Skip to main content
ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #145803
Title: IMPACT OF MATURATION ON CELL WALL DEGRADABILITY IN CORN STEM INTERNODES

Author
item Jung, Hans Joachim

Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 6/22/2003
Publication Date: 7/15/2003
Citation: Jung, H.G. 2003. Impact of maturation on cell wall degradability in corn stem internodes. Journal of Dairy Science. 86 (Supplement 1):288.

Interpretive Summary:

Technical Abstract: Degradability of forage cell wall (CW) material declines with maturity, but the causes have not been adequately described. Stem CW development and degradability were observed in three corn hybrids. The fourth above-ground internode was collected in 1998 and 1999 from a replicated field trial. Sampling began when the internode was 1-cm long and samples were collected 2, 4, 8, 12, 19, 26, 40, 68, and 96 d later. Internodes were analyzed for CW concentration and composition, and 24- and 96-h in vitro rumen degradability. While small differences were observed in CW development and degradability of the three hybrids, impact of maturity was much greater and all hybrids responded similarly to maturation. Internodes increased in length and diameter until 12 d after sampling began. CW concentration was 31% of OM in the first samples and did not change during the next 8 d. Subsequently, CW concentration increased until a maximum (73%) was reached 26 d after sampling began, later CW concentration declined (minimum of 55%) because of sucrose accumulation. CW glucose and xylose concentrations increased from 35 and 18% of CW, respectively, in the first sample to 52 and 24% of CW 12 d later. Klason lignin concentration declined from 11% of CW to 6% by 8 d after sampling had begun and then increased to 20% of CW by d 40. Degradability of CW polysaccharides was high and unchanged through d 4 (88 and 93% after 24 and 96 h, respectively), but declined steeply to 26 and 39% (24 and 96 h, respectively) by d 68. Cross-linking by ferulates of lignin and polysaccharides matched the start of the decline in CW degradability better than lignin concentration. These data indicate that the decline in CW degradability associated with maturation of grasses is a function of both lignin and ferulate cross-linking.