Bovine Congenital Defects Recorded in a National Survey of Dairy and Beef Herds Over Ten Years (2014-2023).

This study describes a novel model of farm-based congenital defect recording, with use of accessory data from a national breeding organisation. The study ran from 2014 to 2023 inclusive resulting in 522 reports of bovine congenital defects with additional data available for a subset (369/522). The most commonly reported defect was intestinal atresia (24.3%), followed by multiple defects (19.9%), and tail abnormalities (13.4%). This is the first national survey of bovine congenital defects in Ireland. It shows that while farmer-reported cases generally lack a veterinary clinical or necropsy examination, farmers are in the unique position of being able to report phenotypic abnormalities first-hand, and provide an unbiased perspective of the true typology and epidemiology of congenital defects on farm.