Trace Minerals Benefit the Beef Cow and Her Newborn Calf
By Dr. Connie Swenson, Research Nutritionist, and Dr.
Bruce Johnson, Director, Research & Nutritional Services
Zinpro Corporation, Eden Prairie, Minnesota
Providing balanced nutrients (energy, protein, minerals and vitamins) is vital for insuring optimum production in the cow herd. Requirements for these nutrients increase during late pregnancy to meet fetal growth demands and milk production, as well as through breeding to help cows achieve timely breed-back.
Body condition score is a visual measurement that allows producers to quickly judge the adequacy of protein and energy in the diet. However, it is much more difficult to assess the mineral status of the cow herd. Marginal trace mineral deficiencies can decrease profits through a loss in animal performance such as lower conception rates and weaning weights, or through increased treatment costs associated with herd health. Trace minerals that have a key role in reproduction, herd health and calf performance include copper, zinc, selenium, manganese and cobalt.
The liver serves as a storage organ for trace minerals and is often the most reliable indicator of trace mineral deficiencies. In order to better understand changes in trace mineral status during the production cycle, liver biopsies were collected from first-calf heifers 45 days prior to calving, at calving, at breeding, after weaning and prior to calving the following year (see figure). The solid lines illustrate changes that occur for copper and zinc in animals that received no trace mineral supplement. When trace mineral supplementation (in the form of Availa
®4) was provided during late pregnancy on through to the start of the breeding season, a shift in the mineral status was seen as shown by the dashed lines. This shift can result in improved reproductive performance of the cow early in the breeding season as well as better calf health and heavier weaning weights.As we begin to evaluate the nutritional needs of the cow herd for next calving season, consideration should be given to trace minerals. Feeding adequate levels of trace minerals is critical for both the cow and her newborn calf. The calf relies on the trace mineral stores that it acquires from the cow during the last 90 days of pregnancy. Approximately 30% of the liver copper and zinc in a newborn calf is mobilized through the blood in the first four days of life. These minerals are needed for immune function and a number of other enzyme systems. A calf born with deficiencies is more prone to health problems that can result in higher treatment costs and lower weaning weights on the ranch.
Bottom Line: Trace mineral supplementation is beneficial for maintaining productivity of the beef herd through immune response and weight gain in calves, and maintaining timely breed-back of cows early in the breeding season.
For more information on Availa®4 trace minerals, you can visit the website for Zinpro trace minerals at www.zinpro.com .
For Farmland Land O'Lakes minerals containing Availa®4, visit your local cooperative and ask for the Techni Breeder line of minerals.