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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #327831
Title: Use of a novel continuous culture fermentor system for in vitro determination of enteric methane output from ruminants

Author
item ROCA-FERNANDEZ, ANA - Universidad De Chile
item Dillard, Sandra
item Rubano, Melissa
item TILLMANN, RYAN - Pennsylvania State University
item Soder, Kathy

Submitted to: Joint Meeting of the ADSA, AMSA, ASAS and PSA
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2016
Publication Date: 7/1/2016
Citation: Roca-Fernandez, A., Dillard, S.L., Rubano, M.D., Tillmann, R., Soder, K.J. 2016. Use of a novel continuous culture fermentor system for in vitro determination of enteric methane output from ruminants. Joint Meeting of the ADSA, AMSA, ASAS and PSA.Journal of Animal Society.94(E-Suppl.5):564.

Interpretive Summary: Interpretive Summary not required.

Technical Abstract: Continuous culture fermentor systems (CCFS) serve to evaluate the effect of diet on in vitro nutrient digestibility, fermentation, and microbial protein synthesis. Limitations of CCFS are: maintaining protozoa populations, and avoiding accumulation of undigested material in the vessels. Therefore, a 4-unit, 3-L bioreactor CCFS (Applikon Biotechnology Inc., Foster City, CA) was adapted to determine pH, DM, protozoa numbers, and enteric CH4 output of a forage diet. Each unit was fed 82 g DM/d of 50% orchardgrass (Dactylis glomerata) + 50% alfalfa (Medicago sativa) in equal portions, 4 times daily (07:30, 10:30, 14:00 and 19:00 h) throughout 10-d periods (n=4, 7 d adaptation and 3 d collection). The CCFS was programmed to maintain temperature = 39oC, stirrer = 255 rpm, and CO2 flux = 1 ml/min. Temperature and pH were recorded every 2 min. On d1 of each period, 1500 ml of rumen fluid + 32 g of digesta were collected from a fistulated cow and added to each fermentor. Vat volume was maintained at 1500 ± 200 ml during the 10 d. Solid mean retention time, solid dilution rate, and liquid dilution rate were adjusted daily to 24 h, 4%/h, and 11%/h, respectively, by regulation of buffer input and effluent removal. Effluent and fermentation vats were sampled daily to determine protozoa numbers and DM. Gas samples for CH4 analysis were collected 6 times daily (07:25, 09:00, 10:00, 13:55, 15:30, 16:30 h) during the 3-d collection periods and analyzed by GC (Varian CP 3800, Agilent Technologies, Santa Clara, CA). Data were analyzed using PROC GLIMMIX (SAS, Inc., Carey, NC). There were no differences (P = 0.067) in total buffer and effluent volume, effluent DM, and CH4 output between periods or among days within a collection period. There were no differences in pH or vat DM (P = 0.445) between periods. However, pH was greater (P < 0.001) on d10 than d8 or d9 (6.51, 6.43, and 6.45, respectively). Preliminary results show fewer (P < 0.001) protozoa during the adaptation vs. collection period (11.5 ± 2.82 × 104 and 34.0 ± 3.95 × 104 cells/ml, respectively). There was no difference (P = 0.786) in protozoa during the 3d of the collection period (34.0 ± 2.25 × 104 cells/ml). This CCFS not only provides a stable fermentation environment, but also preserves protozoal populations, which better simulates in vivo ruminal fermentation conditions compared with previous CCFS methods. Keywords: continuous culture fermentor, methane, ruminants