Skip to main content
ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #327677
Title: Effect of summer annuals on ruminal fermentation and methane output in continuous culture

Author
item Dillard, Sandra
item ROCA-FERNANDEZ, ANA - Universidad De Chile
item BRITO, ANDRE - University Of New Hampshire
item HAFLA, AIMEE - Agri-King, Inc
item Rubano, Melissa
item Soder, Kathy

Submitted to: Joint Meeting of the ADSA, AMSA, ASAS and PSA
Publication Type: Abstract Only
Publication Acceptance Date: 6/15/2016
Publication Date: 10/1/2016
Citation: Dillard, S.L., Roca-Fernandez, A., Brito, A., Hafla, A., Rubano, M.D., Soder, K.J. 2016. Effect of summer annuals on ruminal fermentation and methane output in continuous culture.Journal of Animal Science 94 eSuppl.5:575-575.

Interpretive Summary: Interpretive Summary not required.

Technical Abstract: Summer annuals (SA) provide forage during the summer “forage slump”, yet research on ruminal fermentation and CH4 output of SA is lacking. A 4-unit, dual-flow continuous culture fermentor system was used to assess nutrient digestibility, VFA production, bacterial protein synthesis, and CH4 output of SA. Treatments were randomly assigned to fermentors in a 4 × 4 Latin square design using 7 d for adaptation and 3 d for collection. Treatments were: 1) 100% orchardgrass (Dactylis glomerata) herbage (HERB), 2) 50% herbage + 50% Japanese millet (Echinochloa esculenta; MIL), 3) 50% herbage + 50% sorghum (Sorghum bicolor) × sudangrass (S. sudanense; SSG), and 4) 50% herbage + 25% MIL + 25% SSG (MIX). Feedings (60 g DM/d) occurred 4 times throughout four, 10-d periods; fermentors were fed herbage at 730 and 1030 h and at 1400 and 1900 h, SA treatments received SA herbage, and HERB received herbage. Samples for CH4 were collected 6 times daily (725, 0900, 1000, 1355, 1530, 1630 h) during the last 3 d; samples for NH3-N, VFA, and pH were taken on d 8, 9, and 10. Samples were also analyzed for DM, OM, CP, and fiber fractions for determination of nutrient digestibility, and estimation of bacterial protein synthesis. Data were analyzed using the MIXED procedure of SAS (SAS, Inc., Carey, NC). Apparent DM, NDF, and ADF, and true DM digestibilities were not different (P > 0.062) among treatments. True OM and CP digestibilities, and apparent OM digestibility, were not different (P > 0.084; 76 ± 2.3, 93 ± 2.4, and 66 ± 2.6%, respectively) among treatments. Total N intake was not different (P = 0.389) among treatments (2.3 ± 0.01 g N/d), but bacterial N was greater (P = 0.013) in MIL and MIX than HERB (0.33, 0.34, and 0.25 ± 0.020 g N/d). There was no difference (P = 0.296) in total VFA concentration among treatments (57.5 ± 1.16 mmol/L); MIL had a greater (P = 0.006) acetate to propionate ratio than SSG or MIX (3.3, 2.8, and 2.9 ± 0.06, respectively). There was no difference (P > 0.178) in daily CH4 output (6.7 ± 2.14 mmol/d) or CH4 per gram OM fed (1.9 ± 0.62 mg CH4 /g of OM fed). Addition of SA to an herbage-based diet provided similar nutrient digestibility, VFA production, and CH4 output as orchardgrass herbage alone, suggesting SA would produce similar animal performance to that of HERB. Keywords: Summer annual, pasture, methane