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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Publications at this Location » Publication #247833

Title: Impact of Dietary Markers on Fecal Microbial Ecology, Fecal VFA, and Nutrient Digestibility Coefficients in Finishing Pigs

item Kerr, Brian
item Weber, Thomas
item Ziemer, Cherie

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/6/2010
Publication Date: 9/6/2010
Citation: Kerr, B.J., Weber, T.E., Ziemer, C.J. 2010. Impact of Dietary Markers on Fecal Microbial Ecology, Fecal VFA, and Nutrient Digestibility Coefficients in Finishing Pigs. In: Proceedings of the 3rd International EAAP Symposium on Energy and Protein Metabolism and Nutrition, September 6-10, 2010, Parma, Italy. p. 397-398.

Interpretive Summary:

Technical Abstract: The objective of the experiment was to determine the impact of three commonly utilized markers (Cr, Fe, and Ti) in digestibility studies on fecal microbial ecology, fecal VFA, and nutrient digestibility coefficients. Forty eight gilts, initial BW 115.1 kg, were allotted to 4 dietary treatments based on inclusion (0.5%) of indigestible dietary markers (Cr2O3, Fe2O3, and TiO2) to the diet. All diets were based on corn with soybean hulls, dried distillers grains with solubles, and citrus pulp as fiber sources; and soybean meal and corn gluten meal as plant protein sources. Pigs were adapted to diets for 33 d prior to being placed into metabolism crates for an additional 3 d feeding regimen adaptation followed by a 4 d total fecal collection period. Feces were analyzed for microbial ecology, VFA, and various nutrients by typical microbial and analytical methodologies. Total microbial and bacterial counts in pig feces did not differ due to any markers; however, Fe2O3 resulted in decreased numbers of Archaea (methanogens) in the feces. Inclusion of Cr2O3 and Fe2O3 in diets increased bacterial diversity and altered evenness of bacterial species in the feces. Fecal ammonia or VFA were not affected by dietary marker inclusion, except for isocaproic acid which was higher in pigs fed the diet with no marker relative to pigs fed Cr2O3, Fe2O3, and TiO2.(P < 0.01). Digestibilities of most nutrients (ADF, C, Cr, Cu, DM, EE, GE, NDF, P, and S) were not affected by dietary treatment. Pigs fed the diet containing Cr2O3 had a higher Ca digestibility compared to pigs fed no marker or and TiO2 (P < 0.01). Pigs fed Cr2O3 had the highest Fe digestibility while pigs fed Fe2O3 had the lowest Fe digestibility, while pigs fed no marker or TiO2 had an intermediate Fe digestibility (P < 0.01). Pigs fed no marker or Cr2O3 had the highest Ti digestibility while and pigs fed TiO2 had the lowest Ti digestibility, while pigs fed Fe2O3 had an intermediate Ti digestibility (P < 0.01). Pigs fed TiO2 had the highest Zn digestibility compared to pigs fed no marker, Cr2O3, or Fe2O3 (P < 0.01). There was little effect of indigestible markers on fecal VFA or nutrient digestibility. If a digestibility marker needs to be fed, TiO2 is recommended because it did not alter microbial numbers or bacterial diversity.