Relationship of carbohydrates and lignin molecular structure spectral profiles to nutrient profile in newly developed oats cultivars and barley grain

Abstract

The objectives of this study were to quantify the chemical profile and the magnitude of differences in the oat and barley grain varieties developed by Crop Development Centre (CDC) in terms of Cornell Net Carbohydrate Protein System (CNCPS) carbohydrate sub-fractions: CA4 (sugars), CB1 (starch), CB2 (soluble fibre), CB3 (available neutral detergent fibre - NDF), and CC (unavailable carbohydrate); to estimate the energy values; to detect the lignin and carbohydrate (CHO) molecular structure profiles in CDC Nasser and CDC Seabiscuit oat and CDC Meredith barley grains by using Fourier transform infrared attenuated total reflectance (FTIR-ATR); to develop a model to predict nutrient supply based on CHO molecular profile. Results showed that NDF, ADF and CHO were greater (P<0.05) in oat than in barley. The starch content was greater (P<0.05) in barley than in oat. The CDC Meredith showed greater total rumen degradable carbohydrate (RDC), intestinal digestible fraction carbohydrate (FC) and lower total rumen undegradable carbohydrate (RUC). However, the estimated milk production did not differ for CDC Nasser oat and CDC Meredith barley. Lignin peak area and peak height did not differ (P>0.05) for oat and barley grains as well as non-structural CHO. However, cellulosic compounds peak area and height were greater (P<0.05) in oat than barley grains. Multiple regressions were determined to predict nutrient supply by using lignin and CHO molecular profiles. It was concluded that although there were some differences between oat and barley grains, CDC Nasser and CDC Meredith presented similarities related to chemical and molecular profiles, indicating that CDC Meredith barley could be replaced for CDC Nasser as ruminant feed. The FTIR was able to identify functional groups related to CHO molecular spectral in oat and barley grains and FTIR-ATR results could be used to predict nutrient supply in ruminant livestock systems.

Ruminal kinetics and degradability of energetic feedstuffs used in diets for ruminants

“…Characteristically, corn grains have a stronger protein matrix around starch granules than other cereals, which hinders the action of digestive enzymes and amylolytic bacteria, which interferes with ruminal degradability (6) . And ground oat have a higher proportion of hull compared to ground barley, so the DMD at 24 h and the NDFR were lower, corroborating literature data (12) , which also point to a lower digestible fraction for grain oat varieties compared to grain barley.…”

“…As for the NDF content, among these feedstuffs, the ground oat had the highest NDF content. Prates et al (12) evaluated two oat varieties, and found higher values of NDF and acid detergent fiber (ADF) in relation to barley grain. These differences in fiber content are due to the proportion of hull and grain between the cereals, with oats having a higher proportion of hulls.…”

“…These differences in fiber content are due to the proportion of hull and grain between the cereals, with oats having a higher proportion of hulls. The hull is formed by cellulose, hemicellulose, arabinoxylan, polyphenols and phytonutrients, and a higher proportion of hull generates a higher NDF content and, among whole grains, the proportion of hull is variable (20 to 30%) (12) .…”

Effects of silencing TT8 and HB12 on in vitro nutrients degradation and VFA production in relation to molecular structures of alfalfa (Medicago sativa)

“…This discrepancy could be attributed to ingredient types and spectral processing methods. Spectra were not normalized in the previous publication, which could result in the inclusion of variations from sample thickness during spectra collection . Another study conducted with barley and corn silage discovered a negative correlation between TCA and effective NDF degradation, which was not seen in our study, although TC4 height was negatively correlated with NDF degradation.…”

“…Spectra were not normalized in the previous publication, which could result in the inclusion of variations from sample thickness during spectra collection. 22,26 Another study conducted with barley and corn Structural parameters: TC1-TC4, four major peaks in TC region at ca. 1026 (TC1) 1074 (TC2), 1104 (TC3) and 1149 (TC4) cm −1 , respectively; TCA, TC peak area (ca.…”