Basim Refat

Physiochemical Characteristics and Molecular Structures for Digestible Carbohydrates of Silages

The main objectives of this study were (1) to assess the magnitude of differences among new barley silage varieties (BS) selected for varying rates of in vitro neutral detergent fiber (NDF) digestibility (ivNDFD; Cowboy BS with higher ivNDFD, Copeland BS with intermediate ivNDFD, and Xena BS with lower ivNDFD) with regard to their carbohydrate (CHO) molecular makeup, CHO chemical fractions, and rumen degradability in dairy cows in comparison with a new corn silage hybrid (Pioneer 7213R) and (2) to quantify the strength and pattern of association between the molecular structures and digestibility of carbohydrates. The carbohydrate-related molecular structure spectral data was measured using advanced vibrational molecular spectroscopy (FT/IR). In comparison to BS, corn silage showed a significantly (P < 0.05) higher level of starch and energy content and higher degradation of dry matter (DM). Cowboy BS had lower feeding value (higher indigestible fiber content and lower starch content) and lower DM degradation in the rumen compared to other BS varieties (P < 0.05). The spectral intensities of carbohydrates were significantly (P < 0.05) correlated with digestible carbohydrate content of the silages. In conclusion, the univariate approach with only one-factor consideration (ivNDFD) might not be a satisfactory method for evaluating and ranking BS quality. FT/IR molecular spectroscopy can be used to evaluate silage quality rapidly, particularly the digestible fiber content.

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

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.

Detect molecular spectral features of newly developed Vicia faba varieties and protein metabolic characteristics in ruminant system using advanced synchrotron radiation based infrared microspectroscopy: A preliminary study

Recently, advanced synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-IMS) has been developed as a rapid, direct, non-destructive and bioanalytical technique. To date, there has been very little application of this technique to study the molecular structure make-up in pulse seeds. Thus, the objectives of this study were to detect the interactive association between protein molecular structure and nutrient availability of newly developed Vicia faba varieties. Two different varieties of faba beans (CDC Snowdrop = low-tannin variety; vs. FB9-4 = high-tannin variety) were selected for this study. The molecular spectra data were collected by using SR-IMS. The ratio of both amide I to II area and height were higher (P < 0.01), while the ratio of α-helix to β-sheet was lower (P < 0.05) in CDC Snowdrop compared to FB9-4. The crude protein (CP) content and the predicted truly digestible nutrients as well as the bioenergy values did not vary between two varieties. The CDC Snowdrop had exhibited a higher (P < 0.01) rapidly degradable CP fraction (75.99 vs. 71.45% on CP) and a lower (P < 0.01) moderately degradable CP fraction (19.43 vs. 22.85% on CP), resulting in a higher (P < 0.01) rumen degradable protein and a lower (P < 0.01) rumen undegradable protein content than that of FB9-4 variety. However, the total supply of digestible rumen undegraded feed protein was higher (P < 0.05) in FB9-4 than CDC Snowdrop. Strong positive correlations were found between the ratio of α-helix to β-sheet and CP contents (R = 0.86, P < 0.01) as well as the truly digestible CP contents (R = 0.83, P < 0.01); respectively. In conclusion, the results of this study reveal that the protein are metabolized differently between different type of faba bean varieties and the advanced SR-IMS molecular spectroscopy can be used to rapidly delineate protein molecular structure motifs along with their nutritive value in ruminant livestock system.

Effect of fibrolytic enzymes on lactational performance, feeding behavior, and digestibility in high-producing dairy cows fed a barley silage–based diet

The objectives of this study were to evaluate the effects of pretreating dairy cow rations with a fibrolytic enzyme derived from Trichoderma reesei (FETR; mixture of xylanase and cellulase; AB Vista, Wiltshire, UK) on lactation performance, digestibility, and feeding behavior in response to feeding a barley silage-based diet. Before starting the dairy trial, in vitro incubations were conducted to determine whether the addition of FETR would have an effect on these animal performance characteristics when applied to a barley silage-based diet for dairy cows. The dairy trial was performed using 8 Holstein dairy cows. The cows were blocked by parity and assigned randomly to 1 of 4 treatments: 0, 0.5, 0.75, and 1 mL of FETR/kg of dry matter (DM) diet in a replicated Latin square design. The pretreatment was applied to the complete diet during the mixing process. The experimental period continued for 22 d, with each experimental period consisting of a 16-d adaptation period and a 6-d sampling period. The daily feed intake of each individual cow was monitored using Insentec feed bins (RIC system, Insentec, Marknesse, the Netherlands). Feeding behavior characteristics were measured during the entire sampling period using the feed bin attendance data. Milk samples were collected in the last 3 d of each experimental period. The addition of FETR linearly increased the in vitro DM digestibility and tended to improve the in vitro digestibility of barley silage. There was a cubic effect of the enzyme levels on the total-tract DM and neutral detergent fiber digestibility. Maximal digestibility was reached at 0.75 mL of FETR/kg of TMR. The milk fat yield, fat-corrected milk, and energy-corrected milk quadratically responded to the incremental levels of FETR. The milk protein percentage linearly improved in response to FETR. Increasing FETR levels resulted in a quadratic effect on feed efficiency. There was no effect of FETR level on feeding behavior. In conclusion, pretreating dairy cow barley silage-based diet with 0.75 mL of FETR/kg of TMR increased the milk production efficiency of dairy cows fed diet containing 34% barley silage (DM basis). The positive effect of adding FETR could benefit the dairy industry in western Canada, where barley silage-based diets are common.

Connection of inherent structure with nutrient profiles and bioavailability of different co-products and by-products after processing using advanced grading and vibrational molecular spectroscopy

ABSTRACT This study aims to reveal connection and implication of molecular structure with nutrient profiles, utilization and bioavailability of both conventional and new co-products from bio-energy and bio-oil processing using grading and vibrational molecular spectroscopy with chemometics including univariate and multivariate techniques. The study focused on strategies to improve the utilization of the conventional and new co-products through chemical and heat processing treatments as well as the relationship of the molecular structural changes to nutrient bioavailability. The updated methods advanced molecular spectroscopy techniques with grading NIR, Globar FTIR, ATR-FTIR and Synchrotron SRFTIRM to study feed molecular structures were reviewed. This study provides an insight and a new approach on how to use grading and vibrational molecular spectroscopy to study molecular chemistry and molecular structure and molecular nutrition interaction.

Comparison of barley silages with varying digestible fiber content to corn silage on rumen fermentation characteristics and microbial protein synthesis using rumen simulation technique

Abstract: The objectives of this study were to assess the magnitude of differences among barley silages with different in vitro neutral detergent fiber digestibility (ivNDFD) in comparison with corn silage in (1) predicted carbohydrate digestibility, (2) rumen fermentation characteristics, and (3) microbial protein synthesis using rumen simulation technique (RUSITEC). The experiment was carried out in a completely randomized block design with four treatments. The four whole-plant silages utilized in this study were CS-TMR = corn silage (30 h ivNDFD = 32%), HNDFD-TMR = barley silage with high ivNDFD (30 h ivNDFD = 37%), INDFD-TMR = barley silage with intermediate ivNDFD (30 h ivNDFD = 28%), and LNDFD-TMR = barley silage with low ivNDFD (30 h ivNDFD = 26%). Results from RUSITEC showed that nutrient disappearance, rumen fermentation characteristics, and microbial protein synthesis did not differ among diets that contained different varieties of barley silage (P > 0.1). However, CS-TMR tended to have a higher microbial protein yield than all barley silage diets (P = 0.06). These results show higher ivNDFD of barley silage may not necessarily correspond with greater impact on rumen fermentation and microbial protein synthesis. However, feeding the corn silage had higher microbial protein synthesis in the RUSITEC and might enhance the dairy cattle performance compared with barley silage.