Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/24/2000
Publication Date: 6/1/2000
Citation: Buser, M.D. 2000. Update on dry extruding cotton gin byproducts to reduce chemical residues. National Cotton Council Beltwide Cotton Conference. CD ROM
Interpretive Summary: An estimated 2.8 million tons of cotton gin by-products other than cottonseed are produced by U. S. cotton gins annually, creating a significant problem in the ginning industry. Currently, the most common methods of disposal include composting, direct land application, and livestock feed. Surveys estimate that 37% of the cotton gin by-products produced annually in the U.S. are utilized at a profit or at no cost to th gins, while the other 63% paid for disposal. The nutritional value of cotton gin by-products is similar to roughage-type feeds, which has created an interest in adding cotton gin by-products to livestock feed rations. The primary concern of feeding cotton gin by-products to livestock is the potential for chemical residues in the material. Mixtures of gin waste and cottonseed were extruded under high pressure and temperature to determine the chemical residue reduction associated with the process. Results from the extrusion tests indicated that the chemical residue content of the chemicals tested were decreased by the extrusion process and further diluted by addition of cottonseed to the cotton gin by-products. Although these test indicated that chemical residues were reduced by the extrusion process, feeding of cotton gin by-products is not recommended until tolerances have been established by the Environmental Protection Agency under the Food Quality Protection Act. The ability to utilize cotton gin by-products in livestock rations will increase gin profits, reduce landfill disposal, and generate an alternative roughage in the livestock industry.
Technical Abstract: Whole cottonseed and cotton gin by-products (CGBP) were mixed together and processed in a dry extruder to determine the feasibility of the mixture as a livestock feed. Samples were collected during the study to determine if the temperature, pressure and shear associated with extrusion would reduce the chemical residues in the CGBP and affect the nutritional value of the mixture. The first test focused on mixing ratios of CGBP and cottonseed with a constant temperature and pressure during processing. Results show a significant reduction in Methyl Parathion and DEF, while there were no significant reductions in Karate (Karate levels were below 1 ppm before the CGBP mixture was extruded). The second study focused on the extrusion of a 75% CGBP and 25% cottonseed processed multiple times by dry extrusion. The results of this study show significant reductions in Methyl Parathion and Dropp. A nutritional analysis was completed on the extruded material of the first study, showing significant differences in nutritional values of the various mixtures. Nutritional results from the second study showed significant differences in nutrient values due to the number of times the material was processed.