Drought stressed stockers

By: Dave Hutcheson & Ken Eng

The extreme drought and heat that occurred in the southern plains cow/calf regions have led to wide spread nutritional stress. The lack of protein and energy has decreased growth of calves and decreased cows’ reproduction efficiency. When there is a lack of protein and energy, the effect cascades into the immune system. The development of the immune system is comprised in calves and cows coming from drought areas.  As calves are arriving in background operations and/or feedlots, the immune system is comprised and response (to health programs) will not be adequate.

The first consideration for a functioning immune system is adequate energy and protein. Energy is necessary for rapid growth of immune cells. Proteins are a necessary part of the structure of cells and thus replication and synthesis of antibodies and other components of the immune system. Many of the calves coming from drought areas are protein and energy deficient, weighing as much as 100 pounds less than expected. Many of these deficiencies are marginal, resulting in unrecognized disorders that reduce animal performance and profitability. Some are due to immune dysfunction. Several trace minerals, along with other essential nutrients and vitamins, are important factors in a properly functioning immune system.

Trace element supplementation not only prevents trace mineral deficiencies, but proper trace mineral supplementation optimizes natural resistance through the immune system. Sub-optimal deficiencies of trace minerals are more difficult to correct than acute deficiencies because the outward signs of sub-optimal trace minerals are not evident. Cattle production today considers nutrient supplementation beyond correcting for deficiencies. Trace elements zinc, manganese, selenium and copper as well as antioxidant vitamins and other phyto-chemicals are of particular importance, acting individually and in combination to enhance animal health and to optimize the immune system.

Injectable trace mineral products should contain a combination of trace minerals that can make a significant contribution to the trace mineral status of the animal. The injectable trace mineral product should be compatible for injection and contain trace minerals for essential functions. Injectable trace minerals should enhance the trace mineral dependent functions at critical times in the production and reproduction cycle of ruminants.

It is important that injectable trace mineral combinations should not be considered as an alternative to oral supplementation programs, but as a complementary route for critical trace mineral demands to improve immune function, production and reproduction. When injectable trace minerals are used as a complimentary route to the oral supplementation program, an enhancement of trace mineral dependant functions at critical times will be obtained. Injectable trace minerals have been shown to be effective in increasing trace mineral status in ruminants and should be considered as a complementary route of trace mineral supplementation during critical times. The oral route of supplementation can result in adequate trace mineral consumption if intake is adequate and the proper levels and sources are included in the diet. Injectable trace minerals offer good insurance as to adequacy of trace minerals during stress and critical periods.

Trace mineral absorption is complicated by variation in consumption of mineral supplements and minerals in the feed, the bioavailability of the trace mineral, and interference by other minerals and compounds. Sub-optimal trace minerals conditions can exists and trace mineral dependent functions decreased at critical times. Calving, breeding, adaptation into feedlots, antibiotic treatments are critical events in the life cycle of cattle that can benefit from injectable trace minerals. When animals have been diagnosed with respiratory disease on entering the hospital, the immune system is comprised and trace mineral injection would be a good complement to antibiotic treatment.   Trace element supplementation programs that are based on oral supplementation may be unable to optimize trace element dependant functions in ruminants, especially at critical times when optimal immune function and reproduction efficiency are of economic importance.

The calves from drought areas are deficient in energy and protein prior to arriving in background operations or feedlots and they then begin to receive energy and protein.  Effective trace mineral supplementation of ruminants during this critical period can increase the efficiency of production. These symptoms illustrate clearly that utilizing the oral route of trace element supplementation may not result in the optimization of trace element functions during stress events. During the stress events, injectable trace elements offer a management tool to supply needed trace minerals for improvement of the immune system and production during critical times in the life cycle of cattle.

An injectable trace mineral preparation as a supplement for drought stressed feeder calves offers an effective method to improve the humoral response. A single injection of an EDTA-chelated source of soluble Cu, Se, Mn, and Zn (Multimin, Fort Collins), administered concurrently with a single dose of a modified live vaccine may improve the humoral response, because neutralizing antibody titers were increased when calves were injected with an injectable trace mineral during recent trials.

Trace element supplementation programs that are based on oral supplementation may be unable to optimize trace element dependant functions in ruminants, especially at critical times when optimal immune function is paramount. The use of an injection of an EDTA-chelated source of soluble Cu, Se, Mn, and Zn containing 15 mg copper, 60 mg zinc, 10 mg manganese and 5 mg selenium is prudent to consider when receiving drought stressed calves or stressed calves on arrival and as animals are entering hospital for anti-biotic treatment.

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