| With the rapid development of laying hen culture industry towards scale and intensification,the abuse of antibiotics is very common.The problem of antibiotic residues in poultry and egg products has become a bottleneck restricting the healthy development of the laying hen industry.Taking the “Yue Emperor” hens as the research object,starting from the aspects of chick quality,feed nutrition,environmental control,breeding management,vaccine immunization,preventive health care and biological safety,the formation of the whole hens has no anti-breeding mode.In this study,100,000 one-day-old “Yue Emperor” hens were selected and randomly divided into two groups(no anti-group and anti-group),each group containing 50,000 laying hens and each group containing 5 replicates.The whole feeding trial was 245 days and then eliminated.At the age of 1 day,the quality of chicks no anti-group and anti-group was judged from the appearance of chicks,maternal antibody levels,and germinal diseases.During the test,the three stages of the brooding period(1～8 weeks),the breeding period(9～18 weeks),and the laying period(19～35 weeks)were compared between the no-anti-group and anti-group death rate;Average body weight,tibial length,egg production rate,secondary egg rate,average egg weight,egg quality and antibody level were measured and statistically analyzed.At the end of the whole feeding experiment,the economic benefits were calculated and analyzed.The research results are as follows:(1)The quality of non-anti-group and anti-group 1 day-old chicks were basically the same,and the judging rates of the coat color,the sound,the weight,the navel,the anus,the leg claws and the mental state were all higher than 90%.The positive rates of ALV,MS and Salmonella in the no anti-group 1 day old were 2.4%,4.6% and 2.6%,and those in the anti-group were 1.8%,4.8% and 2.2%.There was no significant difference in maternal antibody levels between no anti-group and anti-group H5,H9,and ND(P>0.05).(2)The three stages of dead-killing rate were 4.69%,0.98%,and 0.93%,respectively,and the anti-groups were 7.39%,1.31%,and 1.19%,The final survival rate of the no anti-group was 93.39%,and the anti-group survival rate was 90.09%.Compared with the anti-group,the average body weight and the length of the tibia increased by 26.91 g and0.44 mm,but the difference was not significant(P>0.05),but it was improved to some extent.Both egg production rate and average egg weight increased,the egg production rate and average egg weight increased by 2.46% and 0.52 g.(3)Compared with the anti-group,the secondary egg rate(broken egg rate,soft shell egg rate,spotted egg rate,abnormal egg rate)decreased to different degrees in the non-resistant group.eggshell strength and thickness,protein height,egg yolk color,egg weight,haugh unitwere were no significant difference at 23 and 30 weeks(P>0.05).(4)The level of H9 antibody significantly improved compared with the anti-group at 15 days after the second immunization(P<0.05),The level of H5 and ND antibody levels were higher than the anti-group at 15 and 45 days after the second immunization,but did not reach significant levels(P>0.05).(5)The total profit of no anti-group and anti-group were RMB 1,604,163 yuan and RMB 1,439,697 yuan,respectively.The profit of each feather chicken was RMB 32.08 yuan and RMB 28.79 yuan,with an increase of RMB 164,466 yuan.The above results concluded that the whole process of Antibiotic-Free breeding was completely feasible for native laying hens,through feed nutrition,prevention and health care,feeding management and other aspects to improve the disease resistance of the chicken group,reduce the incubation period,incubation period,egg-laying period of the dead-killing rate.In this way,the egg yield and average egg weight of the chickens were improved.Finally,the no anti-group obtained better economic benefit.Therefore,the model has important production and application value,and provides good technical support and practical significance for the whole process of Antibiotic-Free breeding of laying hens. |
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