Additional Information on Nutritional Monitoring

Enhancing Nutritional Monitoring: Strategies for Informed Grazing and Feeding Management

At the most basic level, nutritional monitoring to inform grazing, habitat, and or feeding management decisions involves determination of quantity and quality of available forage. Forage quantity (weight per unit area) and quality (nutrient concentration) can be obtained relatively easily by harvesting above ground standing crop samples representative of the pasture in question and then having these samples analyzed at one of the many reputable forage testing laboratories.

This method works reasonably well in monoculture pastures and or low diversity rangelands where animal diet selectivity is limited. Even so, depending on a variety of factors (notably stocking rate), grazing animals will still exhibit some level of attraction for new-live-leaf and thus select a higher quality diet than the average for available forage. In this case, “hand plucking” or sampling plant tissue for analysis that mimics the diet selected by resident grazing animals will yield a more accurate estimate of nutritional status. The method will also require more time and skill from the manager. Emerging remote sensing techniques may also be applied to estimate forage quantity and quality. Many of these tools are readily available at regional to local scales.

All of the aforementioned methods are useful in making informed grazing or nutritional management decisions; each has its advantages and disadvantages (Table 1).

If your management objectives include obtaining knowledge of what your animals are selecting from the forage available on your operation, and how your management is providing for their nutritional needs in real time, then a monitoring method that accounts for individual animal selectivity in a specific time and place is called for. Hand plucking will provide that information if you have the time and experience.

Alternatively, a manager can let the animals inform this process by collecting fecal samples. Fecal chemistry is related to diet chemistry (Figure 1). Fecal samples can be collected in concert with other routine farm/ranch chores such as putting out feed or minerals.

*Please contact us at the Gan Lab for more information concerning sampling strategies and contract structure.