Genetic variation of seven microsatellite loci BM1818,BM1258,BM1443,BM1905,BM302,BM4505 and CYP21 which were closely linked to somatic cell score (SCS) was analyzed in 240 Beijing Holstein cows with nondenaturing polyacrylamide gel electrophoresis.
The aim of this study was to analyze the factors affecting somatic cell score(SCS) which is an indirect criterion to assess susceptibility to mastitis. DHI records (7 082 SCC) of 253 Holstein cattle from 4 dairy farms were grouped into 4 factors, 3 levels according to months of calving ,and 7 levels according to parities, and 4 lactation stages(<65 d,66—150 d,151—225 d,<225 d after calving).
At IGFBP-3 locus, BB genotype had significantly positive effect on 305 days yield and SCS, the protein percent of genotype AB were higher than that of BB genotype(P<0.05).
For P%, genotype CJ of ETH152 was higher than genotype BB and CC(P<0.05), genotype AH of ETH225 higher than genotype DD and EE(P<0.05), genotype BB of HEL13 higher than genotype CC and DD(P<0.05). Genotype CC of ETH152 had higher F% and F/P than genotype B