W. Heyen, H. A- Lewin - Department of Animal Sciences, University of Illinois, Urbana. Illinois 61801, USA
Y. Da,G. R. Wiggans , P. M. Vanraden - Agricultural Research Service, USD A, Beltsville. MD, USA
E. Ezra - Israel Cattle Breeders Association, Pardes Hana. Israel
DNA microsatellites were used to detect individual loci affecting economically important quantitative traits in dairy cattle via the granddaughter design. Eighteen US Holstein grandsires and 1555 of their sons were genotyped for 30 genetic markers located on 19 of the 29 bovine autosomes. From 16 to 205 sons were genotyped per family. Of 14.650 son genotypes determined, 77% were informative. The genotype data was matched to the bulls' daughter yield deviations for milk, fat, and protein production, fat and protein percentage, productive life, and somatic cell score. The within-family allele effect was significant at p<0.01 for TGLA263 on chromosome 3, CSRM60 on chromosome 10, and CSSM66 on chromosome 14. TGLA263 and CSSM66 had significant effects on more than one trait but the effects on fat percent were greatest for both loci. The effect of CSSM66 on fat percent was significant at p<10“ . CSSM66 also had a significant effect on fat percent in the Israel Holstein population (p<0.001), which was analyzed by a daughter design of seven families. By maximum likelihood, it was determined that the QTL has a substitution effect of about 0.28% fat, and is probably located 10 to 20 cM from CSSM66 proximal to the centromere.
W. Heyen, H. A- Lewin - Department of Animal Sciences, University of Illinois, Urbana. Illinois 61801, USA
Y. Da,G. R. Wiggans , P. M. Vanraden - Agricultural Research Service, USD A, Beltsville. MD, USA
E. Ezra - Israel Cattle Breeders Association, Pardes Hana. Israel
DNA microsatellites were used to detect individual loci affecting economically important quantitative traits in dairy cattle via the granddaughter design. Eighteen US Holstein grandsires and 1555 of their sons were genotyped for 30 genetic markers located on 19 of the 29 bovine autosomes. From 16 to 205 sons were genotyped per family. Of 14.650 son genotypes determined, 77% were informative. The genotype data was matched to the bulls' daughter yield deviations for milk, fat, and protein production, fat and protein percentage, productive life, and somatic cell score. The within-family allele effect was significant at p<0.01 for TGLA263 on chromosome 3, CSRM60 on chromosome 10, and CSSM66 on chromosome 14. TGLA263 and CSSM66 had significant effects on more than one trait but the effects on fat percent were greatest for both loci. The effect of CSSM66 on fat percent was significant at p<10“ . CSSM66 also had a significant effect on fat percent in the Israel Holstein population (p<0.001), which was analyzed by a daughter design of seven families. By maximum likelihood, it was determined that the QTL has a substitution effect of about 0.28% fat, and is probably located 10 to 20 cM from CSSM66 proximal to the centromere.