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E B Moser

Publications and source records attributed to E B Moser.

8 recordsLinked to original sources
PubMed2002

Collection frequency affects percent Y-chromosome bearing sperm, sperm head area and quality of bovine ejaculates.

This study evaluated the percentage of Y-chromosome bearing spermatozoal (%Y-CBS) variation from ejaculates within individual males using two experiments. In the first experiment, six ejaculates were taken from each of five sexually rested (>30 days) Holstein bulls. Ejaculates were processed separately and stored in liquid nitrogen. From each ejaculate, five straws were thawed and equal sperm number, pooled samples were constructed using hemacytometer counts. Individual ejaculate DNA samples were extracted and quantified by spectroscopy. AY-chromosome specific segment was amplified by polymerase chain reaction (PCR) and the product separated by gel electrophoresis. Ethidium bromide stained bands were detected by image analysis and equated to a 50 %Y-CBS pool. In the second experiment (91 days), two ejaculates were collected from sexually rested (>21 days) bulls weekly and two ejaculates were collected from bulls every 21 days. Specific Y-chromosome (SRY) and X-chromosome (factor IX, F9) sperm DNA was amplified by PCR and the products separated by gel electrophoresis. Ethidium bromide stained bands were detected by image analysis and compared to a standard curve constructed from pure SRY and F9 PCR product. The log ratio (SRY/F9) of the corrected intensity densities were used to estimate the percent Y-chromosome DNA bearing spermatozoa (%Y-CDBS) in each ejaculate using inverse regression procedures. In Experiment 1, ejaculate differences for the first collection ranged from 17 to 71 %Y-CBS. Differences remained large for the second ejaculates and lessened for the third and fourth collections. Differences were least for the last two collections. Sperm head area also fluctuated. In Experiment 2, collection frequency affected the pattern of %Y-CDBS response. In bulls collected weekly, %Y-CDBS changed in a sinusoid fashion with a period of about 13.5 days. For bulls collected on a 21-day interval, %Y-CDBS ejaculate differences were high in the first ejaculate after sexual rest. Maximization of %Y-CDBS variation between ejaculate and its identification by PCR would allow ejaculate selection to be used to the alter the sex ratio in producers' calf crops.

Animals↗
PubMed1998

Sex ratio variation between ejaculates within sire evaluated by polymerase chain reaction, calving, and farrowing records.

Ejaculates from sires were examined by polymerase chain reaction to determine percentage of sperm bearing the Y chromosome. Results were verified by examining the percentage of male calves per ejaculate used in artificial insemination (AI) and the percentage of male piglets per litter from a controlled mating program. Spermatozoal DNA was amplified by polymerase chain reaction with specific primers for the Y chromosome. Image analysis measured the fluorescent intensity of the 194-bp band. Ejaculates were compared with a pooled standard of spermatozoal DNA equated to a 50% Y-bearing sperm ejaculate. Calving data were obtained from information collected for the National Association of Animal Breeders for dystocia evaluation of cows bred to AI bulls. Breeding data were obtained from AI technician receipts. Calving and breeding data were merged on cow, sire, calving date, and breeding date. The percentage of males were calculated per sire, ejaculate, and herd combination. Farrowing data were evaluated for the percentage of male piglets per litter. Ejaculates within bulls contributed to variation (24 +/- 9.8% to 84 +/- 9.8%) in the percentage of sperm bearing the Y chromosome. Ejaculates from the same bull contributed to variation in the percentage of male calves (16.1 to 72.3%). Ejaculates from the same boar contributed to variation in the percentage of male piglets that ranged from 7.8 to 94.7%. These percentages and the results obtained by polymerase chain reaction analysis of ejaculates suggested that spermatozoa bearing X and Y chromosomes were unequally represented in ejaculates. The use of ejaculates screened by polymerase chain reaction could enhance production of the desired sex of calf.

Acrosome↗
PubMed1993

Ultrasonic measurement of canine testes.

The goals of the present study were to determine if ultrasonic measurement of testicular dimensions (length, width, and height) would provide an accurate assessment of canine testicular size (weight) and to determine the relationship of these measurements to animal body weight. The bodies of 30 intact male dogs of unknown health, breed or breeding history were obtained after the dogs were humanely killed at the local animal shelter. Total scrotal width (TSW) was measured by calipers and the length, width and height of each scrotal testis, excluding the epididymis, were measured by sonography. The testes were then excised and weighed, again excluding the epididymis. Multiple regression was used to predict total testicular weight from 1) only sonographic measurements (Model 1), 2) all testicular measurements (Model 2), 3) only total scrotal width (Model 3), and 4) only body weight (Model 4). In addition, stepwise multiple regression was used to identify models (Models 5 and 6) using external measurements of the testes which seemed most useful in predicting total testicular weight. Models 1, 2, 3, 4, and 6 yielded r(2) values 0.90, 0.94, 0.88, 0.48 and 0.95 respectively. Model 5 yielded an r(2) of 0.90, but the additional accuracy achieved by using the testicular height was minimal. Although sonographic testicular measurement accurately predicted testicular weight, the small degree of additional accuracy achieved over TSW measurement by calipers does not justify the use of sonography in each case. However, if a testicular ultrasound scan is being performed, the ultrasonic measurements could be used to predict testicular weight.

Journal Article↗
PubMed1989

Exploring contingency tables with correspondence analysis.

An algorithm for correspondence analysis is described and implemented in SAS/IML (SAS Institute, 1985a). The technique is shown, through the analysis of several biological examples, to supplement the log-linear models approach to the analysis of contingency tables, both in the model identification and model interpretation stages of analysis. A simple two-way contingency table of tumor data is analyzed using correspondence analysis. This example emphasises the relationships between the parameters of the log-linear model for the table and the graphical correspondence analysis results. The technique is also applied to a three-way table of survey data concerning ulcer patients to demonstrate applications of simple correspondence analysis to higher dimensional tables with fixed margins. Finally, the diets and foraging behaviors of birds of the Hubbard Brook Forest are each analyzed and then a simultaneous display of the two separate but related tables is constructed to highlight relationships between the tables.

Algorithms↗
PubMed1988

Biological applications of the SAS system: an overview.

The SAS system provides biologists with a flexible, easy to use software package for data analysis. Through a combination of data management tools, a wide variety of pre-programmed procedures for sorting, graphing, and statistical analysis and a sophisticated programming language, SAS software can perform all analytical needs for most problems. The recent availability of SAS software on mainframes other than IBM, and more recently on the microcomputer, means that most scientists can have access to the software. In this review we discuss the structure of the SAS language and demonstrate its power in the analysis of biological problems. Although to a lesser extent now than originally, the SAS system is statistically oriented and a working knowledge of statistics is recommended before using its statistical capabilities. However, all biologists will find its data management and summarization capabilities very useful.

Biology↗