Having identified the characteristics of a quality mineral, let's take a look at each of them individually.
Appropriate Formulation is a Key Factor
Above all, a quality range mineral program is one that:
a) Matches the nutritional needs of the target animals.
b) Takes advantage of available forages.
c) Is consumed at the appropriate intake level.
In the last issue we discussed mineral intake and the inherent variability that is common based on seasonality, forage quality, etc. Subsequently, product formulation should be based on carefully conducted research trials to ensure the proper balance between cattle nutrient needs and forage nutrient content. Unfortunately, it's not possible to look at a mineral and determine if it has the proper nutrient composition. However, the product label, including the list of ingredients, nutrient guarantees, and feeding instructions, provides a wealth of information relative to the nutritional adequacy of the product. Coupled with a forage analysis, your mineral supplier's representative should be able to readily determine if the product fits the specific situation for which it is being considered.
Over- or under-consumption reduces the benefits of mineral supplementation by increasing costs or reducing animal performance, respectively. Achieving uniform target intake, however, is not as easy as one may think. Consumption control begins with product formulation. Many products use salt at various levels as the primary means of controlling consumption. Other ingredients may be added to enhance palatability or to further modify consumption patterns.
Not all grazing situations or groups of cattle respond in the same manner to a given mineral. Subsequently, management of the product in the field is needed to fine-tune consumption. Practices such as relocating feeders closer to, or further away from, watering and loafing areas are used to achieve this objective. Management requirements of mineral products to achieve adequate consumption should be demonstrated through feeding trials conducted over a wide range of pasture conditions and cattle types. In other cases it may require a certain a amount of trial and error. Your mineral supplier or nutritionist should be able to provide accurate, reliable assistance in fine-tuning mineral consumption.
Target consumption rates can and do vary from one product to another. Evaluation of a mineral needs to take this into account so mineral cost is compared on a per head per day basis rather than on cost per ton.
Product Consistency -- Each Mouthful Must be the Same
Not only is it important to achieve target consumption, but the mineral consumed each time the animal visits the feeder should be balanced relative to the formulated level of each nutrient. Feed and mineral manufacturers strive to ensure the mineral going into the bag is uniformly mixed. However, this doesn't ensure the product will stay uniformly mixed. The tendency of a product to separate or segregate can be judged by close visual inspection and is affected by several factors. Segregation occurs when particles of the same size move to one part of the overall mix while particles of another size or density remain in place or move to another. Occasionally you will hear this referred to as Particle Size Dynamics (PSD).
Products that have a wide range of particle sizes and are dry and dusty tend to segregate readily. This can occur in the process of pouring the mineral into the feeder and is further enhanced by the sifting action that occurs as the animals bump and jostle the feeder. Many of the trace minerals are fine powders that become concentrated as segregation from the coarser macro-minerals occurs, which can lead to nutritional imbalance as the product is consumed.
On the other hand, products that are more uniform in particle size or that have been formulated and mixed in such a way that the product has a cohesive texture are less prone to segregation. Mineral products incorporating a molasses blend of some type of vegetable oils/fats can greatly reduce the level of segregation that takes place. Intake of the entire mineral product on each trip to the feeder is more likely to occur with products that possess these properties.
Both wind and rain (even heavy moisture or humidity) can affect the mineral once it's in the feeder, leading to difficulties in achieving adequate consumption. Exposure of the mineral to prevailing winds can lead to significant losses through wind erosion, in much the same way that exposed soils are eroded by wind. These losses are more likely to occur if the mineral is dry in texture and contains a high percentage of fine and/or light particles.
The fine particles are often trace minerals that are critical to the animal's nutrition. Light materials are generally organic ingredients, such as grain products (distillers grains, wheat midds, rice bran, etc.), that are added to improve palatability or as a filler to help match target intake to the product formulation. Loss of these ingredients lead to imbalances in the nutrient intake of the product. On the other hand, minerals that have a more uniform, coarse particle size with a cohesive texture will experience little or no loss when exposed to wind.
Exposure of a mineral product to rain can modify consumption patterns due to leaching of nutrients and/or caking of the product. As with wind losses, minerals that are a dry blend of the individual ingredients are more prone to leaching when exposed to rain. Some of the trace minerals used in these products are fine powders that are highly water soluble, making loss of these key nutrients more likely. Salt losses can also be high in these minerals when exposed to rain. Upon drying, the remaining minerals may cake and become hard and difficult for the animal to consume.
In some areas of the country, minerals are typically fed in open box feeders. Losses due to wind and rain exposure can be significant in these situations. Covered feeders are often used (and should be) to provide some protection from these elements. Losses can be substantial in some instances and every precaution should be taken to protect this investment.
The bottom line, however, is that the provision of a good quality, palatable mineral product, adequately consumed does not encounter the same risks of being damaged by or lost to the elements as one that is not well consumed and sits in the feeders for extended periods of time.