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United States Department of Agriculture

Agricultural Research Service

Title: Comparative Effects of Wild-type, bmr-6, bmr-12 and Stacked Sorghum: Sorghum Stover Digestibility

Authors
item Dann, H. M. - W. H. MINER
item Dicerbo, A. M. - W. H. MINER
item Pedersen, Jeffrey
item Grant, R. J. - W. H. MINER

Submitted to: American Dairy Science Association Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 8, 2007
Publication Date: July 8, 2007
Citation: Dann, H., Dicerbo, A., Pedersen, J.F., Grant, R. 2007. Comparative Effects of Wild-type, bmr-6, bmr-12 and Stacked Sorghum: Sorghum Stover Digestibility. American Dairy Science Association Proceedings. Journal Dairy Science 90 (Suppl. 1):556.

Technical Abstract: Comparative Effects of Wild-type, bmr-6, bmr-12 and Stacked Sorghum: Sorghum Stover Digestibility H. M. Dann,1 A. M. DiCerbo,1 J. F. Pedersen,2 and R. J. Grant1 1 William H. Miner Agricultural Research Institute, Chazy, NY 2 USDA, ARS, NPA Wheat, Sorghum and Forage Research, University of Nebraska, Lincoln Samples of wild-type 'Atlas' and its brown midrib near-isolines containing bmr-6, bmr-12, and stacked bmr-6 and bmr-12 genes were used to assess the effect of bmr mutations on in situ digestion kinetics of sorghum stover. Forage sorghum was grown in 2004 at Mead, Nebraska. Panicles were removed from sorghum before harvest. Wild-type, bmr-6, bmr-12, and stacked sorghum stovers had a neutral detergent fiber (NDF) content of 52.7, 53.1, 50.9, and 53.9%, respectively and a lignin content of 5.3, 3.8, 3.6, and 3.6%, respectively. Ruminal in situ digestion kinetics of dry matter (DM) and NDF of sorghum stover were determined with 4 ruminally cannulated multiparous lactating Holstein cows used in a 4×4 Latin square design. Samples of sorghum stover were incubated in N-free polyester in situ bags (5 g sample/bag) for 0, 6, 12, 24, 48, and 96 h and removed simultaneously at 0 h. Residues were analyzed for DM and NDF with residual ash (using '-amylase and without sodium sulfite). Digestion kinetics [lag, fractional rate of digestion (kd), and potential extent of digestion (PED)] for DM and NDF were calculated. Data were analyzed by ANOVA. Dry matter lag (2.0 h), DM kd (0.036 h-1), NDF lag (2.8 h), and NDF kd (0.036 h-1) were similar (P > 0.10) among sorghum stovers. The PED of DM and NDF differed (P < 0.05) among sorghum stovers. The PED of DM was 52.1, 55.6, 64.3, and 73.2% and the PED of NDF was 53.1, 54.7, 65.3, and 74.1% for wild-type, bmr-6, bmr-12, and stacked sorghum stovers, respectively. Digestibility of NDF (% of NDF) was higher for stacked than wild-type sorghum stover at 24 h (P < 0.10; 49.0 vs. 39.1%) and 48 h (P < 0.05; 65.0 vs. 52.8%). In summary, there was more digestible DM and NDF in bmr-6, bmr-12, and stacked sorghum stovers than wild-type sorghum stover. The stacked bmr-6 and bmr-12 mutations had the greatest positive impact on digestibility. Key Words: sorghum, bmr, digestibility

Last Modified: 12/21/2014
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