“A nutritionist and a dairy farmer walk up to a feedbunk.” It sounds like the start of a lame joke, but with shrinking margins and rising input costs feeding dairy cattle is no laughing matter.  It would be really nice if the pastoral idyll of rows of cows contentedly chewing their cud was achievable simply by filling a feedbunk.  However, not only is this picture not the simple equation of feed in equaling milk out, but in actual fact depends more on what you feed the bugs in your cows’ stomachs than it does on what you think you’re feeding the cows.  Ruminants are hosts to numerous microbes and the microbes need to survive and multiply in order for milk to be produced.  So to put it simply, “If you want better rumen health, you need better rumen bugs!”

From Tongue to Dung – Travelling the Fermentation Road

The whole process is one of digestion. Digestion begins when cows draw feed into their mouths with their tongues.  Each mouthful passes into the rumen, flows to the abomasums and then through the small intestine, the large intestine and then out!

For the most part, this entire process is unseen to the human eye.  Except if there’s a problem (such as a twisted abomasums that can be felt by touching the cow’s side) or, when it is finished and the manure gives visual clues to issues.  Of course, out of sight out of mind isn’t the best management tool when you’re trying to effectively monitor or set up dairy cattle diets.  Nutritionists and veterinarians use scientific methods to study the feed and the bugs.  Fortunately the tools being used are continually evolving, as specialist can make the rumen mystery more manageable.  Using lab analysis, ingredient evaluation and computer programs they measure, calculate, forecast and establish precise diets, customized for the dairy cow and the particular operation.

Set Goals and Test, Test, Test

The primary goal of a sound, profitable dairy feeding program is to convert forages into milk.  With feed costs representing 50 to 60 percent of the cost of producing milk, knowing the nutrient content is very important from an economic perspective.  All forages which will be fed to milking cows, heifers and dry cows need to be tested.  All lots of hay should be sampled using a hay probe on 10 or more bales of hay.  Sampling one or two bales is not an accurate way to sample a lot.  A `lot ‘of hay is defined as those bales which were harvested from the same field and cutting.  Your local feed company or extension agent can help you get your forages tested.  Testing forages and balancing rations for heifers and dry cows is critical in order to get heifers to grow efficiently and to prevent dry cows from losing or gaining too much weight.

Every Body Works Better on a Schedule

As we turn our attention to focus on fermentation we have to consider the effect of timing.  Cows and rumen bugs are both creatures of habit.  We all know how dairy cows get into a routine and expect to be milked at the same time every day.  A variation of much more than 10 minutes causes stress.  If feed is expected every day at 10 am, 10:45 will further upset the routine.  The goal is that every day is exactly like the day before and the day after.  Consistency is good not only for the cows but for the rumen bugs too.

Don’t Upset Your Cows or Their Rumens

Rather than upset the rumen vat with constant changes, subpar feed or feed that is presented erratically, it is important for rumen health to make diet changes gradually.  If daily handling is calm, routine and without overcrowding in feed and resting areas, the daily digestion process will be stress free and more likely to be effective. Rumen fermentation can be altered by stresses.  Spoiled silage has a dramatic impact on rumen fermentation and dry matter intake.  Optimum rumen fermentation requires consistent nutrient supply.  If excess spoiled feed is consumed, there is a distinct likelihood that desirable rumen bugs are being killed off.  Even minor changes can have a dramatic effect on the numbers of microbes and even cause a particular bug to become more dominant.  This becomes a domino effect that could result in poor digestion and other problems.

If She is Not Making Milk Targets, You haven’t fed Her Rumen

Too often dairy managers confuse feeding the cow and feeding the rumen. Farmers should work closely with their nutritionist in designing a feeding program so that the nutrient needs of the rumen microbes are met in order for the cow to produce milk.  Once the feeding program has been designed, implementing the feeding program becomes the next critical step.  The final measure of the diet is determined when milk is produced. If the goal was to produce 80 pounds of milk and you only get 70 pounds, there is a discrepancy somewhere and it must be found.

As rumen modeling becomes a more and more exact science, it is important to remember that no model will correct for poor management.

New Ways to Monitor Microbes

As in other areas of dairy cattle management, the rumen is benefitting from new technologies. Gene sequencing and measurement of the expression of genes (genomics), proteins (proteomics) and metabolites (metabolomics) can now be used to better differentiate microbe species in the rumen.  Using these tools it is reported that the rumen contains over 7,000 bacterial and 1,500 archael (single-celled but distinct from bacteria) species.  There are also numerous protozoa, fungi and bacteriophages.  Studying these organisms by use of new approaches is making it easier to understand the physical structure of different ingredients in the rumen and how they impact rumen function.  The payoff is better health and more efficient use of dietary nutrients.  All in all the process is complicated and speedy and analysis needs to provide the best information before the fermentable ingredients escape the rumen.

Happy Bugs Happy Cows

Maximizing rumen function means we work to maximize microbial activity.  It takes energy to produce milk.  Extracting as much energy as possible from the fiber components (NDF digestibility) is the goal. It is necessary to maximize microbial protein production through microbial growth (high quality amino acid supply). For milk production and profitability the goal is to formulate diets that utilize the rumen to the fullest extent.  Supplying the right nutrients, calmly and consistently is the formula for contented milk-producing cows.  Cud chewing is the external sign but it takes good planning, delivery, monitoring and testing to confirm that the “healthy bugs, healthy cows” two step is at work in your herd.

The Bullvine Bottom Line

Happy Bugs.  Healthy Cows.  More milk.  Fewer vet visits.   From the feedbunk to the bank, improved rumen performance putting more dollars on YOUR Bottom Line




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