Location: Dairy Forage ResearchTitle: Nutritive Value of Corn Silage in Mixture with Climbing Beans Author
Submitted to: Animal Feed Science And Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2008
Publication Date: 3/30/2009
Publication URL: http://www.sciencedirect.com.ezproxy.library.wisc.edu/science?_ob=ArticleURL&_udi=B6T42-4T9BXHX-1&_user=443835&_coverDate=03%2F30%2F2009&_alid=957310699&_rdoc=2&_fmt=high&_orig=search&_cdi=4962&_sort=r&_docanchor=&view=c&_ct=184&_acct=C000020958&_version=1&_urlVersion=0&_userid=443835&md5=1fc0969a2e87d5193d002d7dabf556a1
Citation: Contreras-Govea, F.E., Muck, R.E., Armstrong, K.L., Albrecht, K.A. 2009. Nutritive Value of Corn Silage in Mixture with Climbing Beans. Animal Feed Science And Technology. 150(1/2):1-8. Interpretive Summary: Corn silage is a good source of carbohydrates for dairy cattle diets but poor in protein. One potential way of making a more nutritionally balanced silage is to grow corn togther with climbing beans that are high in protein. We grew corn with one of three types of climbing beans (Velvet, LabLab or Scarlet Runner) or alone. In this paper, we report on the quality of the mixtures before and after ensiling. The beans were approximately 10% of the harvested forage, and the mixtures had on average 13% more protein than corn grown alone. The mixtures fermented well in the silo, similar to corn alone. Overall, growing climbing beans with corn permits making a high quality silage of higher protein content than corn silage. More research is needed to assess how well dairy cattle perform on the mixtures before recommending this practice to dairy farmers.
Technical Abstract: Corn (Zea mays L.) for silage is a major forage source for dairy cows in the northern USA. It has high energy density, but crude protein concentration is low. This study was conducted to determine the silage fiber characteristics and fermentation profile of monoculture corn or in mixture with one of three climbing beans. The experiment was conducted in two locations in 2004 and 2005. Three climbing beans, velvet bean [Mucuna pruriens (L.) D.C.], 'Rongai' LabLab bean [Lablab purpureus (L.) Sweet], and 'Scarlet Emperor' Scarlet runner bean (Phaseolus coccineus L.) were intercropped with corn at two corn densities (82.5 and 55 thousand plants/ha). All three beans were sown at the same density (82.5 thousand plants/ha). Corn in monoculture or in mixture with bean was harvested between _ and _ milk line. Two 1-L glass jar mini-silos per treatment per replicate plot were filled at a density of 500 g L-1, eight jars per treatment, and stored for a minimum of 45 days at room temperature (~ 220C). At the time of ensiling a 500-g fresh sub-sample was also taken for dry matter and initial characterization of the corn and corn-bean mixtures. Each silo was analyzed for fiber characteristics, pH, and fermentation products. Silage crude protein (CP) concentration on average increased 12.6% in the mixture with the addition of any of the beans, but neutral detergent fiber (NDF) concentration also increased 8.8%. The pH was 0.06 units greater in corn-bean mixtures than monoculture corn, and lactic acid concentration was on average 6.2% greater in the corn-bean mixtures than monoculture corn. The addition of climbing bean to corn increased CP but also had an effect on fiber concentration and fermentation profile. However, the nutritive value of corn-bean silage was as similar to corn silage, indicating that corn-bean silage mixtures could be used in dairy cow rations.