Timely and ample precipitation and favorable temperatures is a combination for rapid grass growth. May is generally the month when graziers struggle to manage the spring flush and stay ahead of the growth and seed head development. Here are some management reminders and thoughts related to this early season period.
* Manage beginning and ending grass height. In beginning level grazing schools we say to start grazing when plants are around 8 inches in height. Follow the take half, leave half principle and remove livestock from a pasture paddock when grass height is about 4 inches.
* When grass is growing fast, rotate fast. Under the good growing conditions experienced in the spring of the year, a healthy grass plant will begin to re-grow within a couple of days of being grazed or cut off. This new growth should not be grazed again until the plant has recovered back to the target beginning grazing height. In practice, this means that when pasture plants are growing rapidly livestock may not stay in a paddock long enough to graze off half the plant. Remember that it is better to leave more plant residue, more plant height, rather than graze below a 3-4 inch height.
* Provide a rest period for the plant after a grazing pass. Manage this rest period according to plant growth and recovery rather than by calendar. The rest period needs to be long enough to allow plants to grow to the target beginning grazing height. In the spring this could be as short as 15 days. During the summer, as grass growth slows down, the rest period will increase. Summer rest periods are generally 30 days or longer. The key is to watch the plant, not the calendar.
* When the plant shifts to reproductive growth and begins to develop a seed head it will no longer produce other vegetative tillers that have the potential to thicken up a grass sward and fill in empty areas. In addition, when a plant enters reproductive growth quality as measured by crude protein, energy content, mineral percentage, and fiber percentage, begins to decline. This decline in quality continues as the plant matures. If high quality forage is needed then it is advisable to clip off the seed head and get the plant back into vegetative growth.
* When pasture grass is growing fast and seed heads are developing it is very difficult to get good forage utilization. A lot of forage can be wasted unless there is a plan in place to manage the growth. One option is to manage fewer pasture acres during this spring and early summer period. Drop some pasture paddocks out of the rotation and cut them for hay. Work those paddocks back into the grazing rotation during the summer months. Another option is to clip the pasture paddocks ahead of the grazing rotation. This option requires a good manager who can judge how far ahead a paddock must be clipped so that it is at that 8-10 inch grazing height when livestock are ready to enter that paddock. Possibly the best option to get better forage utilization is to drop some paddocks out of the spring rotation and increase the stocking density. Increasing the stocking density will reduce animal selectivity and provide a more even grazing pattern. This brings up the next point: