Variance components for a sire-maternal grandsire (MGS) threshold model were estimated from subsets of the US calving ease (CE) database, which includes over 10 million calving records with CE scored 1 (no problem) to 5 (extreme difficulty). Selected records included sire and MGS among the 2601 most frequently appearing bulls. The data were further restricted by requiring at least 20 records in...

Reduction in Salmonella enteritidis (SE) contamination is of importance for poultry production as well as for food safety. The objectives of this study were to identify potential genetic markers of antibody response to SE vaccine in young broiler chicks and then to confirm this linkage in broiler-cross offspring, as well as to explore interactions of marker alleles with dam line and sex. The in...

Pig breeding companies keep relatively small populations of pure sire and dam lines that are selected to improve the performance of crossbred animals. This design of the pig breeding industry presents challenges to the implementation of genomic selection, which requires large data sets to obtain highly accurate genomic breeding values. The objective of this study was to evaluate the impact of d...

ACKNOWLEDGMENTS This project would not have been possible without the help of several individuals within the dairy industry. My advisor, Dr. Stan Henderson, provided the opportunity to research this project. Dr. Henderson guided me throughout the project and assisted in obtaining these data. Dr. Henderson also assisted in compiling these data and developing the manuscript. Without the help of D...

(Co)variance components for stillbirth in US Holsteins were estimated under a sire-maternal grandsire threshold model using subsets of data from the national calving ease database, which includes over 6 million calving records with associated stillbirth scores. Stillbirth was coded as a binomial trait indicating whether the calf was alive 48 h postpartum. Records were selected for calves whose ...

Fifteen progeny of two Polled Hereford sires were fed endophyte-infected tall fescue seed (E+) to investigate variability in susceptibility to fescue toxicosis. One sire, bred in Missouri, was reputed to produce calves that were resistant to fescue toxicosis. The Control sire, from Virginia, had unknown merit for susceptibility. There were two phases in which E+ was included in the diet (2 and ...

Procedures for selecting sires are compared in terms of making maximum genetic progress in economic lnerit. A quadratic index, a simplified form of the quadratic index and a linear index to evaluate economic merit, and a restricted index to improve milk as much as possible while holding milk fat percentage constant, all result in nearly equal expected genetic progress in economic merit. Selecti...

Effects of inbreeding and heterosis and the difference between them were estimated by comparing linecross (L), topcross (T), inbred (I) and control line (C) Hereford females for reproductive and preweaning growth traits of their progeny. Inbred females (average inbreeding coefficient = 26.5%) originated from four single-sire inbred lines. Control females (average inbreeding coefficient = 6.9%) ...

An animal model with a REML algorithm was used to estimate variances of additive genetic effects and interaction effects of sire and herd. Milk and fat yields were analyzed for first, second, and third lactations of Holsteins from California, New York, and Pennsylvania. Twenty samples of data were used in the study: 10 from California, 4 from New York, and 6 from Pennsylvania. Mean number of la...

Purpose. The purpose of this study was to compare CT-navigated stereotactic IRE (SIRE) needle placement to non-navigated conventional IRE (CIRE) for percutaneous ablation of liver malignancies. Materials and Methods. A prospective trial including a total of 20 patients was conducted with 10 patients in each arm of the study. IRE procedures were guided using either CT fluoroscopy (CIRE) or a ste...