Nutritional Influences on Reproduction: Mineral Supplementation
by Troy Smith for Angus Productions Inc.
NASHVILLE, TENN. (Aug. 6, 2010) — The cost of beef cattle mineral supplements has climbed dramatically in recent years. Prices of some mineral supplements have nearly doubled. It has caused many producers to wonder what is really needed and what might be cut to save money.
Calcium, said UK Extension Beef Cattle Specialist Jeff Lehmkuhler, is well-documented in its role in activation of sperm cells.
“A lot of producers have shown me a tag torn from a bag and asked, ‘Is this a good mineral?’ Or they bring in a couple of different tags and ask, ‘Which one would you buy?’” said University of Kentucky Extension Beef Cattle Specialist Jeff Lehmkuhler during the Applied Reproductive Strategies in Beef Cattle (ARSBC) Conference in Nashville, Tenn.
Lehmkuhler said some producers have turned to cheaper products than they had been using. Others are feeding less mineral or providing cattle with salt only. There’s nothing wrong with being a smart shopper, but Lehmkuhler warned that blindly removing mineral supplementation from beef herds is not advisable. He talked about the roles key macro- and micro-mineral elements play in reproductive function, for both cows and bulls.
Calcium, said Lehmkuhler, is well-documented in its role in activation of sperm cells. The calcium to phosphorus ratio is important, with the latter element being essential for cellular energy metabolism and skeletal development. Phosphorus is the most prevalent mineral deficiency of grazing livestock and severe deficiencies lower fertility in breeding herds.
Lehmkuhler said adequate levels of trace minerals in cow diets aid in the return to estrus after calving. Selenium serves as an antioxidant and cancer preventative, as well as aiding spermatogenesis. Copper deficiency can delay or depress estrus in cows, and hinder spermatogenesis in bulls. Adequate levels of zinc also appear to enhance male fertility. Manganese deficiencies appear to be less common than other trace elements but can reduce first-service conception rates.
According to Lehmkuhler, producers seeking to lower mineral input costs should first sample and test forage resources. Availability of minerals from forage are not static and change seasonally as well as varying by location.
Lehmkuhler said mineral supplementation offered at appropriate levels can be critical to optimizing reproductive success. And while they may seem expensive, mineral supplements usually represent a small portion of total feed costs.
“If a cow eats close to 30 pounds of dry matter a day, that’s about five tons of feed annually. At 4 ounces per day, she consumes about two bags of mineral annually,” said Lehmkuhler. “Relatively speaking, the mineral makes up a small component of total feed cost, but can have a significant impact on animal performance and reproduction."
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