The Bodily Form Linear Assessment, The Genetic Polymorphisms Of κ-CN And FASN Gene, And Their Relation With Some Production Traits In China Holstein Cattle

In 265 China Holstein , using normal measurement, the bodily form linear assessment was conducted; using the method of PCR-RFLP, the genetic polymorphism of the k-CN gene was detected ; using the method of PCR-SSCP, the genetic polymorphism of the FASN gene was detected; using GLM model, the influence of the genetic polymorphisms in the k-CN and FASN genes were analyzed on butter-fat percentage , protein ratio , milk yield , Somatic Cell Count and Somatic Cell Score .The results showed that traits in cows'bodily form linear assessment was significantly correlated with milk performance, while milk yield was significantly correlated with comeliness (p<0.01) , withers stature and body depth (p<0.05) ; however the yield was significantly negatively correlated with the rear udder depth , the rear udder width , udder cleft , rear legs rear view , the rump width , foot angle , breast width , teat length , and teat location . milk fat content was significantly positively correlated with udder cleft and stature but negatively correlated with breast width . Moreover, protein ratio was significantly positively correlated with teat length , body depth (p<0.01) and teat location (p<0.05), but significantly negatively correlated with rear-legrear view and breast width.The genetic polymorphisms were detected in the 4th exon and 5th exon of the K-CN genes in China Holstein , anA/C polymorphism at nt 13100 and a T/C polymorphism at nt 15153. Two genotypes, AA and BB, were found in the 4th exon, with an allele-A frequency of 0.9379 and allele-B frequency of 0.0621. Three genotypes, AA, BB and AB, were found in the 5th exon, with an allele-A frequency of 0.6512 and allele-B frequency of 0.3488. The 4th exon in K-CN gene had a polymorphism information content of 0.1097 while the 5th 0.3511 . Polymorphism in the 4th exon was low and medium in the 5th exon. Effective number of allelic gene for the two exons were 1.1318 and 0.1165, respectively. Heterozygosities for both exons were 1.8324 and 0.4543, respectively The 4th exon in K-caseingene exerted strong influence upon performances such as body depth , udder cleft , rear udder depth , and rear udder width. In comparison, the 5th exon affected a lot the rump width . The 4th exon polymorphismhad a strong influence on milk production . The average production of AA genotype was 8.55% higher than that of BB genotype.Only one polymorphism(A/G) were found at nt 16009 of the 34th exon and no polymorphism found at three other exons.. the allele A and B had frequencies of 0.7752 and 0.2248 respectively . Two genotypes, AA and AB, were found , with a frequency of 0.5505 and 0.4495 respectively . Effective number of alleles for the 34th exons were 0.2980 . Heterozygosities was 0.3644 and polymorphism information content 1.5733 . The polymorphism of the 34th exon in FASN had a great influence upon milk fat content , SCC and SCS . For milk fat content, the average individual value of genotype AB was 7.17% higher than that of genotype AA . For SCC , the average individual value of genotype AB was 71.86% higher than that of genotype AA . For SCS , the average individual value of genotype AB was 13.50% higher than that of genotype AA .