCO2 than with STCO2 (35.9°C; 95% confidence interval, 35.3° to 36.6°C) across all time points. Cardiac index increased during the procedure for both treatments but was not significantly different between treatments. Thromboelastography variables did not differ significantly between treatments as indicated by the coagulation index. Subjective evaluation of peritoneal biopsy specimens revealed mesothelial cell loss with STCO2. There was no significant difference in circulating C-reactive protein or interleukin-6 concentrations. There was a significant increase in the number of postoperative pain scores > 0 for the WHCO2 treatment versus the STCO2 treatment. CONCLUSIONS AND CLINICAL RELEVANCE Analysis of these data suggested that effects on evaluated variables attributable to the use of WHCO2 for creating pneumoperitoneum in healthy mature dogs undergoing laparoscopy did not differ from effects for the use of STCO2.
Mostrar más [+] Menos [-]Retention of sialic acid content in Malaysian edible bird’s nest by heat pump drying
2017
Gan, S. H. | Ong, S. P. | Chin, N. L. | Law, C. L.
This paper presents the resultsof an experimental attempt to improve thedrying kinetics for the retention of colourand sialic acid in edible bird’s nest throughheat pump drying. Kinetics of hot air dryingand heat pump drying were studied byperforming various drying trials on ediblebird’s nest. Isothermal drying trials wereconducted in hot air drying and heat pumpdrying at a temperature range of 40 °C-90 °C and 28.6 °C-40.6 °C, respectively.Intermittent drying trials were carried outin heat pump drying with two differentmodes, which are periodic air flow supplyand step-up air temperature. Experimentalresults showed that heat pump drying withlow temperature dehumidified air not onlyenhanced the drying kinetics but alsoproduced a stable final product of ediblebird’s nest. Heat pump-dried edible bird’ssamples retained a high concentration ofsialic acid when an appropriate dryingmode was selected.
Mostrar más [+] Menos [-]Climatic effects on the prevalence of the Onchocerca arthropod vector in some rural areas of Southwestern Nigeria
2016
Anong, C. I. N. | Akinboade, O. A. | Adediran, O. A.
There is increasing alarm and awareness about the health dangerposed by the arthropod vector causing Onchocerciasis. This study was carried out with the aim to throw more light on the prevalence of the arthropod vector, Simulun damnosum. This research enabled us toproffer preventive advice to government and citizens. In carrying out this study, villages around flowing waters were used as sample sites. The method applied was direct observation, coupled with efficientrecording. Atmospheric temperature readings were periodically taken along with the density of the insect population observed under such temperature. The same was done for relative humidity (%), solar radiation (gm-ca/cm2, lum) and luminescence (cd/m2) in relation to the insect population of available FMH at every given period (fly per man hour). Our findings showed that climate conditions influence the reproductive level and numbers of the vector. The wet season is most conducive for the arthropod vector to reproduce and multiply. The humidity is high and temperature seems to be at the average. It is during this period that greater preventive measures need to beintentionally heightened to subdue the dangerous activities of the vector.
Mostrar más [+] Menos [-]Survival of pseudorabies virus in aerosol
1990
Schoenbaum, M.A. | Zimmerman, J.J. | Beran, G.W. | Murphy, D.P.
The survival of pseudorabies virus in an aerosol was studied under different environmental conditions of temperature and relative humidity. Pseudorabies virus decayed logarithmically with mean half-lives of 17.4 (85% relative humidity, 22 C), 18.8 (25% relative humidity, 22 C), 27.3 (85% relative humidity, 4 C), 36.1 (55% relative humidity, 22 C), and 43.6 (55% relative humidity, 4 C) minutes. Virus survival was significantly improved in environments at 55% relative humidity, compared with those at 85% relative humidity (P = 0.017). Rates of survival were improved in environment at 4 C in comparison with those at 22 C. Results suggest that, under the best conditions of this study, the infectivity of pseudorabies virus in an aerosol decreases by 50% in < 1 hour.
Mostrar más [+] Menos [-]Performance evaluation of quail closed-house system in Institute of Poultry Technology, Malaysia
2015
Nurul Aini M. Y. | Nurshuhada S. | Irdayu H.
Quail closed-house system is a house that support quails’ optimumrequirements as far as temperature, relative humidity, ventilation and light are concerned. One of the four units of quail closed-house systems at the Institute of Poultry Technology, Malacca was used in this study. The objective of this project was to evaluate the performance of the quail closed-house system by comparing the condition of the house under current management condition and after the Standard Operating Procedure determined by DVS was adhered. Thehouse performance was evaluated by observing its ability to achieve an optimum temperature range of 20°C to 27°C with a relative humidity between 60% to 80% as perfect surroundings for quails. At the end of the experiments, the results showed a decline in internal temperature at almost 3°C and increasing in a relative humidity of 10% after all the specifications and procedures were followed.
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