The Effects of Climate Change on Rumen Function and Microbiome in Moose (Alces alces)

Undergraduate #82
Discipline: Biological Sciences
Subcategory: Ecology

William M. Willis - Tuskegee University
Co-Author(s): William B. Collins, Alaska Department of Fish and Game, Palmer, AK Donald E. Spalinger, University of Alaska Anchorage, Anchorage, AK

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The North American Moose (Alces Alces) is a keystone herbivore species in the subarctic boreal forest biome in Alaska and is extremely rare in captivity. Moose populations are declining dramatically across the northern continental U.S. In Minnesota, there has been a 52% decline in moose populations since 2010. It is theorized that the increase of plant secondary compounds, like condensed tannins (CTs), due to climate change is the contributing factor to lower productivity of populations in moose. Also, wild female moose typically live 15-20 years while 70 % of captive moose die in the first year because of intestinal diseases such as Irritable Bowel Syndrome (IBS). The purpose of this study was to assess the change in rumen and microbiome function in response to climate-driven differences in diets and to quantify the influence of tanniferous diets on energy availability (short-chain fatty acids). It was hypothesized that substantially less short-chain fatty acids (SCFAs) would be produced when moose were fed diets high in tannins compared to a nutritionally balanced pelleted ration. Two trials were conducted with two female fistulated moose using various forages high in tannins and by collecting the rumen samples from previously implanted ruminal cannulas. After 1 week, the diet was changed from the commercial pelleted ration to trial feeds. Samples were taken before and after feeding pellets to establish control. The moose were sampled at various times after initial feeding, taking samples from top and bottom fractions of the rumen. Samples were analyzed using an HP 5890 series II plus gas chromatograph at an isothermic 145°C for 15 min. The average levels of SCFAs in the rumen after 1 hour of feeding the treatment to the animal throughout the trials were examined. The data was analyzed using an F-test and standard deviation. The concentrations of the main rumen SCFA’s, acetic, propionic, and butyric acid, were significantly higher on the pelleted ration than on either of the two experimental feeds. Tanniferous forages caused a statistically significant decrease in SCFA production in the rumen. It can be conluded that CT’s, along with other plant secondary metabolites may be responsible for the patterns seen. Further work is necessary to confirm these hypotheses. CTs could also be necessary component of the moose diet and a lack of tannins and an increase of carbohydrates could cause detrimental effects, such as IBS. Samples were also sent to the Ohio State University for Micro-biome DNA and RNA Analysis to gain an accurate analysis of the species variation due to the change in diet.

Funder Acknowledgement(s): Funded by NSF #1263415.

Faculty Advisor: Donald E. Spalinger,