Chopped Wheat Straw Research Articles

Grinding energy and physical properties of chopped and hammer-milled barley, wheat, oat, and canola straws

In the present study, specific energy for grinding and physical properties of wheat, canola, oat and barley straw grinds were investigated. The initial moisture content of the straw was about 0.13–0.15 (fraction total mass basis). Particle size reduction experiments were conducted in two stages: (1) a chopper without a screen, and (2) a hammer mill using three screen sizes (19.05, 25.4, and 31.75 mm). The lowest grinding energy (1.96 and 2.91 kWh t−1) was recorded for canola straw using a chopper and hammer mill with 19.05-mm screen size, whereas the highest (3.15 and 8.05 kWh t−1) was recorded for barley and oat straws. The physical properties (geometric mean particle diameter, bulk, tapped and particle density, and porosity) of the chopped and hammer-milled wheat, barley, canola, and oat straw grinds measured were in the range of 0.98–4.22 mm, 36–80 kg m−3, 49–119 kg m−3, 600–1220 kg m−3, and 0.9–0.96, respectively. The average mean particle diameter was highest for the chopped wheat straw (4.22-mm) and lowest for the canola grind (0.98-mm). The canola grinds produced using the hammer mill (19.05-mm screen size) had the highest bulk and tapped density of about 80 and 119 kg m−3; whereas, the wheat and oat grinds had the lowest of about 58 and 88–90 kg m−3. The results indicate that the bulk and tapped densities are inversely proportional to the particle size of the grinds. The flow properties of the grinds calculated are better for chopped straws compared to hammer milled using smaller screen size (19.05 mm).

Throughput capacity of large quantities of chopped straw in partly slatted farrowing pens for loose housed sows

The aim of the present paper was to study the throughput capacity (i.e. the ability of straw to drain through slatted flooring) of 15 kg of chopped straw used around the time of farrowing. A cohort study including 96 sows was conducted in two commercial herds, comparing chopped wheat straw of three length categories (mass median length 39, 70 and 130 mm). Straw with short and medium chop lengths was completely absent in 83% (plastic slats) and 85% (cast-iron slats), respectively, of the pens on Day 4 after farrowing, compared to 7% and 6% of pens provided with the longest straw category. We conclude that it is technically feasible to have an efficient throughput of straw and to maintain good pen hygiene in partly slatted farrowing pens provided with 15 kg of chopped straw at farrowing. However, straw chop lengths need to be adjusted to the type of slatted flooring used.

Nematode–collembolan-interaction promotes the degradation of Fusarium biomass and deoxynivalenol according to soil texture

Despite well-known positive aspects of conservation tillage combined with mulching on arable fields, one drawback may be the survival of phytopathogenic fungi on plant residues. Therefore, plant pathogen repression is an important ecosystem service to prevent cultivated plants from fungal diseases and mycotoxin contamination. A microcosm-study was conducted under constant laboratory conditions to assess the impact of soil microfauna (Aphelenchoides saprophilus, Nematoda) and soil mesofauna (Folsomia candida, Collembola) on soil-borne phytopathogenic fungi (Fusarium culmorum) and its mycotoxin deoxynivalenol (DON). Our hypotheses were: (1) nematodes and collembolans reduce the biomass of F. culmorum and the content of DON in infected wheat straw; (2) the species interaction of A. saprophilus and F. candida enhances the degradation of Fusarium biomass and DON concentration in wheat straw; (3) the degradation efficiency of nematodes and collembolans is affected by soil texture. Therefore, microcosms were filled with soil of different texture and finely chopped wheat straw (Fusarium-infected vs. non-infected). The microcosms were inoculated with the two species in different combinations (single and mixed species, non-faunal control). After 2 and 4 weeks of incubation, the individual densities in all soil faunal treatments increased with highest individual numbers in the non-infected treatments in case of collembolans and in the infected treatments in case of nematodes. The Fusarium biomass (Fusarium protein equivalents = FPE) of all infected treatments decreased by at least one order of magnitude after 2 weeks. At the end of 4 weeks Fusarium-biomass was reduced by 93% in sandy and silt loam and 89% in clay loam mostly in mixed species treatments. Also DON concentrations were reduced significantly compared to the initial concentration in all treatments after 4 weeks. The highest reduction was found in mixed species treatments, where DON was degraded by 92%, 95% and 39% for sandy loam, silt loam and clay loam, respectively. We concluded that particularly interacting collembolans and nematodes play an important role in plant pathogen repression and mycotoxin degradation. In any case, soil texture matters in the provision of these ecosystem services by collembolans and nematodes.

Low-protein solid feed improves the utilization of milk replacer for protein gain in veal calves

This study was designed to quantify the contribution of low-protein solid feed (SF) intake, in addition to milk replacer, to protein and energy retention in veal calves. Because of potential interactions between milk replacer and SF, occurring at either the level of digestion or postabsorption, this contribution might differ from that in calves fed either SF or milk replacer alone. Forty-eight Holstein Friesian male calves, 55±0.3kg of body weight (BW), were divided across 16 groups of 3 calves each. Groups were assigned randomly to 1 of 4 incremental levels of SF intake: 0, 9, 18, or 27g of DM of SF/kg of BW0.75 per day. The SF mixture consisted of 25% chopped wheat straw, 25% chopped corn silage, and 50% nonpelleted concentrate (on a DM basis). Each group was housed in a respiration chamber for quantification of energy and N balance at each of 2 BW: at 108±1.1kg and at 164±1.6kg. The milk replacer supply was 37.3g of DM/kg of BW0.75 per day at 108kg of BW and 40.7g of DM/kg of BW0.75 per day at 164kg of BW, irrespective of SF intake. Within a chamber, each calf was housed in a metabolic cage to allow separate collection of feces and urine. Indirect calorimetry and N balance data were analyzed by using regression procedures with SF intake-related variables. Nitrogen excretion shifted from urine to feces with increasing SF intake. This indicates a higher gut entry rate of urea and may explain the improved N utilization through urea recycling, particularly at 164kg of BW. At 108kg of BW, the gross efficiency of N retention was 61% for calves without SF, and it increased with SF intake by 5.4%/g of DM of SF per day. At 164kg of BW, this efficiency was 49% for calves without SF, and it increased by 9.9%/g of DM of SF per day. The incremental efficiency of energy retention, representing the increase in energy retained per kilojoule of extra digestible energy intake from SF, was 41% at 108kg of BW and 54% at 164kg of BW. Accordingly, the apparent total-tract digestibility of NDF increased with BW, from 46% at 108kg of BW to 56% at 164kg of BW. On average, 5.5% of gross energy from SF was released as CH4 in veal calves, which is similar to reported values in cattle fed only SF. In conclusion, the provision of low-protein SF resulted in improved N utilization for protein gain, particularly toward the end of the fattening period. In heavy calves, recycling of urea originating from amino acids in milk replacer potentially contributes substantially to the N retention of veal calves fed SF.

A Thermostable Crude Endoglucanase Produced by Aspergillus fumigatus in a Novel Solid State Fermentation Process Using Isolated Free Water.

Aspergillus fumigatus was grown on chopped wheat straw in a solid state fermentation (SSF) process carried out in constant presence of isolated free water inside the fermentation chamber. The system allowed maintaining a constant vapor pressure inside the fermentor throughout the fermentation process. Crude endoglucanase produced by A. fumigatus under such conditions was more thermostable than previously reported enzymes of the same fungal strain which were produced under different conditions and was also more thermostable than a number of other previously reported endoglucanases as well. Various thermostability parameters were calculated for the crude endoglucanase. Half lives (T 1/2) of the enzyme were 6930, 866, and 36 min at 60°C, 70°C, and 80°C, respectively. Enthalpies of activation of denaturation (ΔH D*) were 254.04, 253.96, and 253.88 K J mole−1, at 60°C, 70°C and 80°C, respectively, whereas entropies of activation of denaturation (ΔS D*) and free energy changes of activation of denaturation (ΔG D*) were 406.45, 401.01, and 406.07 J mole−1 K−1 and 118.69, 116.41, and 110.53 K J mole−1 at 60°C, 70°C and 80°C, respectively.

Effect of nitrogen content and additional straw on changes in chemical composition, volatile losses, and ammonia emissions from dairy manure during long-term storage

Twelve 200-L barrels were used to determine the effects of N content and straw addition on changes in chemical composition and volatile losses measured by mass balance of dairy manure during a 136-d storage period. In addition, on d 0, 3, 6, 12, 28, 56, and 136, rate of NH3-N emission was measured, and core samples were collected to characterize fermentation pattern. High N (3.06% N, HN) and low N (2.75% N, LN) manures were obtained from cows fed diets with 17.2 and 15.2% crude protein (dry matter basis), respectively. On d 0, manure scraped from a freestall barn floor was diluted with water to 10% dry matter and loaded in barrels with (+S) or without (−S) mixing 22g of chopped wheat straw per kilogram of undiluted manure. Data were analyzed as a randomized complete block with a 2×2 factorial arrangement of treatments and 3 replications. We observed no interaction between treatments for the reported measurements, but several day-of-storage by treatment interactions were found. Throughout storage, total NH3-N (TAN, NH3-N+NH4+-N; 71.9 vs. 104.3 mg/dL), pH (6.40 vs. 6.74), and total volatile fatty acids (TVFA, starting on d 12) were lower for LN relative to HN manure. In the presence of straw, crust formation occurred between d 12 and 28, and pH became lower and TVFA became higher starting on d 56, compared with no straw. Treatments did not influence loss of organic matter, organic N, organic C, or N, which averaged 31, 29, 26, and 20%, respectively. However, neutral detergent fiber loss was 44% higher for +S relative to −S manure. Consistent reductions in the C:N ratio indicated proportionally higher volatile C loss than volatile N loss during storage. Overall rate of NH3-N emission was 36% lower for LN than for HN manure. In the presence of straw, rate of NH3-N emission did not differ until after crust formation, but was 67% lower on d 56 and 95% lower on d 136, when it was barely detectable, compared with manure with no straw. Manure pH was highly correlated with TVFA:TAN ratio (r=−0.78), and rate of NH3-N emission was correlated with pH, TVFA:TAN, TVFA, and TAN (r=0.47, −0.44, −0.23, and 0.28, respectively). In this trial, both microbial fermentation and crust formation influenced NH3-N emission rate and other measured responses, highlighting the importance of long-term sampling to evaluate treatment effects in manure storage studies.

Effect of Bedding Material on Dust and Ammonia Emission from Broiler Houses

The objective of this study was to determine the effects of different bedding materials on fine dust (PM10 and PM2.5) and ammonia emissions from broiler houses. The effects on broiler performance and footpad lesions were also studied. The study was carried out in a mechanically ventilated broiler house with eight identical rooms, each accommodating 2260 broilers; it compromised two production cycles (rounds) of 35 days. The broilers were raised on four bedding materials: white wood shavings, chopped wheat straw, ground rapeseed straw, and silage maize. PM10, PM2.5, and ammonia concentrations and ventilation rates were measured. Production results and the incidence of footpad lesions were assessed. The results showed that compared with wood shavings, silage maize had 19% lower PM2.5 emission (p < 0.05). The PM2.5 emissions of silage maize were not different from those of wheat straw and rapeseed straw. Type of bedding had no effect on PM10 emission. PM2.5 mass was on average 4.8% of PM10 mass and increased with the age of the birds (p < 0.001). Ammonia emission from silage maize was 36% lower than from wood shavings, 47% less than from wheat straw, and 34% less than from rapeseed straw. Bedding material had no effect on broiler performance or on footpad lesions. It was concluded that silage maize can be a good alternative bedding to wood shavings and wheat straw in broiler houses.

English

This study was carried out to investigate the prospects of using methanolic extracts and residue of wheat (Triticum aestivum&nbsp;L.) for the management of parthenium (Parthenium hysterophorus&nbsp;L.), one of the world&rsquo;s worst weeds. In a laboratory bioassay, the effect of methanol extracts of 1, 2, 3, 4 and 5% (w/v) concentrations of four wheat varieties namely: AS 2002, Inqalab 91, Ufaq and Uqab was studied against the germination and seedling growth of parthenium. Extracts of all the four wheat varieties suppressed germination as well as root and shoot growth of the seedlings. In soil amendment bioassay, dried and chopped wheat straw of the four test wheat varieties was thoroughly mixed in pot soil at 0.5, 1.0 and 1.5% (w/w). Pots were irrigated with tap water and left for one week followed by sowing of seeds in these pots. The effect of residue incorporation of all the wheat cultivars was insignificant on germination of parthenium seeds. However, all the residue incorporation treatments significantly reduced the survival percentage of the parthenium seedlings. Root and shoot growth in terms of length, and fresh and dry biomass were also significantly suppressed by residues of all the four test wheat cultivars. This study concludes that parthenium weed can effectively be managed by amending the soil with wheat residue. &nbsp; Key words:&nbsp;Non-chemical weed control, parthenium, wheat residue.

Effects of dietary protein concentration and balance of absorbable amino acids on productive responses of dairy cows fed corn silage-based diets

A cyclical changeover design experiment (3-wk periods; 12-wk total) was conducted to evaluate whether improving the balance of absorbable AA would allow the feeding of less crude protein (CP) without compromising production, thereby reducing the potential environmental pollution from dairy farms. Sixteen multiparous Holstein cows were assigned to 1 of 8 dietary treatments as total mixed rations (TMR) containing [dry matter (DM) basis] 45% corn silage, 5% coarsely chopped wheat straw, and 50% concentrate mixture. The 8 treatments were formulated to differ in dietary CP (14 and 16%; DM basis) and in the balance of absorbable AA achieved by changing the main protein source (MPS) of the concentrate mixtures [replacing soybean meal (SBM) with corn byproducts (CBP), dried corn distillers grains (DDG), and some corn gluten meal], and by adding a mixture of rumen-protected Lys and Met (RPLM). Feeding lactating dairy cows corn silage-based diets with 16% CP promoted significantly higher DM intakes and milk yields, and lower feed N-use efficiency than feeding diets with 14% CP. Replacing SBM with CBP significantly increased milk yields and decreased milk fat and protein concentrations, but had no effect on the efficiency of conversion of feed N into milk N. With 16% CP diets, the addition of RPLM decreased feed N use efficiency. A significant effect was observed for the MPS × RPLM interaction on milk protein concentrations. Plasma Lys concentration was lower with diets based on CBP, and plasma Met increased with RPLM. We did not find clear benefits of RPLM in facilitating a reduction of dietary protein without loss of production.

Prepartum dietary energy intake affects metabolism and health during the periparturient period in primiparous and multiparous Holstein cows

An experiment was conducted to determine the effect of prepartum plane of energy intake on metabolic profiles related to lipid metabolism and health in blood and liver. Primiparous (n=24) and multiparous (n=23) Holsteins were randomly assigned by expected date of parturition to 1 of 3 prepartum energy intakes. A high energy diet [1.62 Mcal of net energy for lactation (NEL)/kg; 15% crude protein] was fed for either ad libitum intake or restricted intake to supply 150% (OVR) or 80% (RES) of energy requirements for dry cows in late gestation. To limit energy intake to 100% of National Research Council requirements at ad libitum intake, chopped wheat straw was included as 31.8% of dry matter for a control diet (CON; 1.21 Mcal of NEL/kg of dry matter; 14.2% crude protein). Regardless of parity group, OVR cows had greater concentrations of glucose, insulin, and leptin in blood prepartum compared with either CON or RES cows; however, dietary effects did not carry over to the postpartum period. Prepartum nonesterified fatty acids (NEFA) were lower in OVR cows compared with either CON or RES cows. Postpartum, however, OVR cows had evidence of greater mobilization of triacylglycerol (TAG) from adipose tissue as NEFA were higher than in CON or RES cows, especially within the first 10 d postpartum. Prepartum β-hydroxybutyrate (BHBA) was not affected by diet before parturition; however, within the first 10 d postpartum, OVR cows had greater BHBA than CON or RES cows. Prepartum diet did not affect liver composition prepartum; however, OVR cows had greater total lipid and TAG concentrations and lower glycogen postpartum than CON or RES cows. Frequency of ketosis and displaced abomasum was greater for OVR cows compared with CON or RES cows postpartum. Controlling or restricting prepartum energy intake yielded metabolic results that were strikingly similar both prepartum and postpartum, independent of parity group. The use of a bulky diet controlled prepartum energy intake in multiparous and primiparous cows, improved metabolic status postpartum, and reduced the incidence of health problems. When metabolic profiles are considered collectively, cows overfed energy prepartum exhibited an “overnutrition syndrome” with characteristics of clinical symptoms displayed by diabetic or obese nonruminant subjects. This syndrome likely contributed to metabolic dysfunction postpartum.

Thermostable crude endoglucanase produced by Aspergillus fumigatus in a modified solid state fermentation process

Cellulases are used in many industries worldwide and there is an ever increasing need to isolate, produce or develop thermostable cellulases. Manipulation of fermentation techniques in order to obtain desirable product(s) can be one line of action. In this study Aspergillus fumigatus was grown on chopped wheat straw in a modified solid state fermentation (SSF) process carried out in the constant presence of isolated free water inside the fermentation chamber. The system was designed in order to make air inside the fermenter humid throughout the process, so that solid substrate does not dry out quickly. The crude endoglucanase produced by A. fumigatus under such conditions was found to be more thermostable than a number of previously reported endoglucanases. Various thermostability parameters were calculated for the crude endoglucanase. Half lives (T1/2) of the enzyme were 6930, 866 and 36 min at 60, 70 and 80°C, respectively. Enthalpies of activation of denaturation ( * D H ) were 254.04, 253.96 and 253.88 K J mole-1, at 60, 70 and 80°C respectively, whereas entropies of activation of denaturation ( * D S ) and free energy changes of activation of denaturation ( * D G ) were 406.45, 401.01, 406.07 J mole-1 K-1 and 118.69, 116.41, 110.53 kJ mole-1 at 60, 70 and 80°C, respectively. Keywords : Fermentation, cellulase, Aspergillus fumigatus, endoglucanase, thermostability

Splash erosion and infiltration in relation to mulching and polyvinyl alcohol application in semi-arid tropics

Splash erosion, caused due to structural instability, leads to the formation of soil crust, which hampers infiltration rate of soils and affects the germination of seeds. To ensure the optimum infiltration rate and better germination, it is important that splash erosion and crusting are prevented. A study was carried out in sandy loam and silt loam soils to monitor the splash loss and infiltration rates in relation to application of straw mulch and polyvinyl alcohol (PVA) under simulated rainfall. The treatments included spreading chopped wheat straw on tilled soil at a rate of 6 t ha−1 and spraying of 0.1 and 0.5% PVA solutions on tilled soil surface, in addition to an untreated tilled soil as control. The treatments were replicated four times. The straw mulch application decreased the mean splash loss by 68% compared to unmulched soil. The mean basic infiltration rate (IR) measured, as an index of soil crusting, was 54% higher in soils with mulch cover than in soils without mulching. The average splash loss decreased by 56% with 0.1% PVA and 84% with 0.5% PVA application compared to untreated soil. The mean basic IR did not increase significantly, when treated with 0.1% PVA solution compared to untreated soils, whereas 0.5% PVA application increased the basic IR by 77%. The effect of mulch and PVA in decreasing splash loss and increasing IR was more effective in sandy loam than in silt loam.

Fenestration des gaines du nerf optique et régression des anomalies vasculaires péripapillaires dans un cas d’hypertension intracrânienne secondaire

The study investigated the effect of chop length of wheat straw in a high-straw dry cow diet on the feeding behavior, health, and performance of Holstein dairy cows across the transition period. Forty cows were enrolled at dry off, approximately 45 d before expected calving, and assigned to 1 of 2 dietary treatments containing (on a dry matter basis) 36% corn silage, 35% dry cow pellet, and 29% wheat straw. Diets were formulated to target an energy consumption of 19 Mcal/d of net energy for lactation per cow. The diets differed in the chop length of wheat straw: (1) long straw chopped with a 10.16-cm screen (LDD; n = 20), or (2) short straw chopped with a 2.54-cm screen (SDD; n = 20). Dietary treatments were fed throughout the dry period. Feeding behavior, rumination time, and reticulorumen pH were monitored electronically, and feed samples were collected to determine feed sorting. Blood samples were taken weekly, and body condition scores and body weights were taken every 2 wk. Postcalving, all cows were fed the same lactating cow total mixed ration for 28 d; the same measurements were recorded with the addition of daily milk yield and twice weekly milk components. During the dry period, cows fed the SDD treatment consumed more dry matter (15.6 vs. 15.0 kg/d), had more consistent dry matter intake in the week leading up to calving, had a faster feeding rate, consumed 0.4 kg/meal more, and had 0.6 fewer meals per day. No differences were observed in rumination time or mean reticulorumen pH between treatments in both the dry and lactating period. Regardless of treatment during the dry period, cows sorted against the long particles (>19 mm) and in favor of the short particles (<8, >4 mm), but cows fed the LDD treatment sorted to a greater extent than cows fed the SDD treatment. Dietary treatment in the dry period did not influence feed sorting behavior postcalving. Cows fed the LDD treatment had a greater daily change (decline) in rumen pH in the first week postcalving and had a greater blood β-hydroxybutyrate concentration in the third week postcalving. Overall, the results from this study indicate that feeding shorter chopped wheat straw in a high-straw dry cow diet improved intake, reduced sorting during the dry period, and resulted in greater metabolic health and rumen stability in early lactation.

Prepartum dietary management of energy intake affects postpartum intake and lactation performance by primiparous and multiparous Holstein cows

An experiment was conducted to determine the effect of plane of energy intake prepartum on postpartum performance. Primiparous (n=24) and multiparous (n=23) Holsteins were randomly assigned by expected date of parturition to 1 of 3 prepartum energy intakes. A moderate energy diet [1.63 Mcal of net energy for lactation (NEL)/kg; 15% crude protein (CP)] was fed for either ad libitum intake (OVR) or restricted intake (RES) to supply 150 or 80% of National Research Council (2001) energy requirement, respectively, for dry cows in late gestation. To limit energy intake to 100% of NRC requirement at ad libitum dry matter intake (DMI), chopped wheat straw was included as 31.8% of dry matter (DM) in a control diet (CON; 1.21 Mcal of NEL/kg of DM; 14% CP). Multiparous and primiparous cows assigned to OVR gained body condition during the dry period [initial body condition score (BCS)=3.3], but were not overconditioned by parturition (BCS=3.5). Multiparous cows in the OVR group lost more BCS postpartum than multiparous RES or CON cows. Primiparous cows lost similar amounts of BCS among dietary treatment groups postpartum. Addition of chopped wheat straw to CON diets prevented a large decrease in DMI prepartum in both primiparous and multiparous cows. During the first 3 wk postpartum, DMI as a percentage of BW was lower for multiparous OVR cows than for multiparous RES cows. Prepartum diet effects did not carry over through the entire 8-wk lactation period. Because of greater mobilization of body stores, OVR cows had greater milk fat percentage and greater 3.5% fat-corrected milk yield during the first 3 wk postpartum. Multiparous cows assigned to OVR experienced a 55% decrease in energy balance and primiparous cows a 40% decrease in energy balance during the last 3 wk before parturition, compared with CON or RES cows that had little change. Multiparous cows fed OVR had a greater contribution of energy from body energy reserves to milk energy output than either CON or RES cows. Overfeeding energy prepartum resulted in large changes in periparturient energy balance. Even in the absence of overconditioning, a large change in DMI and energy balance prepartum influenced postpartum DMI and BCS loss, especially for multiparous cows. Chopped wheat straw was effective at controlling energy intake prepartum, although primiparous cows did not achieve predicted DMI. Even so, controlling or restricting energy intake in primiparous cows was not detrimental to lactational performance over the first 8 wk of lactation.

Precipitation of proteins in the rumen fluid using tungstic and trichloracetic acid after feeding sheep thermally treated or untreated soybean meal

The aim of the study was to quantify the protein degradation in the rumen of thermal treated and untreated soybean meal postprandial using trichloracetic (TCA) and tungstic acid (TA) as precipitants of N-compounds in the rumen fluid. The hypothesis is that the difference between TA and TCA precipitation represents peptides with small molecular weight. In two experiments, castrated male sheep were used for the determination of digestibility, N-balance, determination of passage rate of the solid phase, ammonia-N determination in the rumen fluid and for the precipitation trial. The animals were assigned to two treatments in experiments 1 and 2 and fed ad libitum twice a day with chopped wheat straw treated with a solution of 4% NaOH and supplemented with soybean meal either thermally treated (149 °C for 4 h) (TT) or untreated (UT). Rumen fluid was sampled 0.5, 2.5, 4.5, 6.5 and 7.5 h after the morning feeding. The precipitation of N-compounds was affected by a significant interaction among thermal treatment, sampling time and precipitant. At 0.5 h postprandial, no differences ( P > 0.05) in the precipitation for treatment or precipitant were observed. In the TT treatment, TA precipitated significantly more N-compounds in rumen fluid (in mg N/100 ml/g of N consumed) at 2.5 h onwards. There were no differences ( P > 0.05) in precipitation of N-compounds in rumen fluid comparing the different postprandial samplings within treatment. Results of ammonia-N determination were in line with those of N precipitation with TA or TCA. At 2.5 h postprandial, ammonia-N was significantly higher in UT than TT fed animals. In conclusion, the punctual accumulation of small peptides was not observed through the precipitation of N-compounds in rumen fluid. In general, more small peptides were precipitated when TA was used as precipitant and soybean meal was thermally treated.

Roughage Amount, Source, and Processing for Diets Fed to Weaned Dairy Calves

ABSTRACT Roughage amount, source, and processing were evaluated using Holstein steer calves initially 8 wk of age in four 56-d trials. In all trials, calves were fed a common textured grower diet (20% CP, 12% NDF) based on whole corn and oats, a protein supplement pellet, and liquid molasses. In trial 1, the treatments were 0, 3, 6, or 9% chopped wheat straw (3% CP). Average daily gain, DMI, hip width, and BCS decreased linearly as straw was increased. In trial 2, the treatments were 0, 5, 10, or 15% long alfalfa hay. Average daily gain and hip width decreased linearly as the level of alfalfa hay in the diet increased. In trial 3, the treatments were 0, 3, 6, or 9% chopped grass hay. Average dairy gain, DMI, and hip width changed quadratically as hay increased. Calf ADG, DMI, and hip width change were maximal at 3% grass hay. Calf BCS declined linearly as grass hay increased. In trial 4, the treatments were 7% alfalfa hay fed as either chopped or long hay, and there were no differences in calf performance. When the treatment means of trials 1, 2, and 3 were combined and regression analysis was performed, ADG and DMI declined quadratically as NDF intake increased, but roughage source was not significant. Dry matter intake and ADG declined the most when NDF from roughage exceeded 1.5% of DM.

Inoculum carrier and contaminant bioavailability affect fungal degradation performances of PAH-contaminated solid matrices from a wood preservation plant

The objective of the study was to investigate the impact of chopped wheat straw (CWS), ground corn cobs (GCC) and commercial pellets (CP), as inoculum carriers, on both growth and polycyclic aromatic hydrocarbons (PAH) degradation performances of Dichomitus squalens, Pleurotus ostreatus and Coprinus comatus. A historically-contaminated soil (HCS) and creosote-treated shavings (CTS) from the Soběslav wood preservation plant, characterized by different relative abundances of the PAH bioavailable fractions, were used to assess the contaminated matrix effect and its interaction with both carrier and fungal strain. In HCS, best results were obtained with CP-immobilized P. ostreatus, which was able to deplete benzo[a]anthracene, chrysene, benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF) and benzo[a]pyrene (BaP) by 69.1%, 29.7%, 39.7%, 32.8% and 85.2%, respectively. Only few high-molecular mass PAHs such as BbF, BkF and BaP were degraded beyond their respective bioavailable fractions and this effect was confined to a limited number of inoculants. In CTS, only phenanthrene degradation exceeded its respective bioavailability from 1.42 to 1.86-fold. Regardless of both inoculum carrier and fungal species, degradation was positively and significantly ( P < 0.001) correlated with bioavailability in fungal microcosms on HCS and CTS and such correlation was very similar in the two matrices ( R adj 2 equal to 0.60 and 0.59, respectively). The ability of white-rot fungi to degrade certain PAHs beyond their bioavailability was experimentally proven by this study. Although CTS and HCS considerably differed in their physico-chemical properties, PAH contents and contaminant aging, the relationship between degradation and bioavailability was not significantly affected by the type of matrix.

Soil organic carbon and nitrogen stocks in Nepal long-term soil fertility experiments

Loss of organic C from tilled agricultural soils has generated interest in C-sequestration in soils. The effects of nutrient and organic inputs on soil organic carbon (SOC) and total nitrogen (TN) stocks were studied in three 23–25-year-old long-term conventional tillage fertility experiments (LTFEs) in the Nepal terai. The sites differed in soil texture and were cropped annually to rice (Oryza sativa L.) and wheat (Triticum aestivum L.). Treatments were control (unfertilized), recommended NPK, and farmyard manure (FYM; 4 Mg dry wt./crop) at all sites, plus FYM (4 Mg ha−1 year−1) or chopped wheat straw (8 Mg dry wt. ha−1 year−1) plus N to rice and NPK to wheat at Parwanipur. Small areas of unfertilized grassland created at the same time as the LTFEs were sampled to provide a no-tillage comparison. Soil samples were collected at 15 cm intervals to a depth of 60 cm.

The effects of partial replacement of corn silage on biochemical blood parameters in lactating primiparous dairy cows

The aim of this experiment was to investigate the effects of partial replacement of corn silage with long alfalfa hay and/or coarse chopped wheat straw on biochemical parameters in late lactating Holstein primiparous dairy cows. Twelve late lactating Holstein primiparous cows including four cows equipped with a rumen cannula, averaging 210 ± 20 days in milk and weighing 575 ± 50 kg were randomly assigned in a 4 × 4 Latin square design. During each of four 21-days periods, cows were fed four total mixed diets that were varied in the forage sources: (1) 50% corn silage (CS), (2) 35% corn silage + 15% wheat straw (CSW), (3) 35% corn silage + 15% alfalfa hay (CSA), (4) 25% corn silage + 10% wheat straw + 15% alfalfa hay (CSWA). At the end of the feeding period, blood samples were taken from jugular vein. Serum glucose, total protein, albumin/globulin, creatinine, creatinin kinase, urea and uric acid levels were determined by using Auto Technicon DAX 72 autoanalyzer. While serum glucose, albumin, globulin, urea, uric acid and creatinine kinase activity were not found significantly different among groups, serum total protein (between CS and CSA, CS and CSWA) and creatinine (between CSA and CSWA) levels had statistical significance at the levels of &lt;i&gt;P&lt;/i&gt; &lt; 0.05. It is concluded that rumen propionate and ammonia levels may be good indicator for glucose and BUN, respectively.

Bulk density and compaction behavior of knife mill chopped switchgrass, wheat straw, and corn stover

Bulk density of comminuted biomass significantly increased by vibration during handling and transportation, and by normal pressure during storage. Compaction characteristics affecting the bulk density of switchgrass, wheat straw, and corn stover chopped in a knife mill at different operating conditions and using four different classifying screens were studied. Mean loose-filled bulk densities were 67.5 ± 18.4 kg/m 3 for switchgrass, 36.1 ± 8.6 kg/m 3 for wheat straw, and 52.1 ± 10.8 kg/m 3 for corn stover. Mean tapped bulk densities were 81.8 ± 26.2 kg/m 3 for switchgrass, 42.8 ± 11.7 kg/m 3 for wheat straw, and 58.9 ± 13.4 kg/m 3 for corn stover. Percentage changes in compressibility due to variation in particle size obtained from a knife mill ranged from 64.3 to 173.6 for chopped switchgrass, 22.2–51.5 for chopped wheat straw and 42.1–117.7 for chopped corn stover within the tested consolidation pressure range of 5–120 kPa. Pressure and volume relationship of chopped biomass during compression with application of normal pressure can be characterized by the Walker model and Kawakita and Ludde model. Parameter of Walker model was correlated to the compressibility with Pearson correlation coefficient greater than 0.9. Relationship between volume reduction in chopped biomass with respect to number of tappings studied using Sone’s model indicated that infinite compressibility was highest for chopped switchgrass followed by chopped wheat straw and corn stover. Degree of difficulty in packing measured using the parameters of Sone’s model indicated that the chopped wheat straw particles compacted very rapidly by tapping compared to chopped switchgrass and corn stover. These results are very useful for solving obstacles in handling bulk biomass supply logistics issues for a biorefinery.