Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Entire DC Network

Generation And Calibration Of Standard Gas Mixtures For Volatile Fatty Acids Using Permeation Tubes And Solid Phase Microextraction, Jacek A. Koziel, Jarett P. Spinhirne Oct 2003

Generation And Calibration Of Standard Gas Mixtures For Volatile Fatty Acids Using Permeation Tubes And Solid Phase Microextraction, Jacek A. Koziel, Jarett P. Spinhirne

Jacek A. Koziel

Volatile fatty acids (VFAs) are major components of odors associated with agricultural operations and livestock housing, solid waste processing and disposal, and industrial and municipal wastewater collection and treatment systems. Emissions estimation and assessment of odor control methods depend on reliable air sampling and analysis methods for VFAs. The objective of this research was to develop and test a method for continuous and reliable generation of standard gas mixtures for VFAs based on permeation tubes. Standard gas mixtures for acetic, propionic, isobutyric, butyric, isovaleric, valeric, and hexanoic acids were generated with permeation tubes and monitored for a 100-day period. The …


Characterizing Volatile Fatty Acids And Other Gases In A Rumen Closed In Vitro Fermentation System Using Solid Phase Microextraction, Jarett P. Spinhirne, Jacek A. Koziel, Norbert K. Chirase Jan 2003

Characterizing Volatile Fatty Acids And Other Gases In A Rumen Closed In Vitro Fermentation System Using Solid Phase Microextraction, Jarett P. Spinhirne, Jacek A. Koziel, Norbert K. Chirase

Jacek A. Koziel

A new method for rapid sampling and qualitative characterization of the headspace gases of closed in vitro cultures using solid phase microextraction (SPME) was evaluated for ruminal fluid and ruminal fluid with feed containing a feed additive. Gas sample collection was achieved by exposing a DVB/Carboxen/PDMS 50/30 .m SPME fiber to the headspace of cultures for 1 min every hour. This was followed by immediate analysis on a GC–MS and then reuse of the SPME fiber. Acetic, propionic, isobutyric, butyric, isovaleric, valeric, and hexanoic acids and toluene, dimethyl disulfide, and pentadecane were identified in the headspace. SPME technology facilitated rapid …


Generation And Calibration Of Standard Gas Mixtures For Volatile Fatty Acids Using Permeation Tubes And Solid-Phase Microextraction, Jacek A. Koziel, Jarett P. Spinhirne Jan 2003

Generation And Calibration Of Standard Gas Mixtures For Volatile Fatty Acids Using Permeation Tubes And Solid-Phase Microextraction, Jacek A. Koziel, Jarett P. Spinhirne

Jacek A. Koziel

Volatile fatty acids (VFAs) are major components of odors associated with agricultural operations and livestock housing, solid waste processing and disposal, industrial and municipal wastewater collection, and treatment systems. Emission estimation and assessment of odor control methods depend on reliable air sampling and analysis methods for VFAs. The objective of this research was to develop and test a method for continuous and reliable generation of standard gas mixtures for VFAs based on permeation tubes. Standard gas mixtures for acetic, propionic, isobutyric, butyric, isovaleric, valeric, and hexanoic acids were generated with permeation tubes and monitored for a 100-day period. The gravimetric …


The Effect Of Different Rations On Some Rumen Fluid And Blood Parameters In Sheep, Taylan Aksu, Suphi̇ Deni̇z Jan 2003

The Effect Of Different Rations On Some Rumen Fluid And Blood Parameters In Sheep, Taylan Aksu, Suphi̇ Deni̇z

Turkish Journal of Veterinary & Animal Sciences

The objective of this study was to evaluate the effects of different combinations of energy (barley and dried molassed sugar beet pulp (DMSBP)) and protein sources (soybean meal (SBM), cotton-seed meal (CSM), SBM-treated with formaldehyde (FTSBM), CSM-treated with formaldehyde (FTCSM), and urea) on some rumen fluid and blood parameters. In this study, four rumen fistulated Morkaraman rams were used. Rumen pH values were around the optimal pH values suggested for rumen fluid (5.2-7.3) at all sampling times. Ruminal NH_3-N concentrations were significantly greater (P < 0.05) in animals fed DMSBP as an energy source compared with animals fed barley as an energy source and were between 10.4 and 32.75 mg/100 ml in all groups. Formaldehyde treatments of protein sources reduced ruminal NH_3-N concentrations in animals fed DSBP as an energy source (P < 0.05). Acetic and propionic acid concentrations were affected by the energy source, although butyric acid concentrations were significantly higher in animals fed groups containing barley than in animals fed groups containing DMSBP. Formaldehyde treatment did not affect propionic acid concentrations, although propionic acid concentrations were generally significantly higher (P < 0.05) in animals fed barley + SBM combinations compared to treatments containing both SBM and CSM combinations (P < 0.05). Serum total protein concentrations were affected by the energy source and these were higher in groups containing DMSBP than in groups containing barley (P < 0.05). However, serum urea-N concentrations were similar among the different diets.


Effects Of Free Methionine And Lysine On In Vitro Fermentation And In Vivo Performance And Ruminal Fermentation Of Late Lactation Holstein Cows, Yi-Hua Chung Jan 2003

Effects Of Free Methionine And Lysine On In Vitro Fermentation And In Vivo Performance And Ruminal Fermentation Of Late Lactation Holstein Cows, Yi-Hua Chung

LSU Master's Theses

Two experiments were conducted to investigate the effects of free Met and Lys supplementation on ruminal fermentation in vitro and in vivo. In the in vitro study, supplementation of Met and Lys had effects on concentrations of total VFA and NH4+, proportions of acetate, propionate, butyrate, isovalerate, valerate, and the ratio of acetate to propionate. Percentages of microbial N synthesis in effluent pellets were not affected by supplementing Lys and Met. The combination of 0.52% Met and 1.03% (90% DM) Lys resulted in the highest concentration of total VFA, second highest concentration of NH4+, …