bluuebunny/crossref_metadata_2025 huggingface dataset:
Large Scale Translucent Y-α-Sialon Ceramics Prepared by Two-Steps Hot Pressing
Authors: Xu Jiu Jun , Shan Ying Chun , Li Jiang Tao , Cao Yong Ge
Published: March 2010

Large scale translucent yttrium-doped α-sialon (80 mm in diameter) with the composition of Y0.4Si9.6Al2.4O1.2N14.8 (m=1.2 and n=1.0) was prepared by two-steps hot pressing sintering (first heating to 1850 °C holding for 30 min, then continue heating to 1900 °C holding for 30 min) at 25 MPa in nitrogen, and the optical property was approached over the wavelength range 900-5000 nm. The results showed that dense sample was obtained and its assemblage only consisted of single α-sialon phase. The large scale sialon had uniform and higher infrared transmittance property. The maximum infrared transmittance for 1.0 mm thick specimen could reach 66% at 3200 nm. It is attributed to the dense, uniform, equaxed microstructure. In addition to high optical transmission property, the sample showed higher hardness of 20 GPa and better fracture toughness of 5 MPa•m1/2.
Frequency Dependence of AC Conductivity in Iron Phosphate Glasses
Authors: Li Tong Wei , Tang Zheng Xin , Gong Xiao Yang , Liu Ying Biao , Guo Zhi Fang
Published: March 2010

Based on Jonscher power law, frequency dependence of ac conductivity of 40Fe2O3–60P2O5 glasses were investigated in a relatively high temperature range. Results indicated the power law exponent first decreases with increasing temperature, reached a minimum at a certain temperature and then in- creases again. Preliminary theoretical explanations and predictions for this phenomenon were presented.
Preparation and Grain Growth of Pb(Zr0.95Ti0.05)O3 Porous Ceramics Prepared by One-Step Pyrolysis Process Using Non-Aqueous Pechini Method
Authors: Fan Hui Qing , Qiu Shao Jun
Published: March 2010

Pb(Zr0.95Ti0.05)O3 powders were prepared by one-step pyrolysis process from non-aqueous Pechini method. Porous Pb(Zr0.95Ti0.05)O3 ceramics were obtained by sintering the chemically prepared powders and the grain growth in the porous ceramics was investigated. For the powders calcined at 450 °C for 10 h by one-step pyrolysis process, the grain growth exponent value was observed to be 3.3 while the apparent activation energy was 193 kJ/mol.
Preparation of GDC Nanopowders and GDC/YSZ Core-Shell Nanocomposites
Authors: Huang Zuo Cai , Li Bin , Liu Wei , Pan Wei
Published: March 2010

Nanocrystalline GDC as small as 5 nm was successfully synthesized via the co-precipitation method. GDC/YSZ core-shell nanocrystals, which were GDC nanocrystals overcoated by a thin YSZ layer, was successfully synthesized by the addition of GDC nanocrystals in the YSZ source solution using sol-gel method. The core-shell structure was supported by its high-resolution transmission electron microscopy results and the composition was investigated by EDX method.
Novel Fabrication Method of FGM Containing Nano-Particles - Centrifugal Mixed-Powder Method -
Authors: Watanabe Yoshimi , Sato Hisashi
Published: March 2010

One of the fabrication methods for functionally graded materials (FGMs) is a centrifugal method, which is an application of the centrifugal casting technique. In the method, a centrifugal force applied to a homogeneous molten composite assists the formation of the desired gradation. The compositional gradient is then achieved primarily by the difference in the centrifugal force produced by the difference in density between the molten metal and solid particles. The centrifugal method has the advantage that it is possible to fabricate large size products with low cost. However, disadvantage of the centrifugal method is the difficult for the gradual distribution of small particles. In this study, we proposed a novel fabrication method, centrifugal mixed-powder method, by which we can obtain FGMs containing nano-particle. On first of this processing, powder mixture of functional nano-particle and matrix material is inserted into rotating mold. After that, matrix ingot is melted in crucible and then the melt is poured into the rotating mold with powder mixture. At that time, powder of matrix material is melted by matrix melt poured from crucible. Finally, an FGM ring with functional nano-particles distributed on its surface is obtained. Using this processing method, Al-based FGMs containing TiO2 nano-particles or SiC particles on its surface were fabricated.
Dependence of Particle Parameters in Flight and Coating Character on Power of the Electric Supply at Plasma Spraying of TiO2
Authors: Ctibor Pavel , Hrabovský Milan
Published: March 2010

The influence of input power on the spayed powder and final coating was quantified for particular case of water-stabilized plasma spray torch (WSP®) and ceramic coating formed from titanium dioxide (TiO2). All other spray setup parameters were fixed during the experiment with electric supply power as the only variable factor. In-flight particles were characterized by Doppler particle velocimetry, microstructure of the coatings was observed by microscopic techniques and computer image analysis and phase composition was studied by X-ray diffraction. Various mechanical properties were measured – microhardness, surface roughness and wear resistance in a slurry. The results indicate that the higher power means better coating quality – its microstructure and mechanical performance. This substantial difference has the same trend for both power supplies utilized for the testing.
Fabrication of High Thermal Conductivity β-Si3N4 Ceramics at Relatively Low Temperature Using MgSiN2 as Additives
Authors: Peng Gui Hua , Liang Zhen Hua , Lu Feng Qi , Liu Qian , Li Wen Lan
Published: March 2010

Silicon nitride ceramics with MgSiN2 as additives were sintered by hot pressing at 1600° ~ 1750 °C for 1-12 h under uniaxial pressure of 20 MPa. The specimens were characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy and photothermal deflection spectroscopy. After sintered at 1750°C for 1 h, the thermal conductivity of the material was 90 W·m-1·K-1. The thermal conductivity could remarkably increase to 120 W·m-1·K-1 by prolonging the dwell time from 1 h to 12 h. The present work demonstrated that MgSiN2 additives were effective to improve the thermal conductivity of β-Si3N4 ceramic.
Preparation of Porous SiO2 Ceramics by Gelcasting
Authors: Li Sha , Du Hai Yan , Yang Duo , Guo Ji Ping , Song Di , Li Gui Yan
Published: March 2010

Porous SiO2 ceramics had been successfully prepared by gelcasting. The open porosity of obtained samples was between 0.40 and 0.46, which reached its maximum at 1100°C. The change of line shrinkage rate was opposite to the open porosity. The microstructure was investigated though X-ray diffraction (XRD) and scanning electronic microscope (SEM).
Microwave Absorption Properties of Nano-Iron Epoxy Resin-Based Composite Material
Authors: Gong Xiao Yang , You Jing Han , Zhang Zhen , Yang Lei Lei
Published: March 2010

A novel nano-iron particulate reinforced polymer-based composite material against electromagnetic pollution was prepared for household appliances. The attenuation, permittivity and various absorbing aspects of the composite materials were investigated. Results indicated that the composite materials exhibit promising effects of microwave absorption. The attenuation was affected by volume fraction of nano-iron powders. A single microwave absorption medium won’t be appreciable, and a combination of different microwave absorption materials is suggested.
First-Principles Study on the Three-Dimensional Structure of Graphane
Authors: Ju Wei Wei , Wang Hui , Li Tong Wei , Fu Zhen Ya , Zhang Qing Guo
Published: March 2010

Four kinds of three-dimensional structure of graphane are investigated using first-principles method. It is found that the energy of four different structures has little difference, so the conclusion can be drawn that the four structures are likely to exist synchronously in experiments.
Morphology Control of Si-Based Nanostructures by Catalyst-Assisted Pyrolysis of Preceramic Precursors
Authors: Zhu Na , Peng Zhi Jian , Wang Cheng Biao , Fu Zhi Qiang , Qi Long Hao , Miao He Zhuo
Published: March 2010

This paper describes a method of catalyst-assisted pyrolysis of preceramic precursors for the synthesis of Si-based nanostructures. Through tuning the processing conditions, clustered SiOx amorphous nanowires, bundled single-crystalline Si3N4 nanowires, Y-shape and network-like branched single-crystalline Si3N4 nanostructures, aligned single-crystalline Si3N4 nanowires, and so on, have been synthesized. The results reveal that it is a simple and easy-controlling method, and has potential for mass production of nanomateirals of controlled morphology.
Analysis of Profitability in Chinese Listed Ceramic Companies
Authors: Hua Rong Hui , Zhou Li Wei
Published: March 2010

There are seven ceramic companies listed in Shanghai and Shenzhen Stock Exchanges. Because they belong to traditional industry sector, the profitability of most companies is weak. Listed companies experienced equity reform from 2005. In the paper, we analyze the impact of the reform and the impact of global financial crisis on those companies.
Growth Mechanism and Optical Property of a Novel ZnO Mesoscale Superstructure
Authors: Qu Xiu Rong , Jia De Chang
Published: March 2010

ZnO mesoscale superstructures (ZMS) with the sizes of 2 to 6 µm were synthesized by a simple solution method without any additives. The novel ZMS were assembled by numerous nanoparticles with the diameter of less than 100 nm, and no pores were found. X-ray diffraction shows that the ZMS mainly evolved in solution. The formation process of the ZMS accords to the classical theory of nucleation and growth. Photoluminescence (PL) analysis shows a sharp UV emission peak at 392 nm and a weak broad green-yellow emission peak at about 600 nm.
Crystallization Behavior of Mg-Doped Titania
Authors: Mei Le Fu , Liang Kai Ming
Published: March 2010

The Mg-doped TiO2 was prepared by Sol-gel method at low temperature. The crystallization of TiO2 was studied by DTA, it was shown that the phase transition temperature of the Mg (NO3)2-doped TiO2 from amorphous to anatase and then to rutile significantly reduce. The XRD results show that the Mg-doped TiO2 has anatase and rutile annealed at 600 °C. Studies of photo-catalytic degradation show that the photo-catalytic activity of Mg-doped TiO2 thin film is higher than that of non-doped TiO2.
Preparation of Mullite by Coating Al(OH)3 on the Surface of Fly Ash
Authors: Xu Rui , Du Hai Yan , Li Shi Hui , Du Xiong Wei , Zheng Qiang , Zuo Zhi Hong
Published: March 2010

Porous mullite were prepared by coating Al(OH)3 on the surface of the particles of waste fly ash. The effects of content of urea on formation of mullite and sintering temperature on microstructure of mullite were investigated by XRD and SEM analysis. It was showed that two kind mullite were obtained, one was growing from original Needle-like mullite existing in original ashfly, and the other was formed through by the reaction between glassy phase and Al2O3 coated on spherical waste fly ash.
A Polymer Complexing Route for Low Temperature Synthesis of Perovskite Lanthanum Aluminate Powder
Authors: Li Shu Ai , Bergman Bill , Zhao Zhe
Published: March 2010

Lanthanum aluminate powders were prepared via a polymer complexing method by using PEG as complexing agent. The LaAlO3 powder was characterized by XRD and SEM. The influence of processing parameters such as molar ratio of PEG monomers to metal cations (PEG:Men+) and aging process on the phase purity and powder morphology were investigated. The calcined powder with the PEG:Men+ ratio larger than 2:1 may contain the secondary phase, namely La2O3. The formation of phase pure LaAlO3 powder occurs when the PEG:Men+ ratio is 1:1 or enough gelation time is involved. Although the phase pure powder is obtained by this PEG method, all the single phase LaAlO3 powders are found to have seriously aggregated particles. The weakly agglomerated powder morphology is only found in the powders which contain La2O3.
Combustion Synthesis of Nanocrystalline Al2O3 Powders Using Urea as Fuel: Influence of Different Combustion Aids
Authors: Meng Fan Cheng , Tian Zhong Qing , Zhang Fan , Tian Chang Cheng , Huang Wei Jiu
Published: March 2010

The present article reports the results of studies related to the synthesis of nano-crystalline alumina powder by combustion process using different combustion aids. Aluminium nitrate as oxidant and urea as fuel were used as reagents. Starch and ammonium nitrate were compared as combustion aids. The results showed that employment of starting fuel with combustion aids resulted in synthesizing nano-crystalline alumina powder with small crystalline size (<20 nm) and fine agglomerates. By using combustion aid, the energetics of the combustion reaction has been changed. The different selection of combustion aid determines the characteristics of the as-synthesized powders.
The responses of growing pigs exposed to cold with varying amounts of straw bedding
Authors: Hayne S. M. , Tennessen T. , Anderson D. M.
Published: March 2010

Confinement housing of pigs allows optimal thermal conditions to be maintained thus reducing the thermal demand placed on the pig. Alternatives tend to cost less to construct, use less energy to operate and possibly have higher welfare standards than conventional housing; however, the thermal demand on the pig could be greater. An experiment consisting of two trials was conducted to examine the effect of varying amounts of straw bedding on the performance and behaviour of growing pigs while exposed to cold conditions. Four straw bedding treatments were studied and referred to as Least (20 kg), Medium-low (80 kg), Medium-high (137 kg) and Most (196 kg) straw usage. Results from the analysis of the two trials indicated that pigs with the three greatest amounts of straw gained more weight than pigs with the Least straw (P < 0.05). Pigs with the Least straw huddled with a sternal posture and piled more than pigs in the other three treatments (P < 0.05). Pigs with the two highest amounts of straw adopted a lateral posture while huddling more than pigs with the two lowest amounts of straw (P < 0.05). Pigs with the Most straw were also lying alone with a lateral posture more than pigs with the two lowest amounts of straw, and burrowed more than pigs in the other three treatments (P < 0.05). This study provides information on the adaptability of growing pigs exposed to different environmental conditions. Straw bedding was shown to be an important resource used by pigs to aid in thermoregulation in cold environments. Behavioural responses were also shown to be an effective means of adaptation. Key words: Straw bedding, cold conditions, thermoregulation, pigs, behaviour, performance
Dietary polyunsaturated fatty acids significantly affect laying hen lymphocyte proliferation and immunoglobulin G concentration in serum and egg yolk
Authors: Wang Y. W. , Cherian G. , Sunwoo H. H. , Sim J. S.
Published: March 2010

Forty eight (48) Single Comb White Leghorn laying hens 24 wk of age were housed in cages and were fed wheat-soybean meal based diets with added oils [sunflower oil (SO), animal oil (AO), linseed oil (LO), or fish oil (FO)] at 5%. After 5 wk on experimental diets, spleen lymphocytes and peripheral blood lymphocytes were obtained from six birds and assayed for polyclonal mitogen Con A-induced proliferative response and the proportions of lymphocyte subsets. The IgG concentration in serum and egg yolk was also measured. Feeding LO and FO resulted in an increase in longer-chain n-3 polyunsaturated fatty acids (PUFA) (C20:5n-3, C22:5n-3, and C22:6n-3) with a concurrent decrease of C20: 4n-6 in spleen lymphocytes (P < 0.05). The highest enrichments of the longer-chain n-3 PUFA were achieved by feeding FO. The content of C20: 4n-6 was higher (P < 0.05) in the lymphocytes of hens fed AO and SO. Subsequently, Con A-stimulated proliferation of spleen and peripheral blood lymphocytes were significantly suppressed (P < 0.05) in the chicks fed high n-3 PUFA diets (LO and FO). The LO diet increased (P < 0.05) the IgG concentration in laying hen serum. The SO diet reduced (P < 0.05) IgY content in egg yolk. Dietary fatty acids did not affect (P > 0.05) the proportions of lymphocyte subsets in spleen and blood lymphocytes. It is indicated that the ratio of n-6 to n3 PUFA plays a major role in modulating cell-mediated and humoral immune responses of laying hens, and various n-3 fatty acids possess different potencies of immunomodulation. Key words: Laying hens, n-3 polyunsaturated fatty acids, lymphocyte proliferation, immunoglobulin G, immunoglobulin Y
Effect of the substitution of urea for soybean meal on digestion in steers
Authors: Kozloski G. V. , Filho H. M. N. Ribeiro , Rocha J. B. T.
Published: March 2010

Four growing Holstein steers (305 ± 33 kg body weight) with ruminal and duodenal cannulae were used in a 4 × 4 Latin square experiment to assess the effect of level of dietary urea (0, 7.3, 14.7 and 22.0 g kg−1 of dry matter) on the site and extent of digestion of some feed components. The diets were isonitrogenous and consisted of 60% ryegrass hay and 40% concentrate and were offered to the animals three times daily in amounts limited to 24 g of dry matter kg−1 liveweight in order to avoid feed refusals. The addition of urea caused a linear increase in ruminal pH and in ruminal ammonia concentration during the first hours after feed ingestion (P < 0.01), and linearly increased ruminal digestibility of cellulose (P < 0.01) and apparent nitrogen (P < 0.05). However, it had no significant effect on apparent total digestibility of feed components, nor did it affect ruminal digestibility of dry matter, organic matter or starch. Flow of microbial nitrogen to the small intestine decreased linearly (P < 0.05), but the efficiency of microbial protein synthesis or the proportion of undegraded feed nitrogen in the rumen that flowed to the small intestine was not significantly affected (P > 0.05). The increase in ruminal ammonia concentration above that necessary for optimal microbial growth increased ruminal nitrogen losses into the blood. However, excess ruminal ammonia concentration also increased ruminal fibre digestion. Key words: Non-protein nitrogen, microbial protein synthesis, ruminants, digestion
Relationship between vaginal and tympanic membrane temperature in beef heifers
Authors: Bergen R. D. , Kennedy A. D.
Published: March 2010

Vaginal and tympanic membrane temperatures were simultaneously monitored in nine beef heifers. Data not associated with ear infections were characterized by respective vaginal and tympanic membrane temperatures of 38.81 and 38.58 °C. A close relationship between the two temperatures was indicated by a correlation of 0.77 and residual standard deviation of 0.29 °C. Key words: Cattle, radiotelemetry, thermoregulation, tympanic membrane, vagina
Effects of barley silage particle length and effective fiber on yield and composition of milk from dairy
Authors: Kononoff P. J. , Mustafa A. F. , Christensen D. A. , McKinnon J. J.
Published: March 2010

A study was conducted to determine the effects of two theoretical lengths of particle (TLP) of barley silage on physically effective neutral detergent fiber (peNDF) content and on yield and composition of milk in dairy cows. Type I peNDF uses the neutral detergent fiber (NDF) of forage materials retained on a 1.18-mm screen while Type II peNDF is based on the NDF content of three different particle size fractions. Cows received diets consisting of 55% concentrate and 45% barley silage of either a 9.5-mm or 4.8-mm TLP. Results showed no difference in Type I peNDF between the two barley silage TLP. However, barley silage with a 9.5 mm TLP contained more (P < 0.05) Type II peNDF than barley silage with a 4.8 mm TLP. Differences in particle size or Type II peNDF content of barley silage had no effect on yield or composition of milk in dairy cows. Key words: Particle size, physically effective fiber, dairy cows
Protein composition and ruminal amino acid degradability of linseed meal
Authors: Mustafa A. F. , Christensen D. A. , McKinnon J. J.
Published: March 2010

A study was conducted to determine amino acid composition and ruminal degradability of linseed meal (LSM) relative to canola meal (CM). Linseed meal had higher (P < 0.05) arginine, isoleucine, and phenylalanine and less (P < 0.05) lysine than CM. Except for histidine, methionine, and threonine, ruminal escape values of essential amino acids were higher (P < 0.05) for LSM than CM. Key words: Linseed meal, amino acids, ruminal degradability
Metabolic responses of the whole body, portal-drained viscera and hindquarter to adrenaline infusion: Effects of nonselective and selective β-adrenoceptor blockade
Authors: Miaron J. O. O. , Christopherson R. J.
Published: March 2010

Propranolol, a nonselective β-blocker and selective β-blockers (metoprolol a β1-blocker and ICI 118551 a β2-blocker) were used to investigate the β-adrenoceptor-mediated adrenaline-induced increase in whole-body and organ VO2 in five whether sheep. Transit time blood flow probes were chronically implanted on the portal vein and the external iliac artery and sampling catheters were placed in the mesenteric artery, iliac vein and portal vein. Oxygen consumption by the whole body was measured by open circuit calorimetry, and oxygen consumption by the portal-drained viscera and the hindquarter was determined from A-VO2 differences and organ blood flow. Absolute pre-infusion VO2 values for the whole body, portal-drained viscera and hindquarters were 236 ± 7.4, 61 ± 6.0 and 13 ± 3.1 mL min−1 respectively. The mean changes in VO2 in response to infusion were 74 vs. 11, 26, 10 and 12 mL min−1 (SE = 9.1) for whole body; 31 vs. −2, −15, 13 and −4 mL min−1 (SE = 7.3) for portal-drained viscera and 8 vs. −0.4, 2.1, 1.0 and −2.7 mL min−1; SE = 4.3) for hindquarters during adrenaline, control, propranolol, metoprolol and ICI 118551 treatments, respectively. Adrenaline increased VO2 (P < 0.05) in the whole body and portal-drained viscera, but not hindquarters relative to controls. All β-blockers suppressed (P < 0.05) the adrenaline-induced increase in VO2 except for the portal-drained viscera where metoprolol was less effective and the hindquarters where β-blockers had no effect. The blood flow pattern was similar to VO2 responses for the portal-drained viscera. The nonselective β1 and β2 blockers were effective in reducing the adrenaline-induced increases in blood flow from the portal-drained viscera and to the hindquarters, with more pronounced β-adrenoceptor-mediated haemodynamic effects. The results indicate that the β-adrenoceptor system modulates whole body VO2, clearly establishes that adrenaline induces an increased VO2 in portal-drained viscera which can be reversed by a β2 or nonselective β blocker and implicates β adrenoceptors as an influencing factor in the maintenance energy requirements of ruminants. Key words: Calorimetry, adrenaline, β blockers, blood flow, sheep
Determination of the true metabolizable energy (TMEN) by roosters of feedstuffs made from seal by-products
Authors: Anderson D. M. , White L. , MacLean J.
Published: March 2010

TMEN values for various seal by-product feedstuffs were determined using roosters. Four samples of seal meal [seal meal 1991, seal meal 1992, seal meal 1994 (juveniles), seal meal 1994 (mixed ages)] and three samples of seal meat (oven-dried at 50 °C, oven-dried at 120 °C, and freeze-dried) were given to 16 roosters (30 g: precision fed) housed in individual wire cages. Total collection of excreta from a 48-h period was used to provide samples for analysis of gross energy, nitrogen, and dry matter content. TMEN results indicate variability in quality of the meals, associated with the different raw materials used to produce the seal meals as well as year of production. The TMEN values for the seal meals ranged from 3896 kcal kg−1 to 4621 kcal kg−1 with an average value of 4283 kcal kg−1. The crude protein content of the seal meals ranged from 64.2 to 67.6%, the crude fat content from 12.7 to 14.7%, the calcium content from 5.38 to 8.98% and the total phosphorus content from 3.16 to 4.79%. Oven-drying the seal meat at 120 °C significantly reduced TMEN (2643 kcal kg–1). The TMEN values for the freeze-dried and the low temperature oven-dried (50 °C) seal meat were not significantly different (4008 kcal kg–1 and 4013 kcal kg–1, respectively). Key words: True metabolizable energy, seal by-products, roosters, seal meal, seal meat, TMEN
Comparison of objective external carcass measurements and subjective conformation scores for prediction of lamb carcass quality
Authors: Stanford K. , Woloschuk C. M. , McClelland L. A. , Jones S. D. M. , Price M. A.
Published: March 2010

Carcass measurements were collected from 1505 lambs over a 2-yr period by a single technician. The lambs (rams, ewes and wethers) were classified as either meat-type or wool-type, with meat-type subdivided by frame size into light, medium or large. Carcass measurements included carcass length (L), length of hind leg (T), depth of hind leg (H) and circumference of hind leg (G). Agriculture and Agri-Food Canada graders measured tissue depth of all lambs at the GR site (11 cm from carcass midline over the 12th rib) and assigned subjective conformation scores for the regions of the leg, loin and shoulder. Sixty-nine lambs across groups were dissected into primal cuts to determine saleable meat yield. Carcass length and T decreased (P < 0.05) with increasing conformation score, whereas G and H increased (P < 0.05) with increasing conformation score. Wool-breed and light-frame lambs had lower conformation scores (P < 0.01) for the regions of the leg and loin than did medium- and large-frame lambs. Comparing the results of carcass dissection, wool-breed lambs had a lower saleable meat yield (P < 0.05) than large-frame lambs. Saleable meat yield also tended to be lower for light-frame than for medium- and large-frame lambs, although the numbers of medium- and light-frame lambs dissected were low. The carcass measurements used in this study accurately predicted percentage of the high priced leg cuts (R2 = 0.80, RSD = 0.6%), and were marginally more accurate than subjective conformation scores in predicting saleable yield from dissection (R2 = 0.61, RSD = 1.3%). However the carcass measurements used in this study were not valuable predictors of percentages of shoulder or loin and rack in the primal cuts. These data do not indicate any unjustified bias in the subjective conformation scores currently in use in the Canadian Classification System for lamb, as the breed types and frame sizes assigned lower conformation scores also had lower saleable meat yields. Key words: Measurement, lamb, carcass, meat yield
Production of ewes rearing twin or triplet lambs fed grass silage with a commercial concentrate or a mixture of beet pulp and soybean meal
Authors: Petit H. V.
Published: March 2010

Forty multiparous Outaouais ewes were used to investigate the effects of number of suckling lambs (2 versus 3) and type of feed supplement in grass silage-based diets on ewe and lamb performance. Treatments were arranged in a 2 × 2 factorial design. Isonitrogenous and isoenergetic supplements were either a mixture of beet pulp and soybean meal (BP) or a commercial concentrate (CO). Dietary treatments continued from 28 d prepartum until 42 d postpartum. Milk yield was measured weekly. Dietary treatments and number of suckling lambs had no effect (P > 0.10) on DM intake. Feeding BP resulted in similar milk yield for ewes nursing twin (TW) and triplet (TR) lambs, and feeding CO resulted in higher milk yield for ewes nursing TW compared to those nursing TR; this resulted in a significant interaction (P = 0.08) between diet and the number of suckling lambs. Dietary treatments and number of suckling lambs had no effect (P > 0.10) on milk composition. Loss of body weight was greater (P < 0.01) for ewes nursing TR than for those nursing TW, while there was no difference (P > 0.10) between ewes fed BP and those fed CO. Body weight at birth and on day 42, and ADG of TW were greater (P < 0.01) than those of TR, but type of supplement had no effect on lamb performance. Intake of DM was below requirements of ewes nursing TW. These data suggest that DM intake is not responsible for all differences observed in milk yield. Factors such as greater body weight loss could have contributed to increased milk yield. Feeding BP compared to CO may have contributed to maintain similar milk yield for ewes nursing TW and TR, but lamb growth was limited by milk yield as less milk was available per lamb for TR compared to TW. Key words: Ewes, lambs, lactation, beet pulp
Modifying duodenal flow of amino acids by manipulation of dietary protein sources
Authors: Robinson P. H.
Published: March 2010

Four multiparous Holstein dairy cows in mid-lactation were utilized in a 4 × 4 Latin square design experiment to measure the response in intestinal amino acid profiles to progressive substitution of blood meal for corn gluten meal as the protein supplement. In addition, the influence of these protein sources on rumen fermentation and digestion as well as forestomach bacterial growth and escape were compared with a diet supplemented with soybean meal, a rapidly rumen-degraded protein source. Cows were offered a mixed silage ration of alfalfa silage (79.8% of DM) and corn silage (20.2% of DM) twice daily. Cows were also offered mixed concentrate at 123% (DM:DM) of the mixed silage ration in six equal meals per day to provide soybean meal, corn gluten meal, blood meal or a combination of the latter two sources as the primary supplemental protein source. Rumen soluble non-ammonia N concentrations were higher in cows fed soybean meal and declined linearly as blood meal substituted for corn gluten meal in the concentrate. Forestomach disappearance of N tended (P = 0.09) to be higher for the cows fed soybean meal vs. all other diets, and tended (P = 0.09) to be higher with the combined corn gluten meal and blood meal diet vs. the diets containing either alone. The latter is consistent with higher forestomach digestion of DM and OM in cows fed the combined diet. Rumen pool sizes of most DM components were lower when cows were fed soybean meal and, with the exception of N pools, increased linearly as blood meal substituted for corn gluten meal. Duodenal flow of amino acid protein was lower when cows were fed soybean meal, due mainly to reduced bacterial flow, and was lowest for the combined diet within the corn gluten meal and blood meal diets. The amino acid profile of duodenal protein differed for 12 of 17 amino acids examined when cows were fed the soybean meal diet vs. the other diets, and 12 of 17 amino acids either increased or decreased linearly as blood meal substituted for corn gluten meal. Data reported here and by previous researchers suggest an associative effect of addition of corn gluten meal and blood meal to the diet which increased rumen degradation of dietary protein. These data also show that manipulating the dietary source of supplemental protein can influence the amino acid profile of duodenally delivered amino acid protein as well as indicate that the rate of rumen degradation of individual amino acids differs among protein sources. In this study, methionine, cystine and histidine appeared to be more rapidly degraded in corn gluten meal than in blood meal, whereas glutamic acid, proline, isoleucine, threonine and lysine were more rapidly degraded in blood meal. Key words: Dairy cow, rumen bacteria, amino acid
Influence of stage of maturity on yield components and chemical composition of cereal grain silages
Authors: Khorasani G. R. , Jedel P. E. , Helm J. H. , Kennelly J. J.
Published: March 2010

The objectives of this study were to determine changes in yield of total grain, stem and leaf DM, leaf:stem ratio and chemical composition during the growth period (boot to soft-dough stage) and during ensiling of whole-crop barley (Hordeum vulgare L. 'Noble'), oats (Avena sativa L. 'Cascade'), triticale (X Triticosecale Rimpani Witt. 'Wapiti'), and a 1:1 barley (Noble):winter triticale (cv. Pika) mixture. Data for whole-crop cereals were compared with a second cut alfalfa (Medicago sativa L. 'Algonquin'). Crude protein and nitrate concentrations of all crops decreased with advancing maturity. Neutral detergent fiber (NDF), acid detergent fiber (ADF), and cellulose concentrations of all crops initially increased and then decreased with advancing maturity whereas acid detergent lignin (ADL) concentrations increased with advancing maturity. During the growth phase, oats and triticale had higher NDF and ADF concentrations, but by harvesting these differences had disappeared. Leaf as percentage of total DM and leaf:stem ratios were higher and the stem as percentage of total DM was lower for the barley:winter triticale mixture compared with the cereal monocrops. Cereal forages were ranked in order of decreasing quality as barley, barley:winter triticale, triticale, and oats. Key words: Alfalfa, barley, oats, triticale, silage, quality
Effect of grazing system, stocking rate and season of use on diet quality and herbage availability of alfalfa-grass pastures
Authors: Popp J. D. , McCaughey W. P. , Cohen R. D. H.
Published: March 2010

A 3-yr field experiment was conducted (1991–1993) near Brandon, MB to determine the effects of continuous and rotational stocking, both at heavy (2.2 steers ha−1) and light (1.1 steers ha−1) stocking rates, and of season of use on nutritive value and sward characteristics of an alfalfa-grass pasture [approximately 70% alfalfa (Medicago sativa L.), 25% meadow bromegrass (Bromus biebersteinii Roem & Schult.) and 5% Russian wildrye (Psathyrostachys juncea (Fisch.) Nevski)]. Grazed herbage quality and herbage mass were determined concurrently on continuous and rotational stocking treatments several times each year, as animals entered and exited the 5th of 10 rotationally stocked paddocks. Grazing system and stocking rate did not affect (P > 0.05) dietary CP and IVDOM, except once (P < 0.05) for IVDOM in 1993. Both ADF and NDF were sometimes greater (P < 0.05) on heavy compared to light stocking rate treatments, but did not differ (P > 0.05) between grazing systems. As the 1991 season advanced, there was a decline (P < 0.05) in CP, but IVDOM, ADF and NDF remained unchanged (P > 0.05). In 1992, seasonal declines (P < 0.05) in CP and IVDOM and increases (P < 0.05) ADF and NDF were observed for all treatments. In 1993, in vitro digestible organic matter and CP decreased (P < 0.05) on most treatments, while ADF and NDF increased (P < 0.05). Herbage mass tended (P < 0.10) to be lower when heavy stocking rates were used in all years, but was not affected (P > 0.05) by grazing system. Significant relationships (P < 0.001) among IVDOM, ADF and NDF were found. Neither grazing system nor stocking rate appeared to affect the quality of herbage ingested by cattle grazing alfalfa-grass pastures. Key words: Alfalfa, pasture, grazing system, stocking rate
The effects of feeding a chocolate product on growth performance and meat quality of finishing swine
Authors: McNaughton E. P. , Ball R. O. , Friendship R. M.
Published: March 2010

The effects of including a waste chocolate confectionary product in swine diets on growth performance, carcass composition and meat quality of finishing pigs were determined. Four isocaloric, isonitrogenous diets were formulated to include 0, 10, 20 and 30% of a chocolate product in a pelleted corn and soybean-meal-based-diet and fed ad libitum to 32 gilts and 32 barrows from 54 kg to 105 kg. There were no significant differences among diets for average daily gain, feed intake and feed efficiency. Fat content in the diets increased from 3 to 7% with increasing inclusion, but there were no significant (P > 0.05) differences for backfat depth, total dissected fat, total lean or percent lean of the dissected carcass. With respect to meat quality, there were no significant differences observed for colour, structure and marbling of the loin and ham muscle. There were no treatment differences for the firmness of the inner backfat of pigs consuming the various diets. Waste chocolate confectionary can be fed to growing swine at inclusion levels up to 30% of the diet with no adverse effects on growth or carcass quality. Key words: Alternative feedstuff, chocolate, pigs, growth performance, carcass quality
Lipid-induced depression of methane production and digestibility in the artificial rumen system (RUSITEC)
Authors: Dong Y. , Bae H. D. , McAllister T. A. , Mathison G. W. , Cheng K-J.
Published: March 2010

An artificial rumen (RUSITEC) equipped with eight fermenters was used to examine the effects of canola oil (CA), cod liver oil (CD) and coconut oil (CO) on methane production, dietary digestibility and rumen microbial populations. The experiment, repeated three times, involved two diets (100% grass hay or a 90%:10% wheat:hay mixture) either untreated (controls) or sprayed with CA, CD or CO (10%, wt/wt) in a 2 × 4 factorial arrangement. Dry matter disappearance and CH4 production were greater (P < 0.05) from untreated concentrate diet than from untreated hay. There were significant interactions (P < 0.05) between diet and lipid type for DM digestion and several of the fermentation parameters. Coconut oil decreased (P < 0.05) DM and neutral detergent fibre disappearance of hay but did not affect digestion of concentrate. All oils, especially CO, depressed (P < 0.05) CH4 production (mmol g−1 digestible DM) and methanogenic populations regardless of diet. Methanogens on CO-treated diets numbered less than 1% of those on CA- and CD-treated diets. Total viable, amylolytic, and cellulolytic bacterial numbers were also substantially reduced (P < 0.05) by CO, but not by CA or CD for both diets. Bacterial colonization and digestion of CO-treated hay was markedly less extensive than that observed on untreated, CA- or CD-treated hay. The molar proportion of propionate produced was increased (P < 0.05) by CA and CD, for the hay diet, but not for the concentrate diet. Coconut oil decreased (P < 0.05) the molar proportion of propionate produced on the hay diet and increased (P < 0.05) it on the concentrate diet. Of the three oils, CO was most inhibitory to CH4 production and depressed fibre digestion. The CA and CD also decreased CH4 production, but did not affect feed digestion in either diet. Consequently, the amount of metabolizable energy of feeds may be increased when diets are supplemented with these oils. Key words: Lipids, methane, digestibility, artificial rumen, bacteria, VFA
Quantitative analysis of nycterohemeral eating and ruminating patterns in beef cattle fed pelleted concentrates with or without supplemental roughage
Authors: Deswysen A. G. , Dutilleul P. , Fischer V. , Campbell C. P.
Published: March 2010

The effects of five diets on nycterohemeral pattern of chewing behaviour were evaluated in 10 Hereford steers according to a replicated 5 × 5 Latin square design. Steers had ad libitum access to diets, fed once daily at 09:00 h and chewing behaviour was continuously measured for 4 d. Dietary treatments were: 1) traditional diet — 80% pelleted concentrate (control) and 20% long timothy hay; 2) 80% control concentrate and 20% alfalfa cubes; 3) 90% control concentrate and 10% alfalfa cubes; 4) a completely pelleted diet with corn cobs; 5) 80% textured concentrate and 20% long timothy hay. Spectral analysis of hourly time spent either eating or ruminating was performed using the finite Fourier transform to decompose the 24-h total dispersion of chewing into 12 RC. Nycterohemeral patterns of time spent eating and ruminating different diets were mainly explained by RC 1, 2 and 3. RC 1 was relatively more important than the others in explaining total daily dispersion of time spent eating traditional completely pelleted with corn cobs and textured diets, while RC 1 and 3 presented similar relative importance for both alfalfa cube diets. Relative importance of RC 1 of time spent eating each diet was related positively to VI of diet DM (r = 0.88, P = 0.047) and NDF (r = 0.92, P = 0.027). Nycterohemeral eating and ruminating patterns of individual steers were mostly explained by RC 1, 2 and 3. Relative importance of RC 11 and 12 of time spent ruminating were related positively to VI by steers of DM (respectively, r = 0.81, P = 0.004 and r = 0.63, P = 0.052) and NDF (respectively, r = 0.69, P = 0.027 and r = 0.67, P = 0.034). Overall, these relationships suggest that with once daily feeding of concentrate-based diets a larger VI is achieved with a more important one main nycterohemeral eating period associated to regular relative important two-hourly rumination periods, these latter are probably enhancing continuity of digesta flow and nutrients uptake. Key words: Beef cattle, nycterohemeral chewing, finite Fourier transform
Variation in chemical composition and nutritional quality among barley cultivars for ruminants. 1. Steer finishing performance, diet digestibilities and carcass characteristics
Authors: Ovenell-Roy K. H. , Nelson M. L. , Froseth J. A. , Parish S. M. , Martin E. L.
Published: March 2010

Inherent variability in chemical composition and nutritional value exists among barley (Hordeum vulgare L.) cultivars due to year grown, head morphology, growth habit and intended end use. Two trials were conducted to identify causal factors for variability among barley cultivars in animal performance, carcass characteristics, diet digestibility and digestible energy (DE) content. In feedlot trials, 144 large-frame beef steers (380 ± 1.6 kg in Trial 1, 372 ± 0.8 kg in Trial 2) were assigned within three weight blocks, eight to a pen, in a randomized complete block design and pens to treatments. Steers were fed a diet of 83% steam-rolled barley (Andre, Camelot, Clark, Cougbar, Harrington or Steptoe for 123 d in Trial 1; Boyer, Camelot, Clark, Harrington, Hesk or Steptoe for 119 d in Trial 2), 10% silage (wheat in Trial 1, oat in Trial 2), and 7% supplement on a dry matter (DM) basis. In Trial 1, Cougbar neutral detergent fiber (NDF) digestibility was significantly lower than Clark. Digestibility of other nutrients tended to be lowest for steers fed Cougbar and as a result, diet DE was lower (P < 0.05) for Cougbar than for Clark and Camelot. Diet DE and NDF digestibility were correlated (r = 0.69; P < 0.0001). Lower nutrient utilization by steers fed Cougbar resulted in lower performance. In Trial 2, steers fed Hesk had a poorer (P < 0.05) ratio of feed to gain than steers fed Camelot and Harrington and lower (P < 0.05) digestibility than steers fed Steptoe. In summary, data from these trials suggest that Cougbar and Steptoe are of lower nutritional value than other cultivars under the conditions of these studies. In these studies, digestibility of NDF was a major factor contributing to differences among cultivars. Key words: Barley, steers, digestibility, energy
Variation in chemical composition and nutritional quality among barley cultivars for ruminants. 2. Digestion, ruminal characteristics and in situ disappearance kinetics
Authors: Ovenell-Roy K. H. , Nelson M. L. , Froseth J. A. , Parish S. M.
Published: March 2010

Two trials were conducted to compare the effects of feeding six different barley (Hordeum vulgare L.) cultivars on diet digestibility, DE content, and ruminal fermentation characteristics. In Trial 1, four steers (455 ± 1.6 kg) were used in a partially balanced incomplete block design and consumed a diet of 83% barley (Andre, Camelot, Clark, Cougbar, Harrington or Steptoe), 10% bromegrass hay and 7% supplement. Organic matter intake was lower (P < 0.10) for steers fed Clark, and in situ rate of disappearance of Steptoe was slower (P < 0.10) than other barleys. Acetate to propionate ratio was lower (P < 0.10) in ruminal fluid of steers fed Camelot than in that of those fed Andre, NDF digestibility was lower (54.7 vs. 69.2%), and digestion of NDF polymeric monosaccarides was lower (P < 0.10) for Camelot than for Andre. Scanning electron micrographs supported differences observed in chemical composition and in situ disappearance kinetics. In Trial 2, six steers (512 ± 1.8 kg) were used in a 6 × 6 Latin square design and consumed a diet of 83% barley (Boyer, Camelot, Clark, Harrington, Hesk or Steptoe), 10% bromegrass hay and 7% supplement. Steers fed Camelot had greater (P < 0.10) total tract NDF digestibility than steers fed Hesk and Steptoe. Total polymeric monosaccharide digestion was lower (P < 0.10) for Boyer (62.9%) than for any of the other cultivars (73.5%, average) except Hesk. In these two trials, NDF and NDF polymeric monosaccharide digestibilities were the major factors contributing to variability among barley cultivars in nutritional quality for ruminants. Key words: Barley, steers, digestibility, energy
Field peas: Chemical composition and energy and amino acid availabilities for poultry
Authors: Igbasan F. A. , Guenter W. , Slominski B. A.
Published: March 2010

Twelve pea cultivars (yellow-, green- and brown-seeded) were evaluated for chemical composition and digestibility in poultry. The evaluation involved analyses for protein, amino acids (AAs), fat, starch, dietary fibre, ash, calcium, phosphorus and tannins. True metabolizable energy [nitrogen corrected (TMEn) and uncorrected (TME)] and true AA bioavailability values were also determined with adult cockerels. The cultivars showed a wide range of protein (207.5–264.0 g kg−1) and starch (385.3–436.8 g kg−1) contents which were not related to the seed coat colours. The concentrations of several AAs varied among the cultivars. With the exception of arginine, the concentrations of all other essential AAs on a protein basis decreased as protein levels increased. Out of 10 essential AAs including cystine, only arginine had a positive correlation (r = 0.79) with protein content. The dietary fibre contents varied between 190.7 and 223.1 g kg−1 and the values were slightly higher in the brown-seeded cultivars. The brown-seeded cultivars contained appreciable quantities of tannins, while the yellow- and green-seeded cultivars were devoid of tannins. The cultivars were almost devoid of fat and calcium but relatively high in phosphorus. Starch and dietary fibre were negatively correlated with protein content (r = −0.78 and −0.46, respectively), and accounted for the greatest difference in protein content. The TME values ranged from 11.6 to 13.3 MJ kg−1 while the TMEn values ranged from 11.0 to 12.9 MJ kg−1. The mean availabilities of AAs ranged from a high of 89.6 to a low of 75.9%, with total sulphur AAs (cystine and methionine) having the lowest value and glutamic acid having the highest value. There was a trend (P ≤ 0.05) towards lower AA bioavailability values in the brown-seeded cultivars. It can be concluded that these cultivars varied in chemical composition, metabolizable energy content and bioavailability of AAs. Key words: Field peas, composition, digestibility, chicken, poultry
Impact of pure fumonisin B1 on various metabolic parameters and carcass quality of growing-finishing swine — preliminary findings
Authors: Rotter B. A. , Prelusky D. B. , Fortin A. , Miller J. D. , Savard M. E.
Published: March 2010

Mycotoxin fumonisin B1 (FB1) is a common contaminant of corn and a causative agent of different animal and human diseases. An experiment was conducted to assess the impact of pure FB1 on carcass quality of growing-finishing swine. Pigs were fed diets containing 0, 0.11, 0.33 and 1.0 mg FB1 kg−1 (ppm) until market weight. Although performance characteristics were not different among the respective treatments, an increase in feed consumption variability was observed between weeks 3 and 9 for the 1 ppm FB1 fed pigs as compared with controls. The same animals showed an increased variability in carcass characteristics, in particular in the fat content of loin and ham. The estimated lean yield tended to decrease with increasing dose, but a high standard deviation abolished treatment differences. An elevated cholesterol value at the end of the experiment for the 1 ppm FB1 fed pigs suggested a disruption of lipid metabolism. No other significant (P > 0.06) changes were observed. We conclude that a diet containing 1 ppm FB1 could have a detrimental effect on the carcass quality of a market pig and be a source of a monetary loss to the producer. Key words: Mycotoxin fumonisin B1, swine, carcass