Author
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DIKMEN, SERDAL - Uludag University |
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DAHL, GEOFFREY - University Of Florida |
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Cole, John |
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Null, Daniel |
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HANSEN, PETER - University Of Florida |
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/9/2017 Publication Date: 2/23/2017 Citation: Dikmen, S., Dahl, G.E., Cole, J.B., Null, D.J., Hansen, P.J. 2017. The Larson Blue coat color phenotype in Holsteins: Characteristics and effects on body temperature regulation and production in lactating cows in a hot climate. Journal of Animal Science. 95(3):1164-1169. Interpretive Summary: Larson Blue Holsteins, located on a dairy in south Florida, exhibit a coloration pattern that is similar to that of black and white or red and white Holsteins, but their coat color varies from grey to taupe. It has been proposed that Larson Blue cattle are better able to resist the effects of heat stress. The inheritance of the phenotype is consistent with the gene being a dominant trait. Analysis of genotypes from Larson Blues shows that the phenotype is not due to inheritance of known mutations causing coat color variation in cattle. Three DNA sequence variants in the melanohpilin gene were identified in two Larson blue cows whose genomes were sequenced. Despite being lighter in color, there was no difference in diurnal variation in vaginal temperature between Larson Blue and other Holsteins when recorded during the summer for cows housed in free-stall barns with shade, fans, and sprinklers. Similarly, there was no effect of the Larson Blue phenotype on seasonal variation in milk yield. Technical Abstract: Here we reported a previously-undescribed coat color phenotype in Holstein cattle. Larson Blue Holsteins, located on a dairy in south Florida, exhibit a coloration pattern that is similar to that of black and white or red and white Holsteins except that, instead of being black or red, darker regions of the body vary in color from grey to taupe. The inheritance of the phenotype is consistent with the gene being a dominant trait. The Larson Blue phenotype was readily apparent in young calves. The phenotype is not due to inheritance of known mutations causing coat color variation in cattle, including dominant red, Telstar, silver color dilutor or Dun color. Three variants with moderate effects on the melanohpilin (MLPH) gene were identified in two Larson blue cows. Despite being lighter in color, there was no difference in diurnal variation in vaginal temperature between Larson Blue and other Holsteins when recorded |