Studies On Meat Quality And Reproductive Trait And Relavent Candidate Genes In Beijing-You Chicken

This experiment, taking Beijing-You, White Leghorn and Divergent-selected lines of Beijing-You chicken as testing material, was studied the laying law and compared the difference of level of hormones in the blood of different varieties (lines). The difference of meat quality and laying performance are studied through correlation analysis. I also studied the impact of fat deposition toward laying performance through testing the correlation IMF level and egg production. The results are as follows:1. The egg-laying time of Beijing-You(161) and White Leghorn(145)chicken are centralized at 8:30 to 12:30 am. The age of laying the first egg and laying peak of Beijing-You chicken is 29 days and 40 days later than White Leghorn respectively. The days for keeping laying peak of Beijing-You chicken is 40 days shorter than White Leghorn. The level of FSH and LH of Beijing-You and egg production of 300-day-old Beijing-You are very significantly lower than White Leghorn (P<0.01), but the level of PRL of Beijing-You is significantly higher than White Leghorn (P<0.05). These demonstrated that the different levels of hormone may be the cause of lower performance of local breed than the imported ones.2. The result, tested BJY(90) and White Leghorn(90), was showed that the IMF content of leg, the weight of abdominal fat, the percentage of abdominal fat and the b* value of Beijing-You chicken are very significantly higher than White Leghorn (P <0.01), but the value of a* is very significantly lower than White Leghorn (P<0.01). The IMF content of breast of Beijing-You and the L* value is significantly higher than White Leghorn (P<0.05). The content of IMF maybe cause superior meat quality of Beijing-You to the White Leghorn3. The result, tested up-selected line (90) and down-selected line (90) of Beijing-You chicken, was showed that the laying time of Divergent-selected lines of Beijing-You concentrated at 8:30 to 14:00. The age of laying the first egg and laying peak showed no difference. The IMF content of breast and leg, the weight of abdominal fat and the percentage of abdominal fat for up-selected line of Beijing-You chicken are very significantly higher than the down-selected line (P<0.01). The concentrations of FSH, LH and PRL show no significant difference for Divergent-selected lines of Beijing-You chicken (P>0.05). The days for keeping laying peak of up-selected line of Beijing-You chicken are 5 days longer than the down-selected line. These showed that the deposition of fat influences the egg-laying performance.4. The egg production of 300d for BB genotype(30) of A-FABP gene is fewer than the genotype of AA(25) and AB(65), and it is significantly different for down-selected line of Beijing-You chicken (P<0.05). The fat deposition didn't show significant difference among the three genotypes (P<0.05), the reason of which maybe the inadequate number of sample. The genotype of PRL for Beijing-You chicken is the BB, which is the AA for White Leghorn.5. In the correlation analysis between fat deposition and egg-laying performance (n=59), the tendency of correlating between the content of IMF and the egg production at 300 days was not consistent, while in other testing varieties (lines), the fat deposition and egg production at 300 days shows negative correlation, especially for the Beijing-You, it is significantly negative correlation (P<0.05), which further demonstrate that excessive fat deposition lead to laying decline.