| The environment is a key factor affecting the health and production performance of laying hens.As the automation and modernization of laying hen breeding continues to accelerate,the theory of chicken house environment regulation,regulation techniques,and facilities and equipment have achieved certain success in various aspects,and it has become increasingly important to evaluate the improved chicken house environment.In order to conduct a comprehensive comfort evaluation of the hen house environment,we first investigated the influence of environmental factors on the comfort of hens through literature research and summarized the threshold values of environmental factors regulation in hen houses.Then,we continuously monitored some environmental factors in an egg house in Jilin Province through field tests,analyzed their distribution patterns and interrelationships,and adjusted the CO2concentration thresholds based on the actual production.Finally,using the idea of fuzzy mathematics,the collected environmental parameters were fused to establish a comprehensive environmental comfort evaluation index for chicken houses based on multivariate environmental parameters and applied.The main research contents and conclusions of the paper are as follows.（1）Through literature research,the influence of various environmental factors on the production performance of laying hens was investigated,and the literature data were summarized and organized to determine the comfort thresholds of environmental factors such as temperature,humidity,wind speed,carbon dioxide and ammonia in different seasons（winter and summer）,which were divided into three intervals:comfortable,more comfortable and uncomfortable,laying the theoretical foundation for comfort evaluation.（2）Environmental factors such as temperature,humidity,carbon dioxide concentration,harmful gas concentration and particulate matter concentration were continuously monitored in an egg house in Jilin Province,and their distribution patterns and interrelationships were analyzed.The results showed that the average temperature in the house was 22.1℃and the average relative humidity was 67%;the average ammonia concentration was 3.21 mg/m3,which was positively correlated with temperature and negatively correlated with relative humidity;the distribution of particulate matter concentration in the house was PM1 and PM2.5 concentration near the fan end>in the house>far fan end,and PM10 and TSP were the opposite,i.e.far fan end>in the house>near fan end.The average CO2 concentration in the shed was 8,576 mg/m3,which was higher than the relevant standard.The minimum ventilation capacity was 0.56m3/（h-kg）,and finally,the minimum ventilation capacity of the northeastern egg house using conveyor belt manure removal was calculated for the problems of winter ventilation in the northeastern egg house.The results were 0.51-0.58 m3/（h-kg）.The results were 0.51-0.58m3/（h-kg）.The results provide a reference for the standard values of CO2 concentration parameters in new and modified conveyor belt manure houses and for the regulation of the contradiction between ventilation and heat preservation in winter.（3）Using fuzzy mathematical methods,the weights of important environmental parameters in the comprehensive evaluation of environmental comfort of large-scale egg houses were studied,and key environmental parameters such as house temperature,humidity,carbon dioxide（CO2）concentration,ammonia（NH3）concentration and wind speed were transformed to establish a comprehensive environmental comfort evaluation index for chicken houses based on multiple environmental parameters.The above environmental parameters were displayed visually in the radar diagram.Through the analysis and verification of the environmental monitoring data of the chicken house in actual use,it can reflect the changes of the overall environmental comfort in the house and show the interaction between environmental factors at various times,especially the time when the temperature decreases leading to the increase of air quality.This study provides a new method for comprehensive environmental evaluation in egg houses.It provides methodological support for comprehensive evaluation of the environmental conditions in egg houses and precise control to improve environmental comfort. |
