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At least 19 recordsLinked to original sources
PubMed1979

Poor growth performance associated with hypocupremia in Hawaiian feedlot cattle.

Poor feedlot performance in native Hawaiian feedlot cattle was investigated. Cattle were first noticed to be affected 40 to 60 days after arrival at the feedlot, as judged by their retarded growth, when compared with penmates. Marked hypocupremia was detected in all 10 cattle examined, irrespective of time in the feedlot. Clinical signs and upper digestive tract lesions in 8 of the 10 cattle suggested secondary involvement of bovine papular stomatitis. The poor performance was attributed primarily to the hypocupremia, as a result of molybdenum-accentuated copper deficiency in forage on the ranch of origin.

Animal Feed↗
PubMed1979

Myopathy and myoglobinuria in feedlot cattle.

Myopathy and myoglobinuria occurred in a group of feedlot cattle in Alberta following transportation. The condition was associated with a deficiency of selenium (Se) in grain and hay fed to these animals on their premises of origin. Clinical findings in affected animals were characterized by a normal body temperature, stiffness, sternal recumbency and the passage of red or coffee-colored urine. Treatment with injectable Se-vitamin E was followed by the recovery of most affected animals within two weeks.

Animal Feed↗
PubMed1979

Treatment of feedlot cattle in Alberta for gastrointestinal nematodes.

The effects of a single treatment at entry with three anthelmintics on rates of weight gain and feed conversion efficiency over a 70 day period were studied in 200 feedlot steers. None of the anthelmintic treatments used appeared to confer any improvement in the above parameters under the conditions of this experiment. The results are discussed in relation to routine anthelmintic treatment in western Canada.

Animals↗
PubMed2025

Genomic prediction and genome-wide association study for liver abscesses in crossbred beef cattle.

Liver abscesses are a concern in feedlot cattle, and little is known about the role of genetics in their development. This study aimed to estimate genetic parameters and to identify single-nucleotide polymorphisms (SNPs) associated with liver abscesses. Crossbred cattle representing 18 breeds in the U.S. Meat Animal Research Center Germplasm Evaluation Program were phenotyped for liver abscesses at slaughter (n&#x2005;=&#x2005;9,044). Seventeen percent of cattle had liver abscesses. These cattle had genotypes that were imputed to sequence variant genotypes. After filtering and quality control, 340,723 SNPs were used in the analysis. Liver abscess prevalence was modeled with a single-step genomic best linear unbiased prediction (ssGBLUP) threshold model using a Bayesian framework. The model included contemporary group (sex, treatment group, and slaughter date), additive genomic, and residual effects. Genomic heritability was 0.039 (95% highest posterior density&#x2005;=&#x2005;0.005, 0.081), which was very small. To assess prediction quality, a 5-fold random cross-validation structure was used. Method Linear Regression was used to assess accuracy, bias, and dispersion by comparing estimated breeding values (EBV) from full and reduced analyses. Cross-validation metrics showed EBV based on genotypes had 0.05 reliability (SD&#x2005;<&#x2005;0.01) with no bias relative to EBV based on genotypes and phenotypes. For the genome-wide association study, SNP effects were back calculated from the EBV solutions from ssGBLUP. No SNPs were associated with liver abscesses at a Benjamini-Hochberg adjusted 0.05 significance level. Although a large dataset was used, this result was because of the low genomic heritability and imprecise EBV used to calculate SNP effects. Based on these results, environmental factors contribute to most of the variation in liver abscesses. Genetic selection to reduce liver abscesses would be slow because of the low genomic heritability, measurement late in life, and inability to measure breeding animals. A faster approach would be finding additional environmental interventions that maintain animal performance.

Animals↗
PubMed1977

Residue content of beef feedlot manure after feeding diethylstilbestrol, chlortetracycline and Ronnel and the use of stirofos to reduce population of fly larvae in feedlot manure.

Two beef cattle feedlot experiments were conducted to determine the amount of certain agricultural chemicals that are likely to be found in both fresh and stored feedlot manure and to investigate fly control in this manure. In experiment 1, diethylstilbestrol (DES), chlortetracycline (CTC), and ronnel were used as feed additives. Fresh manure, stored manure, runoff water, manure weathered on pasture, and soil from pasture fertilized with manure were analyzed for these additives. Stirofos was added to fresh manure as a larvicide for fly control. In experiment 2, the residue aspects of DES and CTC were repeated. In this experiment, stirofos instead of ronnel was fed with DES and CTC. Sixty-eight percent of the DES fed to cattle appeared in fresh manure and 52% in manure stored for 12 weeks. Comparable percentage values were 17 and 11% for CTC and 13 and 3% for ronnel; somewhat less DES and CTC were found when a concentrate diet was fed. Detectable amounts of DES, ACT, and ronnel were not found in runoff water, weathered manure, or soil. Adding an emulsifiable concentrate formulation of stirofos directly to manure at a rate of approximately 45 ppm of wet manure completely controlled the larvae of house fly (Musca domestica L.) whereas feeding stirofos at a rate of 1.5 mg per kg of body weight daily reduced larval counts 82% in manure from forage-fed heifers and 63% in manure from concentrate-fed heifers. Stirofos was not detected in runoff water, weathered waste, or soil.

Animal Feed↗
PubMed1975

Infectious bovine rhinotracheitis virus. History and recent developments.

The infectious bovine rhinotracheitis (IBR) virus belongs to the group of herpes viruses. It causes in cattle a severe disease predominantly in the upper respiratory tract. Morbidity rate is 100 percent, mortality - depending on hygienic and other factors - ranges from 0-15 percent. The IBR virus is serologically indistinguishable from the infect pustulat vulvovaginitis (IPV) virus which causes disorders of the genital tract in both male and female cattle. Possibly the IPV virus is the older of the two. Already in the twenties it had been isolated and described in Europe whereas IBR virus was first isolated from feedlot cattle in the USA during 1955/1956. Most likely - experiments also gave a hint - the IPV virus increased its virulence for the respiratory tract by rapid and numerous passages as this was only possible in accumulations of tremendous heads of animals. Vaccines both live attenuated and killed ones have been developed. Killed ones are always administered parenterally; the live ones are either intramuscularly injected or locally sprayed (into the nasal cavity). Immunity is developed within 3 weeks, however, if vaccinated animals are challenged, virus is again shed for a number of days. Cattle thereby do not exhibit any symptoms of disease. This is true following any kind of vaccination (live or killed). After local administration of live vaccines, however, the production of interferon by the cells of the respiratory tract is remarkable whereas parenterally administration of vaccine does not lead to that.

Administration, Intranasal↗
PubMed1978

Isolation of animal viruses from farm livestock waste, soil and water.

Ten porcine enteroviruses, 2 porcine adenoviruses and 1 coronavirus were isolated directly from 32 samples of slurry collected from a pig fattening house. Concentration of the same samples by adsorption with the polyelectrolyte PE-60 yielded 24 porcine enteroviruses and 3 porcine adenoviruses. A porcine enterovirus was isolated, following PE-60 concentration, from 1 to 6 slurry samples from a sow farrowing house. No virus was isolated from 12 samples of slurry from dairy cows nor from 6 slurry samples from a calf-rearing unit. A porcine enterovirus was isolated from soil samples, after concentration with PE-60, collected 1, 2 and 8 days after pig slurry was spread on hay stubble. Two porcine enteroviruses were isolated by membrane filtration from 26 samples of surface run-off from land on which pig slurry was routinely spread, and 2 bovine enteroviruses were isolated from cattle feedlot run-off after adsorption to layers of talc and celite followed by hydroextraction. A porcine enterovirus was also isolated from 1 of 33 samples of surface water collected on farms on which pig slurry was routinely spread on the land, but no virus was isolated from 36 samples of ground water from the same farms. The surface water and ground water samples were concentrated by talc-celite adsorption and hydroextraction.

Adenoviridae↗
PubMed1975

A bovine adenovirus type 3: isolation, characterization, and experimental infection in calves.

A virus was isolated from a group of feedlot cattle with acute respiratory disease that was characterized by physicochemical methods as an adenovirus and identified serologically as a bovine adenovirus type 3. Intratracheal inoculation of three 4 month old colostrum deprived calves resulted in pyrexia, hyperpnea, dyspnea, anorexia and in one animal a mild diarrhea.

Adenoviridae↗
PubMed2026

Evaluating detection of Histophilus somni immunoglobulin-binding protein A DR2 Fic: A species-specific gene target for recombinase polymerase amplification relative to long-read sequencing of respiratory samples from feedlot calves.

Histophilosis is an important cause of morbidity and mortality as well as antimicrobial use in feedlot cattle across North America. Detection of Histophilus somni by culture is challenging, and there is no standardized tool for distinguishing isolates that carry virulence factors most likely to contribute to disease. The DR2 repeat of H. somni-associated virulence factor 'immunoglobulin-binding protein A' (ibpA DR2) harbors a Fic domain that mediates host cell cytotoxicity and is essential for histophilosis. For rapid detection of ibpA DR2 in extracted DNA, we developed a real-time recombinase polymerase amplification (RPA) assay with a runtime of 24&#xa0;min at 39&#xa0;&#xb0;C. DNA from H. somni-RPA-positive respiratory swabs (n&#xa0;=&#xa0;73) was screened for ibpA DR2 using the novel RPA assay and long-read metagenomic sequencing, as well as nanopore whole-genome sequencing (WGS) of H. somni isolated from the same samples. IbpA DR2 was identified in 71% and 70% of tested samples using RPA and WGS, respectively, and in &#x2264;41% of samples using metagenomic sequencing. The likelihood of detection by RPA did not differ (OR 1.1, 95% CI (0.42, 2.9), P&#xa0;>&#xa0;0.99) from WGS; however, agreement between these assays was only fair (&#x3ba;&#xa0;=&#xa0;0.31). Conversely, RPA (OR 3.4, 95% CI (1.6, 8.2)) and WGS (OR 8.0, 95% CI (2.4, 42)) were more likely (P&#xa0;<&#xa0;0.001) to detect ibpA DR2 than metagenomic sequencing, likely reflecting limited coverage of H. somni by metagenomics. This study demonstrated that RPA and long-read WGS detected ibpA DR2 with similar frequencies in extracted DNA and H. somni isolates, respectively. Further testing of non-target isolates confirmed the analytical specificity of ibpA DR2 to H. somni. Further investigation of the diagnostic validity for RPA-based ibpA DR2 detection is required in a larger cohort of field samples, as a rapid screening tool for H. somni most likely to contribute to disease.

Animals↗
PubMed1978

Metabolic and cellular profile testing in calves under feedlot conditions: protein fractions and lactate dehydrogenase isoenzymes--reference values.

Serum protein and lactate dehydrogenase (LDH) isoenzyme values were determined for frozen serum samples from crossbred yearling feedlot cattle on feed for 56 days. The mean percentage values for serum protein components from 114 samples were: albumin, 46.5; alpha-globulin, 10.4; beta-globulin, 18.7; gamma-globulin, 23.8. For LDH isoenzymes, they were: LDH1, 36.5; LDH2, 24.7; LDH3, 16.9; LDH4, 12.0; LDH5, 9.1. These values are compared with values from dairy cattle.

Animal Feed↗
PubMed1978

Evaluation of a bovine virus diarrhea vaccine.

Singer Strain bovine virus diarrhea (BVD) modified live-virus vaccine, produced in a continuous bovine cell line using equine serum in the growth medium, evoked a high level of serum antibodies and protected against virulent challenge in vaccinated calves. Transmission of vaccinal virus from vaccinated cattle to susceptible controls did not occur when vaccinated and nonvaccinated cattle were kept in constant contact for 23 days. Postvaccinal reactions to the viral vaccine were not observed in vaccinated cattle from 10 feedlots or in cattle vaccinated with multiple doses of the experimental vaccine.

Animals↗
PubMed1978

Bovine coccidiosis. A review, including field safety studies with decoquinate for prevention.

Decoquinate (Deccox: Hess & Clark) has been demonstrated in in-house and university studies to be an active coccidiostat when fed daily at 0.5 mg/kg body weight during periods of oocyst exposure, or when experience indicates coccidiosis is likely to be a hazard. For prevention, feeding should be continued for at least 28 days. In 6 feedlot trials with 1993 cattle in 5 geographic areas, decoquinate fed at this level for 90-120 days had no adverse effects. In 5 of these trials, treated cattle had equal or slightly improved average daily gains and feed conversion by comparison with controls.

Animals↗
PubMed1978

Metabolic and cellular profile testing in calves uncer feedlot conditions: blood cellular components--reference values and changes over time in feedlot.

The cellular components of the blood of 114 calves were measured under feedlot conditions. The results suggest that certain cellular components of the blood of a group of crossbred feedlot-type calves which are homogeneous only with regard to weight are reasonably uniform. More specifically, all red blood cell components have coefficients of variation of less than 10%. The white blood cell counts underwent drastic changes over the first 2 sampling dates, ie, before and after transport and processing of the calves. Later, in the feeding period, the cell counts readjusted to more stable levels. The results were compared with such values obtained from dairy cattle. The total erythrocyte count, total leukocyte count, and red blood cell components were found to be slightly higher in these feedlot calves than in dairy cattle. The difference might partly be due to age. The mean values reported can be used as a base for comparison with values obtained from other such studies or from studies of disease processes in cattle under feedlot conditions (or both).

Animal Feed↗