Animal Health & Nutrition
Rick Lundquist is an independent nutrition and management consultant based in Duluth, Minn. He provides livestock production advice.
A New Diagnostic Tool to Help Tweak Rations
Jun 17, 2011
Gas fermentation analysis actually measures what the rumen bugs are doing with our TMR.
A new lab method is now available to help your nutritionist determine the milk potential of your TMR. It’s a gas fermentation analysis called Fermentrics. The procedure is available at Dairyland Laboratories in Arcadia, Wis., in conjunction with RFS Technologies in Ottawa, Canada.
The lab takes your TMR sample and measures the gas production as it is fermented in rumen fluid. The rumen microbes in the rumen fluid produce the volatile fatty acids (VFAs) proprionate, acetate and butyrate as well as carbon dioxide, ammonia and methane. Fermentrics measures these gases as they are produced and uses this information to estimate the rate of digestion of the carbohydrate fractions. It can also measure the microbial biomass production and the organic matter degraded after 48 hours of incubation. The results of this fermentation can actually predict milk production with relatively good accuracy.
So how is this different from doing standard feed analyses such as crude protein, ADF, NDF, NDF digestibility and starch, and using these measurements to balance rations or predict performance from a model? Well, we still need to balance rations with these measurements. But, we can use gas fermentation to actually measure what the bugs are doing with our TMR.
Optimizing rumen fermentation for maximum cow performance is kind of like optimizing the fuel-to-air mixture in a car engine for maximum performance. Too much fuel dumped into the carburetor at one time floods the engine, reducing performance. Too little fuel makes it run too lean, reducing power.
Likewise, when the cow “steps on the gas” in early lactation, she needs the right mixture and degradability of carbohydrate and protein sources to optimize rumen microbial growth for maximum production.
The gas fermentation lab report gives suggestions on how to improve performance by tweaking the ingredients in the TMR. For example, if the gas measurements show that the carbohydrates are digesting too quickly, indicating a high acidosis potential, replacing fine ground corn with more non forage fiber sources such as beet pulp or soyhulls will be recommended.
This should be a great tool to troubleshoot production problems, fine tune rations or benchmark what you are doing right when production is excellent. The cost is $145/TMR, so it’s not necessarily something you’ll do routinely. The TMR sample should be about ½ gallon in a zip-lock bag shipped for on-day to two-day delivery.