scholarly journals 147 Changes in body temperature of lot-fed Bos taurus and Bos indicus steers during a heat wave

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 150-150
Author(s):  
Stephanie L Sammes ◽  
Angela M Lees ◽  
Judy A Cawdell-Smith ◽  
John B Gaughan

Abstract Body temperature (BT) is a reliable method for evaluating the thermal status of cattle. The objective of this study was to evaluate the regulation of BT in B. indicus and B. taurus steers during a heat wave event. Thirty-five steers (466.30±10.2kg) of mixed genotypes (B. taurus, n = 18; B. indicus, n = 17) were used in a larger 100-d study. Cattle were housed in six un-shaded pens at a commercial feedlot. Body temperature data for this were obtained at 1 h intervals over a 3-d heat wave event using in situ abdominal data loggers. Data were analysed using a repeated measures model, using residual maximum likelihood estimation. The model included genotype (B. taurus; B. indicus) and animal ID as random effects and hour as a fixed effect. Mean maximum BT occurred at 1500 h for B. taurus (40.52±0.03ºC) and 0400 h for B. indicus (40.48±0.31ºC). The BT of B. indicus decreased between 0400 h and 0700 h, and then increased to 1100 h (+0.10±0.01ºC/h), before decreasing again. The BT of B. taurus decreased between 0500 h and 0600 h, and then slowly increased (+0.04±0.01ºC/h) to 1500 h. Mean minimum BT occurred at 2100 h for B. taurus (40.12±0.11ºC) and 0700 h for B. indicus (40.00±0.22ºC). B. taurus maintained lower BT (40.21±0.05ºC) between 1900 h and 2200 h compared to B. indicus (40.27±0.05ºC) which may be due to disrupted heat loss mechanisms during the day, highlighting the importance of night time cooling. In response to increasing heat load, BT in B. taurus had slower increases but retained heat for longer, whilst B. indicus BT responded by a series of rapid increases and decreases. Developing an understanding of the differences in BT regulation in B. indicus and B. taurus will allow for more effective heat load management strategies during heat waves to be established.

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 235-235
Author(s):  
Stephanie L Sammes ◽  
Angela M Lees ◽  
Judy A Cawdell-Smith ◽  
John B Gaughan

Abstract Body temperature (BT) is a reliable method for evaluating the thermal status of cattle. The objective of this study was to evaluate the regulation of BT in B. indicus and B. taurus steers during a heat wave event. Thirty-five steers (466.30±10.2kg) of mixed genotypes (B. taurus, n = 18; B. indicus, n = 17) were used in a larger 100-d study. Cattle were housed in six un-shaded pens at a commercial feedlot. Body temperature data for this were obtained at 1 h intervals over a 3-d heat wave event using in situ abdominal data loggers. Data were analysed using a repeated measures model, using residual maximum likelihood estimation. The model included genotype (B. taurus; B. indicus) and animal ID as random effects and hour as a fixed effect. Mean maximum BT occurred at 1500 h for B. taurus (40.52±0.03ºC) and 0400 h for B. indicus (40.48±0.31ºC). The BT of B. indicus decreased between 0400 h and 0700 h, and then increased to 1100 h (+0.10±0.01ºC/h), before decreasing again. The BT of B. taurus decreased between 0500 h and 0600 h, and then slowly increased (+0.04±0.01ºC/h) to 1500 h. Mean minimum BT occurred at 2100 h for B. taurus (40.12±0.11ºC) and 0700 h for B. indicus (40.00±0.22ºC). B. taurus maintained lower BT (40.21±0.05ºC) between 1900 h and 2200 h compared to B. indicus (40.27±0.05ºC) which may be due to disrupted heat loss mechanisms during the day, highlighting the importance of night time cooling. In response to increasing heat load, BT in B. taurus had slower increases but retained heat for longer, whilst B. indicus BT responded by a series of rapid increases and decreases. Developing an understanding of the differences in BT regulation in B. indicus and B. taurus will allow for more effective heat load management strategies during heat waves to be established.


2014 ◽  
Vol 198-199 ◽  
pp. 105-115 ◽  
Author(s):  
Jeffrey A. Geddes ◽  
Jennifer G. Murphy ◽  
Jon Schurman ◽  
Alexandre Petroff ◽  
Sean C. Thomas

2016 ◽  
Vol 6 (11) ◽  
pp. 3583-3593 ◽  
Author(s):  
Nick Caputi ◽  
Mervi Kangas ◽  
Ainslie Denham ◽  
Ming Feng ◽  
Alan Pearce ◽  
...  

2020 ◽  
Vol 60 (2) ◽  
pp. 305 ◽  
Author(s):  
A. M. Lees ◽  
J. C. Lees ◽  
V. Sejian ◽  
M. L. Sullivan ◽  
J. B. Gaughan

Context Feedlot cattle can be negatively impacted by hot conditions, such that they have reduced performance and wellbeing. This study was conducted at the research feedlot located at The University of Queensland during a southern hemisphere summer (October to April). Aims The objective of this study was to evaluate the influence of shade on the behaviour and panting score of Bos taurus and Bos indicus feedlot cattle during summer. Methods Thirty-six steers (12 Angus, 12 Charolais and 12 Brahman) with an initial non-fasted liveweight of 318.5 ± 6.7 kg were used in a 154-day feedlot study consisting of two treatments: unshaded and shaded (3 m2/animal). Observational data were obtained for each steer at 2 h intervals between 0600 and 1800 hours daily from Day 1 to Day 154. Additional night time observational data were collected at 2-h intervals between 2000 and 0400 hours on 12 occasions. Data collected included activity (feeding, drinking, or ruminating), posture (standing or lying) and panting score. Panting scores were used to calculate a mean panting score for each breed × treatment group. Observational data were converted to a count for each breed × treatment group for each observation time point and were analysed using a binomial generalised linear model. Key results Maximum shade utilisation was the greatest at 1200 hours for Angus (85.5%), Charolais (32.7%) and Brahman (33.3%) steers. All breed × treatment groups exhibited a notable increase in mean panting score as heat load increased. Average increase in mean panting score was 0.36, where shaded Brahman exhibited the smallest increase (0.13) and unshaded Angus had the greatest increase (0.71). When heat load conditions were very hot (heat load index (HLI) ≥ 86) the mean panting score of all breed × treatment groups differed (P < 0.05). Conclusions Overall these results emphasise the importance of providing shade to feedlot cattle, irrespective of genotype. Implications These results further highlight the importance of providing shade to feedlot cattle. These results challenge the general perception that Bos indicus feedlot cattle do not require access to heat load alleviation strategies.


2021 ◽  
Vol 13 (22) ◽  
pp. 12608
Author(s):  
Adil Dilawar ◽  
Baozhang Chen ◽  
Lifeng Guo ◽  
Shuan Liu ◽  
Muhammad Shafeeque ◽  
...  

This study investigates the relative role of land surface schemes (LSS) in the Weather Research and Forecasting (WRF) model, Version 4, to simulate the heat wave events in Karachi, Pakistan during 16–23 May 2018. The efficiency of the WRF model was evaluated in forecasting heat wave events over Karachi using the three different LSS, namely NOAH, NOAH-MP, and RUC. In addition to this we have used the longwave (RRTM) and shortwave (Dudhia) in all schemes. Three simulating setups were designed with a combination of shortwave, longwave, and LSS: E1 (Dudhia, RRTM, and Noah), E2 (Dudhia, RRTM, and Noah-MP), and E3 (Dudhia, RRTM, and RUC). All setups were carried out with a finer resolution of 1 km × 1 km. Findings of current study depicted that E2 produces a more realistic simulation of daily maximum temperature T(max) at 2m, sensible heat (SH), and latent heat (LH) because it has higher R2 and lower errors (BIAS, RMSE, MAE) compared to other schemes. Consequently, Noah-MP (LSS) accurately estimates T(max) and land surface heat fluxes (SH&LH) because uses multiple physics options for land atmosphere interaction processes. According to statistical analyses, E2 setup outperforms other setups in term of T(max) and (LH&SH) forecasting with the higher Nash-Sutcliffe efficiency (NSE) agreement is 0.84 (0.89). This research emphasizes that the selection of LSS is of vital importance in the best simulation of T(max) and SH (LH) over Karachi. Further, it is resulted that the SH flux is taking a higher part to trigger the heat wave event intensity during May 2018 due to dense urban canopy and less vegetated area. El Niño-Southern Oscillation (ENSO) event played role to prolong and strengthen the heat wave period by effecting the Indian Ocean Dipole (IOD) through walker circulation extension.


Epidemiology ◽  
2011 ◽  
Vol 22 ◽  
pp. S24
Author(s):  
Jinliang Zhang ◽  
Ling Liu ◽  
Yun Zhou ◽  
Xiuge Zhao

Author(s):  
Md. Abdul Aziz ◽  
M. A. Samad ◽  
M. R. Hasan ◽  
M. N. U. Bhuiyan ◽  
M. A. K. Mallik

Every year Bangladesh experiences different types of natural hazards and heat wave is one of them. In the present study, an advanced high-resolution Weather Research and Forecasting (WRF-ARW) numerical mesoscale model is used to simulate a severe heat wave event occurred during April over Bangladesh and eastern part of India. The model is integrated for 6 days starting from UTC of 19 April to UTC of 24 April 2016, on a single domain of 10 km horizontal resolution. For validation of the model performance, the model simulated results of temperature at 2 m height, relative humidity (RH), mean sea level pressure (MSLP) at UTC of 6 days are compared with the BMD observed data. And the results indicate that the model is able to simulate the occurrence of the heat wave event with 6 days over Bangladesh.


Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 99
Author(s):  
Olga Shevchenko ◽  
Sergiy Snizhko ◽  
Sergii Zapototskyi ◽  
Andreas Matzarakis

The human-biometeorological conditions in Ukraine during two mega-heat waves were analyzed. The evaluation is based on physiologically equivalent temperature (PET). The calculation of PET is performed utilizing the RayMan model. The results revealed these two mega-heat waves produced strenuous human-biometeorological conditions on the territory of Ukraine. During the summer 2010 mega-heat wave, strong and extreme heat stress prevailed at about midday at the stations where this atmospheric phenomenon was observed. The mega-heat wave of August 2015 was characterized by a lower heat load. The diurnal variation of PET values during the researched mega-HW was similar to that of the diurnal variation of air temperature with minimum values in the early morning and maximum values in the afternoon. On the territory where mega-heat waves were observed, the number of days during which heat stress occurred for 9 h amounted to 97.6% for the period from 31 July to 12 August 2010 and 77.1% for the mega-heat wave of August 2015.


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