Purina Animal Nutrition
For a cow to achieve maximum peak milk, her internal systems need to be in optimum condition. The stress of the transition period can make this a challenge. Researchers are linking more health problems in transition dairy cows back to oxidative stress, which can be caused by an abundance of free radicals.

Understanding the balancing act

Free radicals are a natural by-product of cellular metabolism. Under normal conditions, the body has checks in place that keep the balance between free radicals and antioxidants at acceptable levels. However, problems arise when free radical production exceeds the body's ability to keep the level balanced, as illustrated in Figure 1.

free radical chart


"During periods of stress, a cow's body can produce excessive amounts of free radicals," says Stu Rymph, Ph.D., dairy nutritionist with Purina Animal Nutrition. "Critical periods of stress can include any physiological states associated with increased metabolism such as lactation, growth and calving."

Recognizing the danger zone

Excessive free radicals are a serious concern because they are unstable molecules that can damage other molecules when they come in contact. Free radicals can change how well important enzymes work, damage the physical structure of cells, and even cause breaks and mutations in DNA. This type of damage can weaken the cow's internal systems, and impact milk production.

"When a cow experiences stress during calving, the added stress of an unbalanced system might be more than she can handle, weakening her natural defense system against diseases such as mastitis," explains Rymph.

Formulating a solution

By studying the role antioxidants play in counteracting free radicals, and knowing the critical times a cow might become out of balance, we can formulate rations to help cows cope with stressful situations.

"Understanding metabolism, free radicals and everything that's happening in the cow's body during transition is critical," says Rymph. "It enables us to formulate rations that provide the right nutritional support to help her achieve maximum peak milk."

However, it's not as simple as adding more antioxidants to the ration. There are several different types of antioxidants (vitamins, minerals, polyphenols, etc.). It's important to know that each one plays a unique role in fighting free radicals. Therefore, supplementing more of one specific antioxidant may not necessarily improve performance. It's best to supply a balanced amount of several types of antioxidants during periods of increased metabolism to ensure the animal's body is in balance and performing at its peak.

Talk with your nutritionist about the antioxidants in your ration to deliver the nutritional support your animals need for optimal performance.

For more information, contact Stu Rymph by email: sjrymph@landolakes.com or go to: www.dairyfeedtechnology.com.

For additional information on dairy nutrition and management, sign-up to receive the monthly Purina® HERDSMART® E-Newsletter; a free online tool to improve operational efficiency by visiting: www.bit.ly/purinaherdsmart.

Purina Animal Nutrition LLC (www.purinamills.com) is a national organization serving producers, animal owners and their families through more than 4,700 local cooperatives, independent dealers and other large retailers throughout the United States. Driven by an uncompromising commitment to animal excellence, Purina Animal Nutrition is an industry-leading innovator offering a valued portfolio of complete feeds, supplements, premixes, ingredients and specialty technologies for the livestock and lifestyle animal markets. Headquartered in Shoreview, Minn., Purina Animal Nutrition LLC is a wholly owned subsidiary of Land O'Lakes, Inc.

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8.7.2015