PSVIII-13 Are the heat stress days increasing in central northern Mexico?

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 425-426
Author(s):  
Rafael Rodriguez-Martinez ◽  
Jesús Salvador Rivas-Madero ◽  
Pedro Antonio Robles-Trillo ◽  
César A Meza-Herrera ◽  
Rafael Rodriguez-Venegas

Abstract The Lagunera region, located in north central Mexico (24° 01′-26° 48 ‘LN and 101° 52′-101° 52′ 104° 40′ LO), produce the 21% of the national Mexican cow’s milk despite its climatic conditions (temperatures that fluctuate between 12.7 °C in January and 28.5 °C in June, with extremes of -5 °C and 41.5 °C, in addition to high solar radiation). The Temperature Humidity Index (THI) is the most useful indicator to define if there are heat stress conditions. To identify whether the days in which THI ≥68 (considering the threshold for signs of heat stress to appear in high-producing lactating cows) are increasingly reached at least one hour a day, the information of this indicator was recorded every 10 min daily, from 5 cow farms for 6 years (2015–2020), using the DiGiTH™ application (DiGiTH Technologies, Mexico), and regressions were run to identify if there is a relationship between the years of study and the THI levels. At any level of THI (≥68), there is a tendency to increase the number of days (10.05 d per year; R2 0.37); Disaggregating the data by THI level, this trend is also observed for levels 68 to 71 and 72 to 76 THI, registering an increase of 11.33 d (R2 0.45) and 9.03 d per year (R2 0.45) respectively. At the 77 - 79 THI level there is no trend, while at the ≥80 THI level, a decrease of 5.66 d per year was registered (R2 0.79). The results suggest that in this region, the days of heat stress are increasing, except for the level ≥80 THI, which indicates that palliative measures for heat stress should be intensified, and it is necessary to identify the reason for the decrease in heat stress days at the most dangerous level for livestock.

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 437-438
Author(s):  
Rafael Rodriguez-Martinez ◽  
César A Meza-Herrera ◽  
Rafael Rodriguez-Venegas ◽  
Pedro Antonio Robles-Trillo ◽  
Jesús Salvador Rivas-Madero

Abstract The Temperature Humidity Index (THI) is the most used to identify the risk of heat stress for dairy cattle, which is based on the environmental temperature (ºC) and humidity (%), and of which they are currently considered 68 points as the threshold for high producing dairy cows. In the Comarca Lagunera, located in north central Mexico, 21% of the Mexican dairy production is generated annually, despite its environmental conditions characterized by temperatures up to 41.5 ° C in the summer, low relative humidity and high solar radiation. The objective was to identify the average number of days in which a THI ≥68 is reached per month in each season of the year with 1, 8 and 16 h of exposure in dairy farms of the region, for which, the information recorded every 10 min was analyzed daily in five farms for 6 years (2015–2020), using the DiGiTH ™ application (DiGiTH Technologies, Mexico) and through ANOVA (proc GLM; SAS Inst. Inc., Cary, NC, USA), to identify differences seasonal for this variable. The attached table shows that spring and summer were the seasons in which the highest number of average days per month were recorded, and winter in which the fewest days were recorded. Regarding the hours of exposure, it is observed that spring and summer are very similar in 1 and 8 hours of exposure, while for autumn and winter a clearer decrease is observed according to the hours of exposure for these seasons. These results indicate a very marked seasonal variability and in terms of the hours of exposure, which should be considered in order to adopt the measures to reduce the negative effects for the dairy cattle of the region.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 722
Author(s):  
Jang-Hoon Jo ◽  
Jalil Ghassemi Nejad ◽  
Dong-Qiao Peng ◽  
Hye-Ran Kim ◽  
Sang-Ho Kim ◽  
...  

This study aims to characterize the influence of short-term heat stress (HS; 4 day) in early lactating Holstein dairy cows, in terms of triggering blood metabolomics and parameters, milk yield and composition, and milk microRNA expression. Eight cows (milk yield = 30 ± 1.5 kg/day, parity = 1.09 ± 0.05) were homogeneously housed in environmentally controlled chambers, assigned into two groups with respect to the temperature humidity index (THI) at two distinct levels: approximately ~71 (low-temperature, low-humidity; LTLH) and ~86 (high-temperature, high-humidity; HTHH). Average feed intake (FI) dropped about 10 kg in the HTHH group, compared with the LTLH group (p = 0.001), whereas water intake was only numerically higher (p = 0.183) in the HTHH group than in the LTLH group. Physiological parameters, including rectal temperature (p = 0.001) and heart rate (p = 0.038), were significantly higher in the HTHH group than in the LTLH group. Plasma cortisol and haptoglobin were higher (p < 0.05) in the HTHH group, compared to the LTLH group. Milk yield, milk fat yield, 3.5% fat-corrected milk (FCM), and energy-corrected milk (ECM) were lower (p < 0.05) in the HTHH group than in the LTLH group. Higher relative expression of milk miRNA-216 was observed in the HTHH group (p < 0.05). Valine, isoleucine, methionine, phenylalanine, tyrosine, tryptophan, lactic acid, 3-phenylpropionic acid, 1,5-anhydro-D-sorbitol, myo-inositol, and urea were decreased (p < 0.05). These results suggest that early lactating cows are more vulnerable to short-term (4 day) high THI levels—that is, HTHH conditions—compared with LTLH, considering the enormous negative effects observed in measured blood metabolomics and parameters, milk yield and compositions, and milk miRNA-216 expression.


2021 ◽  
Vol 13 (5) ◽  
pp. 2836
Author(s):  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Muhammad Bilal ◽  
Hadeed Ashraf ◽  
Muhammad Farooq ◽  
...  

Poultry are one of the most vulnerable species of its kind once the temperature-humidity nexus is explored. This is so because the broilers lack sweat glands as compared to humans and undergo panting process to mitigate their latent heat (moisture produced in the body) in the air. As a result, moisture production inside poultry house needs to be maintained to avoid any serious health and welfare complications. Several strategies such as compressor-based air-conditioning systems have been implemented worldwide to attenuate the heat stress in poultry, but these are not economical. Therefore, this study focuses on the development of low-cost and environmentally friendly improved evaporative cooling systems (DEC, IEC, MEC) from the viewpoint of heat stress in poultry houses. Thermodynamic analysis of these systems was carried out for the climatic conditions of Multan, Pakistan. The results appreciably controlled the environmental conditions which showed that for the months of April, May, and June, the decrease in temperature by direct evaporative cooling (DEC), indirect evaporative cooling (IEC), and Maisotsenko-Cycle evaporative cooling (MEC) systems is 7–10 °C, 5–6.5 °C, and 9.5–12 °C, respectively. In case of July, August, and September, the decrease in temperature by DEC, IEC, and MEC systems is 5.5–7 °C, 3.5–4.5 °C, and 7–7.5 °C, respectively. In addition, drop in temperature-humidity index (THI) values by DEC, IEC, and MEC is 3.5–9 °C, 3–7 °C, and 5.5–10 °C, respectively for all months. Optimum temperature and relative humidity conditions are determined for poultry birds and thereby, systems’ performance is thermodynamically evaluated for poultry farms from the viewpoint of THI, temperature-humidity-velocity index (THVI), and thermal exposure time (ET). From the analysis, it is concluded that MEC system performed relatively better than others due to its ability of dew-point cooling and achieved THI threshold limit with reasonable temperature and humidity indexes.


2018 ◽  
Vol 63 (1) ◽  
pp. 57-66
Author(s):  
Balázs Bokor ◽  
Hacer Akhan ◽  
Dogan Eryener ◽  
László Kajtár

Transpired solar collector (TSC) systems are simple solutions for the preheating of ventilation air with solar energy. Their performance is a function of several environmental factors, so the climatic conditions of the location play an important role. In this paper, the effect of different climatic zones on the thermal performance of the TSC is investigated. To exclude other sources of influence, the same reference industrial building is examined in four Turkish locations (Antalya, Istanbul, Ankara and Sivas) representing different climatic conditions. RETScreen simulation is carried out for all four regions to obtain the drop of conventional heating requirement in case absorber azimuth of 0°, 45° and 90°. To illustrate the performance, temperature rise, heating energy savings and annual solar fraction are presented. Generally, it can be stated that a location with cold climate and high solar radiation at the same time benefits most from the use of a TSC system. A mathematical correlation has been found showing the solar fraction's dependence on solar radiation and heating degree days. Finally, simulation results have been compared to a set of measurement data from an industrial building's TSC system near Istanbul.


2004 ◽  
Vol 78 (1) ◽  
pp. 139-147 ◽  
Author(s):  
M. Zähner ◽  
L. Schrader ◽  
R. Hauser ◽  
M. Keck ◽  
W. Langhans ◽  
...  

AbstractThis study aimed to assess whether cows are able to cope with the range of climatic conditions they are exposed to in open stables on commercial farms in central Europe. On each of four farms, ten lactating cows were observed over a total of five weeks in winter, spring and summer. Based on continuous measurements of air temperature (–13·8 to 28·7ºC) and relative air humidity (0·26 to 0·99), a mean value of a temperature humidity index (THI) was calculated for each farm and each observation day for night and day.THI had significant effects on skin temperature and body surface temperature (infra-red thermography) both during night and day. Rectal temperature, duration of lying and cortisol concentration in the milk was significantly affected by THI during the day but not during the night. Heart rate and frequency of lying did not significantly covary with THI. Differences between farms and interactions between THI and farm were significant for most parameters. These results suggest that the climatic conditions during the day induced stronger thermoregulatory responses than the conditions during the night. Within the measured range of climatic conditions the cows were hardly exposed to severe cold or heat stress.


2019 ◽  
Vol 12 (2) ◽  
pp. 183-190 ◽  
Author(s):  
B. Udovicki ◽  
I. Djekic ◽  
S. Stankovic ◽  
A. Obradovic ◽  
A. Rajkovic

The influence of climatic conditions on the levels of fumonisins in maize grown in Serbia was studied over eight years (2008 to 2015), investigating the possible relationship between the levels of fumonisins contamination in maize in relation to registered weather/climatic conditions. Presence of these mycotoxins in maize after harvest was evaluated based on climatic conditions within two periods: 10 days before and 10 days after 50% silking. Categories of fumonisins levels were transformed into classes. Chi-square test for association was used in analysing relationships between results of fumonisins levels and calendar years. Mann-Whitney U-test was used to compare differences between meteorological data of two subsets in years with high and low fumonisins level. There was a statistically significant association between the fumonisins levels and calendar years χ2=247.954; (P<0.05). This study identified low precipitation and low humidity combined with high solar radiation as a critical parameter combination for elevated levels of fumonisins. The statistically significant difference in relation to some of the examined parameters suggests that maize in Serbian agro-climatic conditions is more susceptible to fungal colonisation, and subsequent fumonisin production in the period of 10 days before 50% silking.


2019 ◽  
Vol 17 (2) ◽  
pp. e0405
Author(s):  
Miguel Mellado ◽  
Vanessa Alba ◽  
Leticia Gaytán ◽  
José E. García ◽  
Jesús Mellado

The objective of this study was to evaluate the impact of age at first calving (AFC) and climatic conditions at calving on peripartum disorders and reproductive performance in Holstein heifers in a hot environment. A total of 3000 reproductive records from a large highly technified dairy farm were used; the variables evaluated were temperature humidity index (THI; <77, 77-83, >83) at calving and AFC (<2.0, 2.0-2.2 and >2.2 years). Across age groups, the cases of dystocic parturition increased (p<0.05) when the deliveries occurred with severe heat stress (4.3% vs. 3.3% for THI >83 and <83 units, respectively). Across THI, conception rate at the first postpartum artificial insemination (AI) was lower (p=0.02) for heifers calving for the first time >2.2 years compared to heifers calving between 2.0 and 2.2 and <2.0 years (9.8, 15.3 and 13.7%, respectively). Conception rate at first AI postcalving was higher (p<0.01) in heifers calving with THI less than 83 units than in heifers calving with a THI >83 units (16.8 vs. 5.4%). The conception rate considering all services was affected (p<0.05) by AFC (42.7, 50.4 and 40.9% for AFC <2.0, 2.0-2.2 and >2.2 years, respectively). The interaction AFC × THI at calving was significant (p<0.05). The occurrence of metritis was higher (p<0.05) in heifers <2.0 years of age at calving than those calving after 2 years of age. The presence of ovarian cysts was less common (p<0.05) in heifers with greater AFC. In conclusion, increasing the AFC in Holstein heifers had no benefits in reproduction and health, compared with heifers calving at <2.0 years. These data in a hot climate suggest that heifers should be selected to begin their first lactation before 2 years of age.


2016 ◽  
Vol 3 ◽  
pp. 34
Author(s):  
Edil E. Arauz

The test was conducted, at the facilities of the Dual Purpose Dairy Program of the University of Panama in Chiriqui, Panama, to quantify the main climatic variables during the dry season and their effect on so me physiological indexes of lactating and growing hybrid dairy cattle. The physiological variables were analyzed using the split-plot experimental design in time and contrast of polynomial regression. Ten lactating hybrid cows, with and average weight of 446 kg and a milk production of 6.8 kg/cow/day, and ten calves weighing 118 kg each were used. The animals were Holstein/Brown Swiss X Zebu crossbreeds. The micro-climatic characterization, based on solar radiation, ambient temperature and the temperature-humidity index, indicated that the day time period during the dry season is the representative type of effective climatic heat stress,lactating cows and calves were affected by heat stress, and quadratic and cubic increases were observed in rectal temperature and the respiratory index over the normal physiological pattern.


Author(s):  
Rajalaxmi Behera ◽  
A. K. Chakravarty ◽  
A. Sahu ◽  
N. Kashyap ◽  
S. Rai ◽  
...  

The present study was conducted to identify the most suitable temperature humidity index (THI) model among seven reported THI models for analyzing the impact of thermal stress on monthly test day fat % (MTDF%),monthly test day SNF% (MTSNF%), monthly test day fat yield (MTDFY) and monthly test day SNF yield (MTDSNFY) of Murrah buffaloes at subtropical climatic conditions of Karnal, India. A total of 8868 MTDF% and 8606 MTDSNF% records from 1107 lactational records of Murrah buffaloes under five parities were included in the present study and weather information on dry bulb temperature (Tdb), wet bulb temperature (Twb) and relative humidity (RH in %) for the corresponding period of 20 years (March 1994- December 2013) were collected from ICAR-NDRI and ICAR-CSSRI, Karnal, respectively. The overall least-squares means for MTDF% ranged from 7.71 ± 0.067 in TD1 to 8.10 ± 0.08 in TD 9 and MTDSNF% ranged from 9.61 ± 0.01 in TD5 and TD 6 to 9.65 ± 0.01 in TD 8. The overall least squares means of MTDFY (g) ranged from 411.23 ± 14.74 to 745.98 ± 13.57 while for MTDSNFY (g) the value ranged from 491.90 ± 17.21 to 922.16 ± 15.17. Monthly average THI was computed for each of the seven models. The lowest monthly average THI value was found in January, while either May, June or July showed the highest average THI value for all seven THI models. Regression analysis was performed for identifying the best THI to assess the impact of heat stress on milk constituent traits under study anda negative association was found between the milk constituent traits and monthly average THI values.The THI model[THI = (0.55 × Tdb + 0.2 × Tdp) × 1.8 + 32 + 17.5]developed by NRC(1971)was identified as the most suitable THI model to assess the impact of heat stress on milk composition traits of Murrah indicating maximum decline in MTDF% (-0.005), MTDFY (-0.68 g),MTDSNF% (b=-0.0008) and MTDSNFY (-2.25 g) per unit rise in THI.


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