scholarly journals Efectos de la tensión calórica en la época seca sobre algunos índices fisiológicos y el estado general en lactación y crecimiento en ganado lechero cruzado

2016 ◽  
Vol 3 ◽  
pp. 34
Author(s):  
Edil E. Arauz
Keyword(s):  
Heat Stress ◽  
Polynomial Regression ◽  
Dry Season ◽  
Average Weight ◽  
Physiological Variables ◽  
Lactating Cows ◽  
Time Period ◽  
Respiratory Index ◽  
Humidity Index ◽  
The University

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.

scholarly journals Characterization of Short-Term Heat Stress in Holstein Dairy Cows Using Altered Indicators of Metabolomics, Blood Parameters, Milk MicroRNA-216 and Characteristics

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 722
Author(s):  
Jang-Hoon Jo ◽  
Jalil Ghassemi Nejad ◽  
Dong-Qiao Peng ◽  
Hye-Ran Kim ◽  
Sang-Ho Kim ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Milk Yield ◽  
Milk Fat ◽  
Blood Parameters ◽  
Negative Effects ◽  
Short Term ◽  
Lactating Cows ◽  
Humidity Index ◽  
Holstein Dairy Cows

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.

scholarly journals Influence of sex, reproductive status and foetal number on erythrocyte osmotic fragility, haematological and physiologic parameters in goats during the hot-dry season

2014 ◽  
Vol 59 (No. 10) ◽  
pp. 479-490 ◽  
Author(s):  
B. Habibu ◽  
MU Kawu ◽  
HJ Makun ◽  
T. Aluwong ◽  
LS Yaqub ◽  
...  
Keyword(s):  
Heat Stress ◽  
Rectal Temperature ◽  
Osmotic Fragility ◽  
Dry Season ◽  
Corpuscular Haemoglobin ◽  
Physiological Variables ◽  
Erythrocyte Osmotic Fragility ◽  
Hot Dry Season ◽  
Mean Corpuscular Haemoglobin ◽  
Twin Pregnancies

The current study was aimed at evaluating the effect of heat stress (during the hot-dry period) on some physiological variables, haematology and erythrocyte osmotic fragility (EOF) in bucks, pregnant (single and twin) and lactating Red Sokoto (RS) goats. Forty apparently healthy adult goats were used for the study and were allotted to four groups [bucks (n = 10), pregnant (n = 10) dry (n = 10), and lactating (n = 10) does]. The pregnant goats were further re-grouped according to number of foetuses (single foetus, n = 5 and twins, n = 5). The temperature-humidity index and physiological variables measured were significantly higher in the afternoon compared to morning hours. Pregnant does had higher respiratory and pulse rates than the dry does, but no significant change (P &gt; 0.05) in rectal temperature was observed between groups. On the basis of sex, bucks had lower (P &lt; 0.05) mean corpuscular volume (MCV) than other groups, in addition to having higher (P &lt; 0.01) mean corpuscular haemoglobin (MCH) and total leucocyte counts than dry does. Pregnant does exhibited significantly lower (P &lt; 0.05) packed cell volume, but significantly higher (P &lt; 0.05) MCH and mean corpuscular haemoglobin concentrations (MCHC) than lactating does. Does with a single foetus had significantly lower (P &lt; 0.05) MCV, but higher MCHC than does with twin pregnancies. Using EOF as a biomarker of oxidative stress, erythrocytes of bucks were significantly more resistant to hypotonic haemolysis than those of dry, pregnant and lactating does, with no significant difference in EOF between does of different groups. The erythrocytes of single and twin pregnancies showed similar haemolysis pattern. In conclusion, sex, lactation, and the number of foetuses carried by pregnant does significantly influences physiological and haematological variables in RS goats during the hot-dry season. Also, during heat stress, the changes in physiological variables seem to enhance favourable adaptation by preventing an increase in rectal temperature even in twin pregnancies. &nbsp;

scholarly journals What is the best temperature-humidity index equation to indicate heat stress in crossbred dairy calves in a tropical environment?

2019 ◽  
Vol 49 (1) ◽  
Author(s):  
Fernanda Gatti de Oliveira Nascimento ◽  
Hellen Cris Pinto Aguiar ◽  
Gustavo Moya Rodrigues ◽  
Ednaldo Carvalho Guimarães ◽  
Mara Regina Bueno de Mattos Nascimento
Keyword(s):  
Heat Stress ◽  
Dew Point ◽  
Tropical Environment ◽  
Dairy Calves ◽  
Sensible Heat ◽  
Dew Point Temperature ◽  
Physiological Variables ◽  
Temperature Humidity Index ◽  
Humidity Index ◽  
The One

ABSTRACT: The aim of this study was to determine among nine temperature-humidity index (THI) equations, the one that best represents the effects of heat stress on crossbred dairy calves reared in a tropical environment. Twelve male and female calves, aged 20 to 60 days, and raised in a tropical pen were evaluated. Respiratory (RR) and heart rates (HR), rectal (RT), body surface (BST), dry bulb (Tdb) and wet bulb (Tbw) temperatures, partial vapor pressure (Pv), relative humidity (RH) and dew point temperature (Tpo) were quantified in the morning and afternoon. Nine THI equations were calculated. The highest correlation between physiological variables and this was used to select the best THI equation. Averages for nine THI equations, Tdb, Twb, Pv, Tdp, RR, HR, RT, and BST were higher in the afternoon than in the morning, whereas that for RH was the opposite. The highest values for RT occurred at temperatures above 26.4°C and when humidity was below 55.5%. The Tdb and Pv correlations with RR (0.697 and 0.707), RT (0.703 and 0.706) and BST (0.818 and 0.817) were significant and positive, whereas the RH correlations with the same physiological variables were significant and negative (-0.622, -0.590 and -0.638, respectively). The best index was the THI sensible heat-based ( T H I = 3.43 + 1.058 x T d b - 0.293 x R H + 0.0164 x T d b x R H + 35.7), which was significantly correlated with RR (r=0.668 and r²=0.446), HR (r=0.259 and r²=0.067), RT (r=0.693 and r²=0.479) and BST (r=0.807 and r²=0.650). In conclusion, the THI sensible heat-based equation best represents the effects of heat stress on crossbred dairy calves reared in a tropical environment.

Effect of Shearing Wool and the Hot Months of the Year on some Production Characteristics in Turkish Awassi Ewes

2020 ◽  
Vol 13 (1) ◽  
pp. 50-58
Author(s):  
Taha AL-Sharqi ◽  
Majid Abdullah
Keyword(s):  
Body Weight ◽  
Heat Stress ◽  
Birth Weight ◽  
Total Body Weight ◽  
Average Weight ◽  
Significant Difference ◽  
Group Control ◽  
Humidity Index ◽  
Total Body ◽  
Production Characteristics

This study aimed to investigate the effect of wool shearing and the environmental factors represented by some hot months of the year (July August and September) on some production characteristics in Turkish Awassi ewes. 18 ewes, aged 3-5 years, with an average weight of about 55±1.43 kg, were used. The ewes divided into three treatments. The first group control (T1) were not shorned the wool, the second group (T2) wool of ewes were sheared at a distance of 1 cm from skin, while third group (T3) wool of ewes were sheared at level of the skin. The value of the weekly Temperature-humidity index THI in this study (32.33, 31.08, 31.70, 32.53, 33.45, 33.83, 34.60, 33.91, 31.90, 31.10, 31.84, 32.74) weeks respectively, while the monthly THI was (31.63, 33.48, 31.82) months of the study in July August and September in a respectively. The results showed a significant difference (p<0.05) between the treatments in body weight that were recorded at the tenth week where the THI reached. While the Second group recorded (2.16 ± 0.802) kg compared to T1, T3 (0.916 ± 0.723) (0.583 ± 0.490) kg respectively. While the total body weight of ewes and birth weight showed non-significant differences between different treated groups. From another hand the result showed non-significant differences feed and significant differences in water consumption between different treated groups. From the current study concluded that the level of shearing wool in Turkish Awassi ewes in conjunction with high temperature has an effect in production characteristics by reducing the effect of heat stress on the ewes.

scholarly journals Economic Feasibility of Cooling Dry Cows: Findings and Spreadsheet

EDIS ◽  
2018 ◽  
Vol 2018 (2) ◽  
Author(s):  
Fernanda Ferreira ◽  
Geoffrey E. Dahl ◽  
Albert De Vries
Keyword(s):  
Heat Stress ◽  
Economic Feasibility ◽  
Economic Losses ◽  
Negative Effects ◽  
University Of Florida ◽  
Lactating Cows ◽  
Calf Performance ◽  
Cow Health ◽  
The University ◽  
Animal Sciences

The negative effects of heat stress in lactating cows are well known, but only recent studies have explored those effects along with the full benefits of cooling dry cows. Recent work at the University of Florida has demonstrated the benefits of dry cow cooling on calf performance and cow health in the next lactation. This 5-page fact sheet discusses the economic losses from milk production due to heat stress, investment, utilities, maintenance, and feasibility analysis. Written by Fernanda Ferreira, Geoffrey Dahl, and Albert De Vries, and published by the UF/IFAS Department of Animal Sciences, March 2018.  http://edis.ifas.ufl.edu/an342

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
Keyword(s):  
Heat Stress ◽  
Solar Radiation ◽  
Climatic Conditions ◽  
Central Mexico ◽  
North Central ◽  
Northern Mexico ◽  
Lactating Cows ◽  
High Solar Radiation ◽  
Humidity Index ◽  
Dangerous Level

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.

scholarly journals Silvopastoral System Mitigates the Thermal Stress and Benefits Water Buffaloes’ Comfort in the Eastern Amazon, Brazil

2020 ◽  
Vol 8 (4) ◽  
pp. 193
Author(s):  
Núbia De Fátima Alves dos Santos ◽  
Jamile Andréa Rodrigues da Silva ◽  
Airton Alencar de Araújo ◽  
Alexandre Rossetto Garcia ◽  
Troy Patrick Beldini ◽  
...  
Keyword(s):  
Canopy Cover ◽  
Comfort Level ◽  
Average Weight ◽  
Silvopastoral System ◽  
Environmental Indices ◽  
Traditional System ◽  
Comfort Index ◽  
Physiological Variables ◽  
Management Regime ◽  
Humidity Index

Twenty female Murrah buffaloes between four and five years old were randomly distributed into two groups (traditional system - TS and silvopastoral system - SPS) with 10 animals each and an average weight of 377.78 kg and 356.10 kg, respectively, for the TS and the SPS. The TS had a management regime with no canopy cover and no shade coverage over the drinking and feeding troughs. In the SPS, Racosperma mangium (Fabaceae) trees were used to provide shade, with an estimated 10% shading. The physiological variables studied were rectal temperature and respiratory frequency measured every three days from 6 to 7 AM and from 12 to 1 PM. The following environmental indices were calculated: Temperature Humidity Index (THI), Black Globe Humidity Comfort Index (BGHI), and Benezra’s Index of Adaptability (BIA). The THI values were high in both management systems, between 76.27 and 86.73, higher than the limit of comfort level for buffaloes, which is 75. The maximum values of BGHI for the afternoon were 92.0 and 87.62, for TS and SPS, respectively, and the maximum values of BIA for the afternoon were 4.4 and 3.8, for TS and SPS respectively, which were higher than the critical level of adaptability and represented an uncomfortable condition that causes a reduction in animal performance. It was concluded that the silvopastoral management system is more efficient in terms of animal comfort for the female buffaloes as a result of the shade that provides a more amenable microclimate. 

scholarly journals Is Call Karma Real? Resident After-Hours On-Call Imaging at the University of Saskatchewan: An Assessment of Call Volumes Including Inter-Resident Variability

2021 ◽  
pp. 084653712110263
Author(s):  
James Huynh ◽  
David Horne ◽  
Rhonda Bryce ◽  
David A Leswick
Keyword(s):  
Mean Shift ◽  
Mean Values ◽  
Body Regions ◽  
Time Period ◽  
Relative Value ◽  
Number Of Patients ◽  
After Hours ◽  
Disproportionate Number ◽  
The University ◽  
Changes Over Time

Purpose: Quantify resident caseload during call and determine if there are consistent differences in call volumes for individuals or resident subgroups. Methods: Accession codes for after-hours computed tomography (CT) cases dictated by residents between July 1, 2012 and January 9, 2017 were reviewed. Case volumes by patient visits and body regions scanned were determined and categorized according to time period, year, and individual resident. Mean shift Relative Value Units (RVUs) were calculated by year. Descriptive statistics, linear mixed modeling, and linear regression determined mean values, differences between residents, associations between independent variables and outcomes, and changes over time. Consistent differences between residents were assessed as a measure of good or bad luck / karma on call. Results: During this time there were 23,032 patients and 30,766 anatomic regions scanned during 1,652 call shifts among 32 residents. Over the whole period, there were on average 10.6 patients and 14.3 body regions scanned on weekday shifts and 22.3 patients and 29.4 body regions scanned during weekend shifts. Annually, the mean number of patients, body regions, and RVUs scanned per shift increased by an average of 0.2 (1%), 0.4 (2%), and 1.2 (5%) (all p < 0.05) respectively in regression models. There was variability in call experiences, but only 1 resident had a disproportionate number of higher volume calls and fewer lower volume shifts than expected. Conclusions: Annual increases in scan volumes were modest. Although residents’ experiences varied, little of this was attributable to consistent personal differences, including luck or call karma.

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