Date of Award
Doctor of Philosophy
Cottonseed meal (41% protein, .04% gossypol) was fermented with Aspergillus oryzae NRRL506 and Aspergillus janus NRRL1935 for 48 hr at 30(DEGREES)C. Diets containing each of the fermented meals were compared with diets containing nonsupplemented cottonseed meal, cottonseed meal (CSM) supplemented adequately with lysine and methionine, and a soybean meal diet. Experiments were also conducted using unsterilized fermented cottonseed meal or unsterilized fermented cottonseed meal supplemented with half the amounts of lysine and methionine theoretically needed to balance the protein of cottonseed meal. All diets contained 20% protein and 2940 kcal ME/kg;Fermented cottonseed meal (FCSM) from both species of Aspergillus caused no mortality, but significantly (P (LESSTHEQ) .05) improved weight gain and feed efficiency as compared to unfermented CSM. The responses of weight gain and feed efficiency were similar for both strains of fungi. Amino acid supplementation indicated that lysine and methionine were limiting in CSM and FCSM. Since there was no significant difference in weight gain among chicks fed the CSM diet fully supplemented with lysine and methionine and chicks fed fermented CSM diet partially supplemented with 50% of lysine and methionine needed to meet NRC (1977) requirements, it was inferred that fermentation could spare 50% of lysine and methionine needed to meet NRC (1977) requirements in CSM diet;Chemical analysis indicated that fermentation increased the lysine (27 to 38%), methionine (10%), and branched chain amino acid contents of the protein as compared to unfermented CSM. Concurrently, protein and acid detergent fiber concentration were increased, crude fat content was not changed and the gross energy of the meal was decreased by fermentation;The nutritional value of enriched fermented CSM was also evaluated. Cottonseed meal was enriched with 1, 2, 3, 4, and 5% ammonium sulfate (AS) prior to fermentation with A. oryzae;The essential amino acid contents of FCSM enriched with 1, 2, or 3% AS did not change significantly (P (GREATERTHEQ) .05) as compared with essential amino acid contents of FCSM with no AS. There was a 1.07 to 1.47 percentage unit decrease in crude fat of FCSM enriched with 2, 3, 4, or 5% AS as compared with crude fat concentration in unfermented CSM. Chicks fed diets containing FCSM enriched with 1 or 2% AS gained slightly, but not significantly, more weight than chicks fed diets containing FCSM with no AS. Inclusion of FCSM, enriched with 3, 4, or 5% AS, in diets depressed weight gain of chicks as compared with FCSM with no AS. Weight gain by chicks fed diets containing FCSM enriched with 0, 1 or 2% AS was not significantly different (P (GREATERTHEQ) .05) from weight gain by chicks fed a CSM diet which was supplemented with 50% of lysine and methionine needed to meet NRC (1977) requirements.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Alfred Omale Aduku
Aduku, Alfred Omale, "Effect of fermentation with Aspergillus oryzae NRRL506 and Aspergillus janus NRRL1935 on the nutritional value of cottonseed meal " (1980). Retrospective Theses and Dissertations. 6822.