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T-3-112s - Selenium Supplementation of Feeds for Lactating or Dry Dairy Cows 

March 1, 1995

As a result of the modifications in the T-3-112 published July 1, 1992, free-choice feeds, including feed blocks for lactating or dry dairy cows, may no longer contain supplemental selenium. 

Members of the feed industry have requested that feed blocks designed for feeding to lactating and/or dry dairy cows be permitted to continue to contain supplemental selenium. After consultation with the Bureau of Veterinary Drugs regarding this request, it was decided that inclusion of supplemental selenium in feed blocks for lactating or dry dairy cows may be appropriate where appropriate voluntary consumption data for the feed block is submitted for evaluation. 

Voluntary consumption data will be required for each specific formulation for which selenium supplementation is requested. This voluntary consumption data must be collected on a biweekly basis, for a minimum of 90 days, under the suggested feeding regime (eg. pasture) for both lactating and dry dairy cows. Selenium assay data for the blocks used and an estimate of the coefficient of variation (%CV) must be supplied for each study. A minimum of three (3) studies are required. For additional information on the requirements with respect to experimental design, statistical analysis, etc., please contact the:

Feed Section
Animal Health and Production Division
Canadian Food Inspection Agency
59 Camelot Drive
Ottawa, Ontario
K1A 0Y9
Phone: 613-225-2342
Fax: 613-228-6614