The recently released "Dairy Heifer Raiser, 2011" study, from the USDA's National Animal Health Monitoring System, provides an overview of the management practices used on heifer-raising operations.
Among the results, the study sheds light on the practice of using a single needle to vaccinate multiple heifers:
Almost four of 10 operations (38.8 percent) vaccinated two to 10 heifers with each needle.
One-fourth (25.2 percent) vaccinated 11 to 20 heifers before changing needles.
More than 30 heifers were vaccinated with a single needle on 14.6 percent of operations.
The study authors warn that using a single needle to vaccinate multiple heifers can result in transmission of certain diseases. In addition, needles used on multiple heifers eventually become dull, resulting in tissue trauma, pain and the possibility of broken needles.
Source: Dairy Heifer Raiser, 2011, National Animal Health Monitoring System