Dominant Polled Hereford Mutation

Polled (hornless) herefords originated as a mutation. In the early 1900s, Iowan Warren Gammon exploited the mutation by forming a registry to track this genetic mutation. The polled gene is a dominant trait but horned is recessive.

• How could the offspring of the herefords have no horns (polled) if parents are horned?

• Could this gene happen because of something other than dominant or recessive traits?
• What type of results does Gammon get when he breeds a polled bull to a polled cow?
• What happens when he breeds a horned bull to a polled cow?
• Are horns dominant or recessive?

Students could:

• Research possibilities of mutations in a population.
• Create a claim for how the offspring became polled.
• Devise a working theory of dominant and recessive traits.
• Create and explain a Punnett square showing how horned (heterozygous recessive) and polled work

• Oklahoma State Department of Animal Science | Breeds of Livestock,  This article explains that polled herefords are a mutation that has been expanded upon for “modern Herefords minus the horns.”
• The Biographical Dictionary of Iowa - University of Iowa Press Digital Editions: Gammon, Burton Osmond "Bert": Biographical account of Iowan Warren Gammon as the founder of the polled hereford breed.
• American Hereford Association } Understanding Horned/Polled and Scurred Traits Explanation of dominant versus recessive traits for horned versus polled in Hereford genetics.
• The Concord Consortium | DNA Mutation Simulation: Simulation for modeling mutation of DNA.