Near Infrared Reflectance Spectroscopy Prediction and Heritability of Neutral Detergent‐Soluble Fiber in Alfalfa

Abstract

crude protein, and low fiber concentrations are the results of 20 yr of research in breeding alfalfa for higher Increasing neutral detergent-soluble fiber (NDSF) concentration forage quality and consequently higher digestibility. Inhas been considered a strategy for breeding alfalfa (Medicago sativa L.) with improved quality. Pectin is the main component of NDSF creasing digestibility by increasing pectin concentration and is highly digestible, but the assay for NDSF is time-consuming. has been considered a new strategy for breeding alfalfaThe objectives were (i) to determine the potential use of near infrared with superior quality characteristics (Hatfield, 1996; reflectance spectroscopy (NIRS) to predict NDSF concentration in Van Soest, 1995;Viands, 1995a Viands, , 1995b. Pectin is the alfalfa and (ii) to estimate NDSF heritability and gain from selection. predominant component of NDSF in alfalfa (Hall et al., Herbage was sampled five times across 2 yr from two populations of 1997; Van Soest et al., 1991). Neutral detergent-soluble half-sib (HS) progeny tested at Ithaca, NY. Calibration equations fiber refers to the portion of the forage soluble in neutral were developed by multiple linear regression of laboratory values of detergent solution and resistant to mammalian enzymes, NDSF on NIRS spectra. Samples from one harvest were assayed twice and contains the pectin, ␤-glucan, and fructan fiberto compare extraction methods. Means of NDSF from 90-and 80%fractions (Van Soest et al., 1991). A high NDSF concenethanol extractions were 213.1 Ϯ 7.21 and 179.5 Ϯ 5.89 g kg Ϫ1 , respectively. Assay standard deviations were low for both ethanol concentra-tration in alfalfa forage is desirable because: (i) alfalfa tions. Because a better calibration equation was obtained with the pectin is rapidly and completely fermented by rumen 80%-ethanol assay, all remaining samples were assayed by that techmicroorganisms, providing a better utilization of the nique. Standard errors of calibration were small, ranging from 4.71high protein levels in current cultivars; (ii) pectin ferto 7.54 g kg Ϫ1 . Coefficients of multiple determination (R 2 ) ranged from mentation does not decrease the ruminal pH, often asso-0.72 to 0.97. Most heritability estimates for NDSF were significantly ciated with animal acidosis; and (iii) pectin is not subject greater than zero, ranging from Ϫ0.03 Ϯ 0.20 to 0.56 Ϯ 0.17 and standard error of calibration; SEL, standard error of laboratory deter-

Near Infrared Spectroscopy: fundamentals, practical aspects and analytical applications

“…Perhaps this was a consequence of the great international impact this sector experimented as a result of the unique non-destructive and non-invasive approach to analysis of agricultural and food products when using NIR technology. Other publications, in the last four years, reveal other applications in the agricultural area [86][87][88][89][90]98,[102][103][104][105] with papers on zootechnology, [86][87][88][89] eucalyptus pulp analysis, 90 and organic matter determination 102,103 and nitrogen content determination 105 in soils. Many of these papers show advancements in data analysis and information extraction, improving the Chemometrics employed for NIR calibration.…”

<b>Repeatability, number of harvests, and phenotypic stability of dry matter yield and quality traits of Panicum maximum jacq.

“…High quality forage has been obtained by raising the leaf/stem ratio, crude protein, water soluble carbohydrates, dry matter digestibility, lower content of components of neutral detergent fiber as well as higher detergent neutral soluble fiber, such as pectin (Van Soest, 1994, Fonseca, Hansen, Thomas, Pell, & Viands, 1999, Casler et al 2000. To our best knowledge, no information is available on repeatability estimates of quality traits for P. maximum.…”

Divergent phenotypic selection for alfalfa cell wall fractions and indirect response in digestibility

“…For example, selection was effective for reduced NDF in reed canarygrass (Phalaris arundinaceae L.) (Surprenant et al 1988), smooth bromegrass (Bromus inermis L.) (Han et al 2001;Casler 1999Casler , 2002, and timothy (Phleum pratense L.) (Claessens et al 2004(Claessens et al , 2005. Furthermore, selection was successful for increased neutral detergent soluble fiber (NDSF) or pectin (Fonseca et al 1999;Tecle et al 2006), reduced ADF (Coors et al 1986) and lignin in alfalfa (Kephart et al 1990), reduced ADF, CEL, HEM, and LIG in smooth bromegrass (Carpenter and Casler 1990), reduced ADF, LIG and CEL, and reduced ratios of LIG to CEL, LIG to HEM, LIG to HEM'CEL, and increased ratio of HEM to CEL in timothy (Claessens et al 2004(Claessens et al , 2005. Generally, in all these studies phenotypic selection for increased NDSF, or reduced NDF, ADF, and LIG lignin concentrations resulted in improved forage digestibility.…”