By Karen Hoffman, USDA Natural Resources Conservation Service with some additions by Rick Kersbergen UMaine Cooperative Extension
Added April 5, 2011. One challenge with grazing the organic dairy herd is helping cows adjust to a new feed source in both the spring and fall. The switch from lower-quality stored feeds to high-quality pasture is much like changing silos. If the change is made too quickly, milk production drops until the cows and their rumen microbes become accustomed to the new feed. The rumen microbes are especially sensitive to sudden changes because it takes time to shift their numbers and types to those that are more adapted to higher-quality forage.
Spring Transition
During the transition, the first day of grazing occurs when the grass is only three to four
inches tall. The length of time cows are allowed out on pasture should be relatively short (one
to two hours). If left out for longer than that, they will likely eat too much and when they return to the barn, may refuse quite a bit of the ration. Another option is to "flash graze" a large area of pasture, such as a large paddock with any temporary or semi-permanent fencing removed. This is useful in cases where the ground is still wet and the potential of pugging up
the pastures with too much animal pressure is a concern.
Over the next few days, the length of time the cows spend on pasture should be gradually increased until they are out full-time. At this point there will also be a gradual increase in the amount of feed they refuse in the barn. Depending upon what the "final pasture ration" is going to look like, protein forages such as haylage, baleage and dry hay should be reduced first (unless the ration will be based on one of those forages). Next the amount of protein from grain or concentrate should be cut back because the cows will be increasing their intake of protein from pasture.
If feeding a total mixed ration (TMR), the easiest way to make the transition is to mix for five to ten fewer cows (depending on herd size) each day as they are refusing it anyway. When the TMR is being fed at a rate that is less than 70% of the full ration, begin reducing protein levels by one pound every three days. When the TMR is below 50% of normal, both protein and NFC levels should be checked to make sure they are in balance, and at this time the TMR may need to be reformulated.
Transitioning cows should always be gradual, to avoid digestive upsets. Cows need to be monitored to make sure they have adequate effective fiber in their rumen during the transition.
After 10 to 14 days of transitioning, the ration should be comprised of less than 10 pounds of dry matter from stored forage, and pasture dry matter intake should be greater than 15 pounds. Also, grain mixes should be below 16% protein (or protein concentrates should be fed at a rate of less than two pounds per cow). Mineral and vitamin intakes should be evaluated as well as often cows are less willing to consume concentrates that usually are the source of
those supplements.
Producers should monitor the quality and quantity of the paddocks during the early rotations. Grasses are growing faster than cows can consume them, and often pasture quality can decline rapidly if not grazed early. It is during that period when graziers need to decide to harvest some of the pasture as a stored feed instead of including that paddock in the early rotations.
Let's hope that all this snow will melt and provide a great start to the grazing season!
References and Citations
Hoffman-Sullivan, K., R. DeClue, and D. Emmick. 2000. Prescribed grazing and feeding management for lactating dairy cows. New York State Grazing Lands Conservation Initiative. USDA Natural Resources Conservation Service, Syracuse, NY. (Available online at: ftp://ftp-fc.sc.egov.usda.gov/GLTI/technical/publications/ cow-feeding-mgt.pdf) (verified 20 March 2010).
Reprinted with permission from the eOrganic Dairy team / eXtension. This article can be found online with other organic dairy resources at the following address:
