Fresh Grass Research Articles

Fatty acid profile of the milk of cows reared in the mountain region of Poland

An appropriate composition of milk fatty acids (FA) improves the nutritional value of milk and milk products, and improves milk processing. Polish dairy farms in the mountainous region are rather small, animal nutrition there is based on locally produced forages and this, together with the transitional climate zone brings about seasonal changes in FA composition of milk. The aim of the study was to evaluate the composition of FA in bovine milk fat in relation to fat intake in forages and their FA profiles. The study involved 5 herds reared in low-input mountain farms located at an altitude of 670-780 m above sea level (Beskid Mountains). The cows were fed forages produced locally. FAs in forages and milk samples were subjected to gas chromatography. Highest fat intake observed in grazing season (4·2-4·7%) and high amounts of polyunsaturated FA in forages from that period (51·8-64·1 g/100 g FA) resulted in a markedly high content of valuable FAs: t-11 C18:1 (3·22 g/100 g FA), c-9, t-11 C18:2 (CLA; 1·20 g/100 g FA) in milk. Lower fat intake of forages containing high amount of SFA (32·42-38·83 g/100 g FA) in the indoor period resulted in changes in milk composition. The content of total short-chain saturated FA (SCFA) was highest in winter and early spring samples (14·10 and 13·44 g/100 g FA, respectively), like the amounts of myristic C14:0 and palmitic C16:0 acids (11·80 and 37·92 g/100 g FA). Total odd- and branched-chain fatty acids (OBCFA; 6·58 g/100 g FA) content was highest at the beginning of the grazing period. Fresh grass consumed by cows promoted the activity of Δ(9)-desaturase in mammary gland as evidenced by higher C14:1 : C14:0 (0·054) and C16:1 : C16:0 (0·026) ratios in grazing than in the indoor periods.

Oats (Avena strigosa) as winter forage for dairy cows in Vietnam: an on-farm study

In North Vietnam, during winter, alternative forage resources are needed to balance the feed ration of dairy cows. The objective of this study was to investigate the effect of oat forage as a component of traditional winter roughage diets on feed intake, milk production and feeding cost in dairy cows. The study was conducted on-farm using 24 mid-lactation Holstein-Friesian cows. The feeding experiment consisted of two successive periods and two dietary treatments per period. Traditional basal diets included fresh tropical grasses, maize silage and hay. The oat forage had no effect on the dry matter intake of the basal diet, but the total crude protein intake was higher in cows fed with oat diets than in those fed with control diets. The yield of butterfat-corrected milk (FCM) was not significantly different between diets during period 1, but there was a trend (P = 0.078) of higher FCM yields in cows fed with the oat diet compared to those with control diet during period 2 (17.3 vs. 16.3 kg/day). The decline rate in milk yield was significantly higher (P < 0.001) in cows fed with control diets than in those fed with oat diets in both experimental periods. The total feeding cost of cows fed with oat diets was on average 12 % lower than those fed with control diets (P < 0.01). So, the oat forage is an important winter resource for cows in North Vietnam allowing higher milk yield whilst reducing feeding cost, compared to traditional roughage diets.

Ruminal fermentation response and nitrogen retention from sheep fed rumen undegradable protein

The utilization of rumen undegradable protein, could increase supply of amino acids in small intestine to meet host protein requirement. To increase the utilization of feed protein, feed protein source which is highly degradable should be protected from degradation in the rumen. The objective of the study was to increase nitrogen retention through substitution of fish meal protein with soy bean meal protected by banana stem juice observed from rumen fermentation activities. The study used 18 late pregnant Sumatera Composite breed ewes. Rations consisted of fresh chopped elephant grass, supplemented with a commercial concentrate and mineral block in the form of Comin plus and different types of protein supplement as treatment diets. The type of protein supplements were: soya bean meal (RK), soy bean meal protected with banana stem juice (RKT) and fish meal (RTI). Treatment diets were offered during late pregnancy (from two months before to two months after partus), two weeks adaptation period was carried out before data recording. Design of the study used randomized complete block design. Results of the study show that rumen ammonia concentration in sheep fed on RKT was not significantly different either from RTI or from RK, however, the nitrogen retention was significantly (P 0.05), however, proportion of C2 and nC4 was significantly different between diet treatment. Methane emission was higher (70.3 mM or 37.2% higher from total energy VFA) in diet RKT which is indicated that fermentation system was not efficient. It can be concluded the higher rumen ammonia concentration and lower nitrogen retention in protected soy bean meal supplement indicated that soy bean meal protected by banana stem juice in the ration was not able to substitute fish meal protein which is resistance from degradation in the rumen. Key W ords : Sheep, Rumen Fermentation, Rumen Undegradable Protein

Preparation and characteristic odour of optically active 3‐hydroxy‐2‐octanone

ABSTRACTThe preparation of optically active 3‐hydroxy‐2‐octanone was examined by Sharpless asymmetric dihydroxylation of a silyl enol ether derived from 2‐octanone. (R)‐3‐Hydroxy‐2‐octanone was obtained in 68% yield and 87.8% ee when AD‐mix‐β was used as an oxidant, while the (S)‐enantiomer was produced in 69% yield and 77.3% ee from AD‐mix‐α. The characteristic odour of the optically active products was evaluated by chiral gas chromatography–olfactometry. (R)‐3‐Hydroxy‐2‐octanone has a mushroom‐like, fresh grass odour, while the (S)‐enantiomer presents a mushroom‐like, earthy note. Aroma extract dilution analysis was applied to determine the flavour dilution factors of the two enantiomers. The flavour dilution factor of the (R)‐enantiomer was 1024, which is much higher than that of (S)‐enantiomer (256). They obviously differ in odour intensity. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Changes in goat milk fatty acids during abrupt transition from indoor to pasture diet

Goal of this study was to evaluate the kinetics of goat milk fatty acids during abrupt transition from indoor to pasture-based diets. Twelve Valdostana goats in mid-lactation reared indoors and fed hay and concentrates for 40days were abruptly brought outdoors on natural pasture and fed fresh grass ad libitum. Feed samples and individual milk samples were collected for fatty acids analysis on the last day of indoor feeding (day 0) and after 1, 2, 3, 4, 6, 9, 13, 18 and 23days of fresh grass feeding. Milk fatty acid composition was significantly affected by sampling day. Significant changes already took place few days after transition. The most marked and consistent variations occurred at the expense of some unsaturated fatty acids. Total trans-octadecenoic and trans-octadecadienoic acids, conjugated linoleic acids (CLA) and omega-3 fatty acids constantly increased, reaching concentrations 4.0, 3.0, 3.9, and 2.2 times higher at the end of the trial than at its beginning, respectively. On the last sampling day the omega-6/omega-3 fatty acids ratio was two times lower than its initial value. Considering individual fatty acids, the most consistent and remarkable increasing trends throughout the trial were observed for C18:1 t6–11, C18:1 t12–14+c6–8, C18:1 c14+t16, C18:2 t11c15, C18:2 c9t13+t8c12, CLA isomers c9t11+t7c9+t8c10 and t11c13+c9c11. Alpha-linolenic and eicosapentaenoic acids also increased significantly, but to a lesser extent. In view of the many beneficial biological effects that have been attributed to vaccenic acid (C18:1 t11), rumenic acid (C18:2 c9t11), and omega-3 fatty acids, results showed that, from a human health perspective, goat milk fatty acid composition consistently improved after transition from indoor to pasture feeding. Such improvements, mainly due to the high content of α-linolenic acid in pasture plants, were already significant after two or three days of fresh grass feeding. Further increases of beneficial fatty acids in milk fat were observed till about thirteen (vaccenic acid and CLA) or twenty-three (omega-3 fatty acids) days after transition. These results show that pasture can be considered a natural feeding strategy to quickly enhance the healthfulness of goat milk fat.

Earlier spring staging in Iceland amongst Greenland White-fronted Geese Anser albifrons flavirostris achieved without cost to refuelling rates

Greenland White-fronted Geese wintering in Ireland and Britain stage for 3 weeks in Iceland in spring before migrating onwards to breeding areas in west Greenland. The geese now depart their wintering quarters 12–15 days earlier than in 1973 because they attain necessary fat stores earlier than in previous years. Icelandic temperatures at critical midway staging areas have shown no significant change since 1973, creating a potential mismatch in food availability along the migratory route. Greenland White-fronted Geese have shifted from consuming below-ground plant storage organs in Iceland in spring to grazing managed hayfields created since the 1950s where fresh grass shoot growth occurs despite sub-zero temperatures, when traditional natural foods are physically inaccessible to staging geese due to frozen substrates. Rates of fat accumulation (measured by field scores of abdominal profiles) and mass change (measured in captured geese) were the same in the springs of 1997, 1998 and 1999 as in that of 2007 when the migration episode was 10 days earlier. Hence, earlier arrival in Iceland in 2007 did not occur at cost to refuelling rates there. The shift to acquiring energy from artificial grasslands has enabled Greenland White-fronted Geese to arrive in Iceland earlier, but has apparently not impaired their ability to accumulate fat reserves required for onwards migration, which occurs at the same rate, only earlier in the spring.

Spectral phasor analysis allows rapid and reliable unmixing of fluorescence microscopy spectral images

A new global analysis algorithm to analyse (hyper-) spectral images is presented. It is based on the phasor representation that has been demonstrated to be very powerful for the analysis of lifetime imaging data. In spectral phasor analysis the fluorescence spectrum of each pixel in the image is Fourier transformed. Next, the real and imaginary components of the first harmonic of the transform are employed as X and Y coordinates in a scatter (spectral phasor) plot. Importantly, the spectral phasor representation allows for rapid (real time) semi-blind spectral unmixing of up to three components in the image. This is demonstrated on slides with fixed cells containing three fluorescent labels. In addition the method is used to analyse autofluorescence of cells in a fresh grass blade. It is shown that the spectral phasor approach is compatible with spectral imaging data recorded with a low number of spectral channels.

Comparison of in vitro and in situ methods in evaluation of forage digestibility in ruminants1

The objective of this study was to compare the application of different in vitro and in situ methods in empirical and mechanistic predictions of in vivo OM digestibility (OMD) and their associations to near-infrared reflectance spectroscopy spectra for a variety of forages. Apparent in vivo OMD of silages made from alfalfa (n = 2), corn (n = 9), corn stover (n = 2), grass (n = 11), whole crops of wheat and barley (n = 8) and red clover (n = 7), and fresh alfalfa (n = 1), grass hays (n = 5), and wheat straws (n = 5) had previously been determined in sheep. Concentrations of indigestible NDF (iNDF) in all forage samples were determined by a 288-h ruminal in situ incubation. Gas production of isolated forage NDF was measured by in vitro incubations for 72 h. In vitro pepsin-cellulase OM solubility (OMS) of the forages was determined by a 2-step gravimetric digestion method. Samples were also subjected to a 2-step determination of in vitro OMD based on buffered rumen fluid and pepsin. Further, rumen fluid digestible OM was determined from a single 96-h incubation at 38°C. Digestibility of OM from the in situ and the in vitro incubations was calculated according to published empirical equations, which were either forage specific or general (1 equation for all forages) within method. Indigestible NDF was also used in a mechanistic model to predict OMD. Predictions of OMD were evaluated by residual analysis using the GLM procedure in SAS. In vitro OMS in a general prediction equation of OMD did not display a significant forage-type effect on the residuals (observed - predicted OMD; P = 0.10). Predictions of OMD within forage types were consistent between iNDF and the 2-step in vitro method based on rumen fluid. Root mean square error of OMD was least (0.032) when the prediction was based on a general forage equation of OMS. However, regenerating a simple regression for iNDF by omitting alfalfa and wheat straw reduced the root mean square error of OMD to 0.025. Indigestible NDF in a general forage equation predicted OMD without any bias (P ≥ 0.16), and root mean square error of prediction was smallest among all methods when alfalfa and wheat straw samples were excluded. Our study suggests that compared with the in vitro laboratory methods, iNDF used in forage-specific equations will improve overall predictions of forage in vivo OMD. The in vitro and in situ methods performed equally well in calibrations of iNDF or OMD by near-infrared reflectance spectroscopy.

A comparison between urban livestock production strategies in Burkina Faso, Mali and Nigeria in West Africa

We undertook a comparative analysis of (peri-)urban livestock production strategies across three West African cities. Using a semi-structured questionnaire, livestock-keeping households (HH) were interviewed in Kano/Nigeria (84 HH), Bobo Dioulasso/Burkina Faso (63 HH) and Sikasso/Mali (63 HH). Questions covered livestock species kept, herd sizes and structure, feeds used, manure management, livestock marketing and production constraints. Sheep and goats dominated (p < 0.001) in Kano (76 and 75 % of HH) compared to Bobo Dioulasso (48 and 40 %) and Sikasso (28 and 40 %), while cattle and poultry were more frequent (p < 0.001) in Bobo Dioulasso (82 and 69 % of HH) and Sikasso (65 and 79 %) than in Kano (29 and 20 %). Across cities, ruminant feeding relied on grazing and homestead supplementation with fresh grasses, crop residues, cereal brans and cottonseed cake; cereal grains and brans were major ingredients of poultry feeds. Cattle and sheep fetched highest prices in Kano, unit prices for goats and chicken were highest in Sikasso. Across cities there was little association of gardens and livestock, whereas field cropping and livestock were integrated. There was no relation between the education of the HH head and the adoption of improved management practices (p > 0.05), but the proportion of HH heads with a long-term experience in UPA activities was higher in Kano and in Bobo Dioulasso than in Sikasso (p < 0.001). We therefore postulate that the high illiteracy rate among (peri-)urban livestock keepers in West Africa does not threaten the acceptance of improved technologies and innovations supporting the sustainability of their livestock production.

Study of grass carp (Ctenopharyngodon idellus) quality predictive model based on electronic nose

An electronic nose based quality predictive model of grass carp (Ctenopharyngodon idellus) stored at 277K temperature was proposed in this paper. The changes of sensor array response to samples were caused by the new-generated gas species released by microbial propagations. Principal component analysis method discriminated fresh grass carp samples from medium samples and aged samples. Stochastic resonance signal-to-noise ratio maximums distinguished fresh, medium, and aged grass carp samples successfully. The quality predicting model was developed based on signal-to-noise ratio maximums non-linear fitting regression. Validating experiments demonstrated that the predicting accuracy of this model was 87.5%. This method presented some advantages including easy operation, quick response, high accuracy, good repeatability, etc. This method is promising in aquatic food products quality evaluating applications.

Sweet wines with great aromatic complexity obtained by partial fermentation of must from Tempranillo dried grapes

Musts from Tempranillo grapes sun-dried in the Montilla-Moriles region and containing about 450 g sugar/L were treated in four different ways to obtain sweet wine. One treatment mimicked the traditional procedure and involved supplying the must with wine alcohol to avoid the fermentation. The other treatments involved partial fermentation with the autochthonous flora or with two previously selected osmotolerant yeasts (strains CECT 13014 and CECT 13015). Based on their composition in volatile compounds, the wines obtained by fermentation possessed a more complex aroma. Odorant descriptors allowed the following aroma series to be established for the wines: chemical, ripe fruit, green fruit, floral, milky, fresh grass, dry grass, toasted, and rancid. The chemical, ripe fruit, milky, and toasted series were those exhibiting the highest values in all wines. A principal component analysis and a cluster analysis revealed that the wines obtained by fermentation with selected yeasts were very similar and differed from those fermented in the presence of the autochthonous flora or in the traditional manner. Sensory evaluation of the wines by a tasting panel led to the wines obtained by fermentation with selected yeasts being the best scored. Multiple regression analysis was used to relate the punctuation given by a tasting panel with the volatile composition of the wines using as independent variables the most influential aroma series.

Short communication. Effect of forage source (grazing vs. silage) on conjugated linoleic acid content in milk fat of Holstein-Friesian dairy cows from Galicia (NW Spain)

The aim of this study was to investigate the effect of different feeding proportions of forage ―grazing vs. silage― on milk fatty acids (FA) profile and conjugated linoleic acid (CLA) content of autumn calving Holstein-Friesian cows (n = 61) at CIAM (Galicia, NW Spain). Three treatments (S, 100% silage; G/S, 50% grazing + 50% silage; G, 100% grazing) were set and milk FA profile of dairy cows was determined by gas chromatography-mass spectrometry. The G group showed a decrease in short (p &lt; 0.05) and medium chain FA (p &lt; 0.001), with an increase in long chain FA (p &lt; 0.001) in comparison to the G/S and S groups, which showed the lowest levels (p &lt; 0.001) of mono- and polyunsaturated FA. The CLA content in milk fat increased (p &lt; 0.001) linearly in relation to the increased proportion of fresh grass in the diet of dairy cows from 0.49 and 0.82 to 1.14 g/100 g FA for the treatments S, G/S and G, respectively. During spring and summer, the levels of CLA were three times higher (p &lt; 0.001, +0.76 g/100 g FA) in milk from dairy cows at the G group than in cows at the S group and twice higher (p &lt; 0.001, +0.40 g/100 g FA) than in cows at the G/S group. High proportion of grass in the diet of cows increased CLA content, with the highest levels of unsaturated FA and the lowest levels of saturated FA, increasing the added value of milk on grazing systems using available farm resources.

Arboreal Politics in the Knight's Tale

Arboreal Politics in the <i>Knight's Tale</i>

Potential use of milk mid-infrared spectra to predict individual methane emission of dairy cows

This study investigates the feasibility to predict individual methane (CH4) emissions from dairy cows using milk mid-infrared (MIR) spectra. To have a large variability of milk composition, two experiments were conducted on 11 lactating Holstein cows (two primiparous and nine multiparous). The first experiment aimed to induce a large variation in CH4 emission by feeding two different diets: the first one was mainly composed of fresh grass and sugar beet pulp and the second one of maize silage and hay. The second experiment consisted of grass and corn silage with cracked corn, soybean meal and dried pulp. For each milking period, the milk yields were recorded twice daily and a milk sample of 50 ml was collected from each cow and analyzed by MIR spectrometry. Individual CH4 emissions were measured daily using the sulfur hexafluoride method during a 7-day period. CH4 daily emissions ranged from 10.2 to 47.1 g CH4/kg of milk. The spectral data were transformed to represent an average daily milk spectrum (AMS), which was related to the recorded daily CH4 data. By assuming a delay before the production of fermentation products in the rumen and their use to produce milk components, five different calculations were used: AMS at days 0, 0.5, 1, 1.5 and 2 compared with the CH4 measurement. The equations were built using Partial Least Squares regression. From the calculated R2cv, it appears that the accuracy of CH4 prediction by MIR changed in function of the milking days. In our experimental conditions, the AMS at day 1.5 compared with the measure of CH4 emissions gave the best results. The R2 and s.e. of the cross-validation were equal to 0.79 and 5.14 g of CH4/kg of milk. The multiple correlation analysis performed in this study showed the existence of a close relationship between milk fatty acid (FA) profile and CH4 emission at day 1.5. The lower R2 (R2 = 0.76) obtained between FA profile and CH4 emission compared with the one corresponding to the obtained calibration (R2c = 0.87) shows the interest to apply directly the developed CH4 equation instead of the use of correlations between FA and CH4. In conclusion, our preliminary results suggest the feasibility of direct CH4 prediction from milk MIR spectra. Additional research has the potential to improve the calibrations even further. This alternative method could be useful to predict the individual CH4 emissions at farm level or at the regional scale and it also could be used to identify low-CH4-emitting cows.

Comparison of intake and digestibility of fresh Digitaria decumbens grass fed to sheep, indoors or at pasture, at two different stages of regrowth

The effect of two feeding systems (indoors and at pasture) on intake and digestion of fresh grass was studied at two stages of regrowth (21 and 35 days of regrowth) in two parallel experiments. In Experiment 1, 10 adult Martinik rams weighing, on average, 50.5 (±0.9) kg, including four fitted with rumen cannula, were randomly allocated to two groups according to a 2 × 2 Latin Square design. These rams consumed a 21-day regrowth of Digitaria decumbens grass diet during two successive 28-day periods, indoors (five rams) or at pasture (five tethered rams). In Experiment 2, 10 other Martinik rams weighing, on average, 45.5 (±0.9) kg, including four fitted with rumen cannula, were randomly allocated to two groups according to a 2 × 2 Latin Square design. These rams consumed a 35-day regrowth of D. decumbens grass diet during two successive 28-day periods, either indoors (five rams) or at pasture (five tethered rams). For the indoors groups, in vivo organic matter digestibility (OMD) was measured by total collection of feces. In addition, OMD was estimated indoors and at pasture using the fecal CP (CPf) method (OMDCPf). Organic matter intake (OMI) was then estimated using OMDCPf and fecal organic matter output (OMICPf). Correlations of 0.49 and 0.77 were found between in vivo OMD and OMDCPf (P < 0.05) and between OMI and OMICPf (P < 0.001), respectively. OMDCPf was 1.8% (P < 0.05) and 2.7% (P < 0.01) lower indoors than at pasture at 21 and 35 days of regrowth, respectively, whereas OMICPf indoors was 1.1 and 1.16 times that registered at pasture at 21 and 35 days of regrowth, respectively. The higher OMDCPf at pasture was linked to the higher selective behavior of rams at pasture, whereas the differences in OMICPf between the two feeding systems were linked to differences in the total bulk density of the grass. These studies show that differences in OMDCPf and OMICPf exist between animals fed indoors and at pasture with the same forage and that these differences may vary according to the stage of regrowth of the grass offered.

Fatty acid profile of milk from goats fed diets with different levels of conserved and fresh forages

Aim of the study was to evaluate the effect of different proportions of hay and fresh grass in goats’ diet on milk fatty acid profile. Nine Camosciata goats were fed a fixed amount of concentrate (30% of total diet) and different percentages (40% vs 30%, 50% vs 20% and 60% vs 10%) of hay and fresh grass, respectively. Diminishing amounts of fresh grass percentages in the diet led to significant increases of lauric, myristic and palmitic acids (P ≤ 0.001) and to significant decreases of C18:1 t6‐11, rumenic and α‐linolenic acids (P ≤ 0.001) in milk, thus determining a worsening of the health value of milk fat.

Integration of multi-sensor data to assess grassland dynamics in a Yellow River sub-watershed

Grasslands form the dominant land cover in the upper reaches of the Yellow River and provide a reliable indicator by being strongly correlated with regional terrestrial ecological status. Remote sensing can provide information useful for vegetation quality assessments, but no single sensor can meet the needs for the high temporal–spatial resolution required for such assessments on a watershed scale. To observe long-term grassland dynamics in the Longliu Watershed located in the upper reaches of the Yellow River, Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat images were integrated to obtain Normalized Difference Vegetation Index (NDVI) data. The MODIS images were used to identify patterns of monthly variation. With the temporal dynamics of NDVI provided by the MODIS images, an exponential regression model was obtained that described the relationship between Julian day and NDVI. Four time-series data sets from multi-spectral sensors were constructed to obtain regional grassland NDVI information from 1977 to 2006 in the Longliu Watershed. Using the daily NDVI correlation coefficient, NDVI values for different days were obtained from Landsat series images, standardised to the same day and integrated into TM format by using NDVI coefficients between the four different sensors. Thus, the NDVI data obtained from multi-sensors on different days were integrated into a comparable format. A regression analysis correlating the NDVI data from two sensors with fresh grass biomass showed that the integration procedure was reliable.

Biorefining of perennial grasses: Development of visible and near infrared tools for assessing fineness of extracted fibre

The biorefining of grass offers an opportunity to integrate primary production agriculture with the extraction of fibre. The study was aimed at developing protocols for processing ryegrass to determine fibre content and to generate visible and near infrared reflectance (Vis–NIR) calibrations for estimating fibre fineness with the aid of a new reference airflow method. The method for determining fineness of processed fibres has been adapted from flax fibre protocols. A Vis–NIR calibration using partial least squares (PLS) regression method was employed to generate models with a calibration set consisting of 85 samples obtained from fresh and ensiled grasses. The PLS model was successfully validated with 21 independent samples with a prediction error of 1.26dtex. An optimised PLS model (r2=0.86) consisting of 106 samples has been developed. The quality assurance protocols could be used for assessing fibre content and quality of silage, hay and fresh grass.

Consequences of field N2O emissions for the environmental sustainability of plant‐based biofuels produced within an organic farming system

AbstractOne way of reducing the emissions of fossil fuel‐derived carbon dioxide (CO2) is to replace fossil fuels with biofuels produced from agricultural biomasses or residuals. However, cultivation of soils results in emission of other greenhouse gases (GHGs), especially nitrous oxide (N2O). Previous studies on biofuel production systems showed that emissions of N2O may counterbalance a substantial part of the global warming reduction, which is achieved by fossil fuel displacement. In this study, we related measured field emissions of N2O to the reduction in fossil fuel‐derived CO2, which was obtained when agricultural biomasses were used for biofuel production. The analysis included five organically managed feedstocks (viz. dried straw of sole cropped rye, sole cropped vetch and intercropped rye–vetch, as well as fresh grass–clover and whole crop maize) and three scenarios for conversion of biomass into biofuel. The scenarios were (i) bioethanol, (ii) biogas and (iii) coproduction of bioethanol and biogas. In the last scenario, the biomass was first used for bioethanol fermentation and subsequently the effluent from this process was utilized for biogas production. The net GHG reduction was calculated as the avoided fossil fuel‐derived CO2, where the N2O emission was subtracted. This value did not account for fossil fuel‐derived CO2 emissions from farm machinery and during conversion processes that turn biomass into biofuel. The greatest net GHG reduction, corresponding to 700–800 g CO2 m−2, was obtained by biogas production or coproduction of bioethanol and biogas on either fresh grass–clover or whole crop maize. In contrast, biofuel production based on lignocellulosic crop residues (i.e. rye and vetch straw) provided considerably lower net GHG reductions (≤215 g CO2 m−2), and even negative numbers sometimes. No GHG benefit was achieved by fertilizing the maize crop because the extra crop yield, and thereby increased biofuel production, was offset by enhanced N2O emissions.

A comparative study on mimosine, 3,4-dihydroxy pyridone (3,4-DHP) and 2,3-dihydroxy pyridone (2,3-DHP), purine derivatives (PD) excretion in the urine, thyroid hormone and blood metabolites profiles of Thai swamp buffalo (Bubalus bubalis) and Murrah buffalo (Bubalus bubalis)

Four Thai swamp buffaloes (SB) and four Murrah buffaloes (MB) fed a based diet of fresh ruzi grass (Bachiaria ruziziensis) with an increased proportion of fresh leucaena leaves. Intake of nutrients in animals increased when ruzi grass was mixed with leucaena. Digestibility of nutrients were the highest in SB and MB fed diets containing 25% and 50% of leucaena, respectively, and nitrogen (N) balances in both animal breeds were varied among diets. The regression equation coefficient of mimosine + DHP in the urine was twice as high in SB than in MB. Urinary purine derivatives excretion rate in SB was higher than that in MB. Plasma triiodothyronine and thyroxine declined in both animal breeds fed a diet containing >1 g mimosine intake/kg BW(0.75)/day. Plasma urea-N was the lowest in SB, but the highest in MB when fed a diet containing 84% of leucaena. Plasma β-HBA in SB have declined when diets contained >50% of leucaena but that in MB was not affected by any diet. In conclusion, the effect of leucaena in diet upon buffalo breeds depends on the proportion of leucaena in the diet, mimosine contents and condensed tannins components.