Dr. Ronald L. Boman
USU Extension Dairy Specialist

    Due to the large number of questions we have received concerning the use of BST, we felt that it was necessary to reaffirm our position on its use. Utah State University was involved in demonstrating the safety and efficacy of BST starting in 1986. Controlled research trials at Logan, Utah, and at three other universities clearly demonstrated the safety and milk production stimulating effect of BST. These research trials were monitored very carefully and nutrition and other management aspects were considered to be excellent. Milk production increased an average of 15% for cows receiving 500 mg of BST every two weeks compared to control cows that were fed similarly but received an injection without BST. There were no major cow health or reproductive differences between cows receiving BST and those not receiving BST. There were no differences in body weight or condition score between cows that received BST or those without BST, indicating that cows had been provided with adequate nutrition to allow them to meet the requirements for increased production as well as to replenish their body stores of tissue. This is a key point in the use of BST. Not only do we need to feed a balanced ration, but the ration needs to be formulated for the increased milk production.

     BST is just another management tool much like 3X milking. A common complaint 15 or 20 years ago about 3X milking was that cows milked great in the first lactation they were milked 3X, but in subsequent lactations they didn't maintain the same level of milk production or body condition. We soon learned that we had to feed these 3X milked cows for the extra production and to replenish the body condition prior to them going dry. The same principle holds true with the use of BST,. We feed cows according to milk production and to achieve adequate body condition. BST supplemented cows eat more feed so we manage the feed bunk so that cows never run out of feed. BST not only causes the cow to eat more, but causes her to divert a larger portion of her digested nutrients toward the production of milk.

    Presently dairy producers are finally being paid a reasonable price for their milk and the cost of feed is lower than it has been for a long time. Thus, it makes sense to manage your cows to achieve the maximum profitable level of milk production.

    BST use requires sound management practices. Some of these are outlined as follows:

        1. Feed a balanced ration that has been formulated for the increased level of milk production.
        2. Keep fresh feed and water available at all times.
        3. Provide clean, dry and comfortable conditions for the cows.
        4. Dry-off cows at 3.25 to 3.5 body condition score (1 to 5 scale).
        5. Carefully transition cows during the last 3 weeks of the dry period to get them ready for the lactation ration.
        6. In Utah and the Intermountain West where irrigated alfalfa is grown, pay attention to forage quality. Shoot for relative feed values above 185 (protein 22-23%, ADF 26-27% and NDF 33-36%).

    BST is another management tool, but it does require SUPER-GOOD MANAGEMENT. If you are not willing to provide the management, then you probably shouldn't use BST. ©