Relationship between Neutral Detergent Fiber and In Vitro Digestibility in Test Crosses of Maize Hybrids

Resumen

fiber (NDF) and in vitro dry matter disappearance (IVDMD) of test crosses of maize.

Design/methodology/approach: Crosses of early, intermediate, and late maize lines (total=75) from high valleys and subtropical/tropical testers were sowed in three regions of Central-North Mexico. Male and female flowering days (MFD, FFD); days to harvest (Dcor); plant and cob length (PL, CL); forage, corn stover (CS), and cobs humid base (HB) and dry matter (DM) yields; and NDF, acid detergent fiber (ADF), hemicellulose (Hem), crude protein (CP), and IVDMD were analyzed.

Results: High valleys lines had more MFD, FFD, Dcor, and PL, therefore better forage, MS, and cob yields. More MDF, FFD, and H were related to better HB and DM yields, and CP content, but also were related to more NDF, ADF, and Hem proportions, and therefore to a less IVDMD (r=0.47 to 0.98); however, crosslines with high cob yields also had high CS yields (r=0.57-0.68). Regression linear models showed that one unit of NDF might reduce 0.49 to 56% the IVDMD (R²=0.59-0.78); additionally, NDF<68% was related to IVDMD>60% (R²=0.63-0.78).

Limitations on study/implications: ADF correlated negatively with IVDMD in early lines; NDF composition should also be related to its degradability (NDFD).

Findings/conclusions: Maize-breeding might be directed to obtain hybrids with less NDF CS contents to use them in ruminant diets, maintaining the cob yields for human nutrition and resistance to plant lodging.