scholarly journals The effect of some seasonal conditions on oestrus occurrence in cows

2009 ◽  
Vol 52 (5) ◽  
pp. 459-465
Author(s):  
B. Bülbül ◽  
M. B. Ataman
Keyword(s):  
Seasonal Variation ◽  
Relative Humidity ◽  
Environmental Temperature ◽  
Suppressive Effect ◽  
Climatic Conditions ◽  
Holstein Cows ◽  
Ovarian Activity ◽  
Environment Temperature ◽  
Humidity Index ◽  
Annual Distribution

Abstract. In this study, the effect of climatic conditions on oestrus occurrence was investigated by using 9 972 oestrus records of cows recorded between 1995 and 2003. A distinct seasonal variation in the oestrus occurrence was determined. Oestrus occurrence observed in January, March, November and December was less than that in June and September (P<0.05). Annual distribution of the oestrus occurrence was positively correlated with environment temperature and insulation duration, but it was negatively correlated with rainfall (P<0.01). However, there was no relationship between oestrus occurrence and relative humidity. In addition to these, there was a slight decrease in the oestrus response when the temperature-humidity index (THI) was above 72; nevertheless, this decrease was not significant (P >0.05). The data presented in this study demonstrated that the increase in the environmental temperature up to 23 °C did not cause a suppressive effect on the ovarian activity. In conclusion, annual distribution of the oestrus occurrence is positively correlated with environment temperature and insulation duration whereas it is negatively correlated with rainfall in Holstein cows, in this study.

scholarly journals Effects of thermal stress on physiological state and hormone concentrations in Holstein cows under arid climatic conditions

2021 ◽  
Vol 51 (4) ◽  
pp. 452-459
Author(s):  
H. Djelailia ◽  
N. M’Hamdi ◽  
R. Bouraoui ◽  
T. Najar
Keyword(s):  
Dairy Cows ◽  
Physiological State ◽  
Plasma Concentrations ◽  
Average Concentration ◽  
Climatic Conditions ◽  
Holstein Cows ◽  
Plasma Sodium ◽  
Average Temperature ◽  
Humidity Index ◽  
Environmental Temperatures

This study was conducted to investigate the effect of heat stress on the physiology of dairy cows and to detect the relationship between rectal temperature (RT) and respiration rate (RR), heart rate (HR), and plasma concentrations of cortisol, thyroxine, and prolactin. During the experiment, 44 Holstein cows were allocated to two groups for each season. The average temperature-humidity index (THI) values were 55 ± 2.31 in winter and 78 ± 1.9 in summer. As the THI values increased from 55 to 78, RR rose by 35 inspirations per minute, HR by 3 beats per minute, and RT by 1.2 °C. In addition, the average concentration of cortisol increased from 19.30 to 21.04 nmol/L, and prolactin from 58.52 to 129.79 ngm/L, whereas free thyroxine decreased from 15.43 to 14.01 pmol/L. Plasma sodium and potassium concentrations were similar in the two seasons. These results confirmed that RT is an indicator of the response in dairy cows to hot environmental temperatures. However, they also showed signs of stress, which were reflected in higher levels of cortisol and in certain physiological responses.

Experimental Study on Effect of CO2 Heat Pump Evaporator on Frosting Condition

2014 ◽  
Vol 694 ◽  
pp. 218-221
Author(s):  
Si Qian Zhu ◽  
Jing Lv ◽  
Hui Xia Lu ◽  
Dong Dong Shi ◽  
Feng Xu
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Wind Speed ◽  
Relative Humidity ◽  
Theoretical Analysis ◽  
Environmental Temperature ◽  
Outlet Temperature ◽  
Evaporation Temperature ◽  
Environment Temperature ◽  
Single Heating

The theoretical analysis of frost formation had been made. The wind speed, temperature and relative humidity etc. had different effects respectively. A single heating was studied through the experiment. In different outdoor conditions, experimental data showed evaporator frost at the environment temperature of 10 °C, environment relative humidity was 70%. Comparing the experimental data, it is concluded that temperature of evaporator’s outlet is increasing with the outlet temperature. The refrigerant evaporation temperature and COP under different conditions has been tested. The relation of evaporation pressure and environmental temperature under different evaporation temperature had been concluded. According to the experiment, a defrost measure of this experiment equipment had been proposed.

Experimental Research on Human Metabolism in Hot Environment

2012 ◽  
Vol 599 ◽  
pp. 241-244 ◽  
Author(s):  
Yu Ping Sun ◽  
Neng Zhu
Keyword(s):  
Relative Humidity ◽  
Metabolic Rate ◽  
Thermal Environment ◽  
Climatic Conditions ◽  
The Body ◽  
Labor Intensity ◽  
Hot Environment ◽  
Environment Temperature ◽  
The Impact

In this study, the body metabolic rate of 10 volunteers performing light, medium and heavy physical labor was examined under different climatic conditions in a chamber. The climatic conditions referred to one group of comfort environment (25°C dry bulb temperature and 50% relative humidity) and three groups of thermal environment (30°C, 35°C, 40°Cdry bulb temperature and 90% relative humidity). The results reveal that for the same labor intensity, the human metabolic rate increases with the rise of environment temperature in the scope of 30~40 °C, 90%RH. The impact of environment temperature on metabolic rate increases with the rise of labor intensity. In addition, the classification of physical labor intensity upgrades when the environment temperature exceeds a certain threshold

scholarly journals Experiments on Energy-Efficient Evaporative Cooling Systems for Poultry Farm Application in Multan (Pakistan)

2021 ◽  
Vol 13 (5) ◽  
pp. 2836
Author(s):  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Muhammad Bilal ◽  
Hadeed Ashraf ◽  
Muhammad Farooq ◽  
...  
Keyword(s):  
Heat Stress ◽  
Low Cost ◽  
Evaporative Cooling ◽  
Thermal Exposure ◽  
Climatic Conditions ◽  
The Body ◽  
Dew Point ◽  
Sweat Glands ◽  
Cooling Systems ◽  
Humidity Index

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.

scholarly journals Potential Evapotranspiration Reduction and Its Influence on Crop Yield in the North China Plain in 1961–2014

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Wanlin Dong ◽  
Chao Li ◽  
Qi Hu ◽  
Feifei Pan ◽  
Jyoti Bhandari ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Crop Yield ◽  
North China Plain ◽  
North China ◽  
Potential Evapotranspiration ◽  
The North ◽  
The North China Plain ◽  
Sunshine Hours ◽  
Humidity Index

Climate change has caused uneven changes in hydrological processes (precipitation and evapotranspiration) on a space-temporal scale, which would influence climate types, eventually impact agricultural production. Based on data from 61 meteorological stations from 1961 to 2014 in the North China Plain (NCP), the spatiotemporal characteristics of climate variables, such as humidity index, precipitation, and potential evapotranspiration (ET0), were analyzed. The sensitivity coefficients and contribution rates were applied to ET0. The NCP has experienced a semiarid to humid climate from north to south due to the significant decline of ET0 (−13.8 mm decade−1). In the study region, 71.0% of the sites showed a “pan evaporation paradox” phenomenon. Relative humidity had the most negative influence on ET0, while wind speed, sunshine hours, and air temperature had a positive effect on ET0. Wind speed and sunshine hours contributed the most to the spatiotemporal variation of ET0, followed by relative humidity and air temperature. Overall, the key climate factor impacting ET0 was wind speed decline in the NCP, particularly in Beijing and Tianjin. The crop yield in Shandong and Henan provinces was higher than that in the other regions with a higher humidity index. The lower the humidity index in Hebei province, the lower the crop yield. Therefore, potential water shortages and water conflict should be considered in the future because of spatiotemporal humidity variations in the NCP.

scholarly journals The effect of cooling irrigation on the blooming dynamic of plum

2010 ◽  
Vol 16 (4) ◽  
Author(s):  
L. Lakatos ◽  
I. Gonda ◽  
M. Soltész ◽  
Z. Szabó ◽  
J. Nyéki
Keyword(s):  
Relative Humidity ◽  
Frost Damage ◽  
Relative Effect ◽  
Climatic Conditions ◽  
Water Requirement ◽  
Control Plot ◽  
Logistic Curve ◽  
Treated Plot

The objective of the present study is to explore the effect of cooling irrigation (aspersion) on the beginning of bloom and on the micro-climate of the plantation. The results show that the water sprayed in the orchard by micro-jet influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of temperature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect, The frequent repetition (20 minute intervals) may keep the temperature low also in the buds. The beginning of bloom may delayed for more than ten days. The dynamics of blooming was characterised by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control in spite of equal temperatures measured in the plots. Under our (Hungarian) climatic conditions, the method is successfully used to delay blooming dates. The main result is the diminution of the frost damage in the spring and the security of yield. The costs and water requirement should be calculated later.

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