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

Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 970
Author(s):  
Geqi Yan ◽  
Zhengxiang Shi ◽  
Hao Li

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.

2011 ◽  
Vol 23 (1) ◽  
pp. 179
Author(s):  
M. Tani ◽  
C. Tani ◽  
K. Tomokawa ◽  
D. Funakoshi ◽  
M. Sakatani ◽  
...  

A serious decline in the reproductive performance of dairy cows occurs in southern Japan in the summer period, when the total number of hot days ≥35°C numbers more than 20 days annually. Previous reports have mentioned the effectiveness of embryo transfer (ET) at 7 days after AI (AI/ET) under heat-stressed conditions. In the present study, we investigated the effect of AI/ET on conception rate (CR) under heat-stressed conditions in the summer period. Artificial insemination was performed at 13 commercial dairies in this study from August through September in 2007 and 2008. Seven days after AI, a single embryo was transferred into the uterine horn contralateral to the ovary with a corpus luteum (AI/ET, n = 82). Artificial insemination at oestrus without further treatment was assigned as the control group (AI, n = 367). In 2007, frozen–thawed embryos of Japanese Black cattle were transferred, and the same cattle were used for ET of fresh embryos in 2008. The temperature-humidity index [0.8 × temperature + 0.01 ×relative humidity (temperature –14.4) + 46.4], rectal temperature, and diurnal highest or lowest and average ambient temperatures were measured at the time of AI and ET. Cows were diagnosed for pregnancy at 42 days after AI by palpation per rectum and were reexamined by transrectal ultrasonography at 60 days after AI. The CR was calculated as the number of cows diagnosed as pregnant 60 days after AI divided by the number of cows inseminated. Fetal loss was calculated as the number of cows that did not deliver calves after term divided by the number of cows diagnosed as pregnant. The CR, number of AI, fetal loss, and type of newborn (Holsteins, AI origin; Japanese Black, ET origin) were confirmed retrospectively. For statistical analysis, Fisher’s exact test and Student’s t-test were used for comparison of the CR, fetal loss, and body temperature by using a statistical software program for PC (Excel Statistics 2006). The CR for AI/ET was 30.4% and for AI was 13.8% in 2007 (P < 0.01), and the CR for AI/ET was 30.8% and for AI was 21.5% in 2008 (P = 0.294). The average diurnal temperature was 31.1°C in 2007 and 30.1°C in 2008, and the temperature-humidity index was 81.8 and 80.8, respectively. On Day 8, the pregnant cows had a lower rectal temperature than the open cows in 2007, but not in 2008 (38.9 v. 39.4°C in 2007; P < 0.05; and 39.1 v. 38.9°C in 2008; P > 0.05). The fetal loss was 38.1% in AI/ET v. 7.4% in AI in 2007 (P < 0.05) and 12.5% v. 0% in 2008 (P < 0.05), respectively. The AI/ET procedure could improve CR in dairy cows during the summer period in southern Japan. However, other problems may accompany AI/ET, such as higher fetal losses.


2011 ◽  
Vol 57 (4) ◽  
pp. 450-456 ◽  
Author(s):  
Hisashi NABENISHI ◽  
Hiroshi OHTA ◽  
Toshihumi NISHIMOTO ◽  
Tetsuo MORITA ◽  
Koji ASHIZAWA ◽  
...  

2021 ◽  
Vol 2 ◽  
Author(s):  
Véronique Ouellet ◽  
Izabella M. Toledo ◽  
Bethany Dado-Senn ◽  
Geoffrey E. Dahl ◽  
Jimena Laporta

The effects of heat stress on dry cows are profound and significantly contribute to lower overall welfare, productivity, and profitability of the dairy sector. Although dry cows are more thermotolerant than lactating cows due to their non-lactating state, similar environmental thresholds are currently used to estimate the degree of heat strain and cooling requirements. Records of dry cow studies conducted over 5 years in Gainesville, Florida, USA were pooled and analyzed to determine environmental thresholds at which dry cows exhibit signs of heat stress in a subtropical climate. Dry-pregnant multiparous dams were actively cooled (CL; shade of a freestall barn, fans and water soakers, n = 107) or not (HT; shade only, n = 111) during the last 7 weeks of gestation, concurrent with the entire dry period. Heat stress environmental indices, including ambient temperature, relative humidity, and temperature-humidity index (THI), and animal-based indices, including respiration rate, rectal temperature and daily dry matter intake were recorded in all studies. Simple correlations were performed between temperature-humidity index and each animal-based indicator. Differences in respiration rate, rectal temperature and dry matter intake between treatments were analyzed by multiple regression. Using segmented regression, temperature-humidity thresholds for significant changes in animal-based indicators of heat stress were estimated. Stronger significant correlations were found between the temperature-humidity index and all animal-based indices measured in HT dry cows (−0.22 ≤ r ≤ 0.35) relative to CL dry cows (−0.13 ≤ r ≤ 0.19). Although exposed to similar temperature-humidity index, rectal temperature (+0.3°C; P &lt; 0.001) and respiration rate (+23 breaths/min; P &lt; 0.001) were elevated in HT dry cows compared with CL cows whereas dry matter intake (−0.4 kg of dry matter/d; P = 0.003) was reduced. Temperature-humidity index thresholds at which respiration rate and rectal temperature began to change were both determined at a THI of 77 in HT dry cows. No significant temperature-humidity threshold was detected for dry matter intake. At a practical level, our results demonstrate that dry cow respiration rate and rectal temperature increased abruptly at a THI of 77 when provided only shade and managed in a subtropical climate. Therefore, in the absence of active cooling, dry cows should be closely monitored when or before THI reaches 77 to avoid further heat-stress related impairments during the dry period and the subsequent lactation and to mitigate potential carry-over effects on the offspring.


2016 ◽  
Vol 87 (11) ◽  
pp. 1334-1339 ◽  
Author(s):  
Kerstin Wegner ◽  
Christian Lambertz ◽  
Gürbüz Das ◽  
Gerald Reiner ◽  
Matthias Gauly

2021 ◽  
Vol 24 (2) ◽  
pp. 24-36
Author(s):  
Lazoumi Ouarfli ◽  
Abdelmadjid Chehma

Abstract The objective is to study the effect of heat stress on milk yield (MY) relative to milking records (n=18178) of native Holsteins (n=187), in the region of Ghardaia, according to periods of HS, using the temperature-humidity index (THI). With THI >72 during 07 months in the study area, which significantly (P<0.001) decrease the MY (-15.5% corresponding to 21.73 kg). Also, calving periods led to a significant drop (P < 0.001) in overall MY (7030.35 kg) of the order of (-14.6%), and over the lactation length (353.43 d), which explains 41% of the variations in MY. In addition, the non-significant effect (P=0.212) of the lactation range on the increase in MY, moreover, the lactation length shows a non-significant (P = 0.108) decrease (-4.68%) during heat stress (HS). Furthermore, the significant effect (P <0.001) of the interaction (Milking frequency × THI) on MY, when THI variates from < 74 to > 84, with regression of (-16.82% and -08.82%) of the MF (2X and 3X), respectively. Again, the NH cow is less sensitive to hyperthermia, so THI explains only 2% of the variation in MY levels. Thus, NH in arid regions have the ability to acclimatize to Saharan environmental conditions.


2016 ◽  
Vol 16 (2) ◽  
pp. 131
Author(s):  
Elmy Mariana ◽  
Didik Nurul Hadi ◽  
Nur Qoim Agustin

ABSTRAK. Tujuan dari penelitian ini adalah untuk mempelajari respon fisiologi, produksi dan kualitas susu sapi perah Frisian Holstein pada akhir musim kemarau panjang di Balai Pengembangan Ternak Sapi Perah dan Hijauan Makanan Ternak (BPT-SP HMT) Cikole, Lembang, Bandung.  Penentuan sampel menggunakan metode purposive sampling. Parameter mikroklimat yang diamati antara lain adalah temperatur lingkungan, kelembaban relatif, kecepatan angin, radiasi sinar matahari dalam kandang dan Temperature-Humidity Index (THI). Respon fisiologis yang diamati meliputi suhu rektal, suhu kulit, suhu tubuh, frekuensi respirasi dan denyut jantung. Nilai rerata THI (73.93±5.51) menunjukkan sapi perah berada dalam kondisi  stress ringan. Nilai rerata dari suhu rektal, suhu kulit, suhu tubuh, frekuensi respirasi dan denyut jantung secara berurutan 37.94±0.20°C; 32.15±1.25°C; 37.13±0.32°C; 39.13 ±3.00 dan 79.74±6.19. Nilai rerata persentase bahan kering, lemak dan protein susu secara berurutan 10,19 ± 0,72, 2,14 ± 0,38 dan 2,50 ± 0,32. Temperatur lingkungan yang tinggi  mempengaruhi respon fisiologis antara lain peningkatan denyut jantung yang lebih tinggi dari normal dan kualitas susu yang lebih rendah.   (Physiological responses and milk qualities of holstein friesian during long dry season at high altitude)ABSTRACT. The objectives of this study were to evaluate physiological responses and milk qualities of dairy cows in Balai Pengembangan Ternak Sapi Perah dan Hijauan Makanan Ternak (BPT-SP HMT) Cikole West Bandung at the end of long dry season. Samples were determined by using purposive sampling method. Microclimate parameters  were included  ambient temperature, relative humidity, air velocity, solar radiation and temperature-humidity index (THI). Physiological responses consisted of rectal temperature, skin temperature, body temperature, respiration rate and pulse rate. The mean value of THI (73.93±5.51) showed that dairy cows suffered by heat stress. The mean value of rectal temperature, skin temperature, body temperature, respiration rate and pulse rate were 37.94±0.20°C; 32.15±1.25°C; 37.13±0.32°C; 39.13±3.00 and 79.74±6.19 consecutively. The average percentage value of dry matter, fat and protein content in milk were 10.19±0.72, 2.14±0.38 and 2.50±0.32. High ambient temperature and low relative humidity affected physiological responses such as pulse rate that higher than normal,  and  lower milk yield.


2020 ◽  
Vol 20 (2) ◽  
pp. 613-627 ◽  
Author(s):  
Frederico Márcio C. Vieira ◽  
Matheus Deniz ◽  
Edgar S. Vismara ◽  
Piotr Herbut ◽  
Jaqueline A. Pilatti ◽  
...  

AbstractIn this study, we investigated the influence of a silvopastoral system on the thermal environment, behaviour and thermoregulation of dairy heifers in a subtropical climate. The experiment was conducted on a dairy farm in Southwest Paraná, Brazil, during the summer of 2014. Crossbred Holstein × Jersey dairy heifers (n = 10) were used in a split-plot design. The fixed effects in this study include time of day (9:00–10:00, 13:00–14:00, and 17:00–18:00 h) under silvopastoral or open pastures conditions, which were the main-plot and split-plot factors, respectively. To assess the environmental conditions in both systems, air temperature, relative humidity and wind speed were recorded. In addition, the temperature-humidity index was calculated based on the microcli-mate measurements. Respiratory rate and hair coat surface temperature of heifers were measured in both groups during time of day (30 days). Diurnal behaviour using focal observations with 0/1 sampling was observed. Data were analysed using Bayesian inference with a mixed effects model. The air temperature was higher (P<0.05) in open pasture conditions than the silvopasture system. Temperature-humidity index values for the silvopasture system were lower than open pasture during the hottest hours of the day. Regarding thermoregulation responses, there was an interaction between time of day and pasture environment (P<0.05). Heifers showed lower respiratory rates and hair coat surface temperature values (P<0.05) when access to shade was provided, mainly during the hottest periods in the afternoon. In addition, there was also an interaction between rumination and water intake (P<0.05), which indicates a higher rumination frequency for animals in the silvopasture system during the hottest period, as well as a higher water intake frequency for heifers in open pasture during midday. These findings imply that the arrangement of trees in a silvopasture system provides better thermal comfort conditions for dairy heifers raised in a subtropical climate.


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