Maryam Rahbar; Mehdi Behgar; Mohammad Rasoul Khoshniyat; Farahnaz Farahnaz Motamedi Sedeh; Parvin Shawrang
Abstract
ABSTRACT
Objective: Temperature-Humidity Index (THI) is used to study the effect of heat stress and is one of the critical factors in yield and infertility. This research was conducted to study the effect of THI on motility parameters and sperm motility velocity of Holstein bulls in different months ...
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ABSTRACT
Objective: Temperature-Humidity Index (THI) is used to study the effect of heat stress and is one of the critical factors in yield and infertility. This research was conducted to study the effect of THI on motility parameters and sperm motility velocity of Holstein bulls in different months and to study the internal correlation between these parameters.
Method: Meteorological data from the National Meteorological Organization were used to calculate THI. Semen collection and evaluation were carried out at Nahadehaye Dami Jahed (NDJ). Three Holstein bulls were used in this study. Diluted semen was then loaded into straws and frozen after cooling using a programmable freezer. The straws were immediately stored in liquid nitrogen and thawed in a water bath (37°C for 30 s) before evaluation. Sperm kinematic parameters were evaluated using CASA.
Results: The temperature-humidity index was lower in April than in other months and higher in July than in other months. The average temperature-humidity index in spring and summer was 64.00 and 70.67, respectively. Total motility, progressive motility, and slow motility were higher in May than in other months and lower in August than in other months. Among the sperm motility parameters, only beat cross frequency (BCF) and straightness (STR) showed significant differences in different months. BCF was higher in May compared to other months and lower in August compared to other months. However, STR was higher in July compared to other months and lower in August compared to other months. The temperature-humidity index had a significant negative correlation with progressive sperm motility. Regarding the relationship between motility parameters and sperm motility velocity, the results showed a significant positive correlation between total motility with progressive motility and curved line velocity (VCL). Progressive motility was also positively correlated with VCL and BCF. A significant positive correlation was observed between the sperm motility parameters. A positive correlation was observed between the average path velocity (VAP) and the VCL, straight line velocity (VSL), and BCF parameters. There was a positive correlation between the BCF parameter and the VCL and average path velocity (VAP) parameters.
Conclusions: The data show that mild heat stress leads to a decrease in sperm motility parameters and sperm velocity motility parameters. The negative correlation between temperature-humidity index and sperm progressive motility indicates the importance of heat stress on this important parameter. It is suggested that future studies should investigate the relationship between temperature-humidity index and sperm motility parameters with sperm fertility using regression models.
َAlireza Younesi; Kazem Karimi
Abstract
Introduction:The welfare of domesticated animals raised in industrial environments using mechanical and semi-mechanical tools has always been one of the main concerns of livestock farmers, as attention to the welfare of these animals can lead to increased productivity and reduced injury to the animals.
Material ...
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Introduction:The welfare of domesticated animals raised in industrial environments using mechanical and semi-mechanical tools has always been one of the main concerns of livestock farmers, as attention to the welfare of these animals can lead to increased productivity and reduced injury to the animals.
Material and methods:The present research, considering the importance of the topic of welfare, has designed a model of cow welfare in industrial dairy farms based on a structural-interpretive model and using the fuzzy Delphi method.To this end, the factors affecting the welfare of cows were examined using library studies, and ultimately a final model was presented through the design of a fuzzy questionnaire. The statistical population of the research included experts and specialists in the fields of animal husbandry and industrial dairy farming in Pakdasht County, who were included in the study using a snowball sampling method. A total of 18 experts and specialists in the fields of animal husbandry and cattle breeding participated in the study as knowledgeable individuals in the care and maintenance of dairy cows. The main tool used for the research was a questionnaire developed by the researcher, which included a structured self-interaction matrix to conduct a survey among relevant elites and experts. The questionnaire consisted of two main sections: one included demographic characteristics related to the sample population, such as gender, age, education, work experience, and studies; the other contained a pairwise comparison table of factors affecting cow welfare in industrial dairy farms, where experts indicated the relationship between each component and other presented components using specific letters.The analysis of results was conducted using fuzzy methods, and finally, the nature of the variables was examined through MicMac analysis.
Results and discussin:The results indicated that among the internal factors, the health of the locomotor system had the least influence and the highest dependency, while heat stress and automatic milking systems had the least dependency and the highest influence. The design of the flooring in the stalls and corridors, as well as the design of the barns based on wind direction and sunlight exposure, exhibited the least dependency and the highest influence. Among internal factors, variables such as infectious diseases, gastrointestinal and metabolic disorders, heat stress, automatic milking systems, design, size and dimensions of the barn and stalls, standing in barns, animal density in stalls, flooring design and type in stalls and corridors, density of dairy cows, barn design based on wind direction and sunlight exposure, and control of radiant heating acted as independent variables while other factors played a role as dependent variables. Among internal factors; locomotor health was the most influential factor while heat stress and automatic milking systems were the most susceptible factors. Among environmental factors; feed bunk and water trough conditions were the most influential while design aspects such as flooring type in stalls and corridors, barn designs based on wind direction and sunlight exposure, along with radiant heating control were found to be the most susceptible factors.
Conclusion: Factors such as the health of loco motor organs, feeding and watering facilities, healthcare practices, and humidity were significant at initial levels, while factors such as heat stress, automatic milking systems, design and type of flooring in housing and corridors, hall design based on wind direction and sunlight exposure, and control of radiant heating were significant at later levels affecting the welfare of dairy cows. Attention to these factors could be effective in improving the breeding conditions for cows.