Waiting for Grass
By : Dr. Jeff Lehmkuhler, Associate Extension Professor, University of Kentucky
As spring approaches there a few things to keep in mind. Pasture conditions on many farms are going to be less than ideal. Heavy foot traffic combined with excess precipitation has led to a decline in swards. Spring growth could be hampered as a result. In my travels across the state during the first of March I noticed cows already trying to pick on new growth. Cows going to graze when hay supplies are tight is a welcome change to feeding hay in the mud.
However, the pasture forage will benefit this spring from delaying grazing. Much of the early growth will be supported by plant energy stores until sufficient leaf area has developed for photosynthesis. Continually removing this new growth could further weaken stands or slow spring forage growth. Implement rotational grazing management to provide some rest/recovery time for plants this year.
I typically recommend delaying spring turn out on pastures until the new grass growth has reached a height of your boot toe or about two inches. This can help both the forage and cattle. Early spring growth can be upwards of 90% moisture. A cow requiring 30 pounds of dry matter intake would have to consume 300 pounds of actual grass due to the high water content. Short and thin forage stands require cattle to expend a lot of energy walking fields for every blade of green grass to fill the rumen.
Research has shown that grazing activity requires more energy than either walking or standing. Other studies suggest early spring grazing may require nearly twice the energy as grazing in summer months. This is partially due to forage availability and the amount of forage consumed with each bite. Thicker, taller forage stands provide greater intake per bite improving grazing efficiency. Additionally, cows are not as conditioned to grazing in early spring. Cattle may also need 4-6 weeks to acclimate to the physical activity of grazing. This early season grazing energy expenditure could result in cows expending more energy than consumed resulting in lower body condition, not what we want this spring.
Continue to offer some hay even when you turn cows out on grass in early spring. The high moisture content can limit dry matter intake. Cows will not eat much hay but five pounds of dry hay intake is equivalent to approximately 40 pounds of lush pasture forage. Providing access to hay can provide cows an opportunity to increase daily dry matter intake.
Hopefully, spring will be here soon and pastures will be better than we think. Make plans to manage the pasture stands for production by fertilizing, seeding and controlling weeds as needed. Apply some level of grazing management to provide a rest/recovery period for pastures. For more information on pasture management stop in and visit with your local ANR agent at the Extension office.