UTAH DAIRY EXTENSION SPECIALISTS RECOMMENDATIONS
ON THE USE OF BST
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
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
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
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.