scholarly journals Development of a genetic evaluation for hair shedding in American Angus cattle to improve thermotolerance

2020 ◽  
Author(s):  
Harly J. Durbin ◽  
Duc Lu ◽  
Helen Yampara-Iquise ◽  
Stephen P. Miller ◽  
Jared E. Decker
Keyword(s):  
Beef Cattle ◽  
Tall Fescue ◽  
The United States ◽  
Early Summer ◽  
Genetic Evaluation ◽  
Functional Enrichment ◽  
Fescue Toxicosis ◽  
Beef Industry ◽  
Angus Cattle ◽  
Genetic Evaluations

AbstractBackgroundHeat stress and fescue toxicosis caused by ingesting tall fescue infected with the endophytic fungus Epichloë coenophiala represent two of the most prevalent stressors to beef cattle in the United States, costing the beef industry millions of dollars each year. The rate at which a beef cow sheds her winter coat early in the summer is an indicator of adaptation to heat and an economically relevant trait in many parts of the U.S. Further, research suggests that early-summer hair shedding may be reflective of tolerance to fescue toxicosis, as vasoconstriction induced by fescue toxicosis limits the ability of an animal to shed its winter coat. Here, we developed parameters for routine genetic evaluation of hair shedding score in American Angus cattle and identified genomic loci associated with variation in hair shedding score via genome-wide association analysis (GWAA).ResultsHair shedding score was found to be moderately heritable (h2 = 0.34 to 0.40), with differing repeatability estimates between cattle grazing versus not grazing endophyte-infected tall fescue. Our results suggest modestly negative genetic and phenotypic correlations between a dam’s hair shedding score (lower score is earlier shedding) and the weaning weight of her calf, one metric of performance. Together, these results indicate that economic gains can be made via the use of hair shedding score breeding values to select for heat tolerant cattle. GWAA identified 176 variants significant at FDR < 0.05. Functional enrichment analyses using genes within 50 Kb of these variants identified pathways involved in keratin formation, prolactin signaling, host-virus interaction, and other biological processes.ConclusionsThis work contributes to a continuing trend in the development of genetic evaluations for environmental adaptation. The results of this work will aid beef cattle producers in selecting more sustainable and climate-adapted cattle, as well as enable the development of similar routine genetic evaluations in other breeds.

scholarly journals Development of a genetic evaluation for hair shedding in American Angus cattle to improve thermotolerance

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
Harly J. Durbin ◽  
Duc Lu ◽  
Helen Yampara-Iquise ◽  
Stephen P. Miller ◽  
Jared E. Decker
Keyword(s):  
Heat Stress ◽  
Beef Cattle ◽  
Tall Fescue ◽  
The United States ◽  
Genetic Evaluation ◽  
Functional Enrichment ◽  
Fescue Toxicosis ◽  
Weaning Weight ◽  
Angus Cattle ◽  
Genetic Evaluations

Abstract Background Heat stress and fescue toxicosis caused by ingesting tall fescue infected with the endophytic fungus Epichloë coenophiala represent two of the most prevalent stressors to beef cattle in the United States and cost the beef industry millions of dollars each year. The rate at which a beef cow sheds her winter coat early in the summer is an indicator of adaptation to heat and an economically relevant trait in temperate or subtropical parts of the world. Furthermore, research suggests that early-summer hair shedding may reflect tolerance to fescue toxicosis, since vasoconstriction induced by fescue toxicosis limits the ability of an animal to shed its winter coat. Both heat stress and fescue toxicosis reduce profitability partly via indirect maternal effects on calf weaning weight. Here, we developed parameters for routine genetic evaluation of hair shedding score in American Angus cattle, and identified genomic loci associated with variation in hair shedding score via genome-wide association analysis (GWAA). Results Hair shedding score was moderately heritable (h2 = 0.34 to 0.40), with different repeatability estimates between cattle grazing versus not grazing endophyte-infected tall fescue. Our results suggest modestly negative genetic and phenotypic correlations between a dam’s hair shedding score (lower score is earlier shedding) and the weaning weight of her calf, which is one metric of performance. Together, these results indicate that economic gains can be made by using hair shedding score breeding values to select for heat-tolerant cattle. GWAA identified 176 variants significant at FDR < 0.05. Functional enrichment analyses using genes that were located within 50 kb of these variants identified pathways involved in keratin formation, prolactin signalling, host-virus interaction, and other biological processes. Conclusions This work contributes to a continuing trend in the development of genetic evaluations for environmental adaptation. Our results will aid beef cattle producers in selecting more sustainable and climate-adapted cattle, as well as enable the development of similar routine genetic evaluations in other breeds.

New approaches to genetic evaluation of beef cattle

1988 ◽  
Vol 12 ◽  
pp. 99-110
Author(s):  
E. John Pollak
Keyword(s):  
Animal Model ◽  
Beef Cattle ◽  
Mixed Model ◽  
The United States ◽  
Genetic Evaluation ◽  
Beef Industry ◽  
Widespread Application ◽  
Cattle Industry ◽  
Reduced Animal Model ◽  
Genetic Evaluations

The beef cattle industry in the United States has undergone dramatic changes over the past decade with the adoption of genetic evaluation programs. The method of choice has been Henderson's mixed model methodology for best linear unbiased prediction (BLUP). The most prevalently used model is the animal model (Henderson and Quaas, 1976) computed by the equivalent reduced animal model (Quaas and Pollak, 1980).Neither the methodology or the models being used are particularly new. What is new in this industry is the widespread application of these techniques to the analysis of the data banks maintained by the breed organizations. Today many breed associations publish a national sire evaluation, and most of these have published their first in the last three years. This rapid proliferation of published evaluations has coincided with an attitude in the industry of promoting specification beef and predictable performance. Genetic evaluations provide information not only to achieve goals in selection but as well for merchandizing cattle based on quantifiable potential. The enthusiasm for genetic evaluations right now in the U.S. beef industry is high.

52 Genomic selection in the beef industry: Current achievements and future directions

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 54-55
Author(s):  
Daniel W Moser ◽  
Stephen P Miller ◽  
Kelli J Retallick ◽  
Duc Lu ◽  
Larry A Kuehn
Keyword(s):  
Beef Cattle ◽  
Genomic Selection ◽  
Large Scale ◽  
Genetic Evaluation ◽  
Fiscal Year ◽  
Genomic Testing ◽  
Routine Practice ◽  
The Past ◽  
Angus Cattle ◽  
Genetic Evaluations

Abstract In the past decade, genomic testing of beef cattle has evolved from applications in research to a routine practice for many beef cattle seedstock breeders. Testing for lethal genetic conditions or parentage was many breeders’ first experience with genomic testing. While the American Angus Association (AAA) began utilizing 384 SNP genotypes in genetic evaluations in 2009, the adoption of genotyping with higher density (~50,000 SNP) arrays by AAA in 2010 launched large-scale genotyping of Angus cattle for genetic evaluation. AAA transitioned from semi-annual to weekly genetic evaluations in 2010, and cost of genotyping decreased from $139 per animal in 2011, to $37 in 2017. In fiscal year 2018, AAA members genotyped over 160,000 animals for genetic evaluation, and as of April 2019, the AAA and Canadian Angus Association joint genetic evaluation includes over 635,000 genotyped animals. Now genotyping arrays with Angus-specific SNP content are used. The primary benefit to Angus breeders has been increased accuracy of genetic prediction for young animals, especially for traits with limited phenotypic information such as carcass traits, feed intake and mature cow size. Future benefits from genotyping include identification and selection against embryonic lethal alleles, better characterization of inbreeding, and selection tools for additional traits relevant to or measured in unique environments. Electronic sensors and other novel approaches may yield previously unmeasurable phenotypes for health and efficiency traits, which can be extended to wider populations for selection using genomics. New techniques such as DNA pooling and genotyping by sequencing may reduce costs enabling widespread testing in commercial cow-calf and cattle feeding enterprises. The application of genomic selection has clearly been a significant advancement in genetic selection in Angus cattle in the past ten years. This early adoption will expedite subsequent genomic tools at an increasing rate and will foster innovation.

Genetic evaluation for the beef industry in Australia

2005 ◽  
Vol 45 (8) ◽  
pp. 913 ◽  
Author(s):  
H-U. Graser ◽  
B. Tier ◽  
D. J. Johnston ◽  
S. A. Barwick
Keyword(s):  
Beef Cattle ◽  
Evaluation System ◽  
Carcass Characteristics ◽  
Genetic Evaluation ◽  
Beef Industry ◽  
Linear Unbiased Prediction ◽  
Cattle Industry ◽  
Evaluation Procedures ◽  
Complex Models ◽  
Best Linear Unbiased

Genetic evaluation for beef cattle in Australia has been performed using an animal model with best linear unbiased prediction since 1984. The evaluation procedures have evolved from simple to more complex models and from few to a large number of traits, including traits for reproduction, growth and carcass characteristics. This paper describes in detail the current beef cattle genetic evaluation system ‘BREEDPLAN’ used for the Australian beef cattle industry, the traits analysed and underlying models, and presents a short overview of the challenges and planned developments of coming years.

scholarly journals Clinical manifestations of tall fescue (Festuca arundinacea) and perennial ryegrass (lolium perenne) toxicosis in Oregon and Japan

2007 ◽  
Vol 13 ◽  
pp. 369-372
Author(s):  
L.L. Blythe ◽  
A.M. Craig ◽  
C. Estill ◽  
C. Cebra
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Clinical Manifestations ◽  
Beef Cows ◽  
Fescue Toxicosis ◽  
Angus Cattle ◽  
Multiple Vehicles ◽  
Tall Fescue Toxicosis

There are multiple vehicles for endophyte toxicosis in animals including exposure from pasture, straw residues and seed screenings. This report discusses the clinical cases typically seen with tall fescue and perennial ryegrass toxicosis in Oregon and Japan. Case I involves a herd of 330 Black Angus cattle. Before the March calving season the owner wished to increase the protein content of the feed ration by feeding pellets made of seed screenings and grass hay. Forty two animals were lost to tall fescue toxicosis and dry gangrene of the feet and legs. Case II involves 1300 beef cows in Eastern Oregon fed grass straw; 485 animals were lost due to dry gangrene characteristic of tall fescue toxicosis. Case III describes 4 of 15 cases of both tall fescue and perennial ryegrass toxicosis in Japanese black cattle. Case IV involves llamas and alpacas on pasture and lawn paddocks where some animals were affected by tall fescue and some by perennial ryegrass. Keywords: tall fescue, Festuca arundinacea L., perennial ryegrass, Lolium perenne, endophyte, Neotyphodium coenophialum, Neotyphodium lolii

scholarly journals 36 Matching cow’s genetics to the environment using genomics

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 34-34
Author(s):  
Jared E Decker ◽  
Troy N Rowan ◽  
Sara Nilson ◽  
Harly J Durbin ◽  
Camila U Braz ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Local Adaptation ◽  
Growth Traits ◽  
Genetic Correlations ◽  
The United States ◽  
Early Summer ◽  
Substitution Effects ◽  
Association Analyses ◽  
Functional Variants ◽  
Genomic Predictions

Abstract Cattle poorly adapted to their environment result in lost revenue and jeopardize the stability of the food supply. Genomic data now allows us to rigorously analyze adaptations and avoid the generation of animals that will not thrive. We used selection scans for local adaptation, genotype-by-environment genome-wide association analyses, creation of hair shedding genomic predictions and environmental region-specific genomic predictions of growth traits to characterize and predict local adaptation in beef cattle. Analyzing ~40,000 cattle from three breed associations with ~850,000 high-accuracy imputed SNPs, we used novel selection mapping methods to identify genomic loci responsible for adaptation. We identify 19 different loci (harboring 24 annotated genes) as responding to selection to local adaptation. In cooperation with 74 producers across the United States, over 12,000 cattle were scored on a scale of 1–5 for the early-summer hair shedding phenotype in 2016, 2017, and 2018. Participating cattle were genotyped using the GGP-F250 SNP panel developed by the University of Missouri, which contains ~170,000 candidate functional variants and ~30,000 variants in common with beef cattle industry standard genotyping assays. Genomic breeding values were generated with a repeated records model using these phenotypes. Further, we identified loci with large allele substitution effects for hair shedding. When local adaptations exist, ranking animals using a regional genetic evaluation will be different from national cattle evaluations. We developed region-specific genomic predictions using a multivariate model in which phenotypes from different regions were fit as separate dependent variables. Genetic correlations between regions were moderate, indicating substantial re-ranking between environmental regions. These genomic predictions will allow rapid identification of cattle best suited to an environment.

scholarly journals Evaluation of a commercial genetic test for fescue toxicosis in pregnant Angus beef cattle1

2020 ◽  
Vol 4 (4) ◽  
Author(s):  
Justine M Galliou ◽  
Piush Khanal ◽  
Kyle Mayberry ◽  
Matt H Poore ◽  
Daniel H Poole ◽  
...  
Keyword(s):  
United States ◽  
Body Weight ◽  
Body Condition ◽  
Tall Fescue ◽  
Fixed Effects ◽  
Genetic Test ◽  
The United States ◽  
Economic Losses ◽  
Fescue Toxicosis ◽  
Phenotypic Trait

Abstract Most tall fescue [Lolium arundinaceum (Schreb.) Darbysh] in the Southeastern United States contains an endophyte that causes fescue toxicosis (FT) in grazing animals, a serious disease that causes approximately $1 billion in economic losses to the animal industries in the United States. Recently, a genetic test called T-Snip (AgBotanica, LCC, Columbia, MO), was developed with the objective of identifying animals with genetic variation for FT tolerance. The aim of this study was to validate the use of this genetic test in mature, pregnant cows. Over 13 wk, weekly phenotypic data, including body weight, rectal temperatures, hair coat scores, hair shedding scores, and body condition scores, were collected on 148 pregnant purebred Angus cows at 2 locations in NC where infected fescue was the primary source of feed. Birth weights (cBW) and 205-d adjusted weaning weights (adjWW) from these cow’s calves were recorded. All cows were genotyped for T-Snip. At the end of the trial, each phenotypic trait was calculated as the slope of the linear regression of performance on weeks. The effect of T-Snip rating genotypes (4 levels) on slope traits was tested using a linear model also including the fixed-effects of location, parity, and the initial measurement for each trait (covariate). For cBW and adjWW, the model also included the sex of the calf and the month of birth as categorical effects. Associations of T-Snip genotypes were observed for body weight gain (aBWd) of pregnant cows (P = 0.15; interaction with location), change in body condition score (aBCSd; P = 0.13), and adjWW (P = 0.06; interaction with location). For aBWd and adjWW, associations were found just within one location (P = 0.017 and 0.047, respectively), which was the location with higher endophyte infection rate. For all associations, the direction of the T-Snip genotypes was the same and as expected: the greater the genotype score, the better performance. No associations were found for the other traits (P &gt; 0.10). These results indicate that the T-Snip test may be predictive of cow performance (aBWd, aBCSd, and adjWW) in an endophyte-infected tall fescue environment.

Application and impact of new genetic technologies on beef cattle breeding: a 'real world' perspective

2005 ◽  
Vol 45 (8) ◽  
pp. 739 ◽  
Author(s):  
E. J. Pollak
Keyword(s):  
Beef Cattle ◽  
High Impact ◽  
Commercial Sector ◽  
Beef Industry ◽  
Cattle Breeding ◽  
Breeding Programs ◽  
Genetic Technologies ◽  
Molecular Information ◽  
Genetic Evaluations ◽  
World Perspective

Molecular genetics is a maturing discipline with innovations that are finding application in animal breeding. Currently, DNA tests are available for parent identification or verification, and markers tests also exist for quantitative trait loci affecting important traits in beef cattle. The beef industry is, however, a particularly challenging industry in which to design breeding programs that fully capitalise on the potential of this technology. Hence, adoption within this industry to date has been below expectation. This paper examines several applications that are being investigated and will include discussion on issues constraining the transfer of DNA technology. An example of using DNA parentage testing for expanding the reach of selection programs into the commercial sector of the beef industry is explored in some depth, as it represents a potential high impact application. Use of molecular information in selection programs and in genetic evaluations is also discussed.

scholarly journals PSI-22 Rumen fluid metabolites influenced by endophyte-infected tall fescue seed and red clover isoflavones in beef steers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 269-270
Author(s):  
Juan F Cordero-Llarena ◽  
Brooke A Clemmons ◽  
Emily A Melchior ◽  
Taylor B Seay ◽  
Joshua B Powers ◽  
...  
Keyword(s):  
Tall Fescue ◽  
Rumen Fluid ◽  
Red Clover ◽  
Basal Diet ◽  
Fescue Toxicosis ◽  
Beef Steers ◽  
Seed Type ◽  
Negative Effects ◽  
Beef Industry ◽  
Total Alkaloids

Abstract Fescue toxicosis causes substantial financial losses to the beef industry due to its negative effects on reproduction, growth and feed efficiency. Recent research has demonstrated that the negative effects of fescue toxicosis may be mitigated by supplementation of red clover isoflavones. To determine impacts on the ruminal environment, the objective of this study was to evaluate the effect of red clover isoflavones and endophyte-infected tall fescue on ruminal metabolites. Thirty-six Angus steers weighing 250±20 kg were randomly assigned to treatments in a 2×2 factorial arrangement, consisting of endophyte-free or endophyte-infected tall fescue seed with or without red clover isoflavones. For the 21d trial, steers were provided a basal diet supplemented with fescue seed targeting a minimum of 0.011 mg × kg of BW−1 × d−1 of total alkaloids. A total of 943 mg isoflavones were administered daily via bolus. Following the trial, 50mL of rumen fluid was collected via orogastric tubing. Untargeted metabolomic analysis was performed using an Exactive Plus Orbitrap MS, and 10µL sample was introduced using electrospray ionization into the Dionex UltiMate 3000 UPLC system. Peaks were identified in MAVEN, then normalized and analyzed in MetaboAnalyst 4.0, and 106 known metabolites were identified. Differences in seed type × isoflavone were analyzed by one-way ANOVA and main effects were analyzed by t-test. A total of 11 metabolites differed based on seed type × isoflavone treatment group (P ≤ 0.05), 11 differed by seed type (P ≤ 0.5), and seven differed by isoflavone treatment (P ≤ 0.05), namely amino acids or intermediates of amino acid metabolism. Methane (P = 0.03) and sulfur (P = 0.03) metabolism pathways were both impacted by isoflavone treatment, whereas 20 metabolic pathways were impacted as a result of differences in seed type (P ≤ 0.05). The rumen metabolome appears to be more affected by seed type, but a longer trial will likely result in more profound impacts.

scholarly journals Evaluation of Resistance to Fescue Toxicosis in Purebred Angus Cattle Utilizing Animal Performance and Cytokine Response

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 796
Author(s):  
Daniel H. Poole ◽  
Kyle J. Mayberry ◽  
McKayla Newsome ◽  
Rebecca K. Poole ◽  
Justine M Galliou ◽  
...  
Keyword(s):  
Tall Fescue ◽  
Ergot Alkaloid ◽  
Ergot Alkaloids ◽  
Fescue Toxicosis ◽  
Animal Performance ◽  
Angus Cattle ◽  
Study Support ◽  
Genetic Tolerance ◽  
Post Hoc ◽  
The Impact

Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue; however, varying symptomatic responses potentially imply genetic tolerance to the syndrome. It was hypothesized that a subpopulation of animals within a herd would develop tolerance to ergot alkaloid toxicity. Therefore, the goals of this study were to develop selection criteria to identify tolerant and susceptible animals within a herd based on animal performance, and then examine responsive phenotypic and cytokine profiles to fescue toxicosis. Angus cows grazed endophyte-infected tall fescue at two locations for 13 weeks starting in mid-April 2016. Forage measurements were collected to evaluate ergot alkaloid exposure during the study. A post hoc analysis of animal performance was utilized to designate cattle into either tolerant or susceptible groups, and weekly physiological measurements and blood samples were collected to evaluate responses to chronic exposure to endophyte-infected tall fescue. Findings from this study support the proposed fescue toxicosis selection method formulated herein, could accurately distinguish between tolerant and susceptible animals based on the performance parameters in cattle chronically exposed to ergot alkaloids, and provides evidence to warrant additional analysis to examine the impact of ergot alkaloids on immune responsiveness in cattle experiencing fescue toxicosis.

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