Study On The Determination Of Environmental Parameters Of Horizontal Ventilation Henhouse And Its Relationship With Production Performance Of Laying Hens

The purpose of this experiment was to study the variation of environmental parameters in the horizontal ventilation closed henhouse and its effect on the production performance of laying hens,and to construct a scientific and reasonable environmental quality assessment system.In this experiment,the transverse ventilation mode and the four-layer stacked closed automatic laying henhouse were used as the research object.A total of 36measurement points were selected from the first,second,third and fourth cage layers of the three rows of cage front end（A）,middle end（B）and fan end（C）near the west of the house.The environmental parameters of each position and the laying performance of laying hens in the cage were monitored,the change trend of the environment in the house was analyzed,and the environmental quality of different positions and their effects on the health of laying hens were comprehensively evaluated.The test results are as follows:1.Environmental parameters:Horizontally,there was no significant difference in mean temperature between ends A,B and C（P>0.05）,and the relative humidity at point A was the lowest（P<0.05）;the mean wind speed and mean CO₂concentration at point C were the highest（P<0.05）;the closer to the fan the higher the PM_2.5concentration;the light intensity at point B was significantly lower than at points A and C（P<0.05）.Vertically,there was no significant difference in temperature and humidity between different cage layers（P>0.05）,and light intensity was lowest in layer 3（P<0.05）;CO₂content was significantly higher in layers 3 and 4 than in layers 1 and 2（P<0.05）;wind speed and PM2.5 concentration were highest in layer 4（P<0.05）.2.Environmental parameters:In the horizontal direction,there was no significant difference in temperature between points A,B and C（P>0.05）,and the relative humidity at point A was the lowest（P<0.05）.From point A to point C,the wind speed,CO₂concentration and PM_2.5concentration all showed an upward trend.The light intensity of point B was significantly lower than that of point A and point C（P<0.05）.In the vertical direction,there was no significant difference in temperature and humidity between different cage layers（P>0.05）,and the light intensity of the third layer was the lowest（P<0.05）.The CO₂concentration in the third and fourth layers was significantly higher than that in the first and second layers（P<0.05）.The wind speed and PM_2.5concentration in the fourth layer were the highest（P<0.05）.3.Production performance:In the horizontal direction,the laying rate of laying hens at point A was significantly higher than that at points B and C（P<0.05）,and the haugh unit of eggs at point C was significantly higher than that at point A（P<0.05）.In the vertical direction,the laying rate of the first and fourth layers was significantly higher than that of the second and third layers（P<0.05）.There was no significant difference in egg quality traits among different cage layers（P>0.05）.4.Immune performance:In the horizontal direction,the ND antibody titer of layer A was the lowest（P<0.05）.In the vertical direction,the ND antibody titer of layer 1 was significantly higher than that of layer 3 and layer 4（P<0.05）.5.Blood biochemical indexes:In the horizontal direction,the serum Cortisol,TG and BUN concentrations of laying hens at point A were significantly lower than those at point B（P<0.05）.In the vertical direction,there was no significant difference in blood biochemical indexes among cage layers（P>0.05）.6.Construction of environmental quality evaluation model:There are differences in production performance at different locations of the henhouse,which may be related to the environmental differences of the henhouse.The model is reliable and accurate,which can provide reference for the reasonable regulation of the subsequent chicken house environment,so as to maximize the production efficiency of the chicken house.