Nutrient composition and in vitro fermentability of corn grain and stover harvested at different periods in Goesan, a mountainous area

Kim Margarette Nogoy; Yan Zhang; Ye Hyun Lee; Xiang Zi Li; Hyun A Seong; Seong Ho Choi

doi:10.5187/jast.2019.61.1.18

Nutrient composition and in vitro fermentability of corn grain and stover harvested at different periods in Goesan, a mountainous area

J Anim Sci Technol. 2019 Jan;61(1):18-27. doi: 10.5187/jast.2019.61.1.18. Epub 2019 Jan 31.

Authors

Kim Margarette Nogoy¹, Yan Zhang¹, Ye Hyun Lee¹, Xiang Zi Li², Hyun A Seong³, Seong Ho Choi¹

Affiliations

¹ Department of Animal Science, Chungbuk National University, Cheongju 28644, Korea.
² Co-Innovation Center of Beef Cattle Science and Industry Technology, Yanbian University, Yanji 133002, China.
³ Department of Biochemistry, Chungbuk National University, Cheongju 28644, Korea.

Abstract

With South Korea's limited capability of feed production because of its relatively small cultivable area, the country is pushed to depend on foreign feed imports despite the immensely fluctuating price of corn. Hence, intensive efforts to increase the total cultivable area in Korea like extending of farming to mountainous area is being practiced. Corn was planted in Goesan County, a mountainous area in the country. Grain and stover were harvested separately in three harvest periods: early-harvest (Aug 8), mid-harvest (Aug 18), and late-harvest (Aug 28). The nutrient composition such as dry matter (DM), crude protein (CP), crude fat (EE), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and non-fibrous carbohydrates (NFC) was determined after harvest. Effective degradability (ED) of the major nutrients (DM, NDF, ADF, and CP) were measured through in vitro fermentation of rumen fluid from Hanwoo (Korean cattle). pH, ammonia-N concentration, volatile fatty acid (VFA) concentration, and gas production were periodically measured at 0, 3, 6, 12, 24, 48, and 72 h. Corn grain showed higher nutrient content and ED than stover. It also had higher gas production but its pH, ammonia-N, and total VFA concentration were lower than corn stover. The best nutrient composition of corn grain was observed in early-harvest (high CP, EE, NDF, OM, NFC, and low ADF). Early-harvest of corn grain also had high effective degradability of dry matter (EDDM), effective degradability of neutral detergent fiber (EDNDF), effective degradability of acid detergent fiber (EDADF), and total VFA concentration. On the other hand, the best nutrient composition of stover was observed in mid-harvest (high DM, CP, NDF, and low ADF). EDDM, EDNDF, and EDADF were pronounced in early-harvest and mid-harvest of stover but the latter showed high total VFA concentration. Hence, early and mid-harvested corn stover and grain in a mountainous area preserved their nutrients, which led to the effective degradation of major nutrients and high VFA production.

Keywords: Corn grain; Harvest; In vitro fermentation; Mountainous area; Stover.