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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #329156
Title: Effect of feeding warm-season annuals with orchardgrass on ruminal fermentation and methane output in continuous culture

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

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2016
Publication Date: 2/1/2017
Citation: Dillard, S.L., Hafla, A., Roca-Fernandez, A., Brito, A., Rubano, M.D., Soder, K.J. 2017. Effect of feeding warm-season annuals with orchardgrass on ruminal fermentation and methane output in continuous culture. Journal of Dairy Science. 100(2):1179-1188.

Interpretive Summary: Effect of feeding warm-season annuals with orchardgrass on ruminal 1 fermentation and methane output in continuous culture. By Dillard et al. The aim of this study 2 was to assess the effects of feeding warm-season annuals (sorghum × sudangrass, Japanese 3 millet, or a mixture of both) with orchardgrass on ruminal fermentation and methane output in a 4 dual-flow continuous culture fermentor system. Overall, there was little difference in nutrient 5 digestibility, methane output, and nitrogen metabolism among all treatments. Use of warm-6 season annuals during summer months would provide alternative high-quality forage options for 7 dairy cattle when forage productivity and quality of cool-season pastures decreases.

Technical Abstract: A 4-unit, dual-flow continuous culture fermentor system was used to assess nutrient digestibility, volatile fatty acids (VFA) production, bacterial protein synthesis and CH4 output of warm-season summer annual grasses. Treatments were randomly assigned to fermentors in a 4 × 4 Latin square design using 7 d for treatment adaptation and 3 d for sample collection. Treatments were: 1) 100% orchardgrass [(Dactylis glomerata L.); ORG]; 2) 50% orchardgrass + 50% Japanese millet [Echinochloa esculenta (A. Braun H. Scholz); MIL], 3) 50% orchardgrass + 50% sorghum × sudangrass [(Sorghum bicolor L. Moench × S. bicolor var. sudanense); SSG]; or 4) 50% orchardgrass + 25% millet + 25% sorghum × sudangrass (MIX). mentors were fed 60g dry matter (DM)/d in equal portions of herbage 4 times daily (0730, 1030, 1400, and 1900 h).All fermentors were fed orchardgrass at 0730 and 1030 h and individual treatment herbage(orchardgrass, Japanese millet, sorghum × sudangrass, or 50:50 Japanese millet and sorghum × sudangrass) at 1400 and 1900 h. Gas samples for CH4 analysis were collected 6 times daily at 0725, 0900, 1000, 1355, 1530, and 1630 h. Fermentor pH was determined at the time of feeding and fermentor effluent samples for NH3-N and VFA analyses were taken daily at 1030 h on d 8,9, and 10. Samples were also analyzed for DM, organic matter, crude protein, and fiber fractions to determine nutrient digestibilities and estimation of bacterial protein synthesis. Apparent and true DM and organic matter digestibilities, pH, and total VFA were not different among treatments. Apparent neutral detergent fiber was greater in ORG than MIL. The concentration of propionate was greater in ORG and MIL than SSG and MIX, and that of butyrate was greatest in ORG and MIL, intermediate in SSG, and lowest in MIX. Methane output was greatest in MIL,intermediate in ORG, and lowest in SSG and MIX. Nitrogen intake did not differ across treatments, whereas bacterial N efficiency per kg of truly digestible organic matter as greatest in MIL and MIX, intermediate in SSG, and lowest in ORG. True crude protein digestibility was greater in ORG versus MIL, and ORG had less total N, non-NH3-N, bacterial N, and dietary N in effluent flows than MIL. Overall, there was little difference in nutrient digestibility, CH4 output, and N metabolism among all treatments. Thus, warm-season annual pastures could provide forage quality and animal performance similar to that of ORG pastures during the summer months when ORG is no longer productive.