The Feeding Value of Mangifera indica and its Effects on Crude Protein Metabolism and Energy Partitioning when fed to Djallonke Sheep

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Daniellia oliveri As A Fodder Tree For Small Ruminant And The Interaction Of Its Tannin With Ruminal Ammonia

Daniellia oliveri was examined as a potential fodder for small ruminant, using nine castrated and ruminally fistulated West African Dwarf sheep (29 kg BW) to determine rumen ammonia and nutrient digestibility. Dried leaves of Daniella oliveri were offered at two levels (25% and 50% of DMI) as supplement to a basal hay diet. A digestibility trial of 8 days was conducted after 10 days of adaptation period. Rumen liquor was sampled one hour before, and one, three and five hours after the morning feeding for three consecutive days. Diet D50% showed a higher (P<0.05) pH than both the control and D25% diets, respectively. Diet D25% had an inferior (P<0.05) pH than both the controls. The ruminal ammonia concentration of D25% was superior (P<0.05) to D50% and the controls, respectively. Similarly, diet D50% had a superior (P>0.05) ruminal ammonia concentration than the controls. There were significant increases (P<0.05) in the OM, CP, NDF, ADF, ADL and cellulose intake of D50% diet compared with the controls. Similarly, inclusion level of 50% Daniellia oliveri resulted in a reduction (P<0.05) in digestibility of DMI, OM, NDF, ADF and ADL, in comparison to sheep fed the control diet. Cellulose and hemi-cellulose digestibility of diet D50% was superior (P<0.05) to that of the controls. It would appear that condensed tannins had inhibitory effect on organic matter and detergent fibre digestibility. It was concluded that Daniellia oliveri with a high CP and GE (165 g/KG and 20.3 kJ/g DM) respectively, could serve as a fodder tree for small ruminant in spite of its relatively high content of condensed tannin (48 g/kg DM). An inclusion range of 25 to 50% was recommended during period of scarcity.Keywords: Daniellia oliveri, nutrient digestibilities, ruminal ammonia, WAD shee

The effect of number of lactation and concentrate level on feed intake and performance of dairy cows

International audienc

Radiation Hardness Testing of Materials at the UC Davis/ McClellan Nuclear Radiation Center

The UCD/ MNRC research reactor of the TRIGA type is designed to be operated at a nominal 2 .0 MW steady state power as well as pulse and square wave operation. It is cooled and moderated by light water and reflected by graphite. The reactor core is located near the bottom of a water-filled aluminum vessel 7.0 ft in diameter and 24.5 ft in height. It went first critical in 1990 and has since become the highest power TRIGA reactor in the U.S. Radiation hardness testing of materials is made possible through the so-called “neutron irradiator” which provides fast neutron exposure to samples with minimal contamination from thermal neutrons and gamma rays. This neutron irradiator has three primary components; conditioning well, exposure vessel, and detachable upper shield for the exposure vessel. The conditioning well is installed adjacent to the annular graphite reflector inside the reactor tank. It is held vertically in place and rests at the bottom of the tank. The well-structure is shielded with sufficient boron nitride and lead encased in aluminum to remove thermal neutrons and gamma rays, respectively. The removable and water-tight exposure vessel has a usable inner space of approximately 7” in diameter and 9” in height. There are six removable titanium plates with holes arranged in a hexagonal shape which can hold the components to be irradiated. It also contains a valve at the bottom to purge and pressurize an assembled unit with helium in order to reduce Argon-41 production during irradiation. The exposure vessel is lined with boral and gadolinium paint to insure minimal leakage of thermal neutrons. The detachable upper shield contains boron nitride and lead encased in aluminum to complete the upper shield for the exposure vessel before it is lowered into the conditioning well for irradiation. Monte Carlo code simulation is benchmarked with multiple threshold neutron flux measurements. The converted 1 MeV equivalent silicon neutron flux at 1.5 MW operating power is 2.3 x 10^10 n/cm2.sec. Among others, materials such as silicon based devices, coatings for metals, superconducting magnets which are susceptible to fast neutron exposure and damage in their working environments are examined. This unique irradiation facility enables us to provide credible information regarding fast neutron radiation tolerance of materials used in crucial applications

Non-Destructive Testing with Neutron Radiography at the UC Davis/ McClellan Nuclear Radiation Center

The UCD/ MNRC inherited NDT capabilities from the US Air Force and even though it is now mainly a research facility, it has kept this acquired asset performing at a production level. The UCD/MNRC facility is equipped with a hexagonal grid, natural convection water cooled TRIGA reactor designed to operate at a nominal 2 .0 MW steady state power as well as in pulse and square wave mode. The reactor utilizes a specially designed annular graphite reflector accommodating four removable units to accept four separate source ends of beam tubes. These tangential beam tubes lead to four large investigation bays with neutron radiography setting. The design basis for these beam tubes is to provide a path for primary thermal neutrons with minimum scattering and attenuation between the reflector inserts and radiography bays. Typical unperturbed beam parameters are summarized in the following: Each beam tube ends with a bulk shield as the primary beam stopper and a separate boron-included fast shutter to initiate and complete a neutron exposure. Traditional film system and more recently computed radiology system utilizing reusable storage phosphor imaging plate (SPIP) are extensively used as 2D imaging recording media. Bay 3 is designed with a charge coupled device (CCD) camera with system control hardware and software to perform 3D neutron tomography. Bay 4’s beam tube, different from the others, has an 11”-thick sapphire crystal filter to provide an even higher quality beam, i.e. much lower contamination from fast neutrons and gamma rays, for 2D neutron radiography. UCD/ MNRC is committed to offering state-of-the-art neutron imaging experiences for non-destructive testing projects. Our unique capabilities enable us to provide effective solutions to the customer’s needs. Providing quality assurance of complicated titanium castings for aircraft, inspecting metal loss of pressurized tanks for fighting forest fires, examining binding between corrosion-resistant coatings and base metal for spent fuel containers, are a few of many services rendered

Radiation Hardness Testing of Materials at the UC Davis/ McClellan Nuclear Radiation Center

The UCD/ MNRC research reactor of the TRIGA type is designed to be operated at a nominal 2 .0 MW steady state power as well as pulse and square wave operation. It is cooled and moderated by light water and reflected by graphite. The reactor core is located near the bottom of a water-filled aluminum vessel 7.0 ft in diameter and 24.5 ft in height. It went first critical in 1990 and has since become the highest power TRIGA reactor in the U.S. Radiation hardness testing of materials is made possible through the so-called “neutron irradiator” which provides fast neutron exposure to samples with minimal contamination from thermal neutrons and gamma rays. This neutron irradiator has three primary components; conditioning well, exposure vessel, and detachable upper shield for the exposure vessel. The conditioning well is installed adjacent to the annular graphite reflector inside the reactor tank. It is held vertically in place and rests at the bottom of the tank. The well-structure is shielded with sufficient boron nitride and lead encased in aluminum to remove thermal neutrons and gamma rays, respectively. The removable and water-tight exposure vessel has a usable inner space of approximately 7” in diameter and 9” in height. There are six removable titanium plates with holes arranged in a hexagonal shape which can hold the components to be irradiated. It also contains a valve at the bottom to purge and pressurize an assembled unit with helium in order to reduce Argon-41 production during irradiation. The exposure vessel is lined with boral and gadolinium paint to insure minimal leakage of thermal neutrons. The detachable upper shield contains boron nitride and lead encased in aluminum to complete the upper shield for the exposure vessel before it is lowered into the conditioning well for irradiation. Monte Carlo code simulation is benchmarked with multiple threshold neutron flux measurements. The converted 1 MeV equivalent silicon neutron flux at 1.5 MW operating power is 2.3 x 10^10 n/cm2.sec. Among others, materials such as silicon based devices, coatings for metals, superconducting magnets which are susceptible to fast neutron exposure and damage in their working environments are examined. This unique irradiation facility enables us to provide credible information regarding fast neutron radiation tolerance of materials used in crucial applications

Effects of Varying Dietary Forage Particle Size in Two Concentrate Levels on Chewing Activity, Ruminal Mat Characteristics, and Passage in Dairy Cows

The objective of this study was to investigate the effects of varying dietary forage particle size on chewing activity, ruminal mat characteristics, passage, and in situ ruminal and total tract digestion in dairy cows at a low- and high-concentrate inclusion. The experiment was designed as a 4 x 4 Latin square with a 2 x 2 factorial arrangement of treatments. Four ruminally cannulated late-lactating dairy cows were restrictively fed (17 kg of dry matter/d), in four 23-d periods, 1 of 4 different diets varying in the theoretical particle size (6 and 30 mm) of hay (56.6% NDF of dry matter) and in the levels (approximately 20 and 60%, dry matter basis) of a cereal-based concentrate. Ingredients of the ration were offered separately to the cows; dietary hay and low-level concentrate were offered twice daily at 0800 and 1600 h, whereas concentrate of the high-level treatment was offered in 4 meals a day at 0800, 1200, 1600, and 1900 h. This study showed that altering the forage particle size from 6 to 30 mm in a low-concentrate diet significantly increased the rumination time and ruminal mat consistency without affecting ruminal fermentation and passage. Further, particle breakdown and proportion of mat in the rumen increased, and in situ hay dry matter degradability improved, which in turn indicated a higher capacity of ruminal digesta to degrade fiber. On the other hand, increasing the forage particle size in a diet containing a high amount of concentrate increased the proportion of dry matter retained on a 1.18-mm screen from 37.5 to 42.0% and extended the rumination time by 100 min/d, as well as increasing the ruminal mat consistency. However, ruminal particle breakdown, short-term ruminal pH, fibrolytic capacity of the digesta, and proportion of mat in the rumen decreased. This was also reflected in a higher bailable liquid pool, increased fractional passage rate of solid digesta from the reticulorumen, and increased retention time in the hindgut, which in turn indicated a shift of fiber digestion from the rumen to the lower digestive tract. This study showed that the response of chewing or ruminating activity alone seemed to be insufficient to assess the dietary physical effectiveness or fiber adequacy in limit-fed dairy cows when high-concentrate diets were fed separately. Based on the results of this study, we concluded that inclusion of coarsely chopped hay in the high-concentrate diet did not appear to further improve rumen conditions and digestion when the rations were formulated to exceed the fiber requirements in limit-fed dairy cows

Modeling the Adequacy of Dietary Fiber in Dairy Cows Based on the Responses of Ruminal pH and Milk Fat Production to Composition of the Diet

The main objective of this study was to develop practical models to assess and predict the adequacy of dietary fiber in high-yielding dairy cows. We used quantitative methods to analyze relevant research data and critically evaluate and determine the responses of ruminal pH and production performance to different variables including physical, chemical, and starch-degrading characteristics of the diet. Further, extensive data were used to model the magnitude of ruminal pH fluctuations and determine the threshold for the development of subacute ruminal acidosis (SARA). Results of this study showed that to minimize the risk of SARA, the following events should be avoided: 1) a daily mean ruminal pH lower than 6.16, and 2) a time period in which ruminal pH i