Buffer Soluble Nitrogen Research Articles

Optical chlorophyll measurements as predictors of total nitrogen, nitrogen fractions and in vitro ruminal nitrogen degradability in tropical grass forages

This study evaluated whether the FieldScout CM 1000 NDVI and Yara N–Tester models can produce accurate and reliable estimates of nitrogen (N), buffer-soluble nitrogen (BSN), buffer-insoluble nitrogen (BISN), non-protein nitrogen (NPN) and in vitro ruminal nitrogen degradability after 3, 12 and 24 h incubation (ND3, ND12 and ND24) in three tropical grasses: Brachiaria hybrid, Megathyrsus maximus and Paspalum atratum. Correlation between the Yara N-Tester and N, BISN and in vitro ruminal N degradability of the Brachiaria hybrid and M. maximus were high (r 0.67–0.83). The Yara N-Tester accounted for 81% and 86% (p 0.000) of N variability in the Brachiaria hybrid and M. maximus, respectively. The Yara N-Tester prediction models explained 72% and 70% (p 0.000) BISN variability in the Brachiaria hybrid and M. maximus, respectively. In vitro ND24 of the Brachiaria hybrid (R 2 0.75) and M. maximus (R 2 0.75) was also best predicted with the Yara N-Tester. Model validation showed generally low (≤0.90) concordance correlation coefficients except for Yara N-Tester N and ND24 in M. maximus. Random error was the main source of error. We conclude that the accuracy of the Yara N-Tester prediction models was superior to that of the FieldScout CM 1000 NDVI models, and that the Yara N-Tester can produce accurate and reliable estimates of Brachiaria hybrid and M. maximus N and M. maximus ND24.

The effect of ensiling in round bales on the content of nitrogen fractions in lucerne and red clover protein

The aim of the study was to determine changes in nitrogen fractions during the ensiling of lucerne and red clover herbage in bales. Protein nitrogen and non-protein nitrogen compounds in herbage and silage were distinguished. Furthermore, buffer soluble nitrogen compounds (BSN) were determined and divided into buffer soluble protein and non-protein nitrogen (BSPN and NPBSN, respectively). In addition, peptide nitrogen and amino acid nitrogen were distinguished within the NPBSN fraction, while nitrogen compounds were divided into those of low solubility (NDIN) and completely insoluble (ADIN). The research findings confirmed the effect of a legume plant species on changes in the content of nitrogen fractions during the ensiling in round bales. The ensiling of lucerne herbage grossly decreased the protein nitrogen fraction while raising the total soluble fraction of nitrogen. Nitrogen in the form of soluble proteins, NDIN and ADIN was the least affected. The study demonstrated a different response of the two legume plant species to ensiling with respect to all fractions. A high proportion of protein nitrogen in round bale wilted red clover silage was accompanied by a large contribution of insoluble nitrogen fractions. A large share of the protein nitrogen fraction in red clover silage does not necessarily mean a higher nutritional value of the protein because it may contain a large amount of protein compounds that are non-hydrolysable by bacterial and intestinal enzymes.

Nitrogen fractions and amino acid content in alfalfa and red clover immediately after cutting and after wilting in the field

The aim of this study was to determine the composition of nitrogen fractions in alfalfa and red clover, which differ in proteolytic activity, and to evaluate the effect of wilting on changes in nitrogen fractions in alfalfa and red clover herbage. Total nitrogen was divided into protein and non-protein nitrogen, and the amino acid profile of protein was analyzed. Buffer-soluble nitrogen (BSN), including buffer-soluble protein nitrogen (BSPN) and non-protein buffer-soluble nitrogen (NPBSN), was determined. The NPBSN fraction was further subdivided into peptide nitrogen, amino acid nitrogen, neutral detergent-insoluble nitrogen (NDIN) and acid detergent-insoluble nitrogen (ADIN). Wilting in the field to 40% dry matter content (the swath was tedded once) did not reduce the total nitrogen content of alfalfa and red clover herbage, although it affected the concentration of the BSNfraction, in particular NPBSN, and free amino acid nitrogen. During alfalfa wilting, the soluble protein content decreased and the concentrations of non-protein nitrogen compounds increased, mostly due to an increase in free amino acid nitrogen. A reverse trend was observed during red clover wilting – the concentrations of non-protein nitrogen compounds decreased and soluble protein content increased. A decrease was also noted in peptide nitrogen, NDIN and ADIN. Wilting of alfalfa and red clover had no adverse effect on the amino acid profile of protein. The concentrations of essential amino acids that limit milk protein synthesis, i.e. Lys, Met, His and Arg, did not decrease. Legume wilting in the field contributes to an increase in the concentrations of soluble nitrogen in the plant material intended for ensiling.

Nutritive evaluation of some native range plants and their nutritional and anti-nutritional components

Nutritive values of some native drought-tolerant range perennial shrubs (Artemisia herba-alba, Noaea mucronata, Lavandula officialis, Astragalus spinosus, Capparis spinosa) grown naturally on the south-eastern semi-desert of Syria were evaluated by determination of the in vitro digestible organic matter (IVDOM), metabolizable energy (ME) and net energy lactation (NEL) and the presence of nutritional and anti-nutritional components. The highest concentrations of crude protein and buffer soluble nitrogen (BS-N) were in C. spinosa (229 and 19 g/kg DM, respectively), whereas the lowest concentrations were in other experimental plant species (97–104 and 6–8 g/kg DM, respectively). A. herba-alba had high concentrations of total phenols (TP) and hydrolysable tannins (HT; 45 and 23 g/kg DM, respectively). The range plants had low concentrations of condensed tannins (0.4–1.1 g/kg DM). The IVDOM, ME and NEL values of the evaluated species amounted to 481–702 g/kg DM, 6.25–9.08 MJ/kg DM and 3.03–4.54 MJ/kg DM, respectively. The descending order (P <0.05) of the plant species on the basis of their content of IVDOM, ME and NEL was C. spinosa>A. spinosus>L. officialis>A. herba-alba>N. mucronata. The addition of polyethylene glycol (PEG, 6000) to the plant samples incubated with rumen fluid at a ratio of (2:1 PEG:substrate) did not increase the values of IVDOM, ME and NEL. IVDOM, ME and NEL were negatively correlated with crude fibre and cell wall constituents but positively correlated with crude protein and BS-N. The TP and HT concentrations were negatively correlated with BS-N, but positively correlated with lignin. On the basis of protein and energy, the evaluated species were nutritionally well suited as dietary supplements for ruminants in arid regions.

Comparative evaluation of Jatropha curcas L. seed meals obtained by different methods of defatting on toxic, antinutritional and nutritive factors.

Different methods of defatting have a great impact on toxic, antinutritional and nutritive factors in the oilseed meals. In order to find the most suitable methods of defatting for Jatropha curcas seed meals, the Jatropha curcas L. seed meals, defatted by Soxhlet extraction and screw-press were characterized for their toxic, anti-nutritional and nutrient factors in this study. The toxins (phorbolesters, 3.1 and 2.9mg/g) and some anti-nutritional factors (saponins, 2.9 and 2.6%; phytates, 11.1 and 11.6%) in meals obtained by the two defatting methods were present at high concentrations. However, the trypsin inhibitors activity (TIA) and lectin (2.7mg/g and 1.5mg/ml) in the screw-pressed meal were significantly lower, due to the high temperature (120°C) used in this defatting process. From nutritional side, the values of crude protein (CP), buffer-soluble nitrogen, non-protein nitrogen, pepsin insoluble nitrogen, in vitro protein digestibility (IVPD), as well as essential amino acid index (EAAI), biological value (BV), nutritional index (NI) and protein-digestibility-corrected amino acid score (PDCAAS) of the meal obtained by Soxhlet extraction were better than the screw-pressed meal. However, taking practical application into account, from detoxification side, screw-pressed meal is better for detoxification.

In vitro rumen fermentation kinetics and nutritional evaluation of Kochia indica as affected by harvest time and cutting regimen

Branches of Kochia indica were hand-cut after 60, 90 and 120 days of planting (DAP) at 15 or 30 cm distance from the tip (cutting length). The plants were at a vegetative stage for 60 and 90 DAP, while, for 120 DAP, they were at flowering stage. The nutritive value of the experimental plant samples was evaluated by determination of the crude protein (CP), buffer soluble nitrogen (BS-N), buffer soluble non-protein nitrogen (BS-NPN) and cell wall constituents (neutral-detergent fiber; aNDF, acid-detergent fiber; ADF and lignin (sa)). In vitro digestible organic matter (IVDOM), metabolizable energy (ME), microbial nitrogen (MN) and biomass (MBM) production were also estimated in the experimental samples after their incubation with rumen fluid for 96 h in the absence or presence of polyethylene glycol. The characteristics of fermentation (initial gas production; a, gas production during incubation; b, potential gas production; a + b, fractional rate of gas production; c) were assessed using an in vitro incubation technique with rumen fluid. There was a negative effect of harvest time on all the studied nutritive parameters and fermentation characteristics. The values of CP, BS-N, BS-NPN, MN and MBM declined and concentrations of aNDF, ADF and lignin (sa) increased between early harvest time after 60 DAP and late harvest time after 120 DAP and between cutting length at 15 cm and 30 cm ( P<0.05). IVDOM were positively correlated with BS-N and BS-NPN but negatively correlated with aNDF and ADF. Cutting treatments negatively affected all the studied nutritive parameters and fermentation rates. There were no differences in the values of IVDOM, ME, MN, MBM, fermentation characteristics and gas production over 96 h due to add of PEG ( P<0.05). The greatest proportion of gas production occurred between 6 and 24 h of incubation. C values were negatively correlated with cell wall constituents but positively correlated with CP, BS-N, BS-NPN, MN and MBM. The amount of MN produced from 100 mg substrate amounted to 1.9 or 1.4 mg at early maturity stage and 1.1 or 0.8 mg at late stage for cutting lengths performed at 15 or 30 cm, respectively. Microbial nitrogen and MBM production were negatively correlated with cell wall constituents and gas production but positively correlated with CP, BS-N and BS-NPN. Results revealed that, the harvested branches of K. indica at the vegetative stage were better in terms of nutritional value than those harvested at flowering stage.

An in vitro nutritive evaluation and rumen fermentation kinetics of Sesbania aculeate as affected by harvest time and cutting regimen

The nutritive value of Sesbania aculeate harvested after 60 and 120 days of planting and subjected to two cutting regimen (15 or 30 cm length) was evaluated by determination of the crude protein (CP), crude fibre (CF), buffer soluble nitrogen (BS-N), buffer soluble non-protein nitrogen (BS-NPN) and cell wall constituents (neutral-detergent fibre; NDF, acid-detergent fibre; ADF and lignin). In vitro digestible organic matter (IVDOM), metabolizable energy (ME), microbial nitrogen (MN) and biomass (MBM) production were also estimated in the experimental plant samples after their incubation with rumen fluid for 96 h in the absence or presence of polyethylene glycol (PEG, 6000) at a ratio of 2:1 PEG:substrate. Fermentation characteristics (initial gas production; a, gas production during incubation; b, potential gas production; a+b, fractional rate of gas production; c) were assessed using an in vitro incubation technique with rumen fluid. There was a significant (P < 0.05) effect of harvest time on all studied nutritive parameters and fermentation characteristics. The early harvest plant samples (after 60 days of planting) gave significantly higher values of IVOMD, ME, CP, BS-N, BS-NPN, MN, MBM and fractional rate of gas production and lower values of CF and cell wall constituents than the late harvest. Crude protein, BS-N, BS-NBN, IVOMD and ME were negatively correlated with CF and cell wall constituents. Metabolisable energy and IVOMD were positively correlated with CP, BS-N and BS-NPN. Cutting treatments significantly affected the CP, CF, BS-N, BS-NPN, NDF, ADF, IVDOM, ME, potential gas production and b values. There was no significant (P > 0.05) effect of added PEG on IVDOM, ME, MN, MBM, fermentation characteristics and gas production over 96 h. The greatest proportion of gas production occurred between 6 and 24 h of incubation. The fractional rate of gas production from 100 mg substrate was higher (0.046 mL/h) for the plant samples harvested at early stage and cut at 30 cm length than harvested at late stage (0.018 mL/h). C values were negatively correlated with lignin concentrations. The amount of MN and MBM produced from 100 mg substrate amounted to 1.29 mg and 14.95 mg at early maturity stage and 0.68 mg and 7.89 mg at late stage, respectively. Microbial nitrogen and MBM production were negatively correlated with CF, cell wall constituents and gas production but positively correlated with CP, BS-N and BS-NPN.

Nutritional and Anti-nutritional Components in Sesbania aculeata and Kochia indica at Different Harvest Times

Al-Masri, M.R. and Mrdini, M. 2008. Nutritional and anti-nutritional components in Sesbania aculeata and Kochia indica at different harvest times. J. Appl Anim. Res., 34: 33–37. Tannins level as total phenols (TP), condensed tannins (CT), hydrolysable tannins (HT), phytic acid (PA), cell-wall constituents [neutral-detergent fiber (NDF), acid-detergent fiber (ADF)], total nitrogen and nitrogen forms [buffer soluble nitrogen (BS-N) and non-protein nitrogen (BS-NPN)] were determined in leaves and stalks of Sesbania aculeate and Kochia indica harvested 60, 90, 120 and 150 days after planting. The NDF, ADF, TP and HT concentrations significantly increased and BS-N, BS-NPN and total nitrogen concentrations significantly decreased at the late harvest stage of both S. aculeate and K. indica. Phytic acid and CT concentrations significantly increased with age of S. aculeata. The CT concentrations in K. indica were notably low (0.05 g/kg DM) during the maturity stages. In both plant species, NDF and ADF concentrations were positively correlated with TP and HT but negatively correlated with BS-N, BS-NPN and total nitrogen. NDF and ADF concentrations were positively correlated with CT and PA for S. aculeate but negatively correlated with PA for K. indica. Harvested plants at early maturity stage after 90 days of planting were judged to be nutritionally better for ruminants.

Fermentability and degradability of sorghum grain following soaking, aerobic or anaerobic treatment

This study determined the effect of soaking (steeping), aerobic (germination) and anaerobic (reconstitution) treatments on the solubility of carbohydrate and nitrogen, and on the in vitro fermentability and in sacco degradability of dry matter (DM) of sorghum grain ( Sorghum bicolor cv Western Red). Samples of grain were dry rolled (DR, control), soaked (SK), stored anaerobically for 21 d (reconstitution, AS21), stored aerobically for 5 d (germination, G5) or stored aerobically for 5 d and then anaerobically for 16 d (G5AS16). Compared to the DR treatment, only G5AS16 treatment reduced ( P < 0.05) starch content by 2% units. Free sugar and buffer-soluble nitrogen contents were higher ( P < 0.05) in G5 and G5AS16 sorghum (21 and 54 g kg −1 DM; 241 and 375 g kg −1 total nitrogen, respectively) than in DR sorghum (8 g kg −1 DM; 142 g kg −1 total nitrogen, respectively). Free sugar and buffer-soluble nitrogen contents were similar ( P > 0.05) for SK, AS21 and DR control sorghum. Following a 5-h incubation in buffered rumen liquor, G5 and G5AS21 treatments increased ( P < 0.05) the in vitro fermentability of sorghum compared to the DR control treatment. This was indicated by increases in gas production (121–215%), volatile fatty acid (VFA) production (98.6–210%) and the amount of starch fermented (22–47%), following a 5-h incubation with buffered rumen liquor. In sacco degradability of DM in sorghum after 48 h of incubation was higher for G5 and G5AS16 (0.44 and 0.45, respectively) treatment than for DR, SK and AS21 treatments (0.39, 0.36 and 0.34, respectively). SK and AS21 treatments did not increase the degradability of sorghum compared to the DR treatment. It was concluded that the germination process occurring during aerobic treatment improved the fermentability and degradability of sorghum compared to other treatments investigated in this study.

Nutritive value of Sesbania aculeata grown on salty soil and its effect on reproductive parameters of Syrian Awassi ewes

Nutritive value of Sesbania aculeata hay was determined by estimating the nutritive components, nitrogen forms, in vitro digestible organic matter (IVDOM), and metabolisable energy (ME). A study was carried out to evaluate the effect of feeding 2 groups of Syrian Awassi ewes with 2 wheat straw-concentrate diets without (control) or with (experimental) added S. aculeata hay on some reproductive parameters of the ewes at different stages. Half of the wheat straw in the daily ration of the experimental group of ewes was replaced by S. aculeata hay (whole plant) grown on salty soil and irrigated by saline water. Daily metabolisable energy and crude protein consumed by the ewes in the 2 groups were the same during the different stages (2.5 months before mating, throughout pregnancy, and during lactation). Crude fibre and cell wall constituents’ values were lower, whereas the values of crude protein and crude ash were higher in leaves and pods than in stalks. The values of IVDOM in S. aculeata hay were 537, 380, and 626 g/kg DM, and of ME were 7.19, 5.43, and 8.58 MJ/kg DM for the whole plant, stalks, and leaves and pods, respectively. The values of buffer soluble nitrogen were 27% or 39% and of buffer soluble non-protein nitrogen were 21% or 35% of the total nitrogen in leaves and pods or stalks, respectively. Feeding with S. aculeata hay had no effects on the liveweight of the ewes during the periods before mating and throughout pregnancy, on mating rate, fertility rate, duration of pregnancy, birth weight, or weaning weight of lambs. Furthermore, feeding with sesbania hay had no effect on either the response of ewes to the oestrous synchronisation programme or on the blood serum concentration and pattern of progesterone during the period extending from the commencement of feeding the ewes sesbania hay (2.5 months before mating) until the time of their lambing.

Effect of sodium metabisulphite on proteolysis and rumen degradability of alfalfa silage protein

First cut alfalfa without (16% dry matter (DM)) or after 24 h wilting (28% DM) was ensiled with formic acid (FA) (0.4%) or sodium metabisulphite (SM) (0.5%). The pH tended to be lower for the FA and SM silages compared with the control. At both DMs the control silages had higher ammonia content compared with the experimental silages. At 16% DM the SM treatment resulted in reduction of the ammonia concentration in an extent similar to the FA. The SM silages had higher buffer soluble nitrogen, α-amino nitrogen and lower insoluble trichloroacetic acid nitrogen content than the control and FA silages. The extent of in vitro rumen degradability of the silage protein did not differ significantly between the treatments. A trend for higher degradability of the SM treated silages was observed. In sacco the protein of the SM silages after 48 h rumen incubation was more degradable compared with the control (84.42% and 78.12% at P = 0.005 for 16% DM and 81.82% and 78.72% at P = 0.004 for 28% DM, respectively). The degradability of the FA silage protein was slightly higher compared with the control but the differences were not significant. The effect of the wilting on the silage protein degradability, observed by 24 h tended to disappear by 48 h of rumen incubation. It is concluded that the SM increased alfalfa protein degradability in the rumen.

Effect of a commercial enzyme preparation on alfalfa silage fermentation and protein degradability

A commercial enzyme preparation (trade name Clampzyme) containing cellulases, hemicellulases and glucose oxidases was tested for ensiling of alfalfa at three dry matter levels, 16% and 22% unwilted and 28% wilted, in comparison with untreated control and formic acid treated silages. On average the enzyme-treated silages hd a lower pH (by 14.6% at P = 0.000), lower crude fibre content (by 16.0% at P = 0.000) and ammonia concentration (by 20.3% at P = 0.017), and higher water-soluble carbohydrates (by 115% at P = 0.000) and crude protein (by 11.8% at P = 0.006) contein preservation, increasing the control. The enzyme treatment had an undesirable effect on the silage protein preservation, increasing the buffer soluble nitrogen (by 16.9% at P = 0.014) and the free amino acid nitrogen (by 25.5% at P = 0.007) content compared with the untreated control. The enzyme-treated silages tended to have lower trichloroacetic acid insoluble nitrogen (by 7.8% at P = 0.080) than the control. The degradability of the silage protein in vitro (4-h incubation) was higher (by 28.0% at P = 0.006) for the enzyme-treated silages compared with the control. The same trend was observed in sacco where the difference over the control silages decreased from 11.9% ( P = 0.001) at the 1 h to 8.2% ( P = 0.001) at 24 and 4.3% ( P = 0.001) at 48 h of rumen incubation. In these experiments no protective effect of the formic acid on silage protein degradability in vitro or in sacco was observed. In conclusion, the enzyme treatment had a positive effect on alfalfa silage fermentation, in particular on reducing the crude fibre content and preserving the soluble sugars. An increase in rumen degradability of the silage protein in vitro and in sacco was observed with the rapidly degradable fraction of the protein being the most affected.