Veterinary Medicine Commons^™

Ultrasonographic Evaluation Of Massive Abdominal Wall Swellings In Cattle And Buffaloes, Ashwani Kumar, Jitender Mohindroo, Vandana Sangwan, Shashi Kant Mahajan, Kiranjeet Singh, Arun Anand, Narinder Singh Saini

Turkish Journal of Veterinary & Animal Sciences

Eight cows and 7 buffaloes with massive abdominal wall swellings were examined. The aim of the ultrasonographic study was to learn the contents of the abdominal wall swellings. They were divided into 4 groups: Group I (prepubic tendon rupture or hernia), Group II (fibrino-cystic swelling), Group III (abscess), and Group IV (inflammatory swelling). Palpation of the swelling in semidorsal recumbency, needle aspiration, or surgery was used to confirm the diagnosis. In animals of Groups I, II, and III, in the ultrasound, the muscles appeared to separate from the skin at the margin of swelling, thus creating a gap. In this …

Study On The Relationship Between Single Nucleotide Polymorphisms Of The Coccidiosis-Resistance Candidate Zyxin Gene Exon 1 And Carcass Traits In The Jinghai Yellow Chicken, Guojun Dai, Dahui Sun, Mingming Sun, Yuxin Lin, Xiang Wang, Genxi Zhang, Kaizhou Xie, Miaomiao Shi, Olajide Olowofeso, Jinyu Wang

Turkish Journal of Veterinary & Animal Sciences

Previous research revealed that several single nucleotide polymorphisms (SNPs) of zyxin were significantly associated with coccidiosis-resistance parameters. In this research, the Jinghai yellow chicken was chosen to detect the SNPs of zyxin gene exon 1 by PCR-SSCP and DNA sequencing techniques, and was also used to analyze the effect of zyxin SNPs on carcass traits. A single mutation was found with 3 genotypes, designated as AA, AB, and BB. The results showed that BB was significantly different from AA and AB in terms of abdominal fat weight and slaughter rate for cockerel (P < 0.05), while there was no significant difference between AA and AB (P > 0.05). The heart weight, breast muscle rate, …

The Effects Of Dietary Glutamine Supplementation On Growth Performance And Intestinal Morphology Of Broiler Chickens Reared Under Hot Conditions, Farhad Jazideh, Parviz Farhoomand, Mohsen Daneshyar, Gholamreza Najafi

Turkish Journal of Veterinary & Animal Sciences

Dietary supplementation effects of 0%, 0.25%, 0.5%, and 1% glutamine were investigated on the performance and development of the gastrointestinal tract in broilers reared under hot conditions. No significant differences were observed between the treatments for feed intake and feed conversion ratio during the starter period, grower period, or entire experiment (P > 0.05). During the grower period, only 0.5% glutamine-fed birds had higher body weight gain than others (P < 0.05). For the entire period, body weight gain of 0.5% glutamine-fed birds was greater than that of 0.00% and 0.25% glutamine-fed ones (P < 0.05). Furthermore, 0.5% glutamine-fed birds showed longer villus height than other birds (P < 0.05). In the jejunum, both 0.5% and 1% glutamine consumption caused longer villus height as compared to 0.00% and 0.25% glutamine (P < 0.05). Villus height of 0.25% glutamine-fed birds was higher than that of 0.00% glutamine-fed ones (P < 0.05). None of the ileum morphological parameters were affected by glutamine supplementation (P > 0.05). In conclusion, supplementation of 0.5% glutamine improved the intestinal morphology and body weight gain of broilers under heat stress. Higher dietary glutamine (1%) increased the villus height in the jejunum …

The Effects Of Royal Jelly On Performance And Fatty Acid Profiles Of Different Tissues In Quail (Coturnix Coturnix Japonica) Reared Under High Stocking Density, İsmai̇l Seven, Ülkü Gülci̇han Şi̇mşek, Zehra Gökçe, Pinar Tatli Seven, Aslihan Arslan, Ökkeş Yilmaz

Turkish Journal of Veterinary & Animal Sciences

To study the effects of royal jelly (RJ) on performance and fatty acid profiles, 168 unsexed 8-day-old quails (Coturnix coturnix japonica) were assigned to 4 treatment groups. Groups were arranged as follows: control (LSD; 160 cm2/quail and no supplementation), high stocking density (HSD; 80 cm2/quail and no supplementation), HSD-RJ 250 [80 cm2/quail and 250 mg/kg body weight (BW) RJ given orally], and HSD-RJ 500 (80 cm2/quail and 500 mg/kg BW RJ given orally). Body weight gain decreased significantly in the HSD group at day 42 (P < 0.01). Feed intake (FI) and feed conversion rate (FCR) were also significantly affected in the HSD group (P < 0.01). FI and FCR were improved by both doses of RJ. Both RJ doses increased total polyunsaturated fatty acid ratios in the breast, kidney (P < 0.001), leg, and liver (P < 0.05). Total saturated fatty acid ratios in leg (P < 0.01) and kidney (P < 0.05) tissues increased in the HSD group but decreased in the livers of HSD-RJ 250 group (P < 0.05). In conclusion, RJ supplementation improved performance parameters and unsaturated fatty acid ratios in the examined quail tissues.

Detection Of Sensitive And Mutant Ruminal Bacteria Isolates From Sheep, Cattle, And Buffalo Using 14 Therapeutic Antibiotics, Abdelfattah Zeidan Mohamed Salem, Roberto Montes De Oca Jimenez, Maria Andrea Cerrillo-Soto, Ahmed Eid Kholif, Mohamed Zidan Mohamed Salem, Mona Mohamed Mohamed Yasseen Elghandour

Turkish Journal of Veterinary & Animal Sciences

In the present study, sensitive and mutant colonies of some ruminal bacterial species isolated from sheep, cattle, and buffalo were detected. We counted and considered \"mutant colonies\" the bacterial colonies grown in the clear inhibition zone in the Kirby-Bauer disk diffusion susceptibility test. Detected mutant colonies were higher in buffalo than in cattle and sheep. Duricef and metronidazole caused no mutations in any species. The others formed mutant colonies, where roxithromycin = polymyxin = chloramphenicol = gentamicin < erythromycin < vancomycin < piperacillin = cefotaxime < streptomycin < cefoperazone < ciprofloxacin < amikacin. Sheep had the highest number of sensitive isolates, and the number of sensitive isolates was dramatically lower in cattle and buffalo. There were no sensitive isolates with the antibiotic metronidazole, and there was a low number of sensitive isolates with duricef. The other antibiotics had more sensitive isolates (gentamicin = ciprofloxacin = amikacin > streptomycin = piperacillin > erythromycin > vancomycin = cefoperazone = cefotaxime > roxithromycin > polymyxin > chloramphenicol). The number of sensitive isolates of the different ruminant species for …

The Treatment Of Congenitally Developed Fused Vulva Labia In A Brown-Swiss Heifer, Oktay Yilmaz, Ebubeki̇r Yazici, Mehmet Uçar, Muhammed Kürşad Bi̇rdane

Turkish Journal of Veterinary & Animal Sciences

A case of congenitally developed fused labia in a 13-month-old Brown-Swiss heifer, an uncommon entity, is described. On gross appearance of vulva, it was observed that there were only 2 small openings in the dorsal and ventral vulvar commissures. Ultrasonography of the genital tract revealed the presence of left and right ovaries, uterine horns, and cervix uteri. The abnormality of the vulva was surgically corrected. The heifer was synchronized and artificially inseminated postsurgically. During delivery, no complication was observed and a healthy male calf was born. To the authors' knowledge, this is the first report describing both the surgical treatment …

The Relationship Between Seropositivity And Tissue Cysts In Sheep Naturally Infected With Toxoplasma Gondii, Kader Yildiz, Oğuz Kul, Sami̇ Gökpinar, Hasan Tarik Atmaca, Yilmaz Emre Gençay, Aycan Nuri̇ye Gazyağci, Cahi̇t Babür, İsmayi̇l Safa Gürcan

Turkish Journal of Veterinary & Animal Sciences

Skeletal muscles (tongue, masseter, leg, intercostal, and diaphragmatic muscles) and brain samples of 100 sheep at slaughter were analysed for the presence of T. gondii tissue cysts along with serum IgG titres. Two methods of isolation by percoll gradient centrifugation and tissue microarray (TMA) technique with immunoperoxidase staining were used. Seropositivity was detected in 88% (88/100) of sheep sera analysed by indirect fluorescent antibody test. Tissue cysts were observed in 46 (52.3%, 46/88) and 15 (17%, 15/88) of the seropositive sheep with the isolation technique and TMA and immunoperoxidase staining, respectively. The diameters of the tissue cysts were 25–58 × …

Serological Survey Of Equid Herpesvirus 3 Infection In Turkish Horses, Veysel Soydal Ataseven, Firat Doğan, Seval Bi̇lge Dağalp, Mehmet Tolga Tan, Köksal Altinbay, Cafer Tayyar Ateş

Turkish Journal of Veterinary & Animal Sciences

Sera from 1133 Turkish horses were obtained and tested for equid herpesvirus 3 (EHV-3) antibodies using a sero-neutralisation test. The sample consisted of 420 privately owned working horses from 2 regions of Turkey, 428 brood horses from private stud farms and breeding stations, and 285 racehorses from private stud farms. Neutralising antibodies against EHV-3 were found in 287 (25.3%) of the 1133 analysed sera. The highest seroprevalence for EHV-3 was detected in the brood horses (51.2%), followed by the racehorses (10.2%), and the working horses (9.3%). The seroprevalence rates tended to be higher in female horses than in male horses …

Nmr-Based Metabolomic Evaluation In Dairy Cows With Displaced Abomasum, Abdullah Başoğlu, Nuri̇ Başpinar, Alparslan Coşkun

Turkish Journal of Veterinary & Animal Sciences

This study is the first to evaluate nuclear magnetic resonance (NMR)-based metabolomics in cows with displaced abomasum (DA), which is an internationally recognized problem in dairy cows. Some biochemical parameters have been used for monitoring DA. However, to date, few data have been available on the blood metabolomic profile of dairy cows. Forty Holstein multiparous cows with DA (30 left, 10 right) and 10 clinically healthy Holstein multiparous cows were the subjects of the study. All the animals had similar dry matter intake. An NMR-based metabolomics approach and hematological and biochemical analyses were performed. Some changes in biochemical parameters were …

Injectable Versus Inhalational Anesthesia In Veterinary Medicine, Samantha D. Christ

Natural Sciences Student Research Presentations

Is the better, safer choice in small animal surgery injectible or inhalational anesthsesia? This poster outlines the advantages and disadvantages of the two, with a focus on two widely-used anesthetics, Ketamine and Isoflurane. This project is from the Natural Science Poster Session at Parkland College

Handling Cattle Through High Heat Humidity Indexes, Rob Eirich

Nebraska Beef Quality Assurance Program

As cattlemen enter the summer months, they need to understand and deal with heat and humidity. Consider incorporating the following practices into management plans to help reduce additional stress.

Novel Gammaherpesvirus Functions 1 Encoded By Bovine Herpesvirus (Bovine Lymphotropic Virus), J. Jia, G. Delhon, E. R. Tulman, D. G. Diel, Fernando A. Osorio, X. Wen, G. F. Kutish, D. L. Rock

School of Veterinary and Biomedical Sciences: Faculty Publications

The genus Macavirus of the subfamily Gammaherpesvirinae includes viruses that infect lymphoid cells of domestic and wild ruminants and swine, causing asymptomatic latent infections in reservoir hosts. Here, we describe the genome of bovine herpesvirus 6 (BoHV-6), a

macavirus ubiquitous in healthy cattle populations. The BoHV-6 genome exhibited architecture conserved in macaviruses, including a repetitive H-DNA region and unique, 141 kilobase pair L

DNA region predicted to encode 77 genes. BoHV-6 encoded in variable genomic regions a novel complement of genes relative to other characterized macaviruses, likely contributing to distinctive aspects of BoHV-6 infection biology and host range. Most notably, …

The Roles Of Orthopaedic Pathology And Genetic Determinants In Equine Cervical Stenotic Myelopathy, Jennifer Gail Janes

Theses and Dissertations--Veterinary Science

Cervical stenotic myelopathy (CSM) is an important musculoskeletal and neurologic disease of the horse. Clinical disease occurs due to malformations of the vertebrae in the neck causing stenosis of the cervical vertebral canal and subsequent spinal cord compression. The disease is multifactorial in nature, therefore a clearer understanding of the etiology and pathogenesis of CSM will allow for improved management and therapeutic practices. This thesis examines issues of equine CSM diagnosis, skeletal tissue pathology, and inherited genetic determinants utilizing advances in biomedical imaging technologies and equine genomics. Magnetic resonance imaging (MRI) data provided a more complete assessment of the cervical …

Modulation Of Type-I Interferon Mediated Immune Response: A Novel Innate Immune Evasion Strategy Of Equine Herpesvirus 1, Sanjay Sarkar

Theses and Dissertations--Veterinary Science

Equine herpesvirus-1 (EHV-1) is one of the major viral pathogens causing respiratory disease, abortion, perinatal mortality and neurologic disease among horses resulting in significant economic losses to the equine industry. The virus can also remain latent in the horses and recrudesce at any time. Type-I interferons (IFNs) act as a first line of defense against many viral infections.

In this study we investigated the type-I IFN response against the neuropathogenic T953 strain of EHV-1 in equine endothelial cells (EECs). The results showed that after a transient induction of IFN-β mRNA as well as protein at an early time (3h) post …

Evaluation Of The Susceptibility And Humoral Immune Response Of Foals To Rhodococcus Equi Infection, Macarena G. Sanz

Theses and Dissertations--Veterinary Science

While Rhodococcus equi (R. equi) remains the most common cause of subacute or chronic granulomatous bronchopneumonia in foals, development of a relevant model to study this bacterium has proven difficult. As a result, the reasons for the underlying foal’s susceptibility to this disease are not well understood. Furthermore, data regarding the immune response of foals to R. equi infection remains controversial. We hypothesized that foals are susceptible to R. equi early in life and that this susceptibility decreases with age. Also, we hypothesized that specific subclasses of IgG antibodies to the virulence-associated protein of R. equi, VapA, …

Anti-Müllerian Hormone In Stallions And Mares: Physiological Variations, Clinical Applications, And Molecular Aspects, Anthony N.J. Claes

Theses and Dissertations--Veterinary Science

Anti-Müllerian hormone (AMH) is a homodimeric glycoprotein that is best known for its role in regression of the Müllerian duct in the male fetus. Accumulating evidence indicates that AMH also has an important role during different physiological processes after birth. In contrast to other species, relatively little is known about AMH in the horse. In chapter one, developmental and seasonal changes in serum AMH concentrations in male horses were determined, and the use of AMH for determination of retained cryptorchid testes was established. In chapter two, the interrelationship between plasma AMH concentrations, antral follicle counts (AFC), and age in mares …

Role Of Viral And Host Factors In Influenza Virus Mediated Inhibition Of Interleukin-23, Ashish Tiwari

Theses and Dissertations--Veterinary Science

Influenza virus is one of the major respiratory pathogens of humans as well as animals, including equines. There is an increasing evidence that bacterial infections are the most common cause of the death during influenza. In horses also, secondary bacterial pneumonia can lead to death, and surviving horses may take up to six months for the complete recovery resulting in heavy economic loss to the equine industry. Interleukin (IL)-23 mediated innate immune response has been shown to protect the host from various respiratory bacterial infections. However, studies to investigate the role of host and viral factors in the regulation of …

Examination Of The Snsag Surface Antigen Gene Family In Sarcocystis Neurona, Ablesh Gautam

Theses and Dissertations--Veterinary Science

Sarcocystis neurona is a protozoan parasite that causes the serious neurologic disease equine protozoal myeloencephalitis (EPM). The life cycle of S. neurona progresses through multiple developmental stages that differ morphologically and molecularly. The S. neurona merozoite surface is covered by multiple related proteins, which are orthologous to the surface antigen (SAG) gene family of Toxoplasma gondii. The SAG surface antigens in T. gondii and another related parasite Neospora caninum are life cycle stage-specific and seem necessary for parasite transmission and persistence of infection. The present research was conducted to explore the gene family of SnSAGs in S. …

Studies On Equine Placentitis, Igor Frederico Canisso

Theses and Dissertations--Veterinary Science

Two types of placentitis were studied: ascending and nocardioform placentitis. Although the first diagnosis of nocardioform placentitis was made three decades ago, little is known about the disease, due to the lack of an experimental model. In attempt to develop a research model, Crossiela equi was inoculated through intrauterine, intravenous, intrapharyngeal, and oral routes, but none of the routes resulted in nocardioform placentitis. This may indicate that unidentified factors may play a role in disease pathogenesis and that simple presence of bacteria is not sufficient to induce nocardioform placentitis. The second and major component of this dissertation involved the identification …

Mechanisms Of Innate Immunity In Polymicrobial Sepsis, Liliang Jin

LSU Doctoral Dissertations

Severe bacterial sepsis leads to a pro-inflammatory condition that can manifest as septic shock, multiple organ failure, and death. Neutrophils are critical for the rapid elimination of bacteria, however, the role of neutrophil chemoattractant CXCL1, pattern recognition receptors (PRRs)- NLR protein 3 (NLRP3) and alcohol in bacterial clearance during sepsis remains elusive. We demonstrate that CXCL1 plays a pivotal role in mediating host defense to polymicrobial sepsis following cecal ligation and puncture (CLP) in gene-deficient mice. CXCL1 appears to be essential for restricting bacterial outgrowth and preventing multiple organ failure and death in mice. Moreover, CXCL1 is essential for neutrophil …

The Role Of Viral Glycoproteins And Tegument Proteins In Herpes Simplex Virus Type 1 Cytoplasmic Virion Envelopment, Dmitry Vladimirovich Chouljenko

LSU Doctoral Dissertations

Herpes simplex virus type 1 (HSV-1) is a ubiquitous neurotropic alphaherpesvirus transmitted by contact with mucocutaneous surfaces of infected individuals. HSV-1 enters the host by fusion of the viral envelope with the host cell plasma membrane, followed by translocation of the viral capsids to the nucleus where viral DNA is injected into the host cell nucleus to initiate viral replication. To generate infectious virions, newly assembled capsids travel to the cytoplasm and undergo a process called secondary envelopment by budding into cytoplasmic vesicles derived from the trans-Golgi network. Cytoplasmic envelopment is a complex process involving interactions between a multitude of …

Relationships Between Equine Management Practices And Intestinal Parasite Infection, Abigail Pagel

Honors Projects

Parasitology is an important area of veterinary medicine, but the risk factors for high parasite loads are not well-understood. Equine intestinal parasites can cause extensive disease and death. In the current study, the relationship between equine intestinal parasite loads and adherence to veterinary guidelines for equine management practices was studied. Satisfactory adherence to guidelines regarding food, pasture, and flooding management was related to lower parasite loads. Adherence to guidelines regarding deworming, quarantine, bedding, and water did not appear to lower parasite loads. Still, adhering to these guidelines has been shown to improve equine welfare, even if they are not related …

The Role Of Monocyte Chemoattractant Protein-1 In Innate Immunity Against Methicillin Resistant Staphylococcus Aureus Pneumonia, Mary Katherine Leissinger

LSU Master's Theses

Monocyte chemoattractant protein-1 is critical for monocyte recruitment to the lungs in response to bacterial infection. MCP-1 is also essential for protective neutrophil recruitment to the lungs during Escherichia coli and Klebsiella pneumoniae infection. Staphylococcus aureus pneumonia, specifically strain USA300, carries a high morbidity and mortality rate and is an important pathogen in hospital/ventilator and community acquired pneumonia. In the current study, we investigated the role of MCP-1 in pulmonary innate immunity to S. aureus in C57Bl/6, MCP-1-/- and MCP-1 AB blocked mice. As compared to C57Bl/6, MCP-1-/- mice showed increased concentrations of neutrophils in the airways and lung parenchyma …

Cardiovascular Tolerance And Safety Of Intravenous Lidocaine In The Broiler Chicken (Gallus Gallus Domesticus), Joao Manuel Lemos Brandao

LSU Master's Theses

Lidocaine, an amide local anesthetic agent, is commonly used in mammals, including humans. There is a general assumption that birds are more sensitive to lidocaine than mammals. Relatively low doses of lidocaine have been suggested to cause toxic effects in birds. While this information appears to be anecdotal, it has been perpetuated in the literature. The overall objective of this thesis research was to determine the tolerance and safety of intravenous lidocaine in broiler chickens. To assess the cardiovascular effects of lidocaine, relative changes on heart rate and mean blood pressure were calculated. Clinically significant cardiovascular effects were defined as …

Autologous Adipose Derived Adult Multipotent Stromal Cells Alter The Porcine Systemic Immune And Bone Biomarkers Response To Cancellous Bone Xenografts, Jonathan Francis Bova

LSU Master's Theses

The use of a porcine model in assessing bone grafts in vivo is common when a large animal model is necessary. In this thesis we aimed to improve the porcine model of facial reconstruction through the use of a local anesthesia and novel methods of assessing the immune response to and bone forming ability of adult adipose derived mesenchymal stromal cells (ASC). The goals of the research were: 1) evaluate the effect of a bupivacaine mandibular nerve block on blood pressure (BP) and heart rate (HR) in response to surgical stimulation and the need for systemic analgesics postoperatively, 2) quantify …

Distillers Grains Supplementation In A Forage System With Spayed Heifers, Kari L. Gillespie, Terry J. Klopfenstein, James C. Macdonald Donald, Brandon L. Nuttelman, Cody J. Schneider, Jerry D. Volesky, Galen Erickson

Nebraska Beef Cattle Reports

Spayed heifers were developed into yearlings by grazing corn residue and bromegrass, followed by native range, and were finished on a common diet. Treatments were 2 lb or 5 lb of wet distillers grains with solubles (WDGS; DM basis) supplement on corn residue daily, and modified distillers grains with solubles (MDGS) fed at 0.6% BW daily or no MDGS during summer grazing. Feeding 5 lb increased winter ADG by 0.68 lb (year 1) or 0.40 lb (year 2) compared to 2 lb, and increased HCW after finishing. Summer supplementation increased summer ADG by 0.50 lb (year 1) or 0. 44 …

Feeding Elevated Levels Of Corn Silage And Mdgs In Finishing Diets, Dirk B. Burken, Brandon L. Nuttelman, Terry J. Klopfenstein Klopfenstein, Galen E. Erickson

Nebraska Beef Cattle Reports

A finishing experiment evaluatedsubstitution of corn silage and modified distillers grains with solubles (MDGS) in place of corn. The treatment arrangementwas a 2 X 2 + 1 factorial with 15 or 45% corn silage and 20 or 40% MDGS plus a control containing 5% cornstalks and 40% MDGS. There were interactions between corn silage and MDGS for carcass adjusted performance. As corn silage inclusion was increased in the diet, F:G increased when fed with 20% MDGS, however there was no difference when fed with 40% MDGS.

Transitioning Cattle From Ramp® To A Finishing Diet On Feedlot Performance And Feed Intake Variance, Cody J. Schneider, Brandon L. Nuttelman, Dirk B. Burken Burken, Terry J. Klopfenstein, Galen E. Erickson

Nebraska Beef Cattle Reports

Individually fed cattle were adapted to high grain diets with a traditional grain adaptation program or one of two RAMP^® adaptation programs. RAMP programs adapted cattle to a finishing diet gradually over 28 days in four steps or directly without an adaptation. Feed intake variance among d was greater for traditionally adapted cattle compared to either RAMP program, but DMI was not different during the adaptation period. Over the 138-day period, feedlot performance and carcass traits were not affected by adaptation treatment. Cattle fed RAMP for 10 days can be transitioned to a finishing ration containing 47.5% Sweet Bran …

Use Of A Pelleted Corn Residue Complete Feed In Receiving Diets, Sarah J. Peterson, Brandon L. Nuttelman, Dirk B. Burken Burken, James C. Macdonald, Matt K. Luebbe, Galen E. Erickson

Nebraska Beef Cattle Reports

The effects of feeding a complete pelleted feed to newly received steer calves (585 ± 4 lb; n = 1318 ) was compared to a control ration consisting of 32% (DM basis) wet or modified distillers grains, 32% alfalfa hay, 32% dry-rolled corn, and 4% supplement. The pelleted complete feed consisted of 35% corn residue and a blend of grain byproducts and minerals. Feeding the complete pelleted feed increased DMI but decreased ADG, thereby reducing feed efficiency. The pelleted feed numerically reduced morbidity. Feeding a complete pellet consisting of corn residue appears to be a viable option for receiving calves …

Comparison Of Long-Term Progestin-Based Synchronization Protocols On Fixed-Time Ai Pregnancy Rate In Beef Heifers, Rebecca A. Vraspir, Adam F. Summers, Doug O'Hare Hare, Larry D. Rowden, Rick N. Funston

Nebraska Beef Cattle Reports

Yearling Angus heifers at a commercial ranch in the Nebraska Sandhills were randomly assigned to one of two progestin-based fixed-time AI protocols (MGA or 14-day CIDR) to compare pregnancy rates. Heifers had similar fixed-time AI pregnancy rates between MGA and 14-day CIDR. A similar proportion of MGA and 14-day CIDR heifers displayed a second estrus; however, heifers previously synchronized with MGA tended to have a greater second AI pregnancy rate. Overall pregnancy rate was similar between MGA and 14-day CIDR treatments. The MGA system was the more cost effective synchronization protocol in this study.