How to Adjust a POSILAC® Supplementation Program to a Temporarily Limited Supply of POSILAC

Dr. Mark Armfelt, DVM, DABVP; Adjunct Faculty, Department of Veterinary Preventive Medicine, Ohio State University; Technical Service Representative, Monsanto Dairy Business (top of page)

There is currently a limited supply of POSILAC® (a registered trademark of Monsanto Technology LLC, St. Louis, MO) available. Many dairy producers find themselves in a situation where they cannot supplement all the cows they normally would if the supply were not limited. This article will suggest some ways to deal with this limited supply and make you aware of some choices to avoid when dealing with this situation.

POSILAC provides maximum value when supplementation is started at 57 to 70 days in milk (DIM) and continued until the end of lactation. It takes 4 to 6 weeks (ramp-up period) for cows to maximize milk production and dry matter (DM) intake in response to POSILAC. When supplementation begins at the time approved by the FDA (57 to 70 DIM) and continues to the end of lactation, cows will then spend the maximum number of days at the expected response of 8 to 12 LB/day of milk. When supplementation of POSILAC is discontinued at the end of lactation, cows return to the level of production they would have been had supplementation never occurred.

When considering the biology of POSILAC as described in the previous paragraph, the logical approach to dealing with a limited supply is to supplement fewer cows at label recommended times. Once you determine the number of cows you can supplement (your Monsanto representative can help you with this), there are a couple of things you can do to help you reduce the number of cows being supplemented. One is to immediately stop adding new cows to the supplementation list. The other is to stop supplementing open cows due to be culled, or cows in their terminal lactation. Caution: Stopping supplementation in late lactation may cause milk production to decline to a level that is not profitable, forcing producers to market open cows or dry-off pregnant cows.

Do not use extra-label approaches such as the following [Note: FDA regulations do not allow production drugs such as POSILAC to be used in an extra-label manner.]:

1. Do not extend the interval beyond 14 days. This can cause unwanted variation in DM intake and could lead to a loss of body condition.
2. Do not split injections. Using one dose of POSILAC on more than one cow will increase the risk of disease transmission, increase the risk of injection site abscesses, and increase the labor costs without getting an increase in milk production.
3. Do not start cows later than label recommendations. This is associated with an increased risk of udder edema, and a loss of economic opportunity because cows spend a larger percent of their supplementation period in ramp-up.

If you have any questions, please contact your local Monsanto Dairy representative.