Phosphorus has a long, winding history of use in livestock supplements. For a while, nearly all summer supplements were very high in phosphorus, and for good reason. Phosphorus plays a significant role in reproductive efficiency and growth, and it’s generally the most prevalent mineral deficiency in grazing livestock. Still, the question remains: How much phosphorus do we need to provide?

A key element

Phosphorus has a number of critical functions within the body, but perhaps the most important among producers is reproductive efficiency. Phosphorus also has a vital role in energy utilization (i.e., growth and performance) as well as the formation and strength of teeth and bones. Rumen microbes also require phosphorus for growth and metabolism.

Research conducted by the United States Department of Agriculture (USDA) from the Gulf Coast region of Texas showed that cows supplemented with phosphorus had calves with higher weaning weights than non-supplemented cows. The same study also showed an increase in the percentage of cows that calved in consecutive years when they received supplemental phosphorus.

A review of several studies concluded that a phosphorus deficiency can cause decreased conception rates, irregular estrus (heat cycle), anestrus (no heat cycle), decreased ovarian activity, increased incidence of cystic follicles and generally depressed fertility. In addition to reproductive issues, cattle deficient in phosphorus will experience decreased weight gain and conditioning as a result of their decreased appetite.

Is your forage enough?

Producers may gamble on cattle getting adequate phosphorus from forages. However, phosphorus levels vary depending on plant maturity, weather conditions, soil and fertilizer used.

In 1999, the USDA conducted a forage survey with 709 samples from 23 states. The phosphorus level for all samples ranged between 0.17 percent and 0.30 percent on a dry matter basis. These levels may be adequate for some cows, but it all depends on the stage of production.

For example, let’s take a 1,200-pound cow in her second trimester consuming 24 pounds of dry matter intake. Her phosphorus requirement is 15.8 grams per day. Using an average of the phosphorus range in the study referenced above, the forage would provide adequate phosphorus: 24 pounds per head per day x 0.002 = 0.048 x 454 = 21.7 grams per head per day of phosphorus.

Now, let’s look at that cow during peak lactation at 20 pounds per day. She’s going to be eating roughly 27.8 pounds of dry matter, and her phosphorus requirement is up to 31.8 grams per day. That same forage would leave her a little short: 27.8 pounds per head per day x 0.002 = 0.0556 x 454 = 25.2 grams per head per day of phosphorus. We can make up the missing 6.6 grams of phosphorus with the right supplement. For example, supplementing this cow with CRYSTALYX^® Blueprint^® 6% Phos Mineral provides 6.8 grams of phosphorus at a 4-ounce intake.

Bridging the gap on phosphorus is simple with CRYSTALYX brand self-fed supplements

CRYSTALYX Blueprint 6% Phos, Breed-Up^® MAX, Crystal-Phos^® 8, Crystal-Phos^® 4, Fescue-Phos^® and Mineral-lyx^® deliver phosphorus to carry your cattle through gestation, lactation and the rest of the production year. Breed-Up MAX, Crystal-Phos 8, Crystal-Phos 4 and Fescue-Phos feature superior trace mineral supplementation in the form of added Bioplex^® organic trace minerals.

Are you ready to take your supplements to the next level? Blueprint 6% Phos features Bioplex as the only source of organic trace minerals in the block. Proven research and consistent intake across the herd means each of your cattle will get the phosphorus they need.