Abstract
The objective of this study was to estimate the withers height of cattle in public pastures from 3D digital pictures using an image-analysis technique. The 3D pictures of a cattle’s side were used for withers height estimation. The object distance for the cattle was 3 to 5 m, and the camera height was 160 cm.
Withers height estimation took 3.5 minutes per animal. The actual and estimated withers height of cattle were correlated in both Holstein cattle (r＝0.67) and Japanese Black beef cattle (r＝0.92). The estimated withers height and weight of cattle were also correlated in both Holstein cattle (r＝0.55) and Japanese Black beef cattle (r＝0.83). These results indicate that 3D image analysis is an effective means of evaluating the growth of grazing cattle in pastures.
