Grazing Management for Florida Pastures
Grazing management is often defined as the manipulation of livestock grazing methods to reach the overall desired results. The way you manage your grazing system can be determined by the type of forage species on your operation, the nutritional requirements of the animal, anticipated input costs, expected return on investment, and achieving the desired outcome. The way you graze an operation can affect the yield, nutritive value and longevity of the forage stand. These are all important factors to consider when determining the type of grazing systems for your operation.
Some other important issues to consider in a grazing management system are the requirements of both the forage and the animal for both to be productive. Grazing methods can affect these requirements both positively and negatively. The choices management makes can greatly impact the success and failures of a grazing system. Matching the nutritive value of the pastures to the requirements of the animals is a key component of overall success.
Grazing height management can be considered one of two ways either through stubble height or stocking rate. When using stocking rate as a management format during the dry and cooler months you may have some pastures that are over grazed. While during the summer or moister months you may have some pastures that are under grazed. One method to assist during the under grazing periods is to take some paddocks out of the rotation and use them for hay, haylage or stock piled forage for winter months. This will allow you to shorten the rest periods and allow the animals to graze the paddocks when the forage is in a higher nutritional state.
When managing through stubble height you want the animals to graze the pastures based on the ideal stubble height of a given forage. The ranges for the ideal stubble height can be seen in the chart below.
|Forage Species||Target Height (inches)|
|Limpograss / Hemarthria||8-10|
The reason the Bahiagrass stubble height is a lot less than that of the Limpograss is due to the growing pattern of the plant. The Bahiagrass grows closer to the ground level while the Limpograss grows taller and has growing points further away from the soil or ground level. The closer you graze the forage means the animals will be consuming more stem material. The stem part of the plant is less nutritious for the animal which will require more forage to meet the animal’s needs. When under grazing a pasture the plants are under less stress. This allows the animals to graze at a higher level consuming more leaf material which is more nutritious for the animal. While as a producer you will see higher returns per acre for meat and milk production in an under grazed system. In the same system you will also see production per acre will be lower.
One of the first decisions a producer will need to make is how they want to graze their pastures. Do they want a continuous grazing structure or a rotational structure? Continuous grazing can be appealing as it has a lower input cost and less labor intensive. In this system the cattle will determine the grazing height of the plant and the frequency of grazing. The animals can select what plants they choose to consume. This can lead to depleted leaf and growing points on the plant. If over grazing continues it can lead to pasture decline and a loss of your desired forage species.
In a rotational grazing system the manager controls the stubble height and the length of rest a pasture receives. Even though the cattle are rotating pastures these pastures can also be over grazed and over stocked. If done correctly a rotational system will assist in improving the longevity of a forage stand. The manager also can use the forage when the nutritive value is at its peak. When excess forage is available you can use it as a surplus forage source. In some instances you may also be able to increase the stocking rate in a rotational grazing system vs. a continuous grazing system. It has also been found that when animals are limited on their grazing areas they are more likely to have a more uniform dispersal of their waste leading to a more uniform nutrient dispersal across the pasture. As the labor increases it also allows managers to better manage their animals. This happens due to the fact that they are looking at the animals more frequently and are able to catch health problems earlier.
When figuring how to set up a rotational system you will first need to determine the desired resting period of your paddocks. You will also need to determine the number of days you want to graze each paddock. To get the desired number of paddocks needed you will take the number resting days divided by the number of grazing days and add one. For example if you want to rest for 20 days and graze for one day you will need 21 paddocks. However, your grazing and resting patterns will remain fluid. In periods of slower growing forage you will have longer resting periods and in faster growing forage you will have slower resting periods. This is to utilize the forage at its optimal level. You can remove paddocks from the system to use for stockpiled forage or hay to reduce the resting days and number of paddocks in the rotation.
When using your forage to match the requirements of the animals grazing you have many options. Creep grazing is one of those options. This will allow the younger animals who have a higher nutritional requirement to have access to higher nutrition forage. In this system paddocks with the higher nutrient level forage would be adjacent to the traditional forage paddock. Small gates would allow access only for the young animals and prevent the older animals from gaining access.
In a first / last grazing system the higher nutritional required animals would graze a paddock first with the lower requirement animals coming in grazing second. This allows the younger animals to consume the leaf material which is more nutritious and the older animals to consumer the lower quality forage while still meeting their needs.
Some of the disadvantages to a rotational grazing system are the initial costs involved for new fences, additional water sources, feed bunks, etc. When moving into a rotational system labor requirements will also increase. You will need someone available to move the animals from pasture to pasture. This system also requires more management to meet the needs of the animals while also maintaining stubble height.
Not one system is best for every producer. Each producer must make a decision based on what fits the needs of the operation.