A survey of castration methods and associated livestock management practices performed by bovine veterinarians in the United States

<p>Abstract</p> <p>Background</p> <p>Castration of male calves destined for beef production is a common management practice performed in the United States amounting to approximately 15 million procedures per year. Societal concern about the moral and ethical treatment of animals is increasing. Therefore, production agriculture is faced with the challenge of formulating animal welfare policies relating to routine management practices such as castration. To enable the livestock industry to effectively respond to these challenges there is a need for more data on management practices that are commonly used in cattle production systems. The objective of this survey was to describe castration methods, adverse events and husbandry procedures performed by U.S. veterinarians at the time of castration. Invitations to participate in the survey were sent to email addresses of 1,669 members of the American Association of Bovine Practitioners and 303 members of the Academy of Veterinary Consultants.</p> <p>Results</p> <p>After partially completed surveys and missing data were omitted, 189 responses were included in the analysis. Surgical castration with a scalpel followed by testicular removal by twisting (calves <90 kg) or an emasculator (calves >90 kg) was the most common method of castration used. The potential risk of injury to the operator, size of the calf, handling facilities and experience with the technique were the most important considerations used to determine the method of castration used. Swelling, stiffness and increased lying time were the most prevalent adverse events observed following castration. One in five practitioners report using an analgesic or local anesthetic at the time of castration. Approximately 90% of respondents indicated that they vaccinate and dehorn calves at the time of castration. Over half the respondents use disinfectants, prophylactic antimicrobials and tetanus toxoid to reduce complications following castration.</p> <p>Conclusions</p> <p>The results of this survey describe current methods of castration and associated management practices employed by bovine veterinarians in the U.S. Such data are needed to guide future animal well-being research, the outcomes of which can be used to develop industry-relevant welfare guidelines.</p

Selektive Epitaxie von (GaIn)(AsP) Schichtstrukturen

Summary in EnglishAvailable from TIB Hannover: RR 9531(3) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Supplementation strategies for forage-fed beef steers

A comparison was made of different supplementation strategies for steer calves wintered on brome hay for 109 days. Treatments consisted of no supplement, 1.33 lb/head daily of a 30% protein range cube, a commercially available free-choice block supplement containing 40% crude protein (19% as non-protein nitrogen), and a soy-based block supplement containing soy solubles and full-fat soybeans with 40% crude protein (25% as nonprotein nitrogen). Following the backgrounding phase, steers were placed onto finishing rations and fed for an additional 152 days before being slaughtered. Gain during the growing phase was greater for all supplemented cattle than for unsupplemented controls. Cattle fed blocks or no supplement tended to compensate during the finishing phase, suggesting that differences in gastrointestinal tract fill may have impacted body weights at the end of the back grounding phase. When performance was evaluated over the entire 261-day trial, cattle fed blocks were more efficient than controls, whereas efficiencies of cattle fed range cubes were essentially equal to those of cattle that previously received no supplement. Additionally, soybean solubles and full-fat soybeans were viable alternatives to traditional ingredients for manufacturing free-choice block supplements

Highly sensitive wavefront sensor for characterization of micro- to nanometer-scale surface flatness deviations

Wave front sensing is an optical method allowing non-contacting topography measurements of flat surfaces. Applications of the method are, for instance, the characterization of optical components, semiconductor surfaces, or subcomponents used in semiconductor manufacturing equipment. The method developed here is covering the characterization of flatness on mirror-like surfaces within three orders of magnitude from micro- to nanometer scale. This is due to the high range of detectable surface slopes from very low to relatively high values. Therefore, the method is applicable to both, micro- and nanometer scale height deviations on surfaces. The wave front sensing is capable of studying the topography in a real-time operating mode. The technique enables vertical resolution of approximately 10 nm at a lateral resolution of 0.6 mm on bare silicon wafer surfaces. Moreover, highly reflective surfaces with height deviations of 10-15 µm could be easily resolved at a lateral resolution of 2.4 mm. In this study, we focused on the application in semiconductor surfaces and manufacturing equipment: measurements were performed on bare wafers as well as on the mirror-like surface of a wafer holder used for wafer polishing (a 'polishing head'). An obstacle for measurements is a low reflectivity of surfaces. Both, metallic surfaces and silicon wafers, however, show high surface reflectivity

Optical inspection of flat reflective surfaces by a wave front sensor

The wave front sensor used in this paper is based on Makyoh method: the studied sample is illuminated by a collimated light beam and the reflected beam is collected by a camera. Previously it was demonstrated that this method enables the determination of surface flatness in the nanometer range. For this purpose the deformation of an initially planar wave front is detected and evaluated using patterns projected on the surface. This paper demonstrates that the sensor can also be used without patterns for characterization of surfaces flatness in the sub-micrometer and micrometer ranges. The intensity distribution image obtained can be interpreted in terms of topography as follows: convex areas of the studied surface defocus the beam (dark regions on the image) while the concave areas focus it (bright regions). The main result of this work is the development of a new approach for the fast assessment of the surface quality. This approach estimates the areas and the intensiti es of bright regions on the image and gives the value of the maximum concavity on the studied surface. For evaluation of data a simulation of the reflected from the given profile was made. The setup parameters, e.g. distances between the optical components, were optimized with the parameters obtained from the 2D simulation of the wave front sensor. This paper demonstrates the feasibility of wave front sensing for the topography analysis of reflective surfaces such as bare wafers' surfaces, metallic thin films, etc. used in semiconductor industry