Availability can be highly variable in natural feedstuffs and additives with the former dropping in concentration later in the season. Inorganic sources tend to be more available over organic sources. The quantity of minerals required will vary depending on the age, weight, health, species and type and level of production of the animal. Young animals absorb minerals such as Ca more efficiently than older animals, but they have higher mineral requirements. High rates of gain or milk production and poor health or parasitic burden will increase mineral requirements.
Sheep have different requirements than beef cattle, with copper being the prime example.
As Cu toxicity in sheep is swift and deadly, it is crucial that only minerals designated for sheep be used. Copper supplied in feed usually is adequate and sheep copper supplementation is unnecessary and dangerous. Table 1 lists the major mineral elements along with the recommended level of intake for each element required. The bottom line is one feed or ration will not meet the requirements of every class of livestock. Mineral Interactions Feeds that are improperly combined in a ration will have a marked affect on the quantity and proportions of specific minerals.