| Peking duck is a famous breed of meat duck in China.The study of phenotypic and genetic basis of feeding traits can improve the feed efficiency,increase its production performance and improve the market competitiveness.We selected 358 male Peking ducks and recorded feeding information using automatic electronic feeders between 3 to 6 week of age,and compared the feeding behavior under different residual feed intake(RFI)levels.We observed that total feed time,daily feed intake and feed intake per meal had strong positive correlations with feed efficiency traits;moreover,strong correlation between feed intake per meal and body weight was found(R=0.32,0.36).Daily feeding rate and meal duration had weak correlations with feed efficiency(R=0.14?0.15).The phenotypic correlation of between-meal pauses,with feed efficiency was not observed.When daily changes were analyzed,high RFI ducks had the highest feed consumption over all times,and obvious differences in daily visits.were found among different RFI level animals during the middle period;these differences were magnified with age,but there was no difference in daily meal number.Moreover,our data indicate that high RFI birds mainly take their meals at the edge of the population enclosure,where they are more susceptible to environmental interference.We developed a GBS protocol for ducks and tested it to genotype 49 Peking ducks.A total of 169,209 SNPs were identified from all animals,with a mean of 55,920 SNPs per individual.The average SNP density reached 1156 SNPs/MB.In this study,the first application of GBS to ducks,we demonstrate the power and simplicity of this method.GBS can be used for genetic studies in to provide an effective method for genome-wide SNP discovery.In this study,the growth and feeding phenotypes of 643 Peking ducks were recorded by automatic feeding recording system and then were sequenced using GBS protocol.The genetic parameters of the feeding efficiency were calculated,then association analysis for feeding efficiency was performed.According to 10 different traits,we obtained 34 non overlapping QTLs by using the genome wide association analysis of mixed-linear models,including 42 significant loci.For feed efficiency traits we found 11 significant QTLs.The significant loci on FI and RFI are located at the region of 182Mb of chromosome 1,which was in the downstream region of the gene RNF17,and can explain the phenotypic variation of 2.3%and 3%on FI and RFI,respectively.In QTLs associated with the trait FCR,the highest significance is SNP at the position of 25Mb of chromosome 6,which P-value was to 1.65E-06,at the same time this is significant.A site in SORCS1 gene exon 4th and third,3%of the phenotypic variance.The results of gene-model association showed that there were strong signals in the 10 traits.For BW42,BWG21-27 and RFI,a total of nine significant genes were detected in three different QTL regions on chromosome 1,respectively.Moreover three genes(LOC101791418,TUBGCP3 and ATP11 A)were significantly associated with 42-day body weight from 139.0Mb to 140.3Mb;and four genes(SHISA2,NUPL1,MTMR6,ATP8A2)were found out for association with BWG21-27 in the 179.70-179.80Mb region.There are two genes(PARP4,CENPJ)in.2Mb region,which were significantly associated with RFI.The results of the study provide a new reference for the selection of genomic selection for the feed efficiency of Peking ducks,and also help to better study the genetic mechanism of the feed efficiency. |
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