Just 75¢ of a Manganese supplement per cow per gestation appears to correct a manganese deficiency in dairy and beef cows. Without it, some Minnesota producers are reporting up to 10% of pregnancies with deformed fetuses or unsteady, weak calves born live.
Low manganese is the primary suspect in causing deformities in 10 dairy calf fetuses submitted to the Minnesota Veterinary Diagnostic Laboratory last year. The dead fetuses had skeletal deformities that included twisted or short limbs, dwarfism and shortened upper jaws that exposed the lower teeth.
In 2001, the National Research Council lowered the Manganese requirement by more than half—from 40 mg/kg of dry matter to 17.8 mg for gestating dairy cows. This lower requirement is similar to levels that produced signs of deficiency in beef cows in the 1960s.
“More recent research indicates that lactating and dry dairy cows require 1.6 and 2.7 times higher concentrations than those calculated using the 2001 NRC model,” says Jeremy Schefers, resident pathologist at the University of Minnesota Veterinary Diagnostic Laboratory.
In his pathology work with the fetuses, Schefers ruled out BVD, IBRV, Lepto, other pathogens, genetic defects, goiter, and copper and zinc deficiencies.
Over the past decade, many dairy producers have also shifted to higher levels of corn, distillers grain and corn silage. Corn-based feed is lower in manganese than grass hay or mixed haylage.
The result has been a possible deficiency of the mineral in calves, causing the deformities. When a half a pound of Manganese sulfate or manganese-amino acid complex was fed to cows during their gestation, no further problems were reported. Cost of the supplement per cow for the entire gestation period: 75¢.
Some anti-GMO activists have blamed glyphosphate-tolerant soybeans and corn for the problem. The theory is that glyphosphate interferes with the plant’s ability to absorb and utilize Manganese. But several research trials have failed to document the theory. “Manganese deficiency in corn and soybeans is not a new phenomenon and has been described for decades prior to the use of glyphosphate,” says Schefers. “Everyone wants to pin this on Roundup, but I can’t get there.”