Cattle Minerals 101

After coming through a challenging winter, it is important to make sure your cattle are on a good mineral program. For a cow to calve at the same time next year she must rebreed within 80-83 days after calving. Good nutrition is fundamental to ensuring cows rebreed in time to maintain their status in the herd, and a sound mineral program is an important pillar of their overall nutrition.

Macro minerals are the main category of minerals that make up the animal’s mineral program. The essential macro-minerals are calcium, chlorine, magnesium, sulphur, sodium, phosphorus, and potassium. These minerals are required for bone development and maintenance, muscle development, growth, and fertility. The most talked about macro minerals are calcium and phosphorus and their ratio in the body, which should be at least 2:1 (Ca:P). The type of forage or pasture and production status will influence this ratio. Legumes are generally high in calcium, so in order to maintain the 2:1 Ca:P ratio, the cattle need to be supplemented with a 1:1 Ca:P mineral. Grasses are low in calcium, so pastures that are high in grasses need a 2:1 Ca:P mineral to fulfill the deficient calcium requirements.

The second group of minerals that are equally as important, but are required in smaller quantities, are trace minerals. The essential trace minerals include copper, iron, selenium, cobalt, iodine, manganese, and zinc. These minerals are important for animal health, feed efficiency, growth, proper immune function, and most importantly - fertility. A proper balance in trace minerals is directly related to how quickly the uterus can heal after calving and the cow can successfully rebreed. When supplementing trace minerals, the physical form matters, but price also dictates the quality of the trace mineral you are feeding:

· Oxides: Oxides are the most stable form of a trace mineral and therefore only small amounts are actually absorbed by the animal. For example, copper oxides found in minerals are in the same form as a Canadian penny. This form of a trace mineral is often found in mineralized salt blocks or a basic mineral (loose or tubs) and are typically low on the price scale. Cattle are at risk of not absorbing enough mineral to meet their requirements when being fed this form of trace minerals, especially if there are extenuating circumstances (as discussed below).

· Sulphates: Sulphates are an intermediate form of trace minerals and are the most common type found in mineral programs (including premixes, free choice loose minerals, lick tubs, etc.). Sulphates are a suitable trace mineral source when the animal is not under stress, and other aspects of their ration are not compromised. However, when issues such as molybdenum in forages, or sulphates in water become a concern, the sulphate trace mineral is no longer able to provide the trace minerals that the cow needs.