Tooth development in cattle
Research from the University of Bristol has found a new way to age cattle by looking at their teeth, as well as providing information on the effect of gender and breed on tooth development.
Researchers used data from animals slaughtered over a one-year period between 2007 and 2008, to determine the link between the age of the animal and the number of permanent anterior (PA) teeth present. Gender and breed differences were also examined.
Studying 60,000 animals, researchers found that on average it took 23 months for two teeth to develop, 30 months for four teeth, 37 months to develop six and 42 months to move up to eight teeth. Findings suggest that on average, males develop 22 days earlier than females across all these stages.
Data gathered from a further 23,000 animals was used to compare tooth development in different breeds. Breeds were grouped into dairy and beef-type, and beef-type was subdivided into native and continental beef breeds.
Researchers found that dairy-types moved through the development stages earlier than beef-types, and native breeds developed earlier than continental breeds.
Across the first three stages of development (moving from zero to six teeth), Ayrshires and Guernseys matured three to six weeks later than the Friesian/Holstein and Simmental breeds.
In addition, the Limousin and Blonde Aquitaine developed six to eight weeks later than Aberdeen Angus's, and tooth development in Red Devons and Galloways was delayed by eight to 12 weeks - the biggest delay across all breeds.
Researchers say these findings demonstrate that breed and gender influence tooth development, which should be considered when estimating cattle age. The full report has been published in the journal Animal.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
