Repeatability and accuracy of reproductive tract scoring to determine pubertal status in beef heifers.
The objective of this study was to compare the repeatability and accuracy of palpation per rectum to transrectal ultrasonography and serum progesterone concentrations for determining pubertal status in beef heifers. One hundred and seventy-four rectal examinations were performed on 29 predominantly Angus heifers by two veterinarians (A and B) and assigned individual reproductive tract scores (RTS) during monthly examinations over a 3-month period. Heifers were examined in the morning by both veterinarians, randomized, and re-examined in the afternoon. The size and location of ovarian structures of each heifer were determined by ultrasonography. Heifers with follicles >10mm in diameter or corpora lutea were classified as pubertal. Serum progesterone concentrations at the time of the examination and 10 days later were determined by radioimmunoassay and used to classify heifers as prepubertal (<1 ng/ml in both samples) or pubertal (at least one sample >or=1 ng/ml). Kappa, which describes degree of agreement beyond chance, was used to determine repeatability of the RTS system. Multicategory Kappa for agreement was 0.64 within veterinarian, 0.46 between veterinarian, and 0.35 between palpation per rectum and transrectal ultrasonography. Sensitivity and specificity of palpation per rectum for diagnosis of pubertal status compared to serum progesterone levels were higher (82 and 69%, respectively) than sensitivity and specificity of ultrasonography (79 and 59%, respectively). This study validates the RTS system as a repeatable and accurate screening test to evaluate pubertal status in groups of heifers prior to the onset of the breeding season.
Rosenkrans
Kelly S
KS
Department of Veterinary Medicine and Surgery, University of Missouri, UMC-VMTH, A-364 Clydesdale Hall, Columbia, MO 65211, USA. rosenkransk@missouri.edu
Hardin
David K
DK
D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D015588:Observer Variation; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000254:growth & development / Q000502:physiology*; D010173:Palpation / Q000592:standards / Q000662:veterinary*; D011374:Progesterone / Q000097:blood; D011897:Random Allocation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012741:Sexual Maturation / Q000502:physiology*; D014463:Ultrasonography / Q000662:veterinary
D011374:Progesterone