Effect of Molasses Addition at Ensiling on Ruminal In Situ Dry Matter and Nutrient Degradation of Whole-Plant Soybean Silage Harvested at Different Phenological Stages

Whole-plant soybean ensiling has limitations and challenges that affect silage fermentation patterns and reduce ruminal nutrient degradation. Perhaps either the addition of molasses at ensiling or harvesting at different phenological stages has the potential to enhance whole-plant soybean silage (WSS) ruminal degradation. This experiment was a completely randomized design with a 3 × 2 factorial arrangement of treatments evaluating the effects of molasses (0 and 40 g/kg fresh forage) and phenological stage (R5: beginning seed, R6: full seed, and R7: beginning maturity) on ruminal in situ degradation. Molasses increased effective ruminal degradability (ERD) of dry matter (DM) regardless of the phenological stage and increased ERD of crude protein at R5 and R6. The addition of molasses at later phenological stages increased ERD of neutral detergent fiber (NDF). There was a molasses × phenological stage interaction effect with greater fractions A and B of NDF at R7 and R5, respectively, but lower undegraded NDF at R5 and R6 with molasses addition. Although the benefits of adding molasses were more pronounced in R5 and R6, adding molasses to whole-plant soybean at ensiling is recommended regardless of phenological stage. Increasing the proportion of digestible nutrients at harvesting either by harvesting at later phenological stages or the addition of molasses is a powerful strategy to manage ruminal degradation of DM and nutrients in WSS.

Evaluation of Ruminal Dry Matter Disappearance and pH of Dry Corn, High-Moisture Corn, and Rye under in Vitro Conditions

An in vitro experiment was conducted to evaluate the effects of grain type on in vitro dry matter disappearance (IVDMD) and pH using ruminal fluid and a buffer reagent. Five beef cows were used for ruminal fluid collection and ruminal fluid was pooled prior to use. The cows used for ruminal fluid collection were maintained on a forage-based diet (60:40 forage to concentrate) for 28 d prior to ruminal fluid collection. Three grain types were evaluated: 1) dry corn (89% dry matter;DRC), 2) high-moisture corn (72% dry matter;HMC) and 3) rye (89% dry matter;RYE). Data were analyzed as a completely randomized design. A total of twenty-one replications of each grain type were used for statistical analysis (n = 63 tubes total). IVDMD was greater (P ≤ 0.05) by 97.1% and 46.4% for RYE compared to DRC and HMC, respectively. Additionally, IVDMD was greater (P = 0.05) by 34.6% for HMC compared to DRC. Final pH was decreased (P ≤ 0.05) for RYE by 12.3% and 2.8% for RYE compared to DRC and HMC, respectively. Also, final pH was decreased (P = 0.05) by 9.8% for HMC compared to DRC. These data indicate that corn harvest method (dry vs. high-moisture) influences IVDMD and final pH and that rye has a greater disappearance of dry matter and lower final pH than corn under in vitro conditions.

Predicting the Degradability of Bioceramics through a DFT-based Descriptor

Bioceramics have attracted extensive attention for bone defect repair due to their excellent bioactivity and degradability.However,challenges remain in matching the rate between bioceramic degradation and new bone formation,necessitating a deeper understanding of their degradation properties.In this study,density functional theory(DFT)calculations was employed to explore the structural and electronic characteristics of silicate bioceramics.These findings reveal a linear correlation between the maximum isosurface value of the valence band maximum(VBM_(Fmax))and the degradability of silicate bioceramics.This correlation was subsequently validated through degradation experiments.Furthermore,the investigation on phosphate bioceramics demonstrates the potential of this descriptor in predicting the degradability of a broader range of bioceramics.This discovery offers valuable insights into the degradation mechanism of bioceramics and holds promise for accelerating the design and development of bioceramics with controllable degradation.

Evaluation of ruminal methane and ammonia formation and microbiota composition as affected by supplements based on mixtures of tannins and essential oils using Rusitec

Background Dietary supplements based on tannin extracts or essential oil compounds(EOC)have been repeatedly reported as a promising feeding strategy to reduce the environmental impact of ruminant husbandry.A previous batch culture screening of various supplements identified selected mixtures with an enhanced potential to mitigate ruminal methane and ammonia formation.Among these,Q-2(named after quebracho extract and EOC blend 2,composed of carvacrol,thymol,and eugenol)and C-10(chestnut extract and EOC blend 10,consisting of oregano and thyme essential oils and limonene)have been investigated in detail in the present study with the semi-continuous rumen simulation technique(Rusitec)in three independent runs.For this purpose,Q-2 and C-10,dosed according to the previous study,were compared with a non-supplemented diet(negative control,NC)and with one supplemented with the commercial EOC-based Agolin^(R) Ruminant(positive control,PC).Results From d 5 to 10 of fermentation incubation liquid was collected and analysed for pH,ammonia,protozoa count,and gas composition.Feed residues were collected for the determination of ruminal degradability.On d 10,samples of incubation liquid were also characterised for bacterial,archaeal and fungal communities by high-throughput sequencing of 16S rRNA and 26S ribosomal large subunit gene amplicons.Regardless of the duration of the fermentation period,Q-2 and C-10 were similarly efficient as PC in mitigating either ammonia(-37%by Q-2,-34%by PC)or methane formation(-12%by C-10,-12%by PC).The PC was also responsible for lower feed degradability and bacterial and fungal richness,whereas Q-2 and C-10 effects,particularly on microbiome diversities,were limited compared to NC.Conclusions All additives showed the potential to mitigate methane or ammonia formation,or both,in vitro over a period of 10 d.However,several differences occurred between PC and Q-2/C-10,indicating different mechanisms of action.The pronounced defaunation caused by PC and its suggested consequences apparently determined at least part of the mitigant effects.Although the depressive effect on NDF degradability caused by Q-2 and C-10 might partially explain their mitigation properties,their mechanisms of action remain mostly to be elucidated.

Removal of kathon by UV-C activated hydrogen peroxide:Kinetics,mechanisms,and enhanced biodegradability assessment

Kathon(CMI-MI),a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one(CMI)and 2-methyl-4-isothiazolin-3-one(MI),was extensively used in industry as a nonoxidizing biocide or disinfectant.However,it would show adverse effects on aquatic life when it is discharged into surface water.In this study,the removal performance,parameter influence,degradation products and enhancement of subsequent biodegradation of CMI-MI in UV/H_(2)O_(2)system were systematically investigated.The degradation rate of CMI-MI could reach 90%under UV irradiation for 20 min when the dosage of H_(2)O_(2)was 0.3 mmol·L^(–1).The DOC(dissolved organic carbon)mineralization rate of CMI-MI could reach 35%under certain conditions([H_(2)O_(2)]=0.3 mmol·L^(–1),UV irradiation for 40 min).kobs was inversely proportional to the concentration of CMI-MI and proportional to the concentration of H_(2)O_(2).The degradation rate of CMIMI was almost unchanged in the pH range from 4 to 10.Except the presence of CO_(3)^(2-)inhibited the removal rate of CMI-MI,SO_(4)^(2-),Cl^(-),NO_(3)^(-),and NH_(4)^(+) did not interfere with the degradation of CMI-MI in the system.It was found that UV/H_(2)O_(2)system had lower energy consumption and more economic advantage compared with UV/PS system by comparing the EEO(electric energy per order)values under the same conditions.Two main organic products were identified,namely HCOOH and CH_(3)NH_(2).There’s also the formation of Cl^(-)and SO_(4)^(2-).After UV and UV/H_(2)O_(2)photolysis,the biochemical properties of CMI-MI solution were obviously improved,especially the UV/H_(2)O_(2)treatment effect was better,indicating that UV/H_(2)O_(2)technology is expected to combine with biotechnology to remove CMI-MI effectively and environmentally friendly from wastewater.

Nanostructured ZnO/BiVO_(4)I-scheme heterojunctions for piezocatalytic degradation of organic dyes via harvesting ultrasonic vibration energy

BiVO_(4)porous spheres modified by ZnO were designed and synthesized using a facile two-step method.The resulting ZnO/BiVO_(4)composite catalysts have shown remarkable efficiency as piezoelectric catalysts for degrading Rhodamine B(RhB)unde mechanical vibrations,they exhibit superior activity compared to pure ZnO.The 40wt%ZnO/BiVO_(4)heterojunction composite displayed the highest activity,along with good stability and recyclability.The enhanced piezoelectric catalytic activity can be attributed to the form ation of an I-scheme heterojunction structure,which can effectively inhibit the electron-hole recombination.Furthermore,hole(h+)and superoxide radical(·O_(2)^(-))are proved to be the primary active species.Therefore,ZnO/BiVO_(4)stands as an efficient and stable piezoelectric catalyst with broad potential application in the field of environmental water pollution treatment.

Poly(lactic acid)/Poly(butylene adipate-co-terephthalate)films with simultaneous high oxygen barrier and fast degradation properties

Although poly(lactic acid)(PLA)is a good environmentally-friendly bio-degradable polymer which is used to substitute traditional petrochemical-based polymer packaging films,the barrier properties of PLA films are still insufficient for high-barrier packaging applications.In this study,oxygen scavenger hydroxyl-terminated polybutadiene(HTPB)and cobalt salt catalyst were incorporated into the PLA/poly(butylene adipate-co-terephthalate)(PLA/PBAT),followed by melting extrusion and three-layer co-extrusion blown film process to prepare the composite films.The oxygen permeability coefficient of the composite film combined with 6 wt%oxygen scavenger and 0.4 wt%catalyst was decreased significantly from 377.00 cc·mil·m^(-2)·day^(-1)·0.1 MPa^(-1) to 0.98 cc·mil·m^(-2)·day^(-1)·0.1 MPa^(-1),showing a remarkable enhancement of 384.69 times compared with the PLA/PBAT composite film.Meanwhile,the degradation behavior of the composite film was also accelerated,exhibiting a mass loss of nearly 60%of the original mass after seven days of degradation in an alkaline environment,whereas PLA/PBAT composite film only showed a mass loss of 32%.This work has successfully prepared PLA/PBAT composite films with simultaneously improved oxygen barrier property and degradation behavior,which has great potential for high-demanding green chemistry packaging industries,including food,agricultural,and military packaging.

Dynamic Regulation of Hydrogen Bonding Networks and Solvation Structures for Synergistic Solar‑Thermal Desalination of Seawater and Catalytic Degradation of Organic Pollutants

Although solar steam generation strategy is efficient in desalinating seawater,it is still challenging to achieve continuous solar-thermal desalination of seawater and catalytic degradation of organic pollutants.Herein,dynamic regulations of hydrogen bonding networks and solvation structures are realized by designing an asymmetric bilayer membrane consisting of a bacterial cellulose/carbon nanotube/Co_(2)(OH)_(2)CO_(3)nanorod top layer and a bacterial cellulose/Co_(2)(OH)_(2)CO_(3)nanorod(BCH)bottom layer.Crucially,the hydrogen bonding networks inside the membrane can be tuned by the rich surface–OH groups of the bacterial cellulose and Co_(2)(OH)_(2)CO_(3)as well as the ions and radicals in situ generated during the catalysis process.Moreover,both SO_(4)^(2−)and HSO_(5)−can regulate the solvation structure of Na^(+)and be adsorbed more preferentially on the evaporation surface than Cl^(−),thus hindering the de-solvation of the solvated Na^(+)and subsequent nucleation/growth of NaCl.Furthermore,the heat generated by the solar-thermal energy conversion can accelerate the reaction kinetics and enhance the catalytic degradation efficiency.This work provides a flow-bed water purification system with an asymmetric solar-thermal and catalytic membrane for synergistic solar thermal desalination of seawater/brine and catalytic degradation of organic pollutants.

Residual feed intake in beef cattle and its association with carcass traits, ruminal solid-fraction bacteria, and epithelium gene expression

Background: Residual feed intake(RFI) describes an animal’s feed efficiency independent of growth performance.The objective of this study was to determine differences in growth performance, carcass traits, major bacteria attached to ruminal solids-fraction, and ruminal epithelium gene expression between the most-efficient and the least-efficient beef cattle. One-hundred and forty-nine Red Angus cattle were allocated to three contemporary groups according to sex and herd origin. Animals were fed a finishing diet in confinement for 70 d to determine the RFI category for each. Within each group, the two most-efficient(n = 6; RFI coefficient =-2.69 ± 0.58 kg dry matter intake(DMI)/d) and the two least-efficient animals(n = 6; RFI coefficient = 3.08 ± 0.55 kg DMI/d) were selected. Immediately after slaughter, ruminal solids-fraction and ruminal epithelium were collected for bacteria relative abundance and epithelial gene expression analyses, respectively, using real-time PCR.Results: The most-efficient animals consumed less feed(P = 0.01; 5.03 kg less DMI/d) compared with the leastefficient animals. No differences(P > 0.10) in initial body weight(BW), final BW, and average daily gain(ADG) were observed between the two RFI classes. There were no significant RFI × sex effects(P > 0.10) on growth performance.Compared with the least-efficient group, hot carcass weight(HCW), ribeye area(REA), and kidney, pelvic, and heart fat(KPH) were greater(P ≤ 0.05) in the most-efficient cattle. No RFI × sex effect(P > 0.10) for carcass traits was detected between RFI groups. Of the 10 bacterial species evaluated, the most-efficient compared with least efficient cattle had greater(P ≤ 0.05) relative abundance of Eubacterium ruminantium, Fibrobacter succinogenes, and Megasphaera elsdenii, and lower(P ≤ 0.05) Succinimonas amylolytica and total bacterial density. No RFI × sex effect on ruminal bacteria was detected between RFI groups. Of the 34 genes evaluated in ruminal epithelium, the mostefficient cattle had greater(P ≤ 0.05) abundance of genes involved in VFA absorption, metabolism, ketogenesis, and immune/inflammation-response. The RFI × sex interactions indicated that responses in gene expression between RFI groups were due to differences in sex. Steers in the most-efficient compared with least-efficient group had greater(P ≤ 0.05) expression of SLC9 A1, HIF1 A, and ACO2. The most-efficient compared with least-efficient heifers had greater(P ≤ 0.05) m RNA expression of BDH1 and lower expression(P ≤ 0.05) of SLC9 A2 and PDHA1.Conclusions: The present study revealed that greater feed efficiency in beef cattle is associated with differences in bacterial species and transcriptional adaptations in the ruminal epithelium that might enhance nutrient delivery and utilization by tissues. The lack of RFI × sex interaction for growth performance and carcass traits indicates that sex may not play a major role in improving these phenotypes in superior RFI beef cattle. However, it is important to note that this result should not be considered a solid biomarker of efficient beef cattle prior to further examination due to the limited number of heifers compared with steers used in the study.

High-concentrate feeding upregulates the expression of inflammation-related genes in the ruminal epithelium of dairy cattle

Background： The objective of this study was to characterize the mRNA expression profile related to rumen epithelial inflammation through the in vivo and in vitro experiments. In the in vivo experiment, rumen papillae were collected from four dairy cows adapted to either a 40 % （LC） or 70 % （HC） concentrate feeds for microarray analysis. Results： Results showed that 245 differentially expressed genes （DEGs） were detected in the cows fed the HC relative to the LC diet. The DEGs were first annotated, and results revealed that the expression of inflammation- related genes, including IL-1t8, 1L-2, IL-22, CCL19, CCLS, CX3CR1, CXCL6, INHBE, LEPR, PRL, and TNFRSF9 found in the cytokine-cytokine receptor pathway were up-regulated in the HC-fed cows, indicating local inflammation in the rumen epithelium was triggered. The expression of IL-1~, 1l_-2, and IL-6 was further validated by qRT-PCR. To demonstrate whether there were relationships between cytokine mRNA expression and ruminal factors （pH and LPS）, the isolated ruminal epithelial cells were cultured in vitro. Results showed that the mRNA expression of IL-1, IL-2, IL-6, and IL-8 increased after the LPS treatment, while Iow-pH treatment elevated the mRNA expression of TNF-a, suggesting that Iow-pH coupled with higher levels of LPS in rumen of cows fed the HC may be mainly responsible for the triggered local ruminal inflammation. Conclusions： Our results indicate that ruminal local inflammation response might be triggered during HC feeding and these findings also enhance the knowledge of rumen epithelial adaptation to HC at the molecular level.

Does intra-ruminal nitrogen recycling waste valuable resources? A review of major players and their manipulation

Nitrogenous emissions from ruminant livestock production are of increasing public concern and, together with methane, contribute to environmental pollution. The main cause of nitrogen-(N)-containing emissions is the inadequate provision of N to ruminants, leading to an excess of ammonia in the rumen, which is subsequently excreted. Depending on the size and molecular structure, various bacterial, protozoal and fungal species are involved in the ruminal breakdown of nitrogenous compounds(NC). Decelerating ruminal NC degradation by controlling the abundance and activity of proteolytic and deaminating microorganisms, but without reducing cellulolytic processes, is a promising strategy to decrease N emissions along with increasing N utilization by ruminants. Different dietary options, including among others the treatment of feedstuffs with heat or the application of diverse feed additives, as well as vaccination against rumen microorganisms or their enzymes have been evaluated. Thereby, reduced productions of microbial metabolites, e.g. ammonia, and increased microbial N flows give evidence for an improved N retention. However, linkage between these findings and alterations in the rumen microbiota composition, particularly NC-degrading microbes, remains sparse and contradictory findings confound the exact evaluation of these manipulating strategies, thus emphasizing the need for comprehensive research. The demand for increased sustainability in ruminant livestock production requests to apply attention to microbial N utilization efficiency and this will require a better understanding of underlying metabolic processes as well as composition and interactions of ruminal NC-degrading microorganisms.

Effects of Neutral Detergent Soluble Fiber and Sucrose Supplementation on Ruminal Fermentation, Microbial Synthesis, and Populations of Ruminal Cellulolytic Bacteria Using the Rumen Simulation Technique (RUSITEC)

We evaluated the effects of neutral detergent soluble fiber （NDSF） and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique （RUSITEC）. The experiment had a 2x2 factorial design with two dosages of sucrose, low （ca. 0.26 g d-1, low-sucrose） and high （ca. 1.01 g d-1, high-sucrose）, and two dosages of supplied NDSF, low （1.95 g d-1, Iow-NDSF） and high （2.70 g d-1, high-NDSF）. Interactions between NDSF and sucrose were detected for xylanase activity from solid fraction and apparent disappearance of neutral detergent fiber （NDF） and hemicellulose, with the lowest values observed for high-NDSF and high-sucrose treatment. Supplemental NDSF appeared to increase the molar proportion of acetate and reduce that of butyrate; however, the effects of supplemental sucrose on VFA profiles depended upon NDSF amount. There was a NDSFxsucrose interaction for the production of methane. High-NDSF fermenters had lower ammonia-N production, greater daily N flow of solid- associated microbial pellets and total microorganisms, and greater microbial synthesis efficiency compared with low- NDSF fermenters. Supplementation with NDSF resulted in an increase in 16S rDNA copies of Ruminococcusflavefaciens and a reduction in copies of Ruminococcus albus. Supplementation with sucrose tended to increase the 16S rDNA copies ofR. albus from liquid fraction, but did not affect daily total microbial N flow and cellulolytic bacterium populations from solid fraction. These data indicate that the effects of the interaction between NDSF and sugars on ruminal fermentation and fiber digestion should be taken into account in diet formulation. Ruminal fermentation and metabolism of sugars warrant further investigation.

Changes in feed intake, nutrient digestion, plasma metabolites, and oxidative stress parameters in dairy cows with subacute ruminal acidosis and its regulation with pelleted beet pulp

The objectives of this study were to 1） determine the variation of nutrient digestion, plasma metabolites and oxidative stress parameters triggered by induced subacute ruminal acidosis （SARA）; and 2） evaluate the ability of pelleted beet pulp （BP） as a replacement for ground corn to alleviate SARA. Eight Holstein-Friesian cows were fed four diets during four successive17 day periods： 1） total mixed ration （TMR） containing 0% finely ground wheat （FGW） （WO）; 2） TMR containing 10% FGW （W10）; 3） TMR containing 20% FGW （W20）; and 4） TMR containing 10% BP as a replacement for 10% ground corn （BP10）. The SARA induction protocol reduced the mean ruminal pH from 6.37 to 5.94, and the minimum ruminal pH decreased from 5.99 to 5.41 from baseline to challenge period. Mean ruminal pH increased from 5.94 to 6.05, and minimum daily ruminal pH increased from 5.41 to 5.63, when BP was substituted for corn. The apparent digestibility of nutrients was not affected by the dietary treatments, except that the digestibility of neutral detergent fibre （NDF） and acid detergent fibre （ADF） was reduced in cows fed the W20 diet compared with cows fed the W0 and W10 diets, and cows fed the BP10 diet had higher NDF and ADF digestibility than the cows fed the W20 diet. Cows fed the W20 diet had a lower plasma concentration of 13-hydroxybutyrate （BHBA）, non-esterified fatty acids （NEFA）, cholesterol, triglyceride, and total antioxidative capacity （TAC）, and a higher plasma concentration of glucose, insulin, malonaldehyde （MDA）, super oxygen dehydrogenises （SOD）, and glutathione peroxidase （GSH-Px） than cows fed the W0 diet. Substitution of BP for corn increased concentrations of plasma BHBA and TAC, but decreased concentrations of plasma MDA. Our results indicate that reduction of fibre digestion; the concomitant increase of plasma glucose and insulin; the decrease of plasma BHBA, NEFA, cholesterol, and triglyceride; and changes of plasma oxidative stress parameters are highly related to SARA induced by W20 diets. These variables may be alternative candidates for SARA diagnosis. We also suggest that the substitution of BP for corn could reduce the risk of SARA, increase fibre digestion, and improve the antioxidant status in dairy cows.

Screening and characterization of a novel ruminal cellulase gene(Umcel-1) from a metagenomic library of gayal(Bos frontalis)

Gayal is a rare semi-wild bovine species found in the Indo-China. They can graze grasses, including bamboo leaves, as well as reeds and other plant species, and grow to higher mature live weights than Yunnan Yellow cattle maintained in similar harsh environments. The aim of this study was to identify specific cellulase in the gayal rumen. A metagenomic fosmid library was constructed using genomic DNA isolated from the ruminal contents of four adult gayals. This library contained 38400 clones with an average insert size of 35.5 kb. The Umcel-1 gene was isolated from this library. Investigation of the cellulase activity of 24 random clones led to the identification of the Umcel-1 gene, which exhibited the most potent cellulase activity. Sequencing the Umcel-1 gene revealed that it contained an open reading frame of 942 base pairs that encoded a product of 313 amino acids. The putative gene Umcel-1 product belonged to the glycosyl hydrolase family 5 and showed the highest homology to the cellulase （GenBank accession no. YP_004310852.1 ） from Clostridium lentocellum DSM 5427, with 44% identity and 62% similarity. The Umcel-1 gene was heterologously expressed in Escherichia coil BL21, and recombinant Umcel-1 was purified. The activity of purified recombinant Umcel-1 was assessed, and the results revealed that it hydrolyzed carboxymethyl cellulose with optimal activity at pH 5.5 and 45~C. To our knowledge, this study provides the first evidence for a cellulase produced by bacteria in gayal rumen.

Effect of a bacterial inoculum and additive on dry matter in situ degradability of sugarcane silage

The objective of this study was to evaluate the effect of adding a bacterial inoculum and a handmade additive to sugarcane silage（SCS） on the in situ digestibility of dry matter（DM）. The treatments were： T1） sugarcane silage（SCS） and T2） sugarcane silage with 1% inoculum and 1% additive（SCS＋）. The bacterial inoculum consisted of 10.0% molasses, 1.0% yogurt, 5.0% chicken manure, 0.5% urea, and 83.0% water, and the additive was formulated with 1.0% urea, 0.1% ammonium sulfate, and 0.25% phosphorus. In situ dry matter digestibility（DMD） was determined using the nylon bag technique with four cows equipped with ruminal fistulas. Cows were fed with ensiled sugarcane supplemented with 1 kg of commercial concentrate. 5 g of ground sample for each sugarcane treatment were weighted in nylon bags and incubated for 4, 8, 12, 24, 48, and 72 h in a completely randomized design with six replicates. The DMD（%） was higher（P〈0.05） for SCS＋ for all incubation times when compared with SCS. There were no differences in ruminal p H between the treatments for all the incubation times. The data suggested that the sugarcane silage with bacterial inoculum and additive could be an alternative for providing forage for ruminants during the season of low growth and quality grass.

Effects of Molasses-Urea Supplementation on Weight Gain,Ruminal Fermentation and Major Microbe Populations of Winter-Grazing Sheep in Inner Mongolia

The present experiment was conducted to determine the effects of Molasses-Urea Supplementation （MUS） on weight gain, ruminal fermentation and major microbial populations in sheep on a winter grazing regime in Inner Mongolia. Total 40 sheep, allowed free consumption of MUS after grazing, served as a treatment group, while 30 sheep, fed only by pasture grazing, served as a control group. Ruminal fermentation parameters, consisted of pH, Bacterial Crude Protein （BCP） and ammonia nitrogen （NH3-N） were measured. In addition, numbers of five symbiotic bacteria were investigated. The results showed as follows： the average daily weight gain, concentration of NH3-N and numbers of protozoa were significantly higher （p〈0.05） in the treatment group than those in the control group. Contrastingly, no significant difference was found in BCP concentration and pH between the two groups. At the end of the experiment, the populations of Selenomonas ruminantium, Anaerovibrio lipolytica, Fibrobacter succinogenes, Ruminococcus flaveciens and Ruminococcus albus in the treatment group were significantly higher than those of the control group （p〈0.05）. These results demonstrated that greater weight gain could be induced during winter in Inner Mongolia by improved nutritional status through promotion of microbial populations using urea and sugar.

Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake, digestibility, plasma metabolites, ruminal fermentation and fecal microflora of male Chinese Holstein calves

Twenty-eight male, weaned Chinese Holstein calves（（156.8±33.4） kg） were used to investigate the effects of dietary forage to concentrate ratio（F：C） and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement： whole-length forage（WL） with low F：C（50：50）; WL with high F：C（65：35）; short-length forage（SL） with high F：C（65：35）; and SL with low F：C（50：50）. Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size（-50% particles 〉19 mm）. Dry matter intake（DMI） and organic matter（OM） intake was increased by increasing both F：C（P〈0.01） and forage length（FL）（P〈0.05）, while acid detergent fiber（ADF） and neutral detergent fiber（NDF） intakes were only increased by increasing the F：C（P〈0.01）. The digestibility of NDF was increased as the FL increased（P〈0.01）, and it was also affected by interaction between F：C and FL（P〈0.05）. Cholesterol（CHO）（P〈0.01）, leptin（LP）（P〈0.05）, and growth hormone（GH）（P〈0.01） concentrations in plasma were increased as dietary F：C increased. A significant increase in plasma triglyceride（TG）（P〈0.01）, insulin（INS）（P〈0.05）, and GH（P〈0.01） levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F：C diets were significantly lower than those in high F：C treatment（P〈0.05）. Increasing the F：C enhanced ruminal acetic acid（P〈0.05） and acetic acid/propionic acid（P〈0.01）. Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F：C groups（P〈0.05）. Lower fecal scores（higher diarrhea rate） were observed in calves fed with SL hay compared to WL hay（P〈0.05）. Denatured gradient gel electrophoresis（DGGE） bands and richness index（S） were significantly affected by the interaction between F：C and FL（P〈0.05）, under high F：C, band numbers and richness index from WL group were higher than that from SL group（P〈0.05）, whereas there were no differences between WL andSL groups under low F：C（P〉0.05）. Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F：C（65：35） diet is suitable for weaned calves.

Effect of Soybean Peptides on in vitro Ruminal Fermentation and Microbial Population

This study was conducted to investigate the effect of Soybean Peptides(SPs) on ruminal fermentation and microbial diversity in vitro. Four levels of SPs supplements(0, 0.25%, 0.50% and 0.75% dry matter basis) were tested. p H, NH3-N, Neutral Detergent Fiber(NDF), Acid Detergent Fiber(ADF), Dry Matter Digestibility(DMD) and the Total Volatile Fatty Acid(TVFA) were measured at 6, 24, 48 h of in vitro mixed incubation the fluids. Microbial populations were determined at 24 h and Microbial Proteins(MCP) were determined at 24 and 48 h. The gas production after 48 h in vitro incubation presented linear growth(p<0.05) and the highest content was the level of 0.5% SPs(dry matter basis). NH3-N concentration reached the highest concentration with 0.75%(dry matter basis) at 48 h. p H linearly increased(linear, p<0.05) from 6 to 48 h. The digestion of DMD increased with increasing doses of SPs at 24 h. NDF and ADF linearly(p<0.01) decreased by adding SPs. The concentration of TVFA linearly increased(p<0.05) at 6, 24 and 48 h, and reached the highest concentration at the level of 0.75%(dry matter basis). SPs decreased(p<0.05) the molar proportion of acetate and propionate, respectively at 24 and 48 h. Acetat to Propionate ratio(A/P; linear, p<0.05) increased at 48 h, and reached the greatest value at the level of 0.75%(dry matter basis) at 48 h. The populations of rumen Ruminococcus flavefaciens(R. flavefaciens), Ruminococcusalbus(R. albus), Fibrobacter succinogenes(F. succinogenes), Butyrivibrio fibrisolvens(B. fibrisolvens), Streptococcus bovis(S.bovis), Ruminobacter amylophilus(R. amylophilus) and Succinimonas amylolytica(S. amylolytica) were analyzed based on the total rumen bacterial 16 S ribosomal deoxyribonucleic acid(r DNA). The relative abundance of R. flavefaciens and R. albus increased at 24 h, but the relative abundance of F. succinogenes decreased at this time. The incubation of SPs had no effect on the abundance of S. bovis and R. amylophilus. The relative abundance of B. fibrisolvens and S. amylolytica reached the greatest value(p<0.05) at middle doses of SPs inclusion at 24 h. The value of MCPs linearly increased(p<0.05) at 24 and 48 h. These results showed that SPs could improve in vitro fermentation and nutrient digestion of feed substrates, and had the ability to modulate the ruminal fermentation pattern by regulating the composition of functional rumen microbes. Hence, SPs might be a potential feed additive applied in the diets of ruminants.

Mineral Concentrations and Rumen Degradability of Biodegraded <i>Enterolobium cyclocarpum</i>(Jacq) and <i>Pterocarpus santalinoides</i>(L’Her) with <i>Aspergillus niger</i>

The effects of solid state fermentation on the mineral concentrations and in sacco degradation characteristics of dry matter in two multipurpose tree leaves was investigated. Biodegraded Enterolobium cyclocarpum (EC) and Pterocarpus santalinoides (PS) leaves were previously inoculated with Aspergillus niger and incubated at 30&degC for five incubation periods (0, 7, 14, 21 and 28 days). After each incubation period, samples were oven dried at 60&degC, allowed to cool and ground for mineral analysis and in sacco dry matter degradability. Three fistulated West African Dwarf (WAD) rams (Ovis aries) were then used for the dry matter degradability. Five grams of each sample was emptied into nylon bag (Polymon, Switzeland) with pore size of 4 μ and effective size of 5 cm × 18 cm and incubated in the rumen of the fistulated animals for 6, 12, 24, 48, 72, and 96 h. The results showed that the mineral contents of biodegraded EC samples were affected by incubation period. Mean values of Ca, Cu, K, Na, and Zn were significantly increased (0.05), while mean values of Fe, Mg, and Mn were first reduced before significantly increasing (0.05). However, the composition of P showed significant reduction (0.05) up to day 28 where no change was observed. Mineral concentrations in biodegraded PS were also affected by incubation periods. Values of Ca, Fe, K, Mg, Mn, Na, and Zn were significantly increased (0.05). However values of Cu, and Fe only increased after day 14, while the value of P was reduced significantly over the different incubation periods. Potential degradability (PD) for biodegraded EC was highest at day 0 (50.79%) but not significantly different from potential degradability of longer incubation periods to day 28 (48.68%). PS had higher PD than EC. In spite of high PD values, PS comparatively degraded faster than EC. Effective degradability (ED) for EC was highest for day28 (36.71%) and not significantly different from days 21 (34.83%) and 7 (35.29%) but significantly different from days 0 (31.32%) and 14 (31.75%) respectively. However, the ED for PS was highest for day 0 (31.39) samples and significantly differed from other incubation periods, further increase in period only showed lower but similar ED values for days 7 (27.52%), 14 (26.76%), 21 (27.42%) and 28 (26.86%) respectively. In this study, the continued reduction in P concentrations in both biodegraded EC and PS suggest that Aspergillus niger has preferential demand for P and in sacco degradation showed increase in PD and ED values for fungal biodegraded EC and reduction in PS, suggesting improved quality of EC.

Effects of Supplementation with Increasing Levels of Energy Concentrate on the Productive Response and Ruminal Digestion of Dairy Cows Grazing Lucerne Pasture

The aim of the study was to determine the effect of three levels of energy concentrate intake on dry matter (DM) and energy intake, milk yield and composition, rumen environment and pasture neutral detergent fiber (NDF) digestion. Twelve Holstein multiparous cows in early lactation (69.0 ± 5 days postpartum) producing 32.8 (±4.0) kg milk were assigned to three treatments at (kg/cow day) 3.5 (T3.5), 7.0 (T7.0) and 10.5 (T10.5) kg concentrate in a 3 × 3 Latin Square design. Parameters of ruminal environment and neutral detergent fiber (NDF) digestion were obtained using 3 additional rumen cannulated cows. Concentrate was composed (as fed) by corn grain (68%), soybean meal (22%), wheat bran (8%) and a vitamin-mineral premix including monensin and thoroughly consumed. Yields (kg/cow day-1) of milk, 4% fat corrected milk (4% FCM 4%) and energy corrected milk (ECM) resulted higher (p p -1 without effects on yield of milk fat. Concentrations (g/100 g) of milk fat (3.19), protein (2.97), total solids (11.75), non-fat solids (8.60) and casein (2.40) did not differ. Milk lactose content (g/100 g) was linearly increased (p p p p p < 0.05) in T3.5 due to the increase in acetate and butyrate while the acetate: Propionate ratio remained unchanged. Pasture NDF digestion was affected as concentrate intake increased. To increase milk protein yield and reduce concentrations of N-NH3 in rumen and milk, feeding an energy concentrate at 41% of total DM intake resulted an effective tool.