| As the secondary sexual characteristics of chickens,cockscomb is an important reference to judge whether the chicken has reached sexual maturity and one of the important phenotypic characteristics of poultry breeding.Previous studies have shown that chicken crowns are related to the production performance of chickens,which may affect the growth rate,body weight,egg production,eggshell strength,semen quality,etc.of chicken flocks.Therefore,in order to understand the relationship between different coronal types and chicken production performance,this experiment selected760 black feathered black bone chickens(G01 series)being cultivated by Sichuan Agricultural University as the research subjects,and measured the production performance,blood indicators,semen quality,hatching performance of the single coronal group(300 hens and 80roosters)and the rose coronal group(300 hens and 80roosters)To investigate the effects of comb shape on the production performance,egg quality,and blood biochemical indicators of tianfu G01 line black feathered laying hens,including the expression of genes in the ovaries and testes.The research results of this experiment are as follows:(1)The weight results showed that there was no significant difference in weight between the tianfu G01 single crown group and the rose crown group hens during the brooding,breeding,and laying stages(P>0.05);There was no significant difference in body weight between the single crown group and the rose crown group roosters during the brooding and breeding stages(P>0.05);At 21-29 weeks of sexual maturity,there was no significant difference in weight between single crown group and rose crown group(P>0.05);At 33 to 43 weeks of age,the weight of the single crown group roosters was significantly higher(P<0.05)than that of the rose crown group roosters.(2)The results of production performance comparison showed that during the early,peak,and late stages of egg laying,the egg laying rate of the single crown group hens was extremely significant or significantly lower than that of the rose crown group hens(P<0.01,P<0.05).For egg weight,at the 22 nd,23rd,33 rd,and36-43 weeks of age,the average weekly egg weight of the single crown group was significantly higher than that of the rose crown group(P<0.05),indicating that the average egg weight of the single crown group was generally higher than that of the rose crown group,especially in the early and late stages of egg laying.(3)The comparative analysis of egg production performance and egg production at 300 days of age showed that the egg weight of the single crown group at 300 days of age was significantly higher than that of the rose crown group(P<0.01),while the egg production and egg production weight at 300 days of age were significantly and extremely significantly lower than those of the rose crown group(P<0.05,P<0.01).Although the egg laying weight and 300 day old body weight of the single crown group were higher than those of the rose crown group,the difference between the two was not significant(P>0.05).(4)The results of egg quality analysis showed that the protein height,Hastellan units,and yolk color of the single crown group were higher than those of the rose crown group in the early and late stages of egg laying,and the eggshell thickness and egg shape index were also slightly higher than those of the rose crown group during the peak and late stages of egg laying,but the differences between the two were not significant(P>0.05).Meanwhile,the thickness of the eggshell was also significantly higher than that of the rose crown group(P<0.01),indicating that the egg quality of the single crown group was overall higher than that of the rose crown group.(5)Comparative analysis of hatching performance and semen quality showed that the fertilization rate,hatching rate of hatched eggs,and hatching rate of fertilized eggs in the single crown group were significantly higher than those in the rose crown group(P<0.05).Meanwhile,the semen volume,sperm density,and sperm motility of the single crown group were significantly higher than those of the rose crown group(P<0.01),while the deformity rate was slightly lower than that of the rose crown group,and the difference between the two was not significant(P>0.05).(6)Comparative analysis of serum indicators showed that the cholesterol levels in the pre laying and peak laying periods of the single crown group were significantly lower than those of the rose crown group(P<0.05).The level of Calcitonin in the single crown group was significantly higher than that in the rose crown group at the pre laying and peak laying periods,and the levels of immunoglobulin A and immunoglobulin G in the single crown group were significantly higher than those in the rose crown group(P<0.01).In the early stage of egg laying,the immunoglobulin M of the single crown group was significantly lower than that of the rose crown group(P<0.05),and there was no significant difference during the peak egg laying period.(7)The expression results of related genes in ovarian and testicular tissues of different comb types revealed that the ovarian sex hormone related genes FSHR,LHR,Er in single coronavirus group hens α The proliferation related genes PCNA and Cydin D1 were lower in the pre laying stage than in the rose crown group,but the apoptosis related genes Caspase3 and Caspase9 were higher in the peak and post laying stages than in the rose crown group,and the difference was not significant(P>0.05).Immune related genes IL-1,IL-6,and IL-γ The expression level of the rose crown group was significantly higher than that of the rose crown group in the later stage of egg laying(P<0.05).Unlike hens,in the testicular tissue of roosters,the expression levels of proliferation-related genes PCNA and Cydin D1 in the single crown group were higher than those in the rose crown group at 24 and 36 weeks of age;The expression levels of apoptotic genes Bax and Caspase3 were lower than those of the Rose Crown group at 24 weeks old,and the expression levels of Bax showed significant differences between the two groups(P<0.05).In summary,it can be seen that the single crown group hens have better immune performance,disease resistance,and egg quality compared to the rose crown group hens;Rose crowned hens have better egg laying rates;Single crowned roosters have better semen quality and reproductive performance. |
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