| Huangshan Black Chicken is one kind of multiple places chicken groups that was grazed by the local mountain farmers,it is distributed in most parts of huangshan city,and relatively concentrated distribution in Yixian county and Qimen county border area.It has showed the characters such as disposition lively,crude feed tolerance,strong adaptability,high broodiness and so on after long-term artificial selection and natural domestication.Huangshan Black Chicken is a rare species with tasty flavor and tonic effect of Huangshan Anhui province.In this thesis,a tracing detection was conducted about the infection status of avian leukosis subgroup J and pullorosis of cage-rearing and free-range feeding modes of Huangshan black chicken,and a evaluation was conducted of reproduction performance of Huangshan Black Chickens of the two feeding modes.600 Huangshan Black Chickens breeders were randomly divided into two groups after the hens lay eggs,cage-rearing group and free-range group.ELISA,plate agglutination text and hatching experiment were used to contrast the avian leukosis,pullorosis positive rate,breeding egg quality and reproduction performance of Huangshan Black Chickens between the two groups.the results showed that: 1.The cage-rearing group 200-day-old breeding birds positive rate in cloacal cotton swab was 19.6%,p27 antigen positive rate in cocks' cloacal cotton swab was 21.9% and the hens' was 18.3%;The free-range group p27 antigen positive rate in cloacal cotton swab was 7.8%,p27 antigen positive rate in cocks' cloacal cotton swab was 14.7% and the hens' was 3.6%;The cage-rearing group 300-day-old breeding birds p27 antigen positive rate in egg white was 7.8% while the free-range group's was3.3%;The p27 antigen positive rates in 1-day-old meconium of the cage-rearing group offspring and the free-range group's was 2.9%.The results showed that the positive rate of avian leukosis of cage-rearing group was high than that of free-range group,and the positive rateof avian leukosis of cocks was generally higher than that of the hens,similarly,the positive rate of avian leukosis of cage-rearing group offspring was high than that of free-range group.2.In order to contrast the pullorosis positive rate between the two feeding modes,the blood serum of 231-day-old,251-day-old,274-day-old,301-day-old,327-day-old Huangshan Black Chicken were investigated.The results showed that all the day-old pullorosis positive rates of cage-rearing group were 0%,1.01%,2.38%,1%,0%and free-range group's were 7%,7.44%,3.13%,2%,1%.Pullorosis positive rate of cage-rearing group was high than that of free-range group.3.In order to contrast the egg quality between the two feeding modes,egg weight,egg shape index,egg shell thickness and eggshell color were measured.The results showed that the egg quality between the two feeding modes was significantly different(P<0.05).The egg weight of cage-rearing group was 48.1 g,which significantly higher than that of the free-range group(P<0.05).The eggshell thickness of cage-rearing group was 0.423 mm,which significantly higher than free-range group(P<0.05).The egg shell color depth of cage-rearing group was 41.3,which significantly higher than that of the free-range group(P<0.05).But the egg shape index of free-range group was 1.31,which significantly higher than that of the cage-rearing group(P<0.05).The weight of chicks that were hatched by the breeding eggs of the two feeding modes was measured.The results showed that the chicks weight of the two feeding modes was significantly different(P<0.05).The average weight of chicks,cocksand hens of cage-rearing group were 1.91 g?1.78 g?1.97 g heavier than that of free-range group,it has reached a significant difference level(P<0.05).The incubation indicators of the two feeding modes were recorded when the incubation experiment was carried out.The results showed that the fertility rate of hatching egg,fertilization and hatching rate of cage-rearing group were 93.98%?96.94%?91.10%,the free-range group's were 93.46%?95.52%?89.26%,the death rate of embryo of cage-rearing group was 3.06%,and the free-range group's was4.48%,the indicators of cage-rearing group were better than that of the free-range group.In the study,the infection status of avian leukosis subgroup J and pullorosis,and reproduction performance of Huangshan Black Chickens of the two feeding modes were investigated,which provided the fundamental for the purification and prevention of provenance disease of Huangshan Black Chickens. |
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