Hoof Tape

Obtaining an accurate measure of birth weight using a high-quality digital scale is important for producing meaningful calving difficulty EPDs. However, it is not always feasible to obtain birth weights this way. Digital scales for measuring calf birth weights can cost thousands of dollars. Even with good mechanical scales, trying to catch a calf when the mother is being protective, and lifting that calf is a challenge for many producers and their ranch hands. There are reports of producers estimating the calf weights using visual inspection and this can be seen in many breed association birth weight datasets.

A widely used alternative to weighing or estimating birth weight is the calf hoof tape method. A google search reveals that there are many vendors of calf hoof tape devices. They are relatively low cost and simple to use. Many large breeders have indicated that they use hoof tapes. Large contemporary groups of calves are especially challenging and obtaining an observation on all animals is not always feasible, especially in spring calving herds in the northern states and Canada. While it has been shown that the variance of hoof tape estimated birth weights is substantially smaller than actual birth weights, using a hoof tape is a pragmatic alternative when obtaining actual birth weights is not feasible, and it should be far superior to visual estimates.

The correlation to actual birth weight can be high. While it is possible to model hoof tape observations as a separate but correlated trait, as of this writing, no breed associations have required members to indicate if the weights were obtained by hoof tape. However, given the noticeably reduced variance within contemporary group, it is possible to identify many of these groups when they are larger. It is recommended that a heterogeneous variance procedure be implemented in the EPD production where birth weight is modeled.