by dr. Noélle Steyn, Westside
Over the past 40 years veterinarians, nutritionists and farmers have tried multiple strategies and programs with the aim to reduce clinical and subclinical cases of mastitis. In the 1960’s the 5-point Mastitis Control Program was developed in the United Kingdom by the, then called, National Institute for Research into Dairying (NIRD). In recent years technological development and advances in animal nutrition strategies led to adaptation of existing points and the addition of two new points to the program.
- The 7-point Mastitis Control Plan:
- Disinfection of all teats after each milking
- Treat all mastitis cases once the causative bacteria have been identified and record data
- Application of dry cow teat sealant to all cows, antimicrobial dry cow therapy only in selected cases
- Any cow with a history of three or more mastitis cases should be culled
- Milking machine maintenance remains extremely important
- Milk clean, dry and disinfected teats
- Make use of nutrition (such as trace minerals), stimulants and vaccines to improve immunity
For the purpose of this article, only trace minerals and their ability to provide protection against mastitis will be discussed.
Trace minerals received much attention in recent years as nutritionists realized the importance of various trace mineral forms. By studying the efficacy of these various forms, it is now clear that organic and hydroxy-trace minerals are superior to sulfate minerals, in their ability to provide absorbable minerals at the correct site within the gastrointestinal tract.
Importance of trace minerals in immunity
Inclusion of especially Selenium, Manganese, Copper and Zinc, at the correct levels, is required to optimize health and production in lactating and periparturient cows. The transition period is a physiologically stressful time which affects the efficiency of the immune system, making cows more vulnerable to infections from environmental bacteria. When there is an increased demand, trace mineral absorption from feed is often not sufficient to meet the requirements of the animal, therefore a highly available trace mineral should be supplemented at increased levels, to prevent deficiency. Trace minerals support proper immune function, not only by their role in antioxidant defense systems but also their direct effect on leukocyte (white blood cell) function and migration.
Copper status affects the number of bacteria that can be killed by white blood cells (WBCs), through a process known as phagocytosis. After phagocytosis by WBCs bacteria is killed and eliminated from the udder, thereby preventing bacterial infections from environmental pathogens. During this reaction various enzymes, that require zinc and copper, remove harmful by-products, and convert them to less harmful products. Selenium is once again important in this final step where hydrogen peroxide, which can cause oxidative damage to cells, is converted to water.
By reducing the amount of free radicals, antioxidants protect cells from damage and inflammation. Free radicals are produced as part of normal physiological processes but production of these free radicals increases during times of stress and high metabolic demand, such as calving and peak lactation.
Health benefits of Selenium
Selenium is most probably the most familiar antioxidant, along with Vitamin E. Various studies have shown a decrease in somatic cell count (SCC) of cows supplemented with organic selenium yeast (Figure 1). While this reduction may be explained by the improved antioxidant status, selenium status also influences how many neutrophils reach the udder in case of infection, to actively eliminate pathogens and prevent clinical mastitis. Some of the most recognised benefits of organic selenium supplementation in dairy cows is the lower incidence of retained fetal membranes and fewer mastitis and metritis cases. Cows supplemented with organic selenium also had a lower percentage of bacterially infected udders (Figure 2),
If we consider the function of Selenium in overall immunity and within the udder, the importance of trace mineral supplementation as part of the mastitis control program cannot be overlooked.
Figure 1: A reduction in SCC of up to 34% was observed in dairy cows receiving organic selenium yeast as an antioxidant supplementation.
Figure 2: improved udder health parameters in dairy cows supplemented with organic selenium yeast.
Read more about our Optimin Selenium, SeY3000 or contact Dr. Noélle Steyn at noelle@westside.co.za