Project on intestinal flora in cow stomachs starts
Researchers at the University of Hohenheim work with high-tech and artificial cow stomachs / findings allow more targeted feeding for healthier animals. A cow consumes an average of 18 kilograms of feed per day. But in order to be able to absorb the nutrients from this amount of food, the animal needs the help of millions of different, highly specialized bacteria that colonize the stomachs and digestive tract. A research cooperation between scientists from animal nutrition and microbiology at the University of Hohenheim in Stuttgart is investigating how the bacteria succeed in loosening valuable nutrients from the resilient plant mass. The focus of the investigation is the bacterium Prevotella spp., Which makes up up to 40 percent of the bacteria in the rumen. The German Research Foundation DFG is funding the overall project with a total of 450.000 euros. This makes it one of the heavyweights of research at the University of Hohenheim.
Ruminants such as cattle have to obtain starch, protein, vitamins and minerals from plant-based food. In order for them to be able to do this, highly specialized bacteria work at full speed in the rumen, the largest of the cow's stomachs. "The special achievement of the cow is to obtain protein from exclusively plant-based food", explains microbiologist and animal nutrition expert Jun.-Prof. Dr. Jana Seifert.
According to Jun.-Prof. Dr. Seifert and her colleague Prof. Dr. Julia Fritz-Steuber, the bacterium Prevotella plays an important role. “Since Prevotella makes up a large proportion of the bacteria in the rumen, we assume that it also plays an important role in food utilization. So far, however, we do not know how exactly Prevotella gets its energy from food, ”summarizes Prof. Dr. Fritz-Steuber summarized the goal of the project.
In the cross-faculty project, the two microbiologists are therefore jointly investigating which substances are broken down by the bacterium and which protein substances it produces from them. "To do this, we offer the bacterium various substances and see which ones it absorbs," says Prof. Dr. Fritz-Steuber.
Eating test for the bacterium
The approach sounds amazingly simple, but requires complicated microbiological technology. Therefore, the two scientists divided the work. Prof. Dr. Fritz-Steuber, an expert in microbiology at cell level, breeds Prevotella bacteria in the laboratory and then offers them the various nutrients found in cow feed. Once the bacterium has been isolated from its normal environment, the scientist can understand exactly which substances Prevotella uses. “We know from investigations into the genetic make-up of Prevotella that the bacterium is able to utilize a number of nutrients. So far, however, we have not been able to understand which it ultimately uses and which it does not. "
From the individual building block to the entire recycling chain
The findings from Prof. Dr. Fritz-Steuber's experiments are developed by Jun.-Prof. Dr. Seifert on. However, it leaves the Prevotella bacterium in the rumen juice. "Ultimately, we also want to consider what influence the other components of the rumen juice have on the activity of Prevotella."
In a further step, Jun.-Prof. Dr. Seives the reality in the cow's stomach even further: It repeats the eating test in a mechanical model of the rumen. The model simulates the movements of the rumen, which by regularly tensing different muscles ensures that its contents are constantly mixed.
"We pick out a detail from the utilization chain in the beef stomach, enlarge and examine it and then reinsert the information obtained into the overall picture," says Jun.-Prof. Dr. Seifert.
New core facility enables access to the latest technology
Prof. Dr. Fritz-Steuber emphasizes how important high-performance analysis devices are for their work. “We want to zoom in on the rumen, and thanks to modern devices, the glasses are getting finer and finer.” These devices have been available in the University of Hohenheim's new Core Facility since the beginning of the year and are used by employees from a wide range of specialist areas.
Among other things, the microbiologists there work with the new mass spectrometer: It enables them to analyze proteins and other substances that the microorganisms in the cow's stomach produce during digestion. "This type of research is extremely technology-driven and would not be possible without such large equipment," says Prof. Dr. Fritz-Steuber.
Better understanding of a healthier cow stomach
The next higher level of magnification, the whole cow, is no longer illuminated in the experiment. “We do basic research. In order to use our results in animal nutrition, they first have to be further developed in feeding experiments, ”says Jun.-Prof. Dr. Seifert.
Such a further development could be to stimulate the activity and quantity of the Prevotella bacteria or the formation of certain health-promoting substances by the bacteria through targeted feeding. The scientists hope that this could promote rumen health and make the feed more efficient.
Samples from the rumen thanks to fistula access
Thanks to the fistulated cows at the University of Hohenheim, it is easy for the scientists to get the rumen juice they need: The fistula, an artificial access to the rumen, can be unscrewed to take samples. Five Jersey cows in the university stables are equipped with such an access made of padded plastic.
In contrast to other sampling methods, this causes no pain or stress for the cows and prevents animals from having to be slaughtered to analyze the stomach contents.
Background: "Interaction between fermentative and respiratory energy conservation in the rumen bacterium Prevotella spp."
In the project “Interaction between fermentative and respiratory energy conservation in the rumen bacterium Prevotella spp”, the faculties of agricultural and natural sciences work closely together. The Department of Cellular Microbiology of Prof. Dr. Fritz-Steuber and the junior endowed professorship “Feed-Gut Microbiota Interaction” from Jun.-Prof. Dr. Seifert will each receive 225.000 euros from the German Research Foundation. The project will start in September 2017 and will run for 3 years.
Background: Research heavyweights
Scientists from the University of Hohenheim acquired 29,5 million euros in third-party funding in 2016 for research and teaching. In loose succession, the series “Heavyweights in Research” presents outstanding research projects with a financial volume of at least 250.000 euros for research using equipment or 125.000 euros for non-equipment research.
