Large or Food Animal and Equine Medicine Commons^™

Comparison Of Spayed Heifer Performance To Intact Heifers Fed Melengestrol Acetate On Feedlot Performance And Carcass Characteristics, Tate S. Johnson, Rebecca L. Mcdermott, Halden J. Clark, Jim C. Macdonald, Jessica L. Sperber

Nebraska Beef Cattle Reports

Summary with Implications

Pregnancy and estrous cycle management are critical considerations when feeding intact heifers in the feedyard. Alternatively, producers can opt to spay heifers, which eliminates hormonal fluctuations associated with the estrous cycle. A proportion of U.S. feedlots have spayed heifers on feed, although there is limited data comparing the performance of spayed heifers to intact heifers. A commercial feedlot experiment was conducted to compare performance between spayed and intact heifers fed melengestrol acetate. Intact heifers had greater ADG and tended to have greater DMI compared to spayed heifers, although no difference in feed conversion was observed. Carcass weight …

Recovery And Characterization Of Moraxella Species From Bovine Specimens, Laura G. Leger

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The family Moraxellaceae is made up of a diverse group of 24 named species that fall into three phylogenetic groups. While most Moraxella spp. act as commensal respiratory and/or ocular flora of mammals, some are associated with disease. One of these diseases, infectious bovine keratoconjunctivitis (IBK), has significant welfare and economic impacts to both cattle and cattle producers. Moraxella bovis is the only experimentally determined cause of IBK, however, an association of Moraxella bovoculi with disease has been proposed. Currently, available vaccines do not have high levels of efficacy in the field. Culture based methods are the gold standard for …

Environmental Effects On Preweaning Calf Health, Lindsay L. Waechter-Mead

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Neonatal calf health is an important factor in the productivity and profitability in the beef cattle industry, influencing preweaning survival, growth, and long-term performance. The overall objective of this thesis is to characterize risk factors that contribute to health issues in young beef calves. The first objective is to review literature exploring the environmental factors affecting preweaning morbidity and mortality, including hypothermia, precipitation, and wind. Management strategies such as the effect of environmental conditions of calving location, body condition score in dams at parturition, and the impacts of dystocia on calf health will also be discussed. Gaps in current research …

Artificial Insemination Of Beef Heifers With Multi-Sire Semen, Dempster Christenson, Jordan M. Thomas, Daniel J. Kelly, Richard N. Funston

Nebraska Beef Cattle Reports

This study compared pregnancy rates of beef heifers artificially inseminated with multi-sire semen to single-sire semen. It was hypothesized pregnancy rates resulting from multi-sire semen would be increased compared to single-sire semen. Heifers were artificially inseminated with semen from one of three single-sires or semen from a combination of the same three sires. Pregnancy rates did not significantly differ. Paternity testing suggests sire parentage can be unequal when semen is mixed from multiple sires. In summary, producers can expect similar pregnancy rates using single-sire and multi-sire semen, but progeny may have unequal sire representation.

The Impact Of A Pgym Variant On Myophosphorylase Deficiency In Red Angus Composite Cattle And Changes In The Skeletal Muscle Transcriptome Due To The Intramuscular Administration Of Lidocaine In Wether Lambs, Mackenzie Christin Batt

School of Biological Sciences: Dissertations, Theses, and Student Research

Project 1 focused on eight calves in a Nebraska herd (composite Simmental, Red Angus, Gelbvieh) that displayed exercise intolerance during forced activity. Available sire pedigrees contained a paternal ancestor within 2-4 generations in all affected calves. Pedigrees of the calves’ dams were unavailable, however, the cows were ranch-raised and retained from prior breeding seasons, where bulls used for breeding occasionally had a common ancestor. Therefore, it was hypothesized that a de novo autosomal recessive variant was causative of exercise intolerance in these calves. A genome-wide association analysis followed by whole-genome sequencing led to the identification of a variant in the …

Artificial Insemination And Fetal Programming In Beef Production Systems, Dempster M. Christenson

Department of Animal Science: Dissertations, Theses, and Student Research

Pregnancy to artificial insemination and late gestation fetal programming of the next calf crop are central to genetic development, reproductive longevity, calf crop productivity, and efficiency of cow/calf ranching. The purposes of this research are to find methods to improve pregnancy rate to artificial insemination, the growth and reproductive health of pregnant heifers, and the productivity of their offspring. In the first of four studies we found that extending the period of progesterone administration in an estrus synchronization protocol did not significantly hasten estrus response or increase pregnancy rate to artificial insemination, but timing of estrus within the melengestrol acetate …

Identifying Barriers To Data Use On U.S. Beef Cow-Calf Operations And Developing Solutions To Improve Cow-Calf Record-Keeping, William Isaac Jumper

Theses and Dissertations

Cattle health and production records (CHPR) are data collected by cattle producers and veterinarians in the form of measurements, observations, counts of events over time, and physiologic attributes that describe individual and group-level health and production. These data are useful to both veterinarians and cattle producers for making evidence-based decisions on cow-calf operations. Currently, there are no uniform, industry-wide methods of capturing and recording CHPR in the U.S. cow-calf industry. Although many cow-calf producers in the U.S. are thought to collect some form of CHPR, it is believed that relatively few are doing so in an electronic manner that facilitates …

Pharmacokinetics Of Single Feeding Of Cannabidiol In Cattle: A Pilot Study, Haley Cornette

Honors College Theses

Cannabidiol (CBD) is a substance that has been used in complementary medicine for many years. However, modern medicine has little knowledge of how this substance is utilized and metabolized in ruminant animals. Regulations on quality assurance and use in animals are lacking, and CBD supplementation in livestock is not approved. If CBD supplements can be shown to be safe and effective, detection in the animal will be important for determining regulation of use. A withdrawal period can then be established to allow time for deterioration of product to safe levels before livestock products enter human markets. This study sought to …

The Efficacy Of Extended-Release Eprinomectin For The Reduction Of Horn Flies, Face Flies, And Fecal Egg Counts Of Parasitic Nematodes In Replacement Beef Heifers, Sophia F. Landers

Animal Science Undergraduate Honors Theses

The purpose of this study was to evaluate the efficacy of extended-release eprinomectin against horn flies, face flies, and fecal egg counts of parasitic nematodes in crossbreed replacement beef heifers. Fifty-four heifers were randomly placed into three treatment groups (N=18 heifers/treatment). Group 1 was administered the labeled dosage of extended-release eprinomectin on day 0. Group 2 acted as the negative control. Group 3 received the anthelmintic injection once a quarter of the heifers in the group reached the threshold treatment level for horn flies (N=200 flies/animal; day 41). Nematode infections were measured via fecal egg counts while horn and face …

Environmental Sampling Techniques For Herd-Level Surveillance Of Bovine Viral Diarrhea Virus, Jaden Carlson

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Control of Bovine Viral Diarrhea Virus (BVDV) relies on resource-intensive individual animal sampling to detect and remove persistently infected (PI) cattle. Herd-level surveillance tools would be useful for herds with unknown BVDV status and for monitoring herds with BVDV-free status. The overall objective of this thesis is to explore the viability of BVDV surveillance at a herd-level using samples collected without handling individual animals. The first objective was to determine the feasibility of using stable flies as a sampling tool to detect BVDV. The second objective was to determine the feasibility of using drinking water to detect BVDV. To accomplish …

Evaluating The Epidemiology And Management Of Bovine Congestive Heart Failure, Adam Bassett

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

A form of congestive heart failure is increasingly reported as a cause of death in feedlot cattle located at moderate altitude (≤ 1,524 m.). Significant knowledge gaps exist in the epidemiology and management of this form of bovine congestive heart failure (BCHF) regarding frequency and timing of BCHF cases and ways in which beef cattle producers and veterinarians can mitigate this condition. These knowledge gaps present major barriers to understanding the mechanism of BCHF and mitigating the consequences of BCHF. The purpose of this thesis is to summarize current knowledge about BCHF, define gaps in knowledge for which more research …

The Effect Of Bovine Galectin-1, A Conceptus Secretory Protein, On The Endometrial Transcriptome, Lindsay Faye Grose

Graduate Theses, Dissertations, and Problem Reports (ETD)

Early embryonic loss in cattle is detrimental to reproduction thus, the profitability of both the beef and dairy industries. Therefore, an important aspect of study is to find techniques that beef or dairy producers could use to decrease early embryonic loss Galectin-1, the protein that was investigated in this research is important in modulating the maternal immune system in rodent and human early pregnancies by promoting fetomaternal immune tolerance. The role of galectin-1 within the reproductive tissues has not been thoroughly investigated in cattle. Galectin-1 is located in the caruncular and intercaruncular regions of the bovine endometrium, specifically the maternal …

Evaluation Of Pre-Harvest Screening For Antibiotics And Flunixin Meglumine In Cattle, Shuna A. Jones

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Many antibiotics and medications used in the treatment of animals have a withdrawal time; residues are a concern for the meat industry. The most recently published 2009 USDA-FSIS Residue Program Data Report listed 135,389 Inspector-in-Charge-Generated (IICG) residue samples from 43,142,500 beef and dairy cattle inspected that year at harvest. Of these samples, 1,306 contained violative antibiotic residues and 327 violative flunixin meglumine residues. Two classes of antimicrobials comprised over half of the documented violative antimicrobial residues (beta-lactams that include ceftiofur and sulfa drugs that include sulfadimethoxine). While the violative residue rate seems small, violative residues are unacceptable. Management of carcasses …