Ask the Expert: Why Is Starter Grain Important? – Dr. Noah Litherland, Vita Plus

By Dr. Noah Litherland, Vita Plus dairy youngstock technical specialist

Question:  Why is starter grain important for dairy calves?

Answer:

• Develop rumen tissue important for absorption of microbial end-products of fermentation (VFA).  Calves are only monogastrics for a short few weeks after birth and then start developing a fully functional rumen, which will serve as the primary fuel source for the rest of the animal’s life.  The end-products of microbial fermentation (volatile fatty acids (VFAs)) and the weight of the ingested starter grain both act to kick-start rumen development and maturation.
• Increase energy.  As the rumen develops, fermentation of starter grain begins to contribute energy for the calf’s fast growth and development.
• Increase protein available for growth.  Bacterial cells produced in the rumen offer a highly digestible protein and nearly optimal amino acid profile for growth.
• Increase both microbial mass and diversity (competitive environment for pathogens).  Establishing a healthy and diverse microbial ecosystem results in enhanced immune function.
• Bacterial fermentation results in the production of B-vitamins.  B-vitamins are important in energy metabolism and serve to stimulate feed intake.
• Ensure an adequate amount of coccidiostat is being consumed by the calf.  Medicated calf starters contain a coccidiostat, which aids in control of coccidial infection. However, calves need to consume the labeled minimum amount of starter to provide an effective dose.  Without an adequate amount of coccidiostat consumed, calves will have reduced growth rate, lower immune function and increased susceptibility to other diseases.
• Produce heat from fermentation.  Feeds fermented by bacteria result in production of VFAs, carbon dioxide, water and heat.  The heat of fermentation is a source of inefficiency as this heat is lost to the environment, but plays an important role in keeping the calf warm by heating them from the inside out in cold environments.
• Stimulate cud chewing and rumination while resting.  Chewing cud is a hallmark of being a ruminant.  When chewing cud, saliva production increases, which serves as a buffer and increases nitrogen recycling through saliva.  This results in more microbial protein and a healthier rumen.  Additionally, increased cud chewing helps satisfy the calf’s need for oral behavior and should decrease aberrant oral behavior, such as cross-sucking, eating bedding, or eating soil (geophagy).
• Increased water intake.  Water is the primary component of skeletal muscle.  Starter intake and water intake typically increase in a 1:1 ratio.  Greater water intake helps maintain the hydration status of the calf.
• Increased colonic health.  The colon plays an important role in water absorption and, therefore, fecal consistency.  Fiber from calf starter is important for colon health as some of the fiber making it past the rumen is fermented in the colon, resulting in VFA production and fuel for growth of colonic cells.  The result of a healthy colon is increased water absorption and increased consistency of calf manure.
• Provide minerals needed for calf growth that are not provided in adequate amounts in whole milk.  Quality calf starter contains the required minerals needed by the calf bone and skeletal muscle growth.  Whole milk is nature’s most-balanced food, but does fall short in iron, manganese, copper, iodine, cobalt, selenium, vitamin D and vitamin E.  Starter grains are fortified with these minerals and vitamins, allowing calves to achieve higher growth rates.

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