Research at the University of Minnesota indicates that zinc, manganese and copper status, as measured by concentration in the liver, are decreased in late gestation and early lactation.

Supplementing zinc, manganese and copper from highly available trace mineral sources beginning in the dry period and continuing through lactation helps optimize the trace mineral status of cows at calving, according to Jeff DeFrain, research nutritionist from Zinpro Corp. Research has shown that insufficient status of these three minerals predisposes cows to:

  • Increased incidence of retained placentas, mastitis and uterine infections.
  • Reduced fertility.
  • Increased incidence of lameness.

Following is an overview of how trace mineral supplementation during the dry period impacts lactation performance.


  • Calving disorders affect fertility of cows in the subsequent lactation.
  • Proper trace mineral supplementation helps improve immune function, decrease ketosis and decrease retained placentas and/or minimize the negative effect of retained placentas on fertility.

Udder Health:

  • Research at Ohio State University indicates that incidence of intramammary infections are highest immediately following dry-off and just prior to or at calving.
  • Ensuring that cows have adequate trace mineral status at calving helps to minimize intramammary infections during parturition.

Claw Integrity:

  • Research from Green et al. (2002) indicates that claw abnormalities are highest in early lactation. Horn of the claw is a composite of horn produced over the previous 12 months, including during the dry period.
  • Zinc, manganese and copper play a crucial role in maintaining claw quality and integrity. Adequate intake and improved bioavailability throughout the lifecycle of the cow, including the dry period, helps to minimize the incidence and severity of lameness in early lactation.