When managing pastures, a clear understanding of what’s happening on the ground is crucial. Fractional cover, derived from satellite imagery, is one of the most effective tools available to Australian graziers today. By interpreting this data, graziers can make informed decisions that impact livestock health, pasture sustainability, and overall productivity. Here’s a closer look at what fractional cover is, how to interpret it, and why it matters for energy, intake, and livestock production.
What is Fractional Cover?
Fractional cover breaks down the land surface into three categories:
- Green Vegetation: This represents photosynthetically active (live) vegetation, which typically indicates fresh, nutritious forage.
- Non-Green Vegetation: This includes non-photosynthetically active vegetation, such as dry or aging plant material.
- Bare Ground: Areas with no vegetation, often signalling a need for ground cover management.
Using high-resolution Sentinel-2 satellite imagery, Cibo Labs maps out these cover types, providing clear visual indicators of each fraction. The fractional cover legend makes it easy to see the balance of green, non-green, and bare ground, offering graziers insights into pasture status and trends.
Interpreting Fractional Cover for Pasture Quality
Understanding the fractional cover breakdown gives graziers a quick and comprehensive view of pasture health. Here’s how each category affects pasture quality:
- High Green Vegetation: Indicates a healthy, growing pasture with quality forage that is high in nutrients and digestibility. This is ideal for grazing, especially for livestock needing high energy intake.
- High Non-Green Vegetation: The dominance of non-green vegetation usually points to older forage, which, while still valuable for fibre, may lack the energy and nutrients of fresher pasture. This forage type is less digestible, meaning animals may get less energy.
- High Bare Ground: A high percentage of bare ground signals poor coverage, which can increase risks of soil erosion and reduce feed availability. Managing for lower bare ground percentages can help sustain soil health and pasture resilience.
By assessing these factors visually through Cibo Labs’ fractional cover data, graziers can better plan grazing rotations, avoid overgrazing, and promote sustainable pasture growth.
Linking Digestibility to Energy, Intake, and Livestock Production
While fractional cover tells us what’s on the ground, understanding digestibility explains how beneficial that forage is for livestock.
Digestibility measures the percentage of plant material that animals can absorb and use. Higher digestibility directly correlates with greater energy availability for livestock, supporting higher intake levels and improved production. To illustrate:
- Digestibility Scale: The chart below, ranging from 50% to 80% digestibility, demonstrates how forage quality changes over this spectrum. Forage that’s 50% digestible provides limited energy, meaning livestock intake and production will likely be lower. Conversely, 80% digestibility forage allows for higher intake due to faster digestion, maximizing the energy animals can use and thus enhancing productivity.
- Energy and Intake: Higher digestibility supports faster passage through the digestive tract, enabling animals to consume more without feeling full prematurely. This higher intake leads to better weight gain, milk production, and livestock performance.
- Production Outcomes: Forage at lower digestibility levels will restrict intake and energy availability, limiting production outcomes. By ensuring pastures with higher digestibility are available to livestock when needed, graziers can optimise both animal health and production levels.
Bringing It All Together
Fractional cover and digestibility together provide a powerful toolkit for pasture management. With insights from Cibo Labs’ fractional cover data and a clear understanding of how digestibility impacts livestock energy, intake, and production, graziers can make smarter, data-driven decisions for their operations. Whether planning for the next grazing rotation, adjusting stocking rates, or targeting the best forage for livestock at different life stages, interpreting fractional cover and digestibility helps graziers stay proactive and productive.
For more information, check out the tools available through Cibo Labs that provide graziers with actionable insights for sustainable and profitable pasture management HERE !