Effect of kernel breakage on the fermentation profile, nitrogen fractions, and in vitro starch digestibility of whole-plant corn silage and ensiled corn grain.

The objective of this experiment was to analyze the effect of kernel breakage on the fermentation profile, nitrogen fractions, and ruminal in vitro starch digestibility of whole-plant corn silage and ensiled corn grain. Whole corn plants were harvested, and ears were separated from the forage portion and shelled. Corn kernels were either left intact or broken manually using a hammer. The remaining forage portion of the corn plants was chopped. Samples of the intact and broken kernels were stored for 0 or 30 d in quadruplicate vacuum pouches. Remaining intact and broken kernels were each reconstituted with the chopped forage portion of the corn plant to simulate whole-plant corn forage and were also stored for 0 or 30 d. In kernels separated from whole-plant corn silage, kernel form had no effect on zein protein concentrations. However, it was observed that in vitro starch digestibility at 7 h increased with ensiling only in kernels that were broken. When corn kernels were ensiled alone, concentrations of soluble crude protein and ammonia nitrogen increased with ensiling to a greater extent when kernels were broken. Finally, fermentation of ensiled corn grain was enhanced when kernels were broken. Overall, this study gives insight into the importance of kernel breakage to improve starch digestibility in corn silage through means other than a reduction in particle size and opens the door for continued investigation into the proteolytic activity occurring in the silo.

Graduate Student Literature Review: Current perspectives on whole-plant sorghum silage production and utilization by lactating dairy cows.

The purpose of this literature review is to evaluate current research into and understanding of whole-plant sorghum silage production and the effect of feeding whole-plant sorghum silage on lactation performance of dairy cows. Sorghum's drought tolerance, water efficiency, and low cost of production make it an intriguing crop in areas where whole-plant corn silage production may be limited. Currently, urban land encroachment and reduced water availability have increased social and economic pressures on farms to improve crop production efficiency. As these challenges become more prevalent, greater reliance on sorghum can be expected because of its ability to produce high dry matter yields while maintaining nutritive value, even under less-than-ideal growing conditions. Moreover, whole-plant sorghum silage provides both physically effective fiber and energy through fiber and grain fractions. Advancements in sorghum genetics and mechanical processing have the potential to alleviate common challenges associated with whole-plant sorghum silage supplementation, such as increased neutral detergent fiber and decreased neutral detergent fiber digestibility, starch concentration, and starch digestibility. These nutritive challenges must be overcome for whole-plant sorghum silage to be a viable alternative to whole-plant corn silage.