| With the rapid development of laying hen industry,the environmental sanitation quality in chicken coops has gradually been paid attention by breeding enterprises.Continuous clean drinking water and sanitation are of great significance to the improvement of laying performance of chicken flocks.In this experiment,the eight-layer closed cage laying hen house was taken as the research object,and the bacterial microorganism content and colony structure in different cage drinking water devices in the house were detected to compare the pollution of pipe water and V-trough water and their effects on laying performance and egg quality traits.When laying hens were 371 days old,the first,third,fifth and seventh layers of the front,middle and rear ends of two adjacent rows in the east of the chicken coop were selected,totaling 24 monitoring points.The number of bacteria in aerosol at each point was determined by natural sedimentation method once every 2 weeks.The total copy number of 16 Sr DNA of the bacterial genomes in the pipe water in the cage and in the V-trough water was determined by RT-q PCR method.The microbial abundance and diversity in the V-trough water were analyzed by 16 S r DNA sequencing technology.Meanwhile,the egg quality traits were detected,and the egg laying rate and damaged egg rate of the chickens were recorded every day.The results showed that:1.The total number of bacteria in the air of each cage layer was significantly different(P< 0.01),and the maximum number of bacteria in the third layer was 70.02×103cfu/m3.There was no significant difference between the total copy number of pipe water and V-trough water bacteria in each cage layer(P>0.01).the total copy number of V-trough water bacteria measured in each layer was significantly higher than that of pipe water(P<0.01),up to 46.77～1905.46 times.2.The V-trough on the 7th tier had the lowest 16 S r DNA copy number of bacteria,but had the highest laying rate,albumen height and Haugh unit of the layers.The 16 S r DNA copy number of bacteria in the pipe water was positively correlated with that in the V-trough on different tiers(correlation coefficient,r =0.078-0.183).The 16 S r DNA copy number in V-trough was weakly negatively correlated with laying rate and egg weight on the 3rd,5th and 7th tier(r =﹣0.305-﹣0.127,﹣0.164-﹣0.060),and weakly negatively correlated with albumen height and Haugh unit(r =﹣0.192-﹣0.037,﹣0.138-﹣0.047)on each tier.3.Sequencing showed that the number of OTUs obtained from water samples in V-trough of different cage layers was different,with the highest number(6,297 OTUs)in the fifth layer and the lowest number(5,904 OTUs)in the seventh layer.the distribution characteristics of flora in V-trough of each cage layer tended to be consistent: the dominant phyla were mainly Proteobacteria,actinomycetes,chlamydomonas and bacteroides in sequence,while the relative abundance of other phyla was less(< 0.1%).Dominant bacteriaceae are Moraceae,Burkholderia,Streptococcaceae and Coccidae in turn,and the relative abundance of other bacteriaceae is less(< 5%),among which the relative abundance of harmful bacteria enterobacteriaceae detected in different cage layers is 0.84%～2.24%.To sum up,the bacteria content in the V-trough water in the teat drinking device in the laminated cage laying hen house is much higher than that in the pipe water,and the pollution degree is relatively high,which is easy to breed harmful flora and has a great potential negative impact on the health of laying hens,egg laying performance and egg quality.The chicken farm needs to pay more attention to the pollution situation in the V-trough while controlling the safety and sanitation of the drinking line in the house.The results provide guidance for environmental control and improvement of nipple drinking water system in large-scale laying hen farms. |
