Effect of the amount of concentrate offered in an automated milking system on dry matter intake,milk yield,milk composition,ruminal digestion,and behavior of primiparous Holstein cows fed isocaloric diets

The objective of this study was to determine if the quantity of concentrate provided in an automated milking system (AMS) affects dry matter intake (DMI), attendance to the AMS, milk and milk component yield, feeding behavior, cow activity, and ruminal fermentation of lactating dairy cows fed isocaloric diets. Eight ruminally cannulated primiparous Holstein cows were used in a replicated 4 × 4 Latin square design with 28-d periods. Cows were housed in a freestall facility with a guided-traffic (feed-first) flow barn design. Treatments included 0.5, 2.0, 3.5, or 5.0 kg/d of dry matter of pellet in the AMS with an equivalent reduction of the same pellet in the partial mixed ration (PMR). Days 21 to 24 of each treatment period were used for DMI, milking performance (visits, yield, and composition), behavior, and ruminal pH determination, and d 25 to 28 were used for ruminal short-chain fatty acid and ammonia concentrations as well as total-tract digestibility. As imposed, consumption of AMS pellet linearly increased, equating to 0.50, 2.00, 3.49, and 4.93 kg of dry matter/d for the 0.5, 2.0, 3.5, and 5.0 kg/d treatments, respectively. Correspondingly, the standard deviation in AMS pellet intake among days linearly increased from 0.06 to 0.85 kg of dry matter/d as the quantity of concentrate in the AMS increased from 0.5 to 5.0 kg. The PMR DMI decreased linearly with increasing AMS concentrate allocation, but total DMI (PMR + AMS) was not affected (25.3 kg/d). As the AMS concentrate allocation increased, the selection against particles retained on an 18-mm sieve linearly increased and selection against particles retained on the pan decreased. Milking frequency (3.22 milkings/d), milk yield (37.5 kg/d), milk fat yield (1.43 kg/d), and milk protein yield (1.22 kg/d) were not affected; however, milk urea nitrogen concentration decreased linearly with increasing AMS concentrate. Ruminal pH averaged 6.18 and was not affected by AMS concentrate. Total ruminal short-chain fatty acid concentration was greatest when 3.5 kg of concentrate was allocated in the AMS and ruminal ammonia decreased linearly with increasing AMS concentrate. Time spent lying, the number of lying bouts, and average bout duration were not affected by treatment. These data indicate that increasing the quantity of concentrate in the AMS increases daily variability in AMS concentrate intake while decreasing PMR intake without affecting voluntary visits to the AMS and milk or milk component yield. As such, under isocaloric dietary settings, increasing the supply of pellet in the AMS is not likely to affect voluntary visits to the AMS, milk and milk component yields, or ruminal fermentation.     

Increasing dietary sugar concentration may improve dry matter intake, ruminal fermentation, and productivity of dairy cows in the postpartum phase of the transition period

The current study was undertaken to investigate the effect of feeding diets varying in sugar concentration to postpartum transition cows on productivity, ruminal fermentation, and nutrient digestibility. We hypothesized that the high-sugar diet would increase dry matter intake and lactation performance. The secondary objective was to characterize changes in ruminal fermentation and nutrient digestibility over the first 4 wk of lactation. Fifty-two Holstein cows, including 28 primiparous and 24 multiparous cows, 10 of which were previously fitted with a ruminal cannula, were assigned to the experimental diets containing either high sugar (HS = 8.4%) or low sugar (LS = 4.7%) immediately after calving, based on their expected calving date. Data and samples were collected on d 5.2 ± 0.3, 12.2 ± 0.3, 19.2 ± 0.3, and 26.1 ± 0.3 relative to parturition for wk 1, 2, 3, and 4 respectively. Cows fed HS had increased dry matter intake compared with those fed LS (18.3. vs. 17.2 kg/d). Further, cows fed HS sorted for particles retained on the pan of the Penn State Particle Size Separator to a greater extent than cows fed LS. Feeding HS tended to increase nadir (5.62 vs. 5.42), mean (6.21 vs. 6.06), and maximum pH (6.83 vs. 6.65). The duration (h/d) and area (pH × min/d) that ruminal pH was below pH 5.8 were not affected by treatment. Ruminal volatile fatty acid concentration and molar proportions of individual volatile fatty acids were not affected by treatment. The digestibility of dry matter, organic matter, neutral detergent fiber, and starch were not affected by treatment, averaging 63.3, 65.2, 43.2, and 93.5%, respectively. Feeding HS decreased plasma glucose concentration compared with feeding LS (51.3 vs. 54.0 mg/dL), but concentration of plasma insulin was not affected by treatment, averaging 4.17 μIU/mL. Cows fed HS had higher concentrations of plasma β-hydroxybutrate (17.5 vs. 10.5 mg/dL) and nonesterified fatty acids (344 vs. 280 μEq/L). Milk yield and milk composition were not affected by treatment, but a tendency for increased milk fat yield was observed for cows fed HS compared with LS (1.44 vs. 1.35 kg/d). The results of the current study imply that replacing cracked corn grain with sucrose may improve dry matter intake, ruminal pH status, and lactation performance.     

Scattering and Absorption by Elongated Aerosol Particles

Recently we developed a new technique, the iterative extended boundary condition method, which is suitable for calculating the scattering and absorption by elongated particles in a broad frequency range, including at resonance. This paper briefly describes this technique, illustrates its capabilities, and presents the results of its most recent extensions. This includes the implementation of a sectioning procedure and the use of a new segmentation method for calculating scattering by very long oriented chains of aerosols. Results of absorption cross sections in two different frequency ranges, visible and infrared, and for two different polarizations, parallel and end-fire polarizations, will be presented. The range of validity of some reported relationships between scattering from a single particle and from coagulated particles are discussed. It is shown that in the end-fire polarization case the sum of the absorption by separate n particles (P _sum) is more than the absorption by a chain of n coagulated particles (P _end-fire), while in the parallel polarization case, the ratio between P _parallel/P _end-fire may be as high as a factor of 4. This observation emphasizes the importance of taking the polarization into account in calculating light scattering by elongated chains of aerosols.     

Timothy hay with a low dietary cation-anion difference improves calcium homeostasis in periparturient Holstein cows

The current study was undertaken to evaluate the effects of feeding timothy (Phleum pratense L.) hay differing in dietary cation-anion difference (DCAD) on the capability of cows to maintain calcium homeostasis around parturition. We hypothesized that feeding low-DCAD timothy hay during the prepartum period would induce a mild metabolic acidosis prepartum and improve calcium homeostasis postpartum with no effect on dry matter intake. Forty-one dry pregnant Holstein cows entering their second lactation or greater were used in a randomized complete block design. Timothy hay was obtained from an established timothy stand under a pivot irrigation system. Low-DCAD timothy hay was produced by fertilizing the area between the second and third pivot towers at a rate of 224 kg of CaCl₂/ha, and control timothy hay (high DCAD) was grown on the area between the fourth and fifth pivot towers of the same field. The chloride concentration was 1.07 and 0.15% on a dry matter (DM) basis, and the DCAD was 1.2 and 21.6 mEq/100 g of DM for the low- and high-DCAD timothy hay, respectively. Experimental diets, containing timothy hay at 63% of dietary DM, were fed ad libitum starting 30 d before the expected calving date. The DCAD values were 1.6 vs. 14.5 mEq/100 g of DM for the low- and high-DCAD timothy-based diets, respectively. At the beginning of the study, urine pH and blood bicarbonate concentration averaged 8.22 ± 0.06 and 28.5 ± 0.3 mM, respectively. The low-DCAD timothy diet decreased urine pH compared with the high-DCAD timothy diet on d 21 (7.75 vs. 8.31), d 14 (7.69 vs. 8.22), and d 7 (7.50 vs. 8.19) before calving, and it also decreased the prepartum blood bicarbonate concentration by 2 mM. In addition, cows fed the low-DCAD timothy diet had greater blood ionized calcium concentration prepartum (1.22 vs. 1.19 mM), greater blood ionized calcium concentration at 0 and 8 h after calving, and similar prepartum dry matter intake. These results indicate that timothy hay differing in DCAD affects the acid-base balance of periparturient dairy cows, and that low-DCAD timothy hay improves calcium homeostasis postpartum with no negative effect on dry matter intake.     

Fenestration devices for energy conservation—I. Energy savings during the cooling season

Equations are presented for estimating heat transfer through seven types of fenestrations using the properties of the shading devices and the conditions of the interior and exterior environments. The results have been employed to determine energy savings during the cooling season for buildings located in the transition climatic region of San Diego County. Life-cycle costs for installing various types of shading devices are estimated on the assumption that the shading devices are removed during the heating season or else have no effect on heating-season requirements.     

Multimode detection of hydrogen gas using palladium-covered silicon micro-channels

Palladium was electrodeposited onto lithographically patterned Si(100) "micro-channels" with dimensions of 2 microm (width) x 100 microm (length). The properties of these Pd-covered Si micro-channels for detecting dihydrogen gas were then evaluated. Pd electrodeposition was carried out under conditions favoring an instantaneous nucleation and growth mechanism. This strategy produced size-similar Pd particles at a coverage of (4-6) x 10(9) cm(-2) within the confines of the Si micro-channel. When the mean particle radius, ro, was smaller than a critical value (ro < rc = 70-85 nm), each Pd particle was well separated on the surface from adjacent particles, on average, and no response to H2 gas attributable to the micro-channel was observed. As Pd particles were grown larger, to a mean radius of ro approximately equal to rc, adjacent particles on the surface touched and the electrical resistance of the micro-channel dropped by several orders of magnitude. These "type 2" H2 sensors exhibited a rapid (< 1 s), reversible decrease in their resistance in response to exposure to H2 above 0.5%, but a minimum resistance was observed at 1-2%, and a resistance increase was seen at higher H2 concentration. This complex behavior resulted from the existence of three mechanisms for charge transport across the micro-channel. If still larger quantities of Pd were deposited, the Pd particle ensemble coalesced into an electrically continuous film. These "type 3" sensors became more resistive in the presence of H2, not more conductive as seen for sensors of types 1 and 2, but the amplitude of this response was smaller than seen for type 2 sensors.     

Premorbid anomalies and risk of schizophrenia and depressive disorders in a birth cohort exposed to prenatal rubella.

In a birth cohort prenatally exposed to rubella, we assessed whether prospectively documented premorbid neuromotor dysfunction, mannerisms, deviant behaviors, and temperament during childhood and adolescence were impaired in cases who developed depressive disorder (DD) relative to rubella-exposed controls and cases who developed schizophrenia spectrum psychosis (SSP). Premorbid neuromotor dysfunction and mannerisms were not increased among DD cases compared to controls or SSP cases. With regard to temperament, approachability was greater in DD cases than in controls and SSP cases. There were numerical increases in the proportions of DD cases with premorbid deviant behaviors compared to controls, but the findings fell short of statistical significance; the proportion of subjects with deviant behaviors in DD cases was similar to that found for SSP. These results indicate that premorbid neuromotor dysfunction and mannerisms may be specific to SSP among major psychiatric disorders in this cohort, and suggest that premorbid deviant behaviors are increased in both DD and SSP. Greater premorbid approachability may be associated with an increased risk of adult DD. Implications of these findings for school psychology are furnished. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Model-based automation of the design of user interfaces to digitalcontrol systems

Digital control systems, like those controlling the functions of buildings or industrial processes, pose a number of special problems for good user interface design. The general problems of providing usability, common to all systems, include difficulty in accessing and applying principles of good design. In addition, digital control systems can have multiple users, with multiple roles, and each installation has different configurations of systems, controls, and user interface devices. Providing interactions for the users of building control systems is often achieved by manually implementing each required display. This is an expensive solution, which often produces less than optimal results. We address these problems through the automation of user interface design. Our solution, called DIGBE (dynamic interface generation for building environments), separates the domain knowledge, interaction design, and presentation heuristics into multiple collaborating models. Each model contains knowledge about a particular aspect of interface design, and uses this knowledge to dynamically create each user interface that is needed to support the users of a control system. DIGBE demonstrates that it is possible to automatically and dynamically create consistent and individualized user interfaces from model-based design knowledge