By Catherine Lang, BSA, AAg, Livestock and Feed Extension Specialist, Watrous
Summer is the time of the year that cattle producers persevere all winter for. On pasture, the calves grow, cows graze, but most importantly, cows are preparing to rebreed. For the cow to calve at the same time next year she has to rebreed in 80-83 days after calving. This means that the cow only has 40-43 days (or two cycles) to become pregnant. Good nutrition is fundamental to ensuring cows rebreed in time to maintain their status in the herd; 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. Interestingly, sulphates also have antibacterial properties (such as their use in footbaths for dairy cows).
- Organic/Chelated/Hydroxy: This group of minerals are the highest quality and most available form of trace minerals. Minerals in this form don’t degrade in the rumen, so the animal can absorb the vast majority of these minerals in the small intestine. These forms are not always necessary, and are often expensive, but may be helpful in meeting the animal’s needs under certain circumstances.
Ultimately, the type and form of the minerals you provide will depend on the animal’s stage of production, environmental factors, forage type, water quality, and cost. Depending on your management, certain forms (loose minerals, blocks, or tubs) may be easier to provide but consumption needs to be adequate (as indicated on the product label) and consistent to ensure the animals requirements are met. Cattle are not nutritionally wise and cannot seek out the minerals their body is requiring. However, cattle do crave salt which is often used to encourage intake. There are simple ways to calculate consumption based: the number of days it took for the bag/tub to be consumed, the number of animals in the group, and the weight of the bag/tub.
Finally, don’t forget about vitamins. There are four main types of vitamins: Vitamin, A, B, D, and E. Vitamin B is synthesized by the cow from the cobalt mineral. Vitamin D is the sunshine vitamin which cattle get plenty of in the summer. And while vitamins A and E are present in lush growing forages, they should be supplemented in the mineral to ensure the requirements are being met. A deficiency in vitamins can also cause a cascade of issues including reduced growth, suppressed immunity, and decreased conception rates.
Help your cows heal after calving and cycle quickly by providing a strong mineral program. Cows that breed quickly maintain a healthy pregnancy, calve on time, and wean a large calf in the fall. A mineral program before and during breeding will not only strengthen the health status of your herd, but can reduce the incidences of late or open cows. After all, the bottom line is, the health of your animals is directly related to your wealth as a producer.
Talk to a nutritionist, mineral provider, or your local Regional Livestock and Feed Extension Specialist for specific advice on what mineral program might be best for your operation.
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