Collecting calf birthweights can help producers evaluate genetic selection, dam nutrition and future calf performance. While not a widespread practice on most U.S. dairy farms, it is a useful one.
Researchers at Clemson University and the University of Arizona, led by Dr. Nathan Long, recently evaluated two on-farm methods for assessing calf birth weight – weighing on a spring scale versus using a hoof circumference tape. A total of 872 Holstein and Jersey calves were evaluated with both methods. Study results were reported in the December 2012 Journal of Dairy Science.
The team found that the hoof circumference tape tended to overestimate the birthweight of very small calves (less than 69 pounds) and overestimated the weight of very large calves (greater than 99 pounds). However, the majority of the calves in the study weighed within a middle range of 69 to 99 pounds, and in that group, weights between the two evaluation methods were well-correlated.
The researchers concluded that using the less cumbersome method of the hoof circumference tape was accurate for the majority of births, but that caution should be exercised when using this method for very small and very large calves.
Read the research abstract.
Source: "Short communication: Comparison of 2 methods of assessing calf birth weights in dairy calves," N.M. Long, R.J. Collier, J.F. Smith, Journal of Dairy Science, Vol. 95, No. 12, December 2012,