Effects of ensiling of whole-plant corn on silage processing score and fermentation and long-chain fatty acid profiles

Abstract

Objective: Our objective was to evaluate the effects of ensiling on the corn silage processing score (CSPS) and fermentation and long-chain fatty acids (LCFA) profiles of unprocessed whole-plant corn. Materials and Methods: Eleven corn hybrids were harvested and chopped separately (unprocessed) into approximately 16-mm-length particles and divided in 4 subsamples of approximately 600 g each. Two subsamples were randomly assigned to each treatment (0 or 120 d of ensiling). All samples were vacuum sealed in nylon-polyethylene standard barrier vacuum pouches. Representative samples from 0 and 120 d were immediately frozen and further analyzed for nutrients, CSPS, and fermentation and LCFA profiles. Results and Discussion: Concentration of DM was unaffected (P > 0.10) by ensiling and averaged 36.2% as fed. Crude fat was 0.42 percentage units greater (P = 0.005) and pH levels were lower (P = 0.001) after 120 d, likely due to lactic and acetic acids concentrations that were 7.7 and 1.0 percentage units greater (P < 0.02), respectively, for 120 d compared with 0 d. Conversely, water-soluble carbohydrate concentrations were reduced (P = 0.001) by 9.9 percentage units for 120 d in comparison with 0 d. Concentrations of ammonia-N increased (P = 0.001) with ensiling. Starch concentrations were unaffected (P > 0.10) by ensiling and averaged 31.2% of DM. The CSPS (28.8%) was low in the unprocessed material and was unaffected (P > 0.10) by ensiling. No effects of ensiling were observed on LCFA profile of major fatty acids including C16:0, C18:0, C18:1, C18:2, and C18:3 fatty acids (P > 0.10). Implications and Applications: Ensiling did not affect CSPS and LCFA profile.