scholarly journals A Complex Interrelationship between Rectal Temperature and Dairy Cows’ Performance under Heat Stress Conditions

2016 ◽  
Vol 06 (01) ◽  
pp. 24-30 ◽  
Author(s):  
Meriem Rejeb ◽  
Raoudha Sadraoui ◽  
Taha Najar ◽  
Moncef Ben M’rad
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Rectal Temperature ◽  
Stress Conditions

Genetic variation of rectal temperature and its relationship to milk production in Holstein dairy cows

2009 ◽  
Vol 2009 ◽  
pp. 63-63
Author(s):  
S Khalajzade ◽  
N Emam Jomeh ◽  
A Salehi ◽  
A Moghimi Esfandabadi
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Milk Production ◽  
Heat Tolerance ◽  
Rectal Temperature ◽  
Weather Factors ◽  
And Performance ◽  
Very High ◽  
Selection Of ◽  
Holstein Dairy Cows

Milk production is significantly decreased by thermal stress. The survival and performance of an animal during heat stress periods depend on several weather factors, especially temperature and humidity. Researchers reported dramatic decreases in milk production as temperature rose above 30 degree of centigrade. Very high environmental temperature is common during the summer months in Iran. Rectal temperature is as indicator of heat tolerance and has been the most frequently used physiological variable for estimating heat tolerance in cattle. Some dairy cows are more heat tolerant and productive when subjected to heat stress. Identification and selection of heat stress resistant cattle offers the potential to increase milk yield in tropical environment. The aim of the present study was to estimate genetic parameters of heat tolerance and its relationship to milk production in Holstein Dairy Cows in Iran.

Daily rumination time of lactating dairy cows under heat stress conditions

2020 ◽  
Vol 88 ◽  
pp. 102484 ◽  
Author(s):  
Theresa Müschner-Siemens ◽  
Gundula Hoffmann ◽  
Christian Ammon ◽  
Thomas Amon
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Stress Conditions ◽  
Lactating Dairy Cows

Physiological and growth parameters of fattening lambs after shearing under heat-stress conditions

2017 ◽  
Vol 57 (3) ◽  
pp. 569 ◽  
Author(s):  
F. Moslemipur ◽  
S. Golzar-Adabi
Keyword(s):  
Heat Stress ◽  
Rectal Temperature ◽  
Feed Intake ◽  
Growth Parameters ◽  
Underlying Mechanism ◽  
Stress Conditions ◽  
Free Access ◽  
Research Station ◽  
Feed Conversion ◽  
Protein Levels

Shearing is a common practice for lamb hygiene and health, which can also influence the animal survival and productivity in stressful environments. This study was conducted to investigate the effects of shearing on performance and some metabolic and physiological parameters of fattening lambs exposed to ambient heat stress. Thirty -two male Dalagh fattening lambs (32.4 ± 5.7 kg), 3.5 ± 0.5 months of age, were selected from a herd existing at the research station of the University of Gonbad Kavoos (temperate mild-latitude zone of Iran). Lambs were divided into two groups, maintained individually and fed with a mixture of alfalfa hay and concentrate with free access to drinking water. One group was completely shorn while the other group was left unshorn, and both groups were reared for 10 weeks (July–Sept.) with mean ambient temperature of 29.3°C. Feed intake and liveweight changes were recorded weekly whereas metabolic parameters were measured daily. Fasting blood samples were collected three times a week and used for blood metabolites and hormone assays. Results showed that shearing has no effects on feed intake and weight gain over the study. Feed conversion ratio was improved (P < 0.05) by shearing (10.70 vs 13.26 kg/kg). Shearing also caused a decline in lamb rectal temperature (P < 0.05), whereas heart rate remained unchanged. Respiratory rate was lower in shorn lambs (P < 0.001), whereas blood glucose, urea and total protein levels were not affected. Serum concentrations of thyroxine declined in shorn lambs compared with unshorn lambs (P < 0.05), but cortisol level was unchanged between groups. In conclusion, the study showed that when lambs are kept sheltered under heat stress conditions, shearing appears to induce energy retention via reducing some vital activities such as respiration and heat loss leading to enhanced feed efficiency. The decrease in thyroxine level can be considered as the possible underlying mechanism for the decline observed in rectal temperature.

scholarly journals Feeding systems and productive and physiological parameters of lambs raised under heat stress

2021 ◽  
pp. 181-199
Author(s):  
Abner A. Rodríguez-Carías ◽  
José Israel Suárez-Rodríguez ◽  
Jonathan Collazo ◽  
John Fernández-Van Cleve
Keyword(s):  
Heart Rate ◽  
Heat Stress ◽  
Respiratory Rate ◽  
Rectal Temperature ◽  
Dry Matter ◽  
Physiological Parameters ◽  
Stress Conditions ◽  
Initial Weight ◽  
Rotational Grazing ◽  
Grazing System

The objective of this study was to determine physiological parameters (rectal temperature = RT, respiratory rate = RR, heart rate = HR) and production parameters (dry matter intake = DMI, water intake = WI, average daily weight gain = ADG, and feed conversion = FC) of crossbred and Katahdin lambs raised in rotational grazing of native pastures (NP) and in confinement under heat stress conditions. Nine crossbred lambs (average initial weight = 19.4 kg) were used and fed in a rotational grazing system for 70 days with occupation and rest periods of seven and 21 days, respectively. The lambs had daily access to the grazing area for four to six hours, grass hay and water ad libitum, a daily supplement of 100 g of commercial concentrate and a nutritional block. In the confined system, six lambs of the Katahdin breed (average initial weight = 27.3 kg) were used, and for 28 days these were fed total mixed rations (TMR) containing 30% grass hay, 15.4% soybean meal, 54.6% corn grain and a mineral block. The diet contained 14% Crude Protein (CP) and 66% Total Digestible Nutrients (TDN) and was formulated for an ADG of 200 g. The offered and rejected feed was quantified every day [4% body weight (BW)/dry matter basis (DMB)] to determine the DMI, and the volume of water offered and rejected to determine WI. To validate the stress conditions, the maximum environmental temperature and relative humidity were monitored to calculate the temperature and humidity index (THI), and the RT, HR and RR of the 15 lambs were determined. The lambs were weighed every seven days. In both experiments, the THI oscillated between 78 and 80. The lambs were under environmental heat stress conditions (THI x̅ = 79) during both studies. The averages of HR and RT in the grazing system were 118.0 beats per minute and 38.6° C, while the averages under the confinement system were 108.6 beats per minute and 39.4° C, respectively. The average RR (53.6 and 62.6 breaths per minute, in grazing and in confinement, respectively) was greater than the normal value considered for thermal comfort. Respiratory rate is the main mechanism used by lambs to dissipate heat. The heart rate also showed slightly higher values than those reported for animals in their comfort zone. However, the rectal temperature values were constant. As expected, crossbred lambs fed under grazing conditions with naturalized pastures (NP) had a low ADG (55.6 g). Nevertheless, Katahdin lambs fed in confinement with TMR had a DMI of 935.4 g/day (3.14% BW/DMB), a WI of 3.5 L/day, a FC of 4.74 and an ADG of 226.2 g. In conclusion, raising crossbred sheep in rotational grazing of NP without any type of agronomic management results in ADG that could not be considered viable in traditional production systems. The introduction of pure breeds and feeding them in confined systems with a TMR results in a pre-determined ADG (>200 g/day) and is an alternative that can be evaluated economically for its practical implementation.

scholarly journals Dairy Cows Activity under Heat Stress: A Case Study in Spain

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2305
Author(s):  
Adrián Ramón-Moragues ◽  
Patricia Carulla ◽  
Carlos Mínguez ◽  
Arantxa Villagrá ◽  
Fernando Estellés
Keyword(s):  
Heat Stress ◽  
Dairy Cattle ◽  
Dairy Cows ◽  
Animal Welfare ◽  
Animal Behavior ◽  
Environmental Conditions ◽  
Stress Conditions ◽  
Livestock Farming ◽  
Precision Livestock Farming ◽  
Activity Sensors

Heat stress plays a role in livestock production in warm climates. Heat stress conditions impair animal welfare and compromise the productive and reproductive performance of dairy cattle. Under heat stress conditions, dairy cattle modify their behavior. Thus, the assessment of behavior alterations can be an indicator of environmental or physiological anomalies. Moreover, precision livestock farming allows for the individual and constant monitoring of animal behavior, arising as a tool to assess animal welfare. The purpose of this study was to evaluate the effect of heat stress on the behavior of dairy cows using activity sensors. The study was carried out in Tinajeros (Albacete, Spain) during the summer of 2020. Activity sensors were installed in 40 cows registering 6 different behaviors. Environmental conditions (temperature and humidity) were also monitored. Hourly data was calculated for both animal behavior and environmental conditions. Temperature and Heat Index (THI) was calculated for each hour. The accumulated THI during the previous 24 h period was determined for each hour, and the hours were statistically classified in quartiles according to the accumulated THI. Two groups were defined as Q4 for no stress and Q1 for heat stress. The results showed that animal behavior was altered under heat stress conditions. Increasing THI produces an increase in general activity, changes in feeding patterns and a decrease in rumination and resting behaviors, which is detrimental to animal welfare. Daily behavioral patterns were also affected. Under heat stress conditions, a reduction in resting behavior during the warmest hours and in rumination during the night was observed. In conclusion, heat stress affected all behaviors recorded as well as the daily patterns of the cows. Precision livestock farming sensors and the modelling of daily patterns were useful tools for monitoring animal behavior and detecting changes due to heat stress.

Comparison of estimated core body temperature measured with the BioHarness and rectal temperature under several heat stress conditions

2016 ◽  
Vol 13 (8) ◽  
pp. 612-620 ◽  
Author(s):  
Yongsuk Seo ◽  
Travis DiLeo ◽  
Jeffrey B. Powell ◽  
Jung-Hyun Kim ◽  
Raymond J. Roberge ◽  
...  
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Rectal Temperature ◽  
Core Body Temperature ◽  
Stress Conditions ◽  
Core Body

Pregnancy rates following timed embryo transfer with fresh or vitrified in vitro produced embryos in lactating dairy cows under heat stress conditions

2002 ◽  
Vol 58 (1) ◽  
pp. 171-182 ◽  
Author(s):  
Y.M Al-Katanani ◽  
M Drost ◽  
R.L Monson ◽  
J.J Rutledge ◽  
C.E Krininger ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Stress Conditions ◽  
Lactating Dairy Cows
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