Study On The Air Environment,the Growth And Decline Of Microorganism And The Lactation Performance Of Cows Under The Mode Of "Bed And House Integration"

The treatment of cow manure is the main problem that restricts the development of cow breeding industry.The heat stress will reduce the milk yield of cows in poor body condition and directly affect the economic benefits of dairy farms.The purpose of the model of"bed and house integration"in this study is to solve the problems of rain pollution separation and feces emission during dairy farming,reduce the heat stress of cows,and improve the welfare and milk production of cows.In this study,the hailin farm in Wuqing district of Tianjin city was used as the test site.On the basis of the model transformation of"Bed and house integration",the data of the building structure before and after the transformation were compared.At the same time,the special study will be carried out in three experiments from April to July 2019.Experiment 1:in April in spring and July in summer,5 days with stable weather were selected to record the internal and external air indexes of the"Bed-house integration"mode cattle house,and the warm environment and air quality of the"Bed-house integration"cattle house were evaluated by measuring and analyzing the temperature index,wind speed,NH₃ and CO₂concentration.Experiment 2:in view of the"integration"bed dairy herd barn to different stages,in accordance with the multipoint sampling method random packing samples within the cowshed,once every 15 days gathering,gathering 7 times in a row,through 16 srrna gene amplification sequencing methods,the analysis of cow bed bedding distribution and the change rules of microorganism,to"integration"bed model evaluate the safety of bed bedding processing.Test 3:milk samples were collected for cows of different gestational grades in the"Bed-and-house integration"cattle house,and milk production and milk fat,protein,lactose and urea nitrogen contents of cows in the"Bed-and-house integration"mode were determined to evaluate the heat stress and lactation performance of cows in the"Bed-and-house integration"mode.The results of experiment 1 show that the"Bed housing integration"cowsheds in hailin farm in wuqing district of Tianjin city have a temperature index of less than 72 in spring and less than 89 in summer,failing to reach the severe stress index.The position had a significant effect on the concentration of NH₃ and CO₂（P<0.05）.The contents of NH₃and CO₂ in the cattle house all met the environmental quality standards and were suitable for cow production.The results of experiment 2 showed that:under the model of"bed and house integration",there was no inevitable correlation between the bacterial abundance and diversity of the cow’s bed pad and the rise of temperature and the laying time of the bed pad,and it had no effect on the health and daily production of the cow.The results of experiment 3 showed that:during the temperature rising period under the"bed and house integration"mode,there was no significant decrease in milk production of the second and third litters（P>0.05）.It shows that the model of"bed and house integration"can effectively relieve the heat stress of cows and increase milk production in summer.In a word,the large-span"bed-house integration"model can reduce the heat stress of cows under natural conditions,improve the air quality in the house,and improve the milk production of cows in summer.The treatment method of"bed and house integration"bedding material can guarantee the health and safety of cow bed.Two kinds of cow bed for free choice,to meet the requirements of the use of cows throughout the year,effectively solve the winter bed dank cold problem.The"bed and house integrated"dung treatment mode and rain pollution separation can effectively reduce the environmental pollution caused by dairy farming,and increase the economic benefits and social ecological benefits while improving the welfare of dairy cows and reducing the cost of breeding.