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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #153706
Title: USING MARKERS TO INTRODUCE NOVEL GENES INTO BREEDING STOCKS

Author
item GROSZ, M - GENOMIX
item Macneil, Michael

Submitted to: Research Update for Fort Keogh Livestock and Range Research Laboratory
Publication Type: Popular Publication
Publication Acceptance Date: 10/1/2002
Publication Date: 1/15/2003
Citation: GROSZ, M.D., MACNEIL, M.D. USING MARKERS TO INTRODUCE NOVEL GENES INTO BREEDING STOCKS. RESEARCH UPDATE FOR FORT KEOGH LIVESTOCK AND RANGE RESEARCH LABORATORY. p. 58. 2003.

Interpretive Summary: Hereford cattle are affected disproportionately by two conditions, Bovine Ocular Squamous Cell Carcinoma (cancer eye) and sunburned udders. Both conditions have been linked to lack of pigmentation in and around the face (cancer eye) and on the underbelly (sunburned udders). In a study involving 1,500 cattle representing six different breeds 25.3% of Herefords, 17.6% of Hereford crosses, and <1% of 140 Holsteins showed evidence of early dysplastic lesions and/or cancer eye. Sunburned udders (which occur primarily in regions with late spring snows and early calving seasons) affect the ability of the calf to obtain milk from the mother, leading to malnourishment and, if left unchecked, death of the calf. An experiment was initiated producing females sired by Line 1 bulls out of CGC dams. These ½-Hereford females are being bred to Line 1 bulls and the resulting ¾-Hereford female progeny will be genotyped and those females that are heterozygous for markers flanking the gene causing white-face will be retained. In future years, the selected ¾-Hereford females will again be bred to Hereford bulls to produce 7/8-Hereford progeny and the cycle of genotyping and selection repeated. This process can be repeated for several generations, until the calves produced cannot be distinguished from Hereford except at the narrow region of chromosome 6 containing the causal gene for white-face. At this point, the resulting bulls and heifers will be bred to each other. One fourth of the resulting progeny are expected to have the CGC genotype for the gene causing white-face in an otherwise typical Hereford background.

Technical Abstract: Hereford cattle are affected disproportionately by two conditions, Bovine Ocular Squamous Cell Carcinoma (cancer eye) and sunburned udders. Both conditions have been linked to lack of pigmentation in and around the face (cancer eye) and on the underbelly (sunburned udders). In a study involving 1,500 cattle representing six different breeds 25.3% of Herefords, 17.6% of Hereford crosses, and <1% of 140 Holsteins showed evidence of early dysplastic lesions and/or cancer eye. Sunburned udders (which occur primarily in regions with late spring snows and early calving seasons) affect the ability of the calf to obtain milk from the mother, leading to malnourishment and, if left unchecked, death of the calf. An experiment was initiated producing females sired by Line 1 bulls out of CGC dams. These ½-Hereford females are being bred to Line 1 bulls and the resulting ¾-Hereford female progeny will be genotyped and those females that are heterozygous for markers flanking the gene causing white-face will be retained. In future years, the selected ¾-Hereford females will again be bred to Hereford bulls to produce 7/8-Hereford progeny and the cycle of genotyping and selection repeated. This process can be repeated for several generations, until the calves produced cannot be distinguished from Hereford except at the narrow region of chromosome 6 containing the causal gene for white-face. At this point, the resulting bulls and heifers will be bred to each other. One fourth of the resulting progeny are expected to have the CGC genotype for the gene causing white-face in an otherwise typical Hereford background.