Effect of the brown midrib trait and stage of development at harvest on cell wall composition and degradability of forage pearl millet leaves and stems

Abstract

P. 2007. Effect of the brown midrib trait and stage of development at harvest on cell wall composition and degradability of forage pearl millet leaves and stems. Can. J. Anim. Sci. 87: 421-429. This study was conducted to determine the effect of the brown midrib trait and stage of development [vegetative (VS) vs. heading (HS) stage] on chemical composition and in situ rumen disappearance of forage millet leaves and stems. Forage yield of brown midrib millet was 80 and 50% of that of regular millet at VS and HS, respectively. The reduction in brown midrib millet yield was mainly due to reduction in plant height and tillers m -2 . The brown midrib trait reduced concentrations of neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) in stems by 8, 16, and 58%, respectively, and concentrations of ADF and ADL in leaves by 6 and 49%, respectively. Effects of stage of development on fiber fractions were more pronounced in stems than in leaves. Millet stems harvested at HS had greater concentration of NDF, ADF and ADL than at VS, while only ADL concentration in millet leaves increased with advancing development. Leaves and stems of brown midrib millet (BM) contained more arabinose and xylose than those of regular millet (RM), while glucose concentration was not affected by millet type. Concentrations of xylose and arabinose were higher in leaves, while those of glucose and arabinose were higher in stems of millet harvested at HS than at VS. The brown midrib trait reduced concentrations of ester-linked p-coumaric acid and ether-linked p-coumaric and ferulic acids in both leaves and stems. However, concentration of ester-linked ferulic acid was only reduced in stems. Concentrations of all phenolic acids were higher in stems of millet harvested at HS than at VS. However, the effects of stage of development for most phenolic acids were more pronounced for stems of RM than BM. In situ DM and NDF disappearances were higher in leaves and stems of BM than RM and were higher in leaves and stems of millet harvested at VS than at HS. The brown midrib trait reduced the negative impact of increasing maturity on in situ DM and NDF disappearance in leaves and in situ DM disappearance in stems. It was concluded that the brown midrib trait caused significant changes in cell wall composition of both leaf and stem fractions which resulted in improved in situ nutrient disappearances. The trait also reduced the negative effect of advanced maturity on nutrient digestibility. Toutefois, l'incidence du stade de développement sur la majorité des acides phénoliques est plus prononcée dans la tige du MNB que dans celle du MO. La disparition in situ de la matière sèche et des FDN est plus importante pour les feuilles et les tiges du MNB que du MO; elle est aussi plus évidente dans les feuilles et les tiges du millet récolté au stade végétatif que dans celles du millet récolté à l'épiaison. Le caractère de la nervure brune atténue l'incidence négative d'une plus grande maturité sur la dispari- 4213 To whom corre...

Yield, Nutritional Composition, and Digestibility of Conventional and Brown Midrib (BMR) Pearl Millet as Affected by Planting and Harvesting Dates and Interseeded Cowpea

“…As plants mature, there is a concomitant increase in biomass yield and a reduction in fiber digestibility due to the increase in cross-linkages between lignin with other cell wall components [7]. Although both management tools are frequently used by farmers to maximize both yield and quality, few studies [8,9] have been conducted to compare the impact of planting date and maturity stage at harvest between conventional and BMR pearl millet genotypes.…”

Inheritance and allelism of brown midrib trait introgressed in agronomically promising backgrounds in pearl millet (Pennisetum glaucum (L.) R. Br.)

“…In the materials under investigations in this study, the bmr linked important positive (IVOMD) and negative (ADL) forage quality traits ranged from 43.5 to 54.35%, and 3.15 to 5.05%, respectively, across the three cuts (Table 1). The mean values for ADL were lower and the mean values for IVOMD were higher in the bmr inbreds under investigation than those earlier reported that had normal midrib forage inbreds in pearl millet (Cherney et al 1990;Mustafa et al 2004;Hassanat et al 2006). Additionally, the forage quality trait crude protein (CP) varied 8.50 to 15.21% across the three cuts in the inbreds.…”

“…It has been reported that the bmr mutant lines are highly digestible than normal midrib lines since it has reduced lignin content levels in pearl millet (Cherney et al 1988(Cherney et al , 1990Gupta et al 1993). On the other hand, the bmr mutant phenotype was found to be negatively associated with the forage yield in pearl millet (Hassanat et al 2006) and sudangrass (Casler et al 2003). With the available bmr sources in pearl millet, bmr cultivars/hybrids have been extensively developed and utilised in countries like Canada (Hassanat et al 2006) and the USA (Machicek et al 2019;Ferreira et al 2022).…”

“…On the other hand, the bmr mutant phenotype was found to be negatively associated with the forage yield in pearl millet (Hassanat et al 2006) and sudangrass (Casler et al 2003). With the available bmr sources in pearl millet, bmr cultivars/hybrids have been extensively developed and utilised in countries like Canada (Hassanat et al 2006) and the USA (Machicek et al 2019;Ferreira et al 2022).…”

Performance, agronomic traits, ensilability and nutritive value of pearl millet cultivar harvested at different growth stages

“…Hassanat et al . (2007) reported that IVDMD of pearl millet stover decreased with the increasing plant maturity and was highly correlated with ADF and lignin contents. Although the reduction in IVDMD was associated with the increase in lignin concentrations in the current study, it was found that plant maturity did not affect NDF concentrations despite the linear decrease observed for ADF.…”