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Drewnoski M.E.,Iowa State University | Doane P.,ADM Research | Hansen S.L.,Iowa State University
British Journal of Nutrition | Year: 2014

Dissimilatory reduction of sulphate by sulphate-reducing bacteria in the rumen produces sulphide, which can lead to a build-up of the toxic gas hydrogen sulphide (H2S) in the rumen when increased concentrations of sulphate are consumed by ruminants. We hypothesised that adding ferric Fe would competitively inhibit ruminal sulphate reduction. The effects of five concentrations and two sources (ferric citrate or ferric ammonium citrate) of ferric Fe were examined in vitro (n 6 per treatment). Rumen fluid was collected from a steer that was adapted to a high-concentrate, high-sulphate diet (0·51% S). The addition of either source of ferric Fe decreased (P<0·01) H2S concentrations without affecting gas production (P=0·38), fluid pH (P=0·80) or in vitro DM digestibility (P=0·38) after a 24h incubation. An in vivo experiment was conducted using eight ruminally fistulated steers (543 (sem 12)kg) in a replicated Latin square with four periods and four treatments. The treatments included a high-concentrate, high-sulphate control diet (0·46% S) or the control diet plus ferric ammonium citrate at concentrations of 200, 300 or 400mg Fe/kg diet DM. The inclusion of ferric Fe did not affect DM intake (P=0·21). There was a linear (P<0·01) decrease in the concentration of ruminal H2S as the addition of ferric Fe concentrations increased. Ferric citrate appears to be an effective way to decrease ruminal H2S concentrations, which could allow producers to safely increase the inclusion of ethanol co-products. Copyright © The Authors 2013. Source

Kurylenko O.,Ukrainian Academy of Sciences | Semkiv M.,Ukrainian Academy of Sciences | Ruchala J.,University of Rzeszow | Hryniv O.,Ukrainian Academy of Sciences | And 5 more authors.
Acta Biochimica Polonica | Year: 2016

Increase in the production of 1st generation ethanol from glucose is possible by the reduction in the production of ethanol co-products, especially biomass. We have developed a method to reduce biomass accumulation of Saccharomyces cerevisiae by the manipulation of the intracellular ATP level due to overexpression of genes of alkaline phosphatase, apyrase or enzymes involved in futile cycles. The strains constructed accumulated up to 10% more ethanol on a cornmeal hydrolysate medium. Similar increase in ethanol accumulation was observed in the mutants resistant to the toxic inhibitors of glycolysis like 3-bromopyruvate and others. Substantial increase in fuel ethanol production will be obtained by the development of new strains of yeasts that ferment sugars of the abundant lignocellulosic feedstocks, especially xylose, a pentose sugar. We have found that xylose can be fermented under elevated temperatures by the thermotolerant yeast, Hansenula polymorpha. We combined protein engineering of the gene coding for xylose reductase (XYL1) along with overexpression of the other two genes responsible for xylose metabolism in yeast (XYL2, XYL3) and the deletion of the global transcriptional activator CAT8, with the selection of mutants defective in utilizing ethanol as a carbon source using the anticancer drug, 3-bromopyruvate. Resulted strains accumulated 20-25 times more ethanol from xylose at the elevated temperature of 45°C with up to 12.5 g L-1 produced. Increase in ethanol yield and productivity from xylose was also achieved by overexpression of genes coding for the peroxisomal enzymes: transketolase (DAS1) and transaldolase (TAL2), and deletion of the ATG13 gene. Source

Ileleji K.E.,Purdue University | Li Y.,Purdue University | Ambrose R.P.K.,Purdue University | Doane P.H.,ADM Research
Powder Technology | Year: 2016

Biofeedstocks such as corn coproducts or biomass such as corn stover are typically densified in a dry process using pellet mills to enhance transportability and use as livestock feed. Our work presents data of an experimental study using a non-traditional means, wet granulation with a lab-scale rotary drum granulator to determine key parameters that affect granule properties and yield of desirable sized granules. Granules were manufactured from corn stover and two liquid coproducts from corn bioprocessing, corn steep liquor (CSL) and corn molasses (CM) by varying corn stover particle size, corn stover:coproduct blend ratio and granulation residence time. The results showed that different formulation and processing parameters affected corn stover granulation. Granulation with an initial particle size of 0.88-0.96. mm (from screen size 6.4. mm), low liquid level (1:4) with CM, and short residence time (0.5. min) could be used to produce desirable sized granules (1.78 to 7.87. mm) for ruminant livestock feed with yields of over 98%. The effect of initial particle size of corn stover particles on density of granular products was significant. Corn stover particle size also positively influenced the granule size and negatively influenced yield of desirable granules. While increased coproduct (CM and CSL) levels in the blend increased the granule particle size and density, yield of desirable granules was reduced. © 2016 Elsevier B.V. Source

Hall M.B.,U.S. Department of Agriculture | Nennich T.D.,Purdue University | Doane P.H.,ADM Research | Brink G.E.,U.S. Department of Agriculture
Journal of Dairy Science | Year: 2015

Volatile fatty acid concentrations ([VFA], mM) have long been used to assess the effect of dietary treatments on ruminal fermentation in vivo. However, discrepancies in statistical results between [VFA] and VFA pool size (VFAmol) possibly related to ruminal digesta liquid amount (LIQ, kg) indicate potential issues with the use of [VFA]. We investigated relationships among [VFA], VFAmol, and LIQ measured 2 h postfeeding using individual lactating cow data (n=175) from 7 separate feeding studies. Regression analyses were performed using mixed models with "study" as a discrete random variable. The mean across studies and average range of values within studies, respectively, were 151 and 75 for [VFA], 11.2 and 9.8 for VFAmol, 73.3 and 41.0 for LIQ, and 289 and 83mmol/kg for rumen fluid osmolality. Liquid amount changed with VFAmol (3.76 VFAmol + 31.2; average within-study R2=0.69), but the relationship was weak between [VFA] and LIQ (0.524 LIQ + 112.8; average within-study R2=0.12). The relationship between LIQ and VFAmol was likely a function of the osmotic gradient between rumen liquid and blood. The VFA are a major ruminal solute; VFAmol amounts can affect water flux in the rumen as similar tonicities of rumen fluid and blood are maintained. This also has a damping effect on ruminal solute concentration, creating the weak relationship between [VFA] and LIQ. Within studies, similar [VFA] were found in LIQ differing by 30kg or more. The difference between minimum and maximum LIQ within cow within study was 12.7kg (standard deviation=7.1), so inclusion of "cow" in analyses did not correct for the variation in LIQ. To allow valid comparisons of experimental treatments, responses must be on an equivalent basis; concentrations in different LIQ are not on an equivalent basis and so are not valid to use for comparing treatment effects. The [VFA] changed with VFAmol (5.80 VFAmol + 86.3; average within-study R2=0.56). However, the ratio of [VFA] to VFAmol ranged from 9.0 to 24.1 as a function of 1,000/LIQ; this reflects the inherent calculated relationship among the variables. The varying relationship of [VFA] to VFAmol further indicates that [VFA] is not an appropriate measure to evaluate the progress or effect of treatments on ruminal fermentation. Predictions of LIQ and VFAmol using cow and ruminal measures were insufficiently precise to be used in research. Previously drawn conclusions based on [VFA] need to be reevaluated, and alternate evaluations for in vivo ruminal fermentation are needed. © 2015 American Dairy Science Association. Source

Shi H.T.,China Agricultural University | Cao Z.J.,China Agricultural University | Wang Y.J.,China Agricultural University | Li S.L.,China Agricultural University | And 3 more authors.
Journal of Animal Physiology and Animal Nutrition | Year: 2016

The objective of this study was to determine the optimum conditions for calcium oxide (CaO) treatment of anaerobically stored corn stover by in situ and in vitro methods. Four ruminally cannulated, non-lactating, non-pregnant Holstein cows were used to determine the in situ effective degradabilities of dry matter (ISDMD), organic matter (ISOMD), neutral detergent fibre (ISNDFD), in vitro organic matter disappearance (IVOMD) and gas production in 72 h (GP72h) of corn stover. A completely randomized design involving a 3 × 3 factorial arrangement was adopted. Ground corn stover was treated with different levels of CaO (3%, 5% and 7% of dry stover) at varying moisture contents (40%, 50% and 60%) and stored under anaerobic conditions for 15 days before analysis. Compared with untreated corn stover, the CaO-treated stover had increased ash and calcium (Ca) contents but decreased aNDF and OM contents. The moisture content, CaO level and their interaction affected (p < 0.01) the content of aNDF, ash and OM, and the ratio of aNDF/OM. The greatest ISDMD, ISOMD and ISNDFD were observed when stover was treated with 7% CaO and 60% moisture, while no differences (p > 0.01) in these in situ degradability parameters were observed between the stover treated with 5% CaO at 60% moisture content and those treated with 7% CaO at 60% moisture content. Corn stover treated with 5% CaO at 50% moisture had the maximum IVOMD and GP72 h among the treatments, and there was no difference (p > 0.01) between 50% and 60% moisture. Results from this study suggested that 5% CaO applied at 60% moisture could be an effective and economical treatment combination. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH Source

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