Performance, ruminal fermentation, and site of starch digestion in early lactation cows fed corn grain harvested and processed differently

Two experiments were conducted to assess the effects of corn grain processing on performance, ruminal fermentation, and starch digestion in early lactation dairy cows. Diets were based on wilted alfalfa silage and high moisture or dry corn grain that was either ground or rolled. Thirty-four cows (17 multi-parous) were used to measure effects on intake and lactational performance in a free-stall environment during wk 2 to 15 postpartum. Grinding increased dry matter intake, particularly for cows fed diets containing dry corn, and tended to increase yields of milk, protein lactose, and SNF. Cow performance was not affected by the moisture content of the corn grain. In the digestion experiment, six cows (43 d of lactation) with ruminal, duodenal, and ileal cannulas were used to measure ruminal and intestinal digestion. Search digestion in the rumen and small intestine was greater for high moisture corn, but disappearance of starch in the large intestine was greater for dry corn. Both the grinding process and the high moisture content of the corn increased starch digestibility in the total tract. Flow of microbial N in the duodenum was not affected by treatment. High moisture corn increased starch digestion in the rumen and total tract and enhanced ruminal fermentation as indicated by increased volatile fatty acids and decreased NH3 concentrations in the rumen. In the production experiment, however, only grinding improved the value of corn; ensiling at high moisture content had little effect.     

Effect of dietary rumen-protected choline in lactating dairy cows

Two experiments were conducted to test the effects of graded amounts of rumen-protected choline on milk yield and composition in lactating dairy cows fed 40% corn silage and 60% concentrate diets (DM basis). In Experiment 1, 48 Holstein cows were fed 0, .078, .156, and .234% rumen-protected choline (choline chloride basis) from wk 5 to 21 postpartum. Increasing choline had no effect on DMI and tended to increase milk yield only from 1 to 2.2 kg/d. Milk fat percentage was reduced in the .078% choline treatment and increased to control levels thereafter with .156 and .234% choline. In Experiment 2, 16 Holstein cows in midlactation were assigned randomly to either 13.0 or 16.5% dietary CP (DM basis). Within CP concentration, cows were fed 0, .08, .16, and .24% rumen-protected choline in a replicated 4 x 4 Latin square design. Dietary protein had no effect on milk yield, although milk protein percentage and yield were increased .25 percentage units and 63 g/d, respectively, by increased dietary CP. Increasing dietary choline to .24% linearly increased milk yield 2.6 kg/d, although it had no consistent effects on milk fat or protein percentage. There was only a slight tendency for greater responses in milk yield to dietary choline with lower dietary CP. Data from these experiments confirm earlier results with postruminal choline infusions, suggesting that choline may be a limiting nutrient for milk production.     

The winged bean as an oil and protein source: A review

Despite high protein contents in its ripe seeds, tubers and fresh leaves (ranging from 29.3–39.0%, 3.0–15.0% and 5.0–7.6% respectively) and the high quality of that protein, the winged bean (Psophocarpus tetragonolobus) remained an obscure food source until about 10 years ago. Recently, this legume has received increasing attention from scientists because of its potential multiple uses as a food protein source in the humid tropics. This article reviews the utilization and nutrition literature of winged bean published during the last 10 years. The following aspects are covered: classification of winged bean proteins, nutritional properties and antinutritional components of the protein, protein quality, functional properties, and protein-based food products. The oil content of winged bean seeds ranges from 15.0–20.4%, and use of the winged bean as a potential oilseed crop is discussed. Areas of needed research are identified and described. Presented at the 74th Annual Meeting of American Oil Chemists’ Society, Chicago, May 8–12, 1983.     

Complex Mode Dynamic Analysis of Flexible Mechanism Systems with Piezoelectric Sensors and Actuators

A method has been developed for analyzing the elastodynamic response ofhigh-speed flexible linkage mechanisms with piezoelectric sensors andactuators. The finite element analysis model is obtained by using amixed variational approach with Hamilton's principle. An efficientsolution method is developed on the basis of complex mode theory. Afour-bar linkage mechanism with all flexible links is employed as anexample to demonstrate the capability of the proposed method. Theinvestigation provides a theoretical basis for complex mode activevibration control of high-speed flexible mechanism systems.     

Characteristics of shaft voltage and bearing currents

This article reviews investigations into reduced bearing life due to voltage source adjustable speed drive (ASD) AC motor operation. Relevant bearing failure mechanisms and indicators are discussed. dv/dt and electric discharge machining (EDM) contributions are discussed and experimental data presented showing the voltage levels on motor shafts when operating with ASDs. Finally, techniques to reduce shaft voltage are discussed, along with the electrical characteristics and interaction of system components. The example chosen is electrostatic shielded induction motors     

Oilseed phytates: Nutritional implications

The protein quantity and quality, caloric value, and overall nutrient content of oilseeds are quite good. However, oilseeds are high in phytic acid and contain fiber and perhaps other binding agents which reduce mineral bioavailability from the seeds. Phytic acid, the hexaphosphate of myoinositol, functions as the chief storage form of phosphate and inositol in mature seeds. On a dry basis, whole oilseeds contain about 1.5% while some oilseed protein concentrates can contain over 7.0% of the compound. Phytic acid is a strong chelating agent that can bind mono- and divalent metal ions to form the complex phytate. Published results from numerous animal feeding trials suggest poor bioavailability of minerals such as zinc, calcium, magnesium, phosphorus and possibly iron from diets containing high phytate foods. Recent studies involving the feeding of soy products to rats suggest that zinc is the mineral of most concern as its bioavailability from some soy products is quite low. Prediction of mineral bioavailability from phytate-containing foods is complicated by the complex interactions between the minerals and phytic acid contained in the foods, intestinal and the meal phytase activities, previous food processing conditions (especially pH), digestibility of the foods as well as the physiological status of the consumer of the foods. Very little is known about the chemistry of such interactions. Therefore, most of the emphasis in controlling or reducing mineral binding in oilseed products has been placed upon development of methodology for phytate removal.     

Hot pin welding of thin poly(vinyl chloride) sheet

This paper develops a method of welding two thin sheets of poly(vinyl chloride) (PVC) with a heated pin, thus allowing construction of a relationship between the weld temperature and weld strength. Constructing a relationship between weld strength and temperature is necessary for modeling many welding processes, including laser transmission welding. An experimental approach to establishing this relationship is required because of the complex melting behavior of PVC. The designed experimental device uses a single heated pin to weld samples by using varying pressure and temperature for one second dwell time. An electro‐mechanical loadframe pulled the welded samples until joint failure occurred, thereby allowing determination of the weld strength. An experiment varying welding pin temperature and joining pressure found the temperature to be a highly significant determiner of weld strength, while the pressure was found to be not significant. A transient numerical heat transfer model was used to calculate the weld interface temperature for each pin temperature. The relationship established in this paper can be used to predict the weld strength from the temperature output from models of alternative welding methods. J. VINYL ADDIT. TECHNOL., 13:110–115, 2007. © 2007 Society of Plastics Engineers.     

Thermal Conductivity of ZrB2?SiC?B4C from 25 to 2000 °C

The thermal diffusivities of ZrB₂–SiC (10.7, 21.9, or 48.7 vol% SiC) with B₄C sintering aid were measured over 25–2000 °C using laser flash. The composition with the highest SiC showed the highest thermal conductivity (k) at 25 °C, but the lowest above ≈400 °C, because of the greater k temperature sensitivity of the SiC phase. Finite difference calculations of k, using selected literature data for the individual phases, and the concentration of phases from microstructures, correctly predicted temperature and phase concentration dependencies, but were lower than experimental results. The k of pure ZrB₂ and SiC as a function of temperature were back‐calculated from the experimental results for the multi‐phase materials; they were in good agreement with specific literature values.