Evaluation of thermal indices based on their relationships with some physiological responses of housed lactating cows under heat stress

Yan, Geqi; Li, Hao; Zhao, Wanying; Shi, Zhengxiang

doi:10.1007/s00484-020-01999-6

Cited by 20 publications

(19 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We found that the RT, ST, and ET correlated the most closely with the CCI. High correlations of CCT with ST and ET agreed with another study conducted in southern China (Yancheng, Jiangsu, China), which reported that the CCI showed higher correlations (0.443 ≤ r ≤ 0.849) with the body surface temperature than other TIs (e.g., THI1, BGHI, THIadj, ETI, ETIC) [33]. Consistent with the present study, a study from Da Silva et al [34], in which the data were collected from a tropical environment, reported that the CCI showed a higher correlation (r = 0.374) with RT than the BGHI and other TIs (e.g., the heat load index (HLI) and the index of thermal stress for cows (ITSC)).…”

Section: Discussionsupporting

confidence: 87%

“…Figure6dshows that nine significant (p < 0.05) increases in RT were found at 64, 70, 72, 74, 76, 78, 80, 82, and 84 BGHI. Likewise, nine significant (p < 0.05) increases in RT were reported at19,21,23,25,27,29,31,33, and 35 CCI (Figure6g). However, only seven significant (p < 0.05) increases in RT were found at 68, 70, 72, 74, 78, 80, and 82 THIadj (Figure6e), 23, 25, 27, 29, 31, 33, and 35 ETI (Figure 6f), and 9, 15, 17, 19, 21, 23, and 25 ETIC (Figure 6h), respectively.…”

mentioning

confidence: 77%

“…There were eleven significant (p < 0.05) and continuous increases in ST that were observed from 64 to 84 THIadj. Figure 8f shows that nine significant (p < 0.05) increases in ST were reported at 19,23,25,27,29,31,33,35, and 39 ETI. Apart from one significant decrease observed at 17 CCI, twelve significant (p < 0.05) increases in ST were found from 15 to 39 CCI (Figure 8g).…”

Section: Correlations Between Indices and Animal-based Indicatorsmentioning

confidence: 96%

See 2 more Smart Citations

Evaluation of Thermal Indices as the Indicators of Heat Stress in Dairy Cows in a Temperate Climate

Yan

Shi

2021

Animals

Self Cite

View full text Add to dashboard Cite

Many thermal indices (TIs) have been developed to quantify the severity of heat stress in dairy cows. Systematic evaluation of the representative TIs is still lacking, which may cause potential misapplication. The objectives of this study were to evaluate the theoretical and actual performance of the TIs in a temperate climate. The data were collected in freestall barns at a commercial dairy farm. The heat transfer characteristics of the TIs were examined by equivalent air temperature change (ΔTeq). One-way ANOVA and correlation were used to test the relationships between the TIs and the animal-based indicators (i.e., rectal temperature (RT), respiration rate (RR), skin temperature (ST), and eye temperature (ET)). Results showed that the warming effect of the increased relative humidity and the chilling effect of the increased wind speed was the most reflected by the equivalent temperature index (ETI) and the comprehensive climate index (CCI), respectively. Only the equivalent temperature index for cows (ETIC) reflected that warming effect of solar radiation could obviously increase with increasing Ta. The THI and ETIC showed expected relationships with the RT and RR, whereas the CCI and ETIC showed expected relationships with the ST and ET. Moreover, CCI showed a higher correlation with RT (r = 0.672, p < 0.01), ST(r = 0.845, p < 0.01), and ET (r = 0.617, p < 0.01) than other TIs (p < 0.0001). ETIC showed the highest correlation with RR (r = 0.850, p < 0.01). These findings demonstrated that the CCI could be the most promising thermal index to assess heat stress for housed dairy cows. Future research is still needed to develop new TIs tp precisely assess the microclimates in cow buildings.

show abstract

Section: Discussionsupporting

confidence: 87%

mentioning

confidence: 77%

Section: Correlations Between Indices and Animal-based Indicatorsmentioning

confidence: 96%

See 1 more Smart Citation

Evaluation of Thermal Indices as the Indicators of Heat Stress in Dairy Cows in a Temperate Climate

Yan

Shi

2021

Animals

Self Cite

View full text Add to dashboard Cite

show abstract

“…The eye was outlined using an ellipse. The shapes that were used also agreed with the previous literature on ST assessments using infrared imaging in cattle [26][27][28][29]. The software automatically computed the STmax and STave of the region.…”

Section: Environmental and Animal Measuresmentioning

confidence: 62%

Critical Temperature-Humidity Index Thresholds Based on Surface Temperature for Lactating Dairy Cows in a Temperate Climate

Yan

Shi

2021

Agriculture

Self Cite

View full text Add to dashboard Cite

Detecting the early signs of heat stress is highly important in dairy farming. The surface temperature (ST) of cattle can reflect their thermal status and using such a measuring method can be efficient and non-invasive. However, few studies have reported the temperature-humidity index (THI) thresholds for ST. This study aimed to identify the critical THI thresholds for the ST of dairy cows and to evaluate the effects of the lactation stage and the lactation number. The study included 233 Holstein lactating cows from July 2020 to October 2020 in a temperate climate in China. There were 1556 records of the rectal temperature, and the maximum ST (STmax) and average ST (STave) of the head, eye, cheek, ear, neck, trunk, udder, foreleg, and hindleg were recorded. Air temperature and relative humidity were recorded to calculate the average THI. Physiological data were collected twice daily (08:00–12:00, 14:00–16:00). The critical THI thresholds were determined using the breakpoints of piecewise linear models. The significance of breakpoints was tested using the Davies test. A one-way ANOVA was used to test the effect of the lactation stage (0–60 DIM, 61–200 DIM, 201–300 DIM, DIM is days in milk) and the lactation number (1, 2, 3+) on the THI thresholds. The results showed that the rectal temperature was significantly positively correlated with all the ST variables (0.57 ≤ r ≤ 0.71, p < 0.01). The critical THI thresholds for STmax (mean of 76.1 THI, range of 73.6 to 77.9 THI) were significantly higher than those for STave (mean of 72.6 THI, range of 69.1 to 77.2 THI) (p < 0.01). The lactation stage only significantly affected the thresholds for STmax (p < 0.05), and the lactation number did not significantly influence the thresholds for both STmax and STave (p > 0.05). This study concluded that the STave was more appropriate to define thresholds than the STmax. The threshold for the STave of the cheek (69.1 THI) was the lowest among the thresholds, indicating that the STave of the cheek could be a prior ST variable to determine critical THI thresholds. Our findings demonstrated the potential of using ST variables to define critical THI thresholds.

show abstract

“…As pointed out in other reviews, there is no recognized best index at present [12,13]. In a recent study by Yan et al [143], nine typical cattle-related thermal indices have been compared using 273 lactating Holstein-Friesian dairy cows in a naturally ventilated commercial barn in Jiangsu, China. The results show that some indices could not even reflect the response of physiological indicators (RR, VT) to heat stress, and CCI was determined as the best thermal index.…”

Section: Selection Of Thermal Indices Suitable For Specific Environmentsmentioning

confidence: 99%

Recent Advances on Early Detection of Heat Strain in Dairy Cows Using Animal-Based Indicators: A Review

Shu

Wang

Guo

et al. 2021

Animals

View full text Add to dashboard Cite

In pursuit of precision livestock farming, the real-time measurement for heat strain-related data has been more and more valued. Efforts have been made recently to use more sensitive physiological indicators with the hope to better inform decision-making in heat abatement in dairy farms. To get an insight into the early detection of heat strain in dairy cows, the present review focuses on the recent efforts developing early detection methods of heat strain in dairy cows based on body temperatures and respiratory dynamics. For every candidate animal-based indicator, state-of-the-art measurement methods and existing thresholds were summarized. Body surface temperature and respiration rate were concluded to be the best early indicators of heat strain due to their high feasibility of measurement and sensitivity to heat stress. Future studies should customize heat strain thresholds according to different internal and external factors that have an impact on the sensitivity to heat stress. Wearable devices are most promising to achieve real-time measurement in practical dairy farms. Combined with internet of things technologies, a comprehensive strategy based on both animal- and environment-based indicators is expected to increase the precision of early detection of heat strain in dairy cows.

show abstract

Evaluation of thermal indices based on their relationships with some physiological responses of housed lactating cows under heat stress

Cited by 20 publications

References 44 publications

Evaluation of Thermal Indices as the Indicators of Heat Stress in Dairy Cows in a Temperate Climate

Evaluation of Thermal Indices as the Indicators of Heat Stress in Dairy Cows in a Temperate Climate

Critical Temperature-Humidity Index Thresholds Based on Surface Temperature for Lactating Dairy Cows in a Temperate Climate

Recent Advances on Early Detection of Heat Strain in Dairy Cows Using Animal-Based Indicators: A Review

Contact Info

Product

Resources

About