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.
“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.”
Click here to see more...