Agronomic Factors in Evaluating Forage Crops II. Predicting Fiber Components (NDF, ADF, ADL) from Crop Leafiness

Abstract

The relationship of the stage‐to‐stage changes in alfalfa herbage leaf percentage and the corresponding changes in fiber components represented by neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) was tested in alfalfa crop diverse in stand and canopy ages, stages of maturity harvested across seasons in two separate years. Regression analyses showed that for all fiber components, leaf percentage consistently provided highly significant linear relationships for predicting herbage fiber content; NDF (r2= 0.915), ADF (r2= 0.937) and, ADL (r2= 0.851). These were highly comparable with the application of the mean stage by weight (MSW) system for predicting NDF (r2= 0.946), ADF (r2= 0.891) and ADL (r2= 0.841) thus indicating the practical use of leaf percentage as a good alternative approach for predicting fiber content of the alfalfa crop.

Canopy Visible and Near‐infrared Reflectance Data to Estimate Alfalfa Nutritive Attributes Before Harvest

“…Thus, a number of researchers have investigated more simple, less time‐consuming, and more cost‐effective in‐field, pre‐harvest approaches to assess alfalfa quality. These approaches include mathematical models based on weather variables (Hakl et al, 2010), plant morphology (Hall et al, 2000), leafiness (Kalu et al, 1989), and stage of development of representative plants (Sulc et al, 1997). Predictive equations for alfalfa quality (PEAQ) relate the length of the longest stem and maturity stage of the most mature stem from a given alfalfa plant to both ADF and NDF (Hintz and Albrecht, 1991; Sulc et al, 1997; Parsons et al, 2006; Hakl et al, 2010; Santillano‐Cazares et al, 2014).…”

Using botanical resources to select wild forage legumes for domestication in temperate grassland agricultural systems

“…Leaf area can be an important trait when selecting wild forage species for use in production, as the leaf:stem ratio of forages can be indicative of their quality. Plants with higher leaf:stem ratios at harvest are generally higher in crude protein and digestibility and lower in NDF (Terry and Tilley 1964;Kalu et al 1988Kalu et al , 1990. Even with a high leaf:stem ratio, it is unlikely that any of the selected wild species would have a forage quality or yield that could compete with red clover.…”

Growth, development, and composition of temperate forage legumes and grasses in varying environments

“…Maturity of plants is a common denominator describing the decline in leaves relative to shoots even when interactions of environmental factors take place (Brignall et al, 1989;Marten, 1970;Deinum et al, 1981;Kilcher and Heinrichs, 1974). The decline in leaf growth relative to stem growth has been attributed to leaf loss and senescence (Kalu et al, 1990). Input time of environmental factors, however, may affect leaf and shoot production in a way that is unrelated to maturity of plants.…”

“…Deinum et al (1981) reported that digestibility of organic matter declined faster at higher latitudes because stem development proceeded faster and because less leaf dry matter was produced. Thus, the leaf:stem ratio decreases with increase in latitude and because leaves have lower digestibility than stems, total herbage digestibility also declines (Brignall et al, 1989;Kalu et al, 1990;Marten, 1970). In contrast, Deinum et al (1981) reported that increased stem development at higher latitudes might not have much effect on digestibility because the more rapid development at northern latitudes does not have a negative effect on forage quality.…”