Age Determination in Cattle

Determining the age of a cow can be an important factor in making decisions related to buying, culling, breeding, retaining, etc. Practices such as branding or tagging with ages are a good measure and can add value especially when selling bred cows. Unfortunately, many producers cannot or do not take the time for such practices (often times they may not be practical). Examination of the teeth can however provide an approximate age of a cow. This method evaluates the appearance of temporary and permanent teeth and the degree of wear. At maturity cattle have 32 teeth of which 8 are the incisors in the lower jaw which are typically evaluated. There are no upper incisors only a thick dental pad. Depending upon range and pasture conditions the degree of wear can vary. Cattle on sandy, rangeland type country typically wear quicker than cattle on higher clay content soil with improved pasture. Because this method is approximate it is important to note that it may not ascertain a cow’s biological age but rather gauge her youthfulness in terms of grazing ability. A second method to determine age would include looking at the brucellosis tattoo in the right ear. This would indicate the year the cow was a weaned calf. The first digit represents the quarter of the year it was tagged, the middle digits are a shield and the last number is the year vaccinated. A good resource and aging table can be accessed at http://www.avc-beef.org/AgingCattle-Griffin/AgingCattle-CL712.pdf.