Dairy Channel: Saying so long to a dairy master


Cowboy hat, red (OK, gray and light red) beard, cowboy boots, colorful vocabulary, udder man, sand bedding advocate, knows his somatic cells and refers to them as “puss.”

If that last clue didn’t finally tip you off, then you never had the opportunity to participate in a lecture on mastitis or bedding delivered by Dr. K. Larry Smith, uninhibited lecturer, teacher and a fine researcher who is retiring after 37 years dedicated to the bovine mammary system.

Behind the scenes. What we often don’t realize is the incredible amount of research, both fundamental and applied, that lies behind the good management practices that we take for granted.

Larry, his research lab staff, the OARDC research farm, cooperating commercial farms and colleagues in other research disciplines are behind quite a few of the practices we employ today.

Larry has been around cows all of his life. He was, in fact, born on a small dairy farm outside of Moultrie in Columbiana County.

Even though his family moved a great deal and eventually settled in Arizona, Larry’s interest in dairy cows continued.

While milking cows as a student at the University of Arizona, Smith became curious about why colostrum can have a reddish-orange color. Some of his early research identified the source of the color as lactoferrin, a milk protein.

Lactoferrin. Larry determined that lactoferrin plays in important role in the inhibition of some bacterial growth in the udder (known to us as mastitis) by tying up the iron molecules that the bacteria need to grow.

It is this and subsequent work by Larry and his colleague, Joe Hogan, that ultimately seek to develop vaccines to control coliform mastitis.

Continuing research with lactoferrin showed that it had a greater effect on coliform (environmental) pathogens than the gram-positive contagious pathogens staph and strep.

This and following discoveries led to major changes in the on-farm management of dairy cows.

The environmentalist. Larry the environmentalist: While to some this statement might bring visions of Greenpeace and the Sierra Club, for Larry “environmental” is clearly a reference to a type of mastitis in dairy cows.

Contagious mastitis pathogens lurk in the udder and infections between cows usually occur during milking.

Smith and Hogan showed that environmental pathogens survive in bedding, soil and other non-mammary sites, multiplying and just waiting to cause infections between milkings.

While we now take for granted that management of bedding materials is directly related to environmental mastitis, Larry showed that organic bedding materials such as sawdust, straw and wood shavings support higher numbers of bacteria than inorganic bedding such as sand and limestone.

While we know that some people can do an excellent job of controlling environmental infections while housing cattle on organic bedding, many others do not.

Larry’s summary of the best bedding materials for lactating dairy cows: 1) sand, 2) sand and 3) sand.

Mineral man. Health, nutrition, housing and management. Smith knew that the functions of a dairy cow are inter-related and collaborated with other researchers in those areas.

One important outcome of these collaborations is our current understanding of the role that vitamin E and selenium play in the control and minimization of mastitis.

Insufficient levels of vitamin E and selenium were shown to result in an increased incidence of mastitis.

Supplementing either vitamin E or selenium decreased both the incidence and duration of infections. Supplementing both did an even better job.

Ohio’s cows, being in a selenium-deficient state, have greatly benefited from this discovery.

It is impossible to give even barely adequate credit to 37 years of work in 12 inches of column space. The few projects mentioned barely scratch the surface.

Induced lactation. Smith’s training as an immunologist and an inquiring mind led to work with lactation induction (the first induced lactation happened right here in Ohio.)

That first cow is the cover girl on his retirement symposium proceedings, the source of much of this information.

A long working relationship with Ross Labs in Columbus, maker of infant formulas and nutritional supplements, encompassed many issues.

One in particular evaluated the potential to provide passive immunization from diarrhea caused by rotavirus or e coli. This particular collaboration developed a model to evaluate how well bovine antibodies could prevent diarrhea in humans.

Cells the limit. How many cells are too many cells? Larry is a strong advocate for lowering the SCC limit to 400,000.

Why? Clearly herd health and production benefit from a lower level of clinical and subclinical mammary infections, which are reflected by the SCC.

Milk quality, yield of manufactured products and shelf life are also increased.

This has been an up-hill battle that must be continued.

In the blood. When you really like cows and have made them your life work, either in the barn or in the lab, you don’t get cows out of your blood just because you retire.

While Larry claims he will spend his retirement watching Fred and Ed, his longhorn steers grow horns, I bet a bottle of horn polish he will be back among “the girls” before Ed and Fred add a full inch.

On behalf of Ohio’s dairymen, (even those who don’t want to bed with sand), thanks for the many contributions you have made to improved udder health and milk quality.

The biggest thanks however, comes from thousands of dairy cows for all those infections that they didn’t get. To you, Larry, an udder-felt “Moo!”

(The author is the northeast Ohio district dairy specialist with OSU Extension. Send comments or questions in care of Farm and Dairy, P.O. Box 38, Salem, OH 44460.)


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