Effect of Breed on Carcass Merit

Ten years ago most cattle found in feedlots in the Corn Belt and the Northern Great Plains were straightbreds representing one of the British breeds. However, with the increased use of Charolais and the importation of bulls from at least 12 other European breeds into Canada, a large variety of breeds and breed crosses is found in the feedlots at the present time. This increased variety along with emphasis on increased efficiency has caused many feeders to ask questions concerning the performance of these breeds and breed crosses. The purpose of this paper is to review research results in an attempt to identify some breed differences that are of most interest to the cattle feeder

Evaluation of Final Weight in the Selection of Performance Tested Bulls

Selection of herd sires, in the past, by the beef breeders in South Dakota has primarily been based on type. In general, the beef breeder has attempted to purchase the bull with the most attractive conformation based on his personal judgement. This method of selection has brought limited progress to the largest industry in South Dakota from which 35% of the cash farm income is derived. The purpose of this study was to check the feasibility of using final weight as a criterion in the selection of performance tested bulls. The other phases of the study concerned final weight as affected by inbreeding and the importance of length of feeding period as it affects the accuracy of selection

Choosing Breeds and Crossbreeding Systems by Computer

The first report dealing with this project appeared in the Cow-Calf Field Day bulletin, August, 1972. That report presented an example to demonstrate the utility of the program for the cow-calf man. The example was based on estimates of performance traits for specific breeds under a particular environment and management situation and on market conditions existing at that time. The management system basic to the program took the weaning calf to 700 pounds in a backgrounding phase and then through a 140-day feedlot phase which was split into a 50-day growing period and a 90-day finishing period. The purpose of this report is to investigate varying certain of the marketing conditions, specifically selling on a retail cut basis rather than a carcass weight basis, and, secondly, eliminating the carcass quality grade as a basis for pricing the carcass. The results should assist the producer in evaluating breeds and crossbreeding systems for the marketing system he thinks will be most commonly used in the future

Choosing Breeds and Crossbreeding Systems by Computer

A computer program called Simumate has been developed that will allow a producer to evaluate crossbreeding systems for his particular nutrition and management situation using the breeds of his choice. This program, based on a method suggested by Dearborn (1970), takes into account energy requirements for maintenance of the cow, for milk production and for gain required during the gestation period (Neville and McCullough, 1969). It also takes into account the reproductive rate, growth rate, selling prices at several stages and the costs of production both feed and fixed in arriving at a net return for all straightbreds, all possible two breed rotation, three breed rotation and specialized crosses. In order to acquaint the producer with the program, the following example has been calculated. This example is intended only to acquaint the producer with what the program can do for him and should not be used for planning a program. The cost situation should be tailored to the individual ranch unit and the breed estimates will vary with the nutrition and management levels of different operations

Application of the Cubed-Sphere Grid to Tilted Black-Hole Accretion Disks

In recent work we presented the first results of global general relativistic magnetohydrodynamic (GRMHD) simulations of tilted (or misaligned) accretion disks around rotating black holes. The simulated tilted disks showed dramatic differences from comparable untilted disks, such as asymmetrical accretion onto the hole through opposing "plunging streams" and global precession of the disk powered by a torque provided by the black hole. However, those simulations used a traditional spherical-polar grid that was purposefully underresolved along the pole, which prevented us from assessing the behavior of any jets that may have been associated with the tilted disks. To address this shortcoming we have added a block-structured "cubed-sphere" grid option to the Cosmos++ GRMHD code, which will allow us to simultaneously resolve the disk and polar regions. Here we present our implementation of this grid and the results of a small suite of validation tests intended to demonstrate that the new grid performs as expected. The most important test in this work is a comparison of identical tilted disks, one evolved using our spherical-polar grid and the other with the cubed-sphere grid. We also demonstrate an interesting dependence of the early-time evolution of our disks on their orientation with respect to the grid alignment. This dependence arises from the differing treatment of current sheets within the disks, especially whether they are aligned with symmetry planes of the grid or not.Comment: 15 pages, 11 figures, submitted to Ap

Influence of Nutrition During the Postweaning-Preflushing Period on Ewe Performance

The objective of this experiment was to study the feasibility of maintaing ewes in drylot on a limited ration during the postweaning - pre-flushing period. The cost of treatment and resulting ewe performance were used to evaluate the feasibility

Information Seeking Behaviors, Attitudes, and Choices of Academic Physicists

Physicists in academic institutions utilize a variety of resources and strategies to seek, find, and use scholarly information and news. Using a sample of physicists, researchers surveyed 182 students and faculty at seven Canadian university institutions to explore self-perceived success rates, resources consulted, databases used, and use of social media and citation management systems. To complement the survey, 11 follow up interviews/focus groups were completed with participants to further uncover information-seeking behaviors, choices, strategies, and feelings around keeping up to date with information needs. According to survey results, a minority of physicists (15.4%) acknowledged that they were successfully keeping up to date. However, a significant number of physicists (28.6%) indicated that they were unsuccessful and could do better in remaining current with information needs. Co-investigators, using qualitative analyses, identified four emergent themes: (1) There are “too many papers – and not enough time” to effectively search, evaluate and read scholarly papers of interest; (2) Staying up to date is important especially in competitive research areas; (3) Graduate students seek information differently than faculty and experienced researchers; and (4) The arXiv database is important to many physicists. Additional minor themes included physics-related publishing is constantly evolving; physicists use a variety of information-seeking behaviors; and, information-seeking methods can differ between physics subdisciplines. This study aims to shed light on opportunities for academic librarians to identify and meet physicists’ evolving information behaviors, attitudes, choices, and needs