Endometrial biopsy in Bos indicus beef heifers.

An endometrial biopsy allows for a comprehensive assessment of the uterine environment of a breeding female. Although routine in mares, devices used for endometrial biopsies are impracticable in heifers due to the size and structure of the cervix. This report describes the use of a human bronchoscopy biopsy device (Karl Storz® 10366L) for collection of endometrial biopsies in Bos indicus beef heifers. The Storz® device is smaller and thinner and enabled the collection of an endometrial biopsy in 86% of heifers (n = 44/51). The biopsied tissue was of good quality and suitable for transcriptomic assessment of the endometrium, with total RNA yield and RNA integrity number (RIN) averaging 1.3 μg (range 0.4-5.3 μg) and 7.4 (range 5.7-8.4), respectively.