Effects of hops β-acid extract (Humulus lupulus L.) on cattle performance and fermentation by ruminal microbes
dc.contributor.author | Axman, Justin | |
dc.date.accessioned | 2015-11-20T21:06:48Z | |
dc.date.available | 2015-11-20T21:06:48Z | |
dc.date.graduationmonth | December | |
dc.date.issued | 2015-12-01 | |
dc.description.abstract | Hops β-acid extract was fed to 80 heifers (389 ± 23.6 kg initial BW) to assess impact on feedlot performance and ruminal fermentation. Heifers were randomly assigned to individual pens and fed once daily for 147 d. Treatments were a control (no additive); 33 mg monensin (Elanco Animal Health, Greenfield, IN)/kg diet DM; and 10, 25, 50 mg β-acid extract of hops (DSM Nutritional Products, France)/kg diet DM. Ruminal fluid was collected on d 44 and 86 by rumenocentesis for analyses of VFA, lactate, and NH[subscript]3 concentrations. Cattle were harvested at a commercial abattoir on d 147. Hops β-acids decreased propionate (P = 0.01) concentrations and increased caproate (P = 0.05), A:P (P = 0.04), and ammonia concentrations (P = 0.03) compared to monensin. Growth performance of heifers fed β-acid or monensin was not different than that of heifers fed the control diet. Additionally, two in vitro studies were conducted to evaluate effects of hops β-acid extract on starch fermentation by mixed microbial populations from the bovine rumen. In trial 1, 2 treatments were assigned in triplicate to fermentation bottle, fitted with Ankom[superscript]RF1 Gas Production System modules (Ankom[superscript]RF Technology, Macedon, NY) using starch as substrate (Difco Soluble Starch; Dickinson and Company, Sparks, MD) and either 0 or 33 mg hops β-acid extract (10.99% active hops beadlet; DSM Nutritional Products, France)/kg substrate. Gas production was measured over 30 h. Terminal pH, IVDMD, and VFA and lactate were measured after 30 h of fermentation. Gas production increased in response to β-acid (P ≤ 0.05). Terminal pH, IVDMD, VFA, and lactate were unaffected by addition of β-acid extract (P ≤ 0.05). In trial 2, pH, VFA concentrations, and IVDMD were measured at 6-h intervals during a 30-h incubation period using 36 fermentation tubes. There was no effect of hops β-acid on in vitro fermentation (P > 0.05). In conclusion, under the conditions of these experiments, hops β- acid extracts hops had little impact on feedlot performance, though there are indications of an impact on ruminal fermentation. | |
dc.description.advisor | James S. Drouillard | |
dc.description.degree | Master of Science | |
dc.description.department | Department of Animal Sciences and Industry | |
dc.description.level | Masters | |
dc.identifier.uri | http://hdl.handle.net/2097/20569 | |
dc.language.iso | en_US | |
dc.publisher | Kansas State University | |
dc.rights | © the author. This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). | |
dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | |
dc.subject | Beta-acid | |
dc.subject | Hops | |
dc.subject | Feedlot | |
dc.subject | In vitro | |
dc.subject | Cattle | |
dc.subject.umi | Animal Sciences (0475) | |
dc.title | Effects of hops β-acid extract (Humulus lupulus L.) on cattle performance and fermentation by ruminal microbes | |
dc.type | Thesis |