Effects Of Abdominal Fat Deposition On Reproductive Performance Of Wannan Three Yellow Chicken S3 Strain

The reproductive performance of local poultry is generally low.In this study,the S3 strain selected within this breed of Wannan three yellow chicken was used to determine the high and low abdominal fat groups by in vivo measurement of abdominal fat thickness index by ultrasound instrument at 60 weeks of age,and the data of breeding egg hatching performance,egg production,slaughter performance,blood lipid index at each stage and gene expression related to fat metabolism were analyzed to compare the effects of high and low abdominal fat on the reproductive performance of local native chickens,and the results were as follows.The thickness of abdominal fat in the high abdominal fat group was 3.7 times thicker than that in the low abdominal fat group,and the skin thickness in the high abdominal fat group was significantly higher than that in the low abdominal fat group(P < 0.05).The dead embryo rate of breeding eggs in the low abdominal fat group was 2.64%,which was significantly lower than that in the high abdominal fat group(6.87%,P < 0.05),and the healthy chick rate in the low abdominal fat group was 99.69%,which was significantly higher than that in the high abdominal fat group(P < 0.05).The average egg production of the low-belly fat group was significantly higher than that of the high-belly fat group(P < 0.05),with 217.51 eggs in the low-belly fat group and204.14 eggs in the high-belly fat group.The results of the inter-group analysis of the abdominal fat thickness and egg production showed that there were significant differences between the egg production of different abdominal fat thickness groups,among which those with abdominal fat thickness of 0.8-1.0 cm and 0.4-0.6 cm had significantly higher egg production than the other groups,with average egg production of 217.18 and 215.57 eggs,respectively.The egg production was lower in both the high and low abdominal fat groups,with 198.5 eggs laid for abdominal fat >1.7 cm and 199.84 eggs laid for abdominal fat 0.2-0.4 cm thickness(P < 0.05).The live weight,slaughter weight,semi-clean bore weight and belly fat weight of chickens in the high belly fat group were significantly higher than those in the low belly fat group(P < 0.05).The slaughter rate,semi-clean chamber rate,and abdominal fat rate of chickens in the high-belly fat group were significantly higher than those in the low-belly fat group(P < 0.05).The VLDL levels in the high abdominal fat group were significantly higher than those in the low abdominal fat group at all ages,and the lipid levels increased and then decreased with increasing age,reaching the highest VLDL concentration at 28 weeks of age(P <0.05).The expression of ACACB,ITGAV and ZC3H12 A genes in the abdominal lipids of the high abdominal lipid group at 60 weeks of age was significantly lower than that of the low abdominal lipid group(P < 0.05).There was a significant positive correlation between abdominal fat thickness and skin thickness(0.296),and the relationship between abdominal fat thickness and egg production could be expressed as Y(egg production)= 205.95385 + 15.85964 × abdominal fat thickness-10.53446(abdominal fat thickness)2(P < 0.05).In conclusion,ultrasound in vivo measurement can be used for poultry abdominal fat amount selection to improve egg production;excessive abdominal fat deposition affects breeder egg hatching,egg production,blood lipid index,slaughter performance and gene regulation related to fat synthesis.0.4-1.0 cm abdominal fat thickness can be used as the optimal interval as a reference basis for breeder retention.The results showed that the best range was 0.4-1.0 cm abdominal fat thickness.